Re: [Emc-users] How come....

[Erik Christiansen]

On 26.05.19 12:48, Dave Cole wrote:
> 
> We still use BTU's for small Furnace and Air Conditioner sizing...
> For larger units its BTUs for furnaces and Tons of cooling for Air
> Conditioners.

The BTU is almost metric (within 6%):

$ units
You have: 1 btu
You want: kJ
* 1.0550559

Polish a bit off, and it'd be fully compatible. ;-)

Erik


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Re: [Emc-users] How come....

[Andy Pugh]

> On 26 May 2019, at 17:48, Dave Cole  wrote:
> 
> MJs of gas would make way too much sense.

Moles of carbon would make even more sense. 


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Re: [Emc-users] How come....

[Dave Cole]

We still use BTU's for small Furnace and Air Conditioner sizing...
For larger units its BTUs for furnaces and Tons of cooling for Air 
Conditioners.
Everyone knows that 12,000 btus is required to melt 1 ton of ice.  Hence 
12,000 btus is equal to "one ton" of cooling.
Who would have known that we could figure out some method to represent a 
measure of energy by a measure of weight!
So its  a value that we can relate to. And its not at all confusing! 
:-/


BTUs.. *defined* as the amount of heat required to raise the 
temperature of one pound of water by one degree Fahrenheit


So now you know why we can't get in gear with the metric system.  
Nothing would work.   We would have to discard all of our old notions of 
hot and cold.
We would be buying the wrong size air conditioners and furnaces!   Our 
houses would be way too hot when we set the thermostat to 70 degrees C...


Gas BTU's  ha ha ha... no, we have invented a different unit of 
measure called the Therm.

A Therm is 100,000 BTUS of gas.
Currently a Therm of natural gas costs about $0.75 for me right now.
On my gas bill, I get a meter reading from the meter on the side of my 
house.   That meter reading is based on 1/2 psi gas delivery, 
unfortunately I have 2 psi gas delivery, so they apply a correction 
factor to get cubic feet that is then translated into therms based upon 
some testing that occurred on their gas some time ago for heat content.


I think my gas bill is more of an estimation of my gas use rather than 
an actual measurement!


MJs of gas would make way too much sense.

Dave




Wikipedia suggests that you still use BTUs for gas?



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Re: [Emc-users] How come....

[Erik Christiansen]

On 21.05.19 16:17, grumpy--- via Emc-users wrote:
> i have no knowledge to add to this subject but it is all very good
> info for possible future projects i have been waiting for someone to
> add saltwater batteries to the discussion

The battery survey at one of the two links in my post on another
subthread of this thread shows the Aquion saltwater battery. They've
unfortunately bowed out of the market. While these (yes 48v) batteries
were rated for 3000 cycles at 100% DoD, they were very large, very
heavy, and could only be slowly charged/discharged. Once enough were
parallelled to provide adequate power delivery, they were then very
expensive.

When looking at them back then, I made these notes:

   ---
   Not really suitable for off-grid, as it charges too slowly!
   ---
   Approximate Price: $2500/stack
   Nominal Voltage: 48 V
   Energy: 2.2 kWh if charged for 10 hrs, then 20 hr discharge = only 110W !!! )
   1.4 kWh if charged for  4 hrs, then 12 hr discharge = only 117W !!! 
)   
   Discharge Limitation: Recommended: 14 A (672 W);  Max: 17 A
   Round Trip Efficiency: 80% at 10A in/out, 90% at 2A in/out
   Usable Depth of Discharge: 90% 
   Cycle Life:  3,000 cycles (to 70% retained capacity)
   Operating Temperature: -5 to 40°C ambient
   Chemistry: Aqueous Hybrid Ion (AHI™)
   Limited Warranty: 5-year full plus 3-year prorated
 
   Physical Characteristics
   Dimensions: 935 x 330 x 310 mm (36.8 x 13.0 x 12.2″)
   Weight: 188 kg (260 lbs)

To "integrate" capacity decay over time, I'd just take it as straight
line, allowing an average lifetime capacity of (100 - 70)/2 + 70 = 85%
to be used.

Erik


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Re: [Emc-users] How come....

[Kirk Wallace]

On 5/21/19 7:17 AM, grumpy--- via Emc-users wrote:
i have no knowledge to add to this subject but it is all very good info 
for possible future projects
i have been waiting for someone to add saltwater batteries to the 
discussion


Alt-E used to sell these:


https://www.altestore.com/store/deep-cycle-batteries/saltwater-batteries-c1260/



https://www.youtube.com/watch?v=1EhnmWo2CZ8


but it looks like the manufacturer went bankrupt, was bought, moved to 
China, and disappeared.



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Re: [Emc-users] How come....

[grumpy--- via Emc-users]

i have no knowledge to add to this subject but it is all very good info for 
possible future projects
i have been waiting for someone to add saltwater batteries to the discussion


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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Chris Albertson]

On Mon, May 20, 2019 at 7:55 PM Erik Christiansen 
wrote:

>
> Switching normal loads is back to less than 100 A for less than 5 kW, but
> still hard on contacts. (The contacts on the starter solenoid for an old
> Caterpillar D6 are blocks of copper with a mm of silver on the surface,
> to take the several hundred amps at 24v. IIUC, silver oxide conducts.)
>

This is why no one builds 24 or 48 volt DC power system for solar or backup
batteries.
Not on electric cars either.  Car batteries are usually 400+ volts.   You
need to
be carful when working on even a Toyota Prius as there is 400 VDC present.

You were talking abou the cost of a high amp switch.  That si NOTHING
compared to the cost of the inverter you would need.You would need
racks of MOSFETs.  No one does that.

You all know the formula for power loss right?  i^2R.  That's "i squared R"
because the current is squeared you REALLY want to make it small.
not more than about 40  amps for a residence.

Also no one is every going to dichage a batter at the 100 amp rate.
you design the system so it cycles only one per day.Even with lead acid
batteries you can place a 10  amp fuse oneach one of them.   Then you
KNOW the maximum current on the switch is 10 amps.

If you wire 20 lead acid batteries in series you can have 1KW of power at
only 4 amps.
if the switch is rated at 10A you are good.






> > It is not hard to find a good 60 or 80 amp switch.  You can
> > buy one on Amazon.com for $120.  Switches that can handle high DC loads
> are
> > very common.   Here is one examle
> > amazon.com/Siemens-HNF362-600-volt-...
> > <
> https://www.amazon.com/Siemens-HNF362-600-volt-Non-Fused-Switches/dp/B005G953DE/ref=pd_day0_hl_60_1/140-9661733-2175833?_encoding=UTF8&pd_rd_i=B005G953DE&pd_rd_r=a160cb45-7b31-11e9-b1ee-5b598291dad5&pd_rd_w=8QFZM&pd_rd_wg=4YekC&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=QQK03FTGP5PQVYKFENBP&psc=1&refRID=QQK03FTGP5PQVYKFENBP
> >
> > These DC disconnects are a code requirement and are installed by the
> > million, literally.
>
> All the switches I've come across are stamped with their AC and DC
> current breaking capacity. That must cover the potential fault current,
> if there's no HRC fuse, or you're building a fire starter. (I.e. you
> still need the fuse.)
>
> > No competent engineer will design a high power low voltage system because
> > you can no longer us wire, you'd n=be into solid copper busses.
>
> The hundred amps only flows from battery to inverter - and yes, the
> cables are about half an inch in diameter, much like starter motor
> cables in a car.
>
> I'll be running low voltage DC for LED lighting, but that's at modest
> current.
>
> Erik
>
>
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Re: [Emc-users] How come....

[Chris Albertson]

On Mon, May 20, 2019 at 3:25 AM Erik Christiansen 
wrote:

> On 20.05.19 02:02, Chris Albertson wrote:
> > Total KWH meant if you have a  10 KHW battery and you chrage and
> discharge
> > it 200 times then you have 2000 "lifetime" KHW
> > If you can charge the battery 400 times then you have 4000 "lifetime KWH.
> > The second battery as twice as much value.
>
> As a first approximation, yes, but the value is also affected by
> loss of utility through degradation of capacity over cycle life.
> Looking at:
>

Yes, but I wanted to avoid math that requires calculus. I think you need to
integratt the power output over time.

There are quick ways and exact ways to calculat the number but what you
realy would
like is to mearuse the total amount of energy the battery supplies over its
usfull lifetime.

One thing that makes it hard with lead acid is that you get a LOT more
cycles it you
don't discharge the battery deeply.   But then you need a more batteries.
So you have to
find the optimal discharge level, or just assume it is 50%.

What we really should be taloking about is the INVERTER.   There are
non-trivial
what you get th=o the size where you are powering a house




>
> "In comparison, the Tesla Powerwall is a 6.4 kilowatt-hour battery and
> only 5.44 kilowatt-hours of that is actually warranted to be usable.
> But after the first 2 years that drops to 4.6 kilowatt-hours.  And 3
> years later it drops down to only 3.8 kilowatt-hours of warranted
> storage."
>
> from:
>
> https://www.solarquotes.com.au/blog/redflows-zinc-bromide-zcell-battery-may-have-the-edge-over-lithium-ion/
>
> I'm reminded that phone and laptop battery capacity doesn't take long to
> nosedive. That's a much bigger problem with house batteries.
>
> One outlier is the ZnBr flow battery - it is claimed to maintain
> capacity for its full life, with efficiency falling instead. As that can
> be compensated by adding cheap solar panels, it's a very interesting
> variation in the cost/energy equation.
>
> OK, reasonable efficiency is still necessary, especially in polar climes
> in winter, but in generally sunny Australia, it's just the high initial
> cost which detracts.
>
> Erik
>
> P.S. That web page is inordinately folksy, but if you skip the waffle,
>  it does cover some of the battery's properties.
>
>
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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Erik Christiansen]

On 20.05.19 12:11, Chris Albertson wrote:
> How much DC current are we talking about?Let's say the house is running
> an air conditioning load and you are doing laundry and the 'fridge is
> cycling and you have a few computers on and every light build is turned on
> and you own a 200-gallon saltwater aquarium.Let's call it 20 KW of use
> in a really big house. This a very-worst case scenario.
> 
> Your DC is set up for 480 volts going into the inverter.   20KVA / 480 is
> is 41 amps.

Even there, the fault current is the short-circuit current of the array.
That's not too bad for PV, as it's internally strongly current limited.
But upthread we were mostly talking about DC from the battery, i.e. at
48v in most cases. As I've mentioned upthread, you can expect a fault
current of 10 times AH rating, i.e. 2000 A for a 200 AH battery bank.
That's the strength of the arc we must be able to rupture in the event
of a fault.

Switching normal loads is back to less than 100 A for less than 5 kW, but
still hard on contacts. (The contacts on the starter solenoid for an old
Caterpillar D6 are blocks of copper with a mm of silver on the surface,
to take the several hundred amps at 24v. IIUC, silver oxide conducts.)

> It is not hard to find a good 60 or 80 amp switch.  You can
> buy one on Amazon.com for $120.  Switches that can handle high DC loads are
> very common.   Here is one examle
> amazon.com/Siemens-HNF362-600-volt-...
> 
> These DC disconnects are a code requirement and are installed by the
> million, literally.

All the switches I've come across are stamped with their AC and DC
current breaking capacity. That must cover the potential fault current,
if there's no HRC fuse, or you're building a fire starter. (I.e. you
still need the fuse.)

> No competent engineer will design a high power low voltage system because
> you can no longer us wire, you'd n=be into solid copper busses.

The hundred amps only flows from battery to inverter - and yes, the
cables are about half an inch in diameter, much like starter motor
cables in a car.

I'll be running low voltage DC for LED lighting, but that's at modest
current.

Erik


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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Chris Albertson]

How much DC current are we talking about?Let's say the house is running
an air conditioning load and you are doing laundry and the 'fridge is
cycling and you have a few computers on and every light build is turned on
and you own a 200-gallon saltwater aquarium.Let's call it 20 KW of use
in a really big house. This a very-worst case scenario.

Your DC is set up for 480 volts going into the inverter.   20KVA / 480 is
is 41 amps.  It is not hard to find a good 60 or 80 amp switch.  You can
buy one on Amazon.com for $120.  Switches that can handle high DC loads are
very common.   Here is one examle
amazon.com/Siemens-HNF362-600-volt-...

These DC disconnects are a code requirement and are installed by the
million, literally.

No competent engineer will design a high power low voltage system because
you can no longer us wire, you'd n=be into solid copper busses.

On Mon, May 20, 2019 at 3:33 AM Erik Christiansen 
wrote:

> On 19.05.19 09:43, Nicklas Karlsson wrote:
> > For safety I learned relays fail open circuit while MOSFETs fail short
> > circuited, I also experienced MOSFET short circuit failure. Happen to
> > know anything more about this?
>
> I'd only use the MOSFETs to replace relay contacts, and wire a HRC fuse
> in series to rupture the fault current. Otherwise, once a DC arc is
> established, it could bridge a MOSFET package effortlessly, maintaining
> current flow until enough copper flowed away to build a large gap.
>
> Erik
>
>
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Re: [Emc-users] How come....

[Ralph Stirling]

> Wikipedia suggests that you still use BTUs for gas?

Unfortunately, yes.  Fortunately, I don't have gas, so
can ignore that.  Guess you can say we are more British
than the Brits, since we still use British Thermal Units.

-- Ralph

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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Erik Christiansen]

On 19.05.19 09:43, Nicklas Karlsson wrote:
> For safety I learned relays fail open circuit while MOSFETs fail short
> circuited, I also experienced MOSFET short circuit failure. Happen to
> know anything more about this?

I'd only use the MOSFETs to replace relay contacts, and wire a HRC fuse
in series to rupture the fault current. Otherwise, once a DC arc is
established, it could bridge a MOSFET package effortlessly, maintaining
current flow until enough copper flowed away to build a large gap.

Erik


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Re: [Emc-users] How come....

[Erik Christiansen]

On 20.05.19 02:02, Chris Albertson wrote:
> Total KWH meant if you have a  10 KHW battery and you chrage and discharge
> it 200 times then you have 2000 "lifetime" KHW
> If you can charge the battery 400 times then you have 4000 "lifetime KWH.
> The second battery as twice as much value.

As a first approximation, yes, but the value is also affected by
loss of utility through degradation of capacity over cycle life.
Looking at:

"In comparison, the Tesla Powerwall is a 6.4 kilowatt-hour battery and
only 5.44 kilowatt-hours of that is actually warranted to be usable.
But after the first 2 years that drops to 4.6 kilowatt-hours.  And 3
years later it drops down to only 3.8 kilowatt-hours of warranted
storage."

from:
https://www.solarquotes.com.au/blog/redflows-zinc-bromide-zcell-battery-may-have-the-edge-over-lithium-ion/

I'm reminded that phone and laptop battery capacity doesn't take long to
nosedive. That's a much bigger problem with house batteries.

One outlier is the ZnBr flow battery - it is claimed to maintain
capacity for its full life, with efficiency falling instead. As that can
be compensated by adding cheap solar panels, it's a very interesting
variation in the cost/energy equation.

OK, reasonable efficiency is still necessary, especially in polar climes
in winter, but in generally sunny Australia, it's just the high initial
cost which detracts.

Erik

P.S. That web page is inordinately folksy, but if you skip the waffle,
 it does cover some of the battery's properties.


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Re: [Emc-users] How come....

[andy pugh]

On Mon, 20 May 2019 at 10:04, Chris Albertson 
wrote:

What you just wrote almost what I wrote.  Except that " big enough" is not
> a number you can put in a calculator.
>
> Cost per "KWh over the lifetime" is a very standard measure to define the
> value of a battery. I did not make it up.


My point is that if you consider only cost/kWh then you could end up
spending many billions on a pumped storage scheme...
https://en.wikipedia.org/wiki/Dinorwig_Power_Station
I am exaggerating, obviously, but my point is that cost/kWh tends to
decrease with increased size, so first you need a system suitable for your
needs, only then does cost/kWh become the right metric.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] How come....

[Chris Albertson]

On Sun, May 19, 2019 at 3:09 PM andy pugh  wrote:

> On Sun, 19 May 2019 at 22:30, Chris Albertson 
> wrote:
>
> > You just have to do a calculation,  What is the cost per KWH over the
> > remaining
> > life of the battery.
>
>
> I am not sure that that is the correct calculation.
> What really matters is that the battery is big enough for your purposes,
> and then cost-per-year is more important that cost / kWh.
>

What you just wrote almost what I wrote.  Except that " big enough" is not
a number you can put in a calculator.

Cost per "KWh over the lifetime" is a very standard measure to define the
value of a battery. I did not make it up. The figure combines three
things
1) The size of the battery bank
2) The cost of the battery bank and
3) how long it will last, measured in "cycles"
Those three things are what you said, but only with numbers attached

Total KWH meant if you have a  10 KHW battery and you chrage and discharge
it 200 times then you have 2000 "lifetime" KHW
If you can charge the battery 400 times then you have 4000 "lifetime KWH.
The second battery as twice as much value.

Again I'll say what matters is *lifetime* KWH divided by the cost.

"lifetime KWH is the total amount of energy you can get out of a battery
before you have to retire the battery.

Your formula of "big enough then cost per year" does not result in a number
where you and I can compare performance because "big enough" can vary.

Look at the Power Wall and try to apply your formula.  "big enough" means
two units.  Cost for the first year is  $13,700.  Cost for the next 10
years is zero.  Is that a good price?   How would you compare that to a
personwith a smaller house But if you divide by the amount of power
used in ten years and it scales to a more universal number that just
happens to be the same units as the power company uses on their bills.
Makes comparing easy

(And, while we are at it, kWh is a horrible unit. What is wrong with MJ? )
>

The power company does not bill in MJ.   The meter reads KWH and all the
batteries and solar pannels are KWH.  It's an indury standard.

>
> --

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Redondo Beach, California

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Re: [Emc-users] How come....

[andy pugh]

On Mon, 20 May 2019 at 02:50, Ralph Stirling 
wrote:

>
> > (And, while we are at it, kWh is a horrible unit. What is wrong with MJ?
> )
>
> kWh is ubiquitous in the US.


They use them in the UK too. It doesn't make it any less irritating to a
physicist.

Wikipedia suggests that you still use BTUs for gas?

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] How come....

[Ralph Stirling]

> (And, while we are at it, kWh is a horrible unit. What is wrong with MJ? )

kWh is ubiquitous in the US.  Our electrical bills are all based on kWh.
Just be glad we don't use horsepower-hours :-/

-- Ralph

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Re: [Emc-users] How come....

[Kirk Wallace]

On 5/19/19 5:25 PM, Bruce Layne wrote:



On 5/19/19 6:01 PM, Kirk Wallace wrote:


There are a lot of surplus Leaf batteries available. My opinion on
 these is that these were removed for warranty replacement due to 
overheating. These are air cooled and don't do well if they are 
rapid charged more than once during long trips. I am tending to 
avoid these.


I saw those Nissan Leaf batteries as related eBay links.  The price 
per energy storage looked very good.  I assumed these were some sort 
of warranty replacement batteries, but didn't search to learn the 
reason these are on the surplus market.


Vendors don't seem to be too keen on providing information on their 
batteries. Either they don't know, don't understand what they have, or 
choose not to share. BatteryHookup.com seems to be the best DIY battery 
vendor so far. My opinion on Leaf batteries is based on the RapidGate 
chatter, where rapid charging was slowed way down on the second charge 
which you don't want to learn about in the middle of a long trip.

https://www.youtube.com/watch?v=Dpwyue9IiBE


I vaguely recall hearing of technical problems with the Nissan Leaf.  If the problem was 
overheating when fast charging or discharging in a car, that

wouldn't deter me from using them in an off-the-grid home.  It
probably wouldn't be an issue in a properly sized system, and the
Nissan batteries could easily be mounted vertically with air gaps and
even inexpensive heat sinks could be used to accentuate cooling.


For properly sized stationary batteries I don't think the battery will 
come close to working hard enough to even get warm. It would be nice if 
vendors would test cells or battery capacity and post this in their ads. 
Testing is likely to be expensive so there isn't much incentive for 
testing if one is selling cells well enough anyway.




I'd need to research the cell balancing and battery management as 
that's critical.  A lot of those electronics are built into the

Tesla battery packs which sounds good, but it's proprietary so using
them in a home requires the batteries to be fooled into thinking
they're in a car.  An entrepreneur makes a device to do that.  Jack
Rickard of EVTV.


The $1200 class batteries are for a module within the battery pack, so 
it is just ~5 kWh(?) of 18650 cells and no electronics. In my view 
balancing isn't nearly as important as monitoring which is much easier 
to do with off-the-self products.




http://store.evtv.me/proddetail.php?prod=1FullpackController

I sent links earlier in this thread to a friend who used a Tesla 
battery for his off-the-grid home, and he displays battery life in 
odometer miles.  I think he largely does this for a lark and he 
displays more conventional units as well, but keeping it in terms of 
miles, even though not applicable to a house, does provide a battery 
life indication that compares well to the original automotive use. No
doubt he'll get more "miles" from his off the grid batteries than 
they'd get in a car where they're typically charged and discharged

at a faster rate.

Part 3 of the series, where the custom battery monitoring is 
demonstrated: https://www.youtube.com/watch?v=AIY2EWke-AA




On 5/19/19 6:07 PM, andy pugh wrote:
(And, while we are at it, kWh is a horrible unit. What is wrong 
with MJ? )


Kilowatt hours is easier for me to convert into miles.   :-)

An American arguing with an Englishman over the metric system is 
funny. You guys invented this crummy system.  Just because you were 
smart enough to switch to the metric system and we're still stuck on 
stupid is no call for being cheeky.   :-P


- and there is no such word as "maths".


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Re: [Emc-users] How come....

[Bruce Layne]

On 5/19/19 6:01 PM, Kirk Wallace wrote:

> There are a lot of surplus Leaf batteries available. My opinion on
> these is that these were removed for warranty replacement due to
> overheating. These are air cooled and don't do well if they are rapid
> charged more than once during long trips. I am tending to avoid these.

I saw those Nissan Leaf batteries as related eBay links.  The price per
energy storage looked very good.  I assumed these were some sort of
warranty replacement batteries, but didn't search to learn the reason
these are on the surplus market.  I vaguely recall hearing of technical
problems with the Nissan Leaf.  If the problem was overheating when fast
charging or discharging in a car, that wouldn't deter me from using them
in an off-the-grid home.  It probably wouldn't be an issue in a properly
sized system, and the Nissan batteries could easily be mounted
vertically with air gaps and even inexpensive heat sinks could be used
to accentuate cooling.

I'd need to research the cell balancing and battery management as that's
critical.  A lot of those electronics are built into the Tesla battery
packs which sounds good, but it's proprietary so using them in a home
requires the batteries to be fooled into thinking they're in a car.  An
entrepreneur makes a device to do that.  Jack Rickard of EVTV.

http://store.evtv.me/proddetail.php?prod=1FullpackController

I sent links earlier in this thread to a friend who used a Tesla battery
for his off-the-grid home, and he displays battery life in odometer
miles.  I think he largely does this for a lark and he displays more
conventional units as well, but keeping it in terms of miles, even
though not applicable to a house, does provide a battery life indication
that compares well to the original automotive use.  No doubt he'll get
more "miles" from his off the grid batteries than they'd get in a car
where they're typically charged and discharged at a faster rate.

Part 3 of the series, where the custom battery monitoring is demonstrated:
https://www.youtube.com/watch?v=AIY2EWke-AA



On 5/19/19 6:07 PM, andy pugh wrote:
> (And, while we are at it, kWh is a horrible unit. What is wrong with MJ? )

Kilowatt hours is easier for me to convert into miles.   :-)

An American arguing with an Englishman over the metric system is funny. 
You guys invented this crummy system.  Just because you were smart
enough to switch to the metric system and we're still stuck on stupid is
no call for being cheeky.   :-P








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Re: [Emc-users] How come....

[Dave Cole]

Apparently you guys didn't notice that the Ebay guy selling Tesla cells 
had already sold over a hundred of those battery packs.

So I doubt he got them from crashed Teslas.
To me buying a used Lithium battery makes only a little more sense than 
buying a used Lead Acid battery.
I bet I could buy a bunch of used 6 volt golf cart batteries from the 
golf courses around me as well..
If those battery packs were $300, it would be one thing, but at $1200 
plus, I don't see that as much of a deal.


Dave

On 5/19/2019 7:10 PM, Gregg Eshelman via Emc-users wrote:

There seems to be a pretty good supply of battery packs from wrecked Tesla 
Model S cars, often with fairly low mileage. People have been taking those 
apart to shoehorn the modules and one or both motor drivetrains into various 
other vehicles. Of course by doing that they lose the crash protection of the 
aluminum battery housing. One person flipped an empty Model S battery upside 
down, attached a couple of trailer spindles and fenders and a tongue to make a 
little flatbed trailer.

I think it'd be fun to 'gassify' a Model S. Either convert the empty battery housing to a 
fuel tank or build a tank to fit in its place, then stuff some FWD drivetrain in the 
"frunk".

 On Sunday, May 19, 2019, 10:32:52 AM MDT, Dave Cole 
 wrote:
  I do have to wonder though... if these Tesla cells were no longer usable
for a Tesla, why would anyone think they would be good in a stationary
application unless they were derated by quite a bit.
$1200 is far from free.

Dave

On 5/17/2019 12:24 PM, Kirk Wallace wrote:

Here is a fairly common surplus Tesla module:


https://www.ebay.com/itm/262333679871

If these have have not been abused after they were removed from the
car they should last many thousands of deep cycles.  They are 6s but a
7th s can be added in order to cycle them deeper on a common 24 volt
system.

My system (single, living in an RV) is close to this except I am using
two Johnson Controls modules rewired as 7s:

https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
https://www.ebay.com/itm/123187038180

This technology is changing so quickly that it is hard to keep current
and reviews become stale in a month or two.

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Re: [Emc-users] How come....

[Gregg Eshelman via Emc-users]

There seems to be a pretty good supply of battery packs from wrecked Tesla 
Model S cars, often with fairly low mileage. People have been taking those 
apart to shoehorn the modules and one or both motor drivetrains into various 
other vehicles. Of course by doing that they lose the crash protection of the 
aluminum battery housing. One person flipped an empty Model S battery upside 
down, attached a couple of trailer spindles and fenders and a tongue to make a 
little flatbed trailer.

I think it'd be fun to 'gassify' a Model S. Either convert the empty battery 
housing to a fuel tank or build a tank to fit in its place, then stuff some FWD 
drivetrain in the "frunk".

On Sunday, May 19, 2019, 10:32:52 AM MDT, Dave Cole 
 wrote:  
 I do have to wonder though... if these Tesla cells were no longer usable 
for a Tesla, why would anyone think they would be good in a stationary 
application unless they were derated by quite a bit.
$1200 is far from free.

Dave

On 5/17/2019 12:24 PM, Kirk Wallace wrote:
>
> Here is a fairly common surplus Tesla module:
>
>> https://www.ebay.com/itm/262333679871
>
> If these have have not been abused after they were removed from the 
> car they should last many thousands of deep cycles.  They are 6s but a 
> 7th s can be added in order to cycle them deeper on a common 24 volt 
> system.
>
> My system (single, living in an RV) is close to this except I am using 
> two Johnson Controls modules rewired as 7s:
>> https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
>> https://www.ebay.com/itm/123187038180
>
> This technology is changing so quickly that it is hard to keep current 
> and reviews become stale in a month or two.  
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Re: [Emc-users] How come....

[andy pugh]

On Sun, 19 May 2019 at 22:30, Chris Albertson 
wrote:

> You just have to do a calculation,  What is the cost per KWH over the
> remaining
> life of the battery.


I am not sure that that is the correct calculation.
What really matters is that the battery is big enough for your purposes,
and then cost-per-year is more important that cost / kWh.

(And, while we are at it, kWh is a horrible unit. What is wrong with MJ? )

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] How come....

[Kirk Wallace]

On 5/19/19 9:34 AM, Dave Cole wrote:
I do have to wonder though... if these Tesla cells were no longer usable 
for a Tesla, why would anyone think they would be good in a stationary 
application unless they were derated by quite a bit.

$1200 is far from free.

Dave


My take on this is that Tesla batteries become available from wrecked 
vehicles where the car was written off, but not the battery. As far as I 
know, a Tesla battery under proper use has not worn out yet. There has 
been data on normal-use degradation but this seems to indicate that I 
will likely be dead before current batteries are.


There are a lot of surplus Leaf batteries available. My opinion on these 
is that these were removed for warranty replacement due to overheating. 
These are air cooled and don't do well if they are rapid charged more 
than once during long trips. I am tending to avoid these.


The Johnson batteries I have are said to be from an electric bus 
conversion study and were liquid cooled and likely well cared for.


So these batteries can come to the market for various reasons but for 
simply being worn out doesn't seem to be a common reason yet.



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Re: [Emc-users] How come....

[Chris Albertson]

You just have to do a calculation,  What is the cost per KWH over the
remaining
life of the battery. A new power wall costs $6,700 and has 13 KWH that
can be
cycled daily for 10 years.   so 3650 days times 13KW =  47 megawat hours
for $6,700
or 14 cents per KWH.

DO the math on the used battery.  If it is much less then $0.14/KWH buy it

So if the price is $1,200 and it still can store 7,000 watt-hours and has a
5 year remaining
life it would be useless in a car but it works out to  $0.09/KWH and
would not is a truly horrible deal.

So it is possible a battery that is usless in the car could be used for a
house.  Better
is to keep the battery in thr car and use the car for short trips, less
than 100 miles. round trip

Cell become usless in a car when you reach about 1/2 capasity but if the
price per KWH is OK
they can work in a house.   FOr a house, you might need the cells for
multiple salvage cars.



On Sun, May 19, 2019 at 9:32 AM Dave Cole  wrote:

> I do have to wonder though... if these Tesla cells were no longer usable
> for a Tesla, why would anyone think they would be good in a stationary
> application unless they were derated by quite a bit.
> $1200 is far from free.
>
> Dave
>
> On 5/17/2019 12:24 PM, Kirk Wallace wrote:
> >
> > Here is a fairly common surplus Tesla module:
> >
> >> https://www.ebay.com/itm/262333679871
> >
> > If these have have not been abused after they were removed from the
> > car they should last many thousands of deep cycles.  They are 6s but a
> > 7th s can be added in order to cycle them deeper on a common 24 volt
> > system.
> >
> > My system (single, living in an RV) is close to this except I am using
> > two Johnson Controls modules rewired as 7s:
> >> https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
> >> https://www.ebay.com/itm/123187038180
> >
> > This technology is changing so quickly that it is hard to keep current
> > and reviews become stale in a month or two.
> >
> >
> > ___
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> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
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>


-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] How come....

[Dave Cole]

That's what I understood...  I won't be owning a Tesla until that changes.
Dave

On 5/18/2019 2:50 PM, Bruce Layne wrote:

Tesla has adopted the software
rental model where the customer doesn't really own anything.



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Re: [Emc-users] How come....

[Dave Cole]

I do have to wonder though... if these Tesla cells were no longer usable 
for a Tesla, why would anyone think they would be good in a stationary 
application unless they were derated by quite a bit.

$1200 is far from free.

Dave

On 5/17/2019 12:24 PM, Kirk Wallace wrote:


Here is a fairly common surplus Tesla module:


https://www.ebay.com/itm/262333679871


If these have have not been abused after they were removed from the 
car they should last many thousands of deep cycles.  They are 6s but a 
7th s can be added in order to cycle them deeper on a common 24 volt 
system.


My system (single, living in an RV) is close to this except I am using 
two Johnson Controls modules rewired as 7s:

https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
https://www.ebay.com/itm/123187038180


This technology is changing so quickly that it is hard to keep current 
and reviews become stale in a month or two.



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Re: [Emc-users] How come....

[Dave Cole]

I do have to wonder though... if these Tesla cells were no longer usable 
for a Tesla, why would anyone think they would be good in a stationary 
application unless they were derated by quite a bit.

$1200 is far from free.

Dave

On 5/17/2019 12:24 PM, Kirk Wallace wrote:


Here is a fairly common surplus Tesla module:


https://www.ebay.com/itm/262333679871


If these have have not been abused after they were removed from the 
car they should last many thousands of deep cycles.  They are 6s but a 
7th s can be added in order to cycle them deeper on a common 24 volt 
system.


My system (single, living in an RV) is close to this except I am using 
two Johnson Controls modules rewired as 7s:

https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
https://www.ebay.com/itm/123187038180


This technology is changing so quickly that it is hard to keep current 
and reviews become stale in a month or two.



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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Nicklas Karlsson]

> > For safety I learned relays fail open circuit while MOSFETs fail short
> > circuited, I also experienced MOSFET short circuit failure. Happen to
> > know anything more about this?
> >
> It is for this reason that higher current dc loads, which will often be 
> inductive are often of the t-bar design. The armature, when released 
> will rise and hit the crossbar contact with enough force to break the 
> microweld, but even that isn't trusted, so I've seen circuits that used 
> a 4 pole contactor with all 4 poles in series.

Tried two in series with buzzing sound sometimes but do not care to much about 
it since it's only temporary.

Maybe AC is a better choice then using relays?

> I'm sure you've all seen the familiar flywheel diode placed across the 
> relay coil to prevent the inductive spike when turning off the relay, 
> from rising more than a volt or two above the supply voltage, it is 
> absorbing the relay coils currant during the turn off period, preventing 
> the transistor from being over voltaged by the inductance and punched 
> thru for a permanent short.

Yes I also added this diode for myself.

> This also delays the relays release by a 
> few milliseconds. If controlled by a relay, the circuit should be 
> expected to have a few milliseconds of lag anyway.

How fast current decrease depend on resistance and should be possible to make 
this time shorter by for example adding zener diode or resistor in series with 
diode with a higher but limited turn off voltage spike.

> Modern mosfets can often withstand 1000 volts or more for short periods 
> of time, so a lot of research has gone into mosfet _drivers_ to do 2 
> things, 1st being to switch it as fast as possible to reduce its heat 
> dissipation during the transition,

This is indeed important for low switching losses.

> and 2nd to get the opposite side of a 
> switching circuit turned on just slow enough you don't have a short 
> because both sides are on at the same time, but you must get the 
> opposite side turned on with a minimum of dead time between them to 
> short circuit the voltage stress on the one just turned off. 5ns can 
> make or destroy in this case. The diff is that it works for decades, or 
> you break the mirror and let all the smoke out.

The dead time may add some voltage distortion and some devices have lower 
voltage drop then turned on, otherwise current is thru free wheeling diode.


Nicklas Karlsson


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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Gene Heskett]

On Sunday 19 May 2019 03:43:45 am Nicklas Karlsson wrote:

> On Fri, 17 May 2019 20:23:57 +1000
>
> Erik Christiansen  wrote:
> > On 16.05.19 21:18, Nicklas Karlsson wrote:
> > > > ...
> > > > I'd put the battery bank in an outbuilding.  If something shorts
> > > > out and the battery bank melts down, the little building may
> > > > burn but my house won't.
> > >
> > > There certainly is a lot of power from a byttery and it could be a
> > > little bit hard to turn off. You put a fuse at battery cable?
> >
> > If local regulations do not require a HRC (High Rupture Capacity)
> > fuse between the battery bank and any connection to it, then it's an
> > invitation to disaster. A dc arc is much more difficult to
> > extinguish, because there are no zero crossings, and molten metal
> > can end up flowing on the floor.
>
> I got the feeling DC arc is much hard to extinguish but found no good
> information about it. Then reading about how welding should be done
> and EDM I learned then air i ionized resistance get lower, in practice
> I know it is often hard to ignite the weld while it work for some
> distance then lit. I suspect and get the feeling then welding not the
> least from the ignition problem some distance could be kept then lit
> distance to keep air ionized depend on current, happen to anything
> about this?
>
> > Small HRC fuses are generally in ceramic tubes, and are sand-filled,
> > to quench the arc when the element fuses. The one I have on the desk
> > beside me is a 100 A with a 100 kA (100,000 A) arc rupture capacity,
> > but it's 27x44x49 mm, and is overkill. Just 10 times AH rating seems
> > to be normal, i.e. 2000 A rupture capacity for a 200 AH bank. (The
> > fault current will be limited by battery internal resistance.)
> >
> > > I also think DC relays have to be a little bit different than AC
> > > relays, used an ordinary AC relay for a few few days connected to
> > > a DC voltage and even though two switches is connected in series
> > > it sometimes make a buzzing sound then turned off.
> >
> > Most relays and switches are marked with both AC and DC current
> > ratings. The DC rating is always much lower, due to the difficulty
> > of rupturing a DC arc. Rather than bother with
> > maintenance/replacement due to contact deterioration after many
> > switching cycles, I prefer to switch DC loads with MOSFETs - they're
> > easy to parallel, as the inherently share.
>
> Agree, as is evindent furher up in message.
>
> For safety I learned relays fail open circuit while MOSFETs fail short
> circuited, I also experienced MOSFET short circuit failure. Happen to
> know anything more about this?
>
It is for this reason that higher current dc loads, which will often be 
inductive are often of the t-bar design. The armature, when released 
will rise and hit the crossbar contact with enough force to break the 
microweld, but even that isn't trusted, so I've seen circuits that used 
a 4 pole contactor with all 4 poles in series.

I'm sure you've all seen the familiar flywheel diode placed across the 
relay coil to prevent the inductive spike when turning off the relay, 
from rising more than a volt or two above the supply voltage, it is 
absorbing the relay coils currant during the turn off period, preventing 
the transistor from being over voltaged by the inductance and punched 
thru for a permanent short.  This also delays the relays release by a 
few milliseconds. If controlled by a relay, the circuit should be 
expected to have a few milliseconds of lag anyway.

Modern mosfets can often withstand 1000 volts or more for short periods 
of time, so a lot of research has gone into mosfet _drivers_ to do 2 
things, 1st being to switch it as fast as possible to reduce its heat 
dissipation during the transition, and 2nd to get the opposite side of a 
switching circuit turned on just slow enough you don't have a short 
because both sides are on at the same time, but you must get the 
opposite side turned on with a minimum of dead time between them to 
short circuit the voltage stress on the one just turned off. 5ns can 
make or destroy in this case. The diff is that it works for decades, or 
you break the mirror and let all the smoke out.

> Regard Nicklas Karlsson
>
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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Re: [Emc-users] How come.... --> battery safety due to high current, DC relay

[Nicklas Karlsson]

On Fri, 17 May 2019 20:23:57 +1000
Erik Christiansen  wrote:

> On 16.05.19 21:18, Nicklas Karlsson wrote:
> > > ...
> > > I'd put the battery bank in an outbuilding.  If something shorts out and 
> > > the battery bank melts down, the little building may burn but my house 
> > > won't.
> > 
> > There certainly is a lot of power from a byttery and it could be a
> > little bit hard to turn off. You put a fuse at battery cable?
> 
> If local regulations do not require a HRC (High Rupture Capacity) fuse
> between the battery bank and any connection to it, then it's an
> invitation to disaster. A dc arc is much more difficult to extinguish,
> because there are no zero crossings, and molten metal can end up flowing
> on the floor.

I got the feeling DC arc is much hard to extinguish but found no good 
information about it. Then reading about how welding should be done and EDM I 
learned then air i ionized resistance get lower, in practice I know it is often 
hard to ignite the weld while it work for some distance then lit. I suspect and 
get the feeling then welding not the least from the ignition problem some 
distance could be kept then lit distance to keep air ionized depend on current, 
happen to anything about this?

> Small HRC fuses are generally in ceramic tubes, and are sand-filled, to
> quench the arc when the element fuses. The one I have on the desk beside
> me is a 100 A with a 100 kA (100,000 A) arc rupture capacity, but it's
> 27x44x49 mm, and is overkill. Just 10 times AH rating seems to be normal,
> i.e. 2000 A rupture capacity for a 200 AH bank. (The fault current will
> be limited by battery internal resistance.)
> 
> > I also think DC relays have to be a little bit different than AC
> > relays, used an ordinary AC relay for a few few days connected to a DC
> > voltage and even though two switches is connected in series it
> > sometimes make a buzzing sound then turned off.
> 
> Most relays and switches are marked with both AC and DC current ratings.
> The DC rating is always much lower, due to the difficulty of rupturing a
> DC arc. Rather than bother with maintenance/replacement due to contact
> deterioration after many switching cycles, I prefer to switch DC loads
> with MOSFETs - they're easy to parallel, as the inherently share.

Agree, as is evindent furher up in message.

For safety I learned relays fail open circuit while MOSFETs fail short 
circuited, I also experienced MOSFET short circuit failure. Happen to know 
anything more about this?


Regard Nicklas Karlsson


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Re: [Emc-users] How come....

[Gregg Eshelman via Emc-users]

But Rich's "Dolores" still supercharges, despite Tesla not providing any 
support or most parts sales. He was (eventually) able to purchase some lug nut 
covers after initially being denied - though he had to get them from two or 
more places because for some reason no Tesla shop stocks enough for a full set.
 
There was an instance where Tesla remotely disabled Supercharging and the 
onboard map that shows where all the Supercharger locations are - but they did 
it while the owners of the Model S were hundreds of miles from home on a family 
vacation. The reason given was because the car came up listed as "salvaged" 
despite having had a collision that only damaged replaceable parts, no 
structural damage. Tesla did come around to saying they would inspect and 
recertify the car, for (IIRC) $1500 and if it passed their inspection they 
would re-enable all functions.

On Saturday, May 18, 2019, 12:53:33 PM MDT, Bruce Layne 
 wrote:  
 It's interesting that Tesla maintains a record of all Tesla vehicles,
and once a car is scrapped, it's black listed in their records.  There
is no factory support.  The vehicles that were eligible for free
charging at Tesla Superchargers are barred from using the chargers, even
on a paying basis.  You can only recharge the car at home so it's a
commuter car and is no longer practical for interstate use.  Tesla won't
sell any spare parts to support scrapped or rebuilt Tesla vehicles, and
they won't help with any information.  Tesla has adopted the software
rental model where the customer doesn't really own anything.

On 5/18/19 3:06 AM, Gregg Eshelman via Emc-users wrote:> Look up Rich Rebuilds 
on YouTube. He built himself a really cheap Tesla Model S by buying one that 
was in a flood and another that was rolled. Stripped the flooded one of nearly 
everything, put the electrics and electronics from the rolled one into it, then 
sold a bunch of leftover parts. Now he's fixing up a flood damaged Model X, 
which has been built with a much higher degree of water resistance. Nearly 
every electronics box on the Model S had been full of water. The battery had 
water in it. The motors, inverters, and gearboxes were full of water. The Model 
S, if it could be IP rated at all, would be at the lowest rating. See a clogged 
storm drain making a pond at an intersection? Don't go through it to have 
splashy fun with a Model S. Could get water into a motor and/or inverter.
>
> During the Model X teardown, Rich has been finding there isn't much needing 
> replacing with the electronics due to much better sealing of the boxes and 
> connectors have better gaskets. The charge regulator on the X, mounted inside 
> behind the right rear wheel, was totally dry inside despite being almost 
> completely submerged. The one on the S was full of water. Apparently Tesla 
> has learned what IP65 means, which is what everything on an electric car that 
> runs on electricity ought to be, especially the parts outside the cabin.  
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Re: [Emc-users] How come....

[Bruce Layne]

It's interesting that Tesla maintains a record of all Tesla vehicles,
and once a car is scrapped, it's black listed in their records.  There
is no factory support.  The vehicles that were eligible for free
charging at Tesla Superchargers are barred from using the chargers, even
on a paying basis.  You can only recharge the car at home so it's a
commuter car and is no longer practical for interstate use.  Tesla won't
sell any spare parts to support scrapped or rebuilt Tesla vehicles, and
they won't help with any information.  Tesla has adopted the software
rental model where the customer doesn't really own anything.





On 5/18/19 3:06 AM, Gregg Eshelman via Emc-users wrote:
> Look up Rich Rebuilds on YouTube. He built himself a really cheap Tesla Model 
> S by buying one that was in a flood and another that was rolled. Stripped the 
> flooded one of nearly everything, put the electrics and electronics from the 
> rolled one into it, then sold a bunch of leftover parts. Now he's fixing up a 
> flood damaged Model X, which has been built with a much higher degree of 
> water resistance. Nearly every electronics box on the Model S had been full 
> of water. The battery had water in it. The motors, inverters, and gearboxes 
> were full of water. The Model S, if it could be IP rated at all, would be at 
> the lowest rating. See a clogged storm drain making a pond at an 
> intersection? Don't go through it to have splashy fun with a Model S. Could 
> get water into a motor and/or inverter.
>
> During the Model X teardown, Rich has been finding there isn't much needing 
> replacing with the electronics due to much better sealing of the boxes and 
> connectors have better gaskets. The charge regulator on the X, mounted inside 
> behind the right rear wheel, was totally dry inside despite being almost 
> completely submerged. The one on the S was full of water. Apparently Tesla 
> has learned what IP65 means, which is what everything on an electric car that 
> runs on electricity ought to be, especially the parts outside the cabin.
>
> On Friday, May 17, 2019, 8:20:05 AM MDT, Dave Cole 
>  wrote:  
>  OK,
> Buy  a new "cheap" Tesla - about $35,800 right now.
> Remove the battery pack  ;-)
>
> You guys on the west coast make it sound like you have Tesla's sitting 
> on the side of the road with "$500 or best offer" sale signs.
>
> We now have 11 supercharger stations in the state of Indiana.
> If Tesla's burned coal or biowaste we would be all set.   :-/
>
> What is is a "cheap" Tesla going for in places where they are popular?
>
> Dave
>
>> So, let's turn that on its head. How can I run my cordless tools from Tesla
>> cells...
>   
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Re: [Emc-users] How come....

[Gregg Eshelman via Emc-users]

These look interesting. Caps that push onto the ends of 18650 cells then snap 
together. Metal bus bars connect the cells in any configuration you want.
https://vruzend.com/
There are videos on YouTube from various people testing them. The connection 
resistance is less than spring clips but higher than spot welded. The cells do 
get warmer due to the resistance.
What I wonder is if a lower temperature solder could be developed for these? 
Have it melt at the peak temp the cells will hit, then when the solder melts 
the connection resistance drops, which reduces the temperature below the solder 
melting point, making the connections permanent.

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Re: [Emc-users] How come....

[Gregg Eshelman via Emc-users]

Look up Rich Rebuilds on YouTube. He built himself a really cheap Tesla Model S 
by buying one that was in a flood and another that was rolled. Stripped the 
flooded one of nearly everything, put the electrics and electronics from the 
rolled one into it, then sold a bunch of leftover parts. Now he's fixing up a 
flood damaged Model X, which has been built with a much higher degree of water 
resistance. Nearly every electronics box on the Model S had been full of water. 
The battery had water in it. The motors, inverters, and gearboxes were full of 
water. The Model S, if it could be IP rated at all, would be at the lowest 
rating. See a clogged storm drain making a pond at an intersection? Don't go 
through it to have splashy fun with a Model S. Could get water into a motor 
and/or inverter.

During the Model X teardown, Rich has been finding there isn't much needing 
replacing with the electronics due to much better sealing of the boxes and 
connectors have better gaskets. The charge regulator on the X, mounted inside 
behind the right rear wheel, was totally dry inside despite being almost 
completely submerged. The one on the S was full of water. Apparently Tesla has 
learned what IP65 means, which is what everything on an electric car that runs 
on electricity ought to be, especially the parts outside the cabin.

On Friday, May 17, 2019, 8:20:05 AM MDT, Dave Cole 
 wrote:  
 OK,
Buy  a new "cheap" Tesla - about $35,800 right now.
Remove the battery pack  ;-)

You guys on the west coast make it sound like you have Tesla's sitting 
on the side of the road with "$500 or best offer" sale signs.

We now have 11 supercharger stations in the state of Indiana.
If Tesla's burned coal or biowaste we would be all set.   :-/

What is is a "cheap" Tesla going for in places where they are popular?

Dave

>
> So, let's turn that on its head. How can I run my cordless tools from Tesla
> cells...
  
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Re: [Emc-users] How come....

[Chris Albertson]

On Fri, May 17, 2019 at 3:05 AM Erik Christiansen 
wrote:

> On 16.05.19 23:25, andy pugh wrote:
> > On Thu, 16 May 2019 at 23:07, Chris Albertson  >
> > wrote:
> >
> >
> > > ill never beat Tesla's price.  Even if you build a factory and mass
> > > produce them
> >
> >
> > So, let's turn that on its head. How can I run my cordless tools from
> Tesla
> > cells...
>
> IIRC, the individual cells¹ are around 3.2 or 3.4v, so 4 would make a
> 12v pack, 6 for 18v, etc. Since their form factor probably won't suit an
> existing tool, it's either fabricate a new battery compartment, or run a
> cable to a pack on your belt or the floor. (I was going to do the latter
> with a small spare 12v lead acid battery, but in the end fitted an even
> smaller one into the existing battery compartment. It's adequate for the
> small jobs I use the cordless for.)
>

Almost all power tools use packs of cylindrical batteries.  The batteries
come in
a standardized size.   Cheaper notebook PCs also usethese  cylindrical
batteries.
They are easy to buy but you need a spot welder to make the packs, Soldering
or spring clips do not work

Some high-end equipment does use custom batteries made in a space to fit the
space, Apple does this in their Macs but mostly replacment cells will just
drop in like C size cells, if you have a spot welder.

For Lipo the nominal voltage is 3.7 per cell.  Howerev that can be at 4.2
when fully
charged and 3.0 when completely dead.Never dischange then below 3.5
volts
or you can shorten the life of the cell dramatically.

So a 3-cell battery is a goo replacement for a Lead Acid as the 3-cell pipo
will
range for 12.6 to 10.5   A fully changed 4-cell (at 16.8 volts might damage
equipment
designed for 12V LA.

I've build a lot of stuff that uses LiPo and the best solution, the OLNLY
way to go
is to design-in a monitoring system.  Human operators will destroy any LiPo
battery quickly.   But computers are good at this kind of thing.



> A 13.8v LA charger was easier to make out of a spare plugpack than would
> be a Li-Ion charger. Might have to snoop fleabay.
>
> Erik
>
> ¹ The ones which flew in the air, spewing flame and smoke, in one EV
>   battery pack repurposing I saw on youtube.
>
>
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-- 

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Redondo Beach, California

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Re: [Emc-users] How come....

[Kirk Wallace]

On 5/17/19 7:20 AM, Dave Cole wrote:

OK,
Buy  a new "cheap" Tesla - about $35,800 right now.
Remove the battery pack  ;-)

You guys on the west coast make it sound like you have Tesla's sitting 
on the side of the road with "$500 or best offer" sale signs.


Here is a fairly common surplus Tesla module:


https://www.ebay.com/itm/262333679871


If these have have not been abused after they were removed from the car 
they should last many thousands of deep cycles.  They are 6s but a 7th s 
can be added in order to cycle them deeper on a common 24 volt system.


My system (single, living in an RV) is close to this except I am using 
two Johnson Controls modules rewired as 7s:

https://www.mobile-solarpower.com/tesla-solar-battery-diy.html
https://www.ebay.com/itm/123187038180


This technology is changing so quickly that it is hard to keep current 
and reviews become stale in a month or two.



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Re: [Emc-users] How come....

[Gene Heskett]

On Friday 17 May 2019 10:20:54 am Dave Cole wrote:

> OK,
> Buy  a new "cheap" Tesla - about $35,800 right now.
> Remove the battery pack  ;-)
>
> You guys on the west coast make it sound like you have Tesla's sitting
> on the side of the road with "$500 or best offer" sale signs.
>
> We now have 11 supercharger stations in the state of Indiana.
> If Tesla's burned coal or biowaste we would be all set.   :-/
>
Our local Sheets, in a WV county (Lewis) of about 9k two legged air 
breathers, installed 8 charger stations about 18 months back. I saw 3 of 
them occupied a few days ago. But wasn't close enough to determine where 
the plates they were wearing said they were from.

> What is is a "cheap" Tesla going for in places where they are popular?
>
> Dave
>
> > So, let's turn that on its head. How can I run my cordless tools
> > from Tesla cells...
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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Re: [Emc-users] How come....

[Dave Cole]

OK,
Buy  a new "cheap" Tesla - about $35,800 right now.
Remove the battery pack  ;-)

You guys on the west coast make it sound like you have Tesla's sitting 
on the side of the road with "$500 or best offer" sale signs.


We now have 11 supercharger stations in the state of Indiana.
If Tesla's burned coal or biowaste we would be all set.   :-/

What is is a "cheap" Tesla going for in places where they are popular?

Dave



So, let's turn that on its head. How can I run my cordless tools from Tesla
cells...




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Re: [Emc-users] How come....

[Dave Cole]

Chris,
You need to look at the link... they look at the costs over a 10 year 
period.
Including battery bank replacement for the Lead Acid batteries.   Lead 
Acid is still cheaper.
And I think their prices for Lead Acid batteries are inflated.   I would 
also consider using a Lead Acid forklift battery (or multiples).

They are made to be rebuilt.

Sure they are heavy.   And that might be an issue for some, but if you 
have a tractor with a loader, or a forklift, then that is really not an 
issue.


Dave


On 5/16/2019 6:24 PM, Chris Albertson wrote:

Let's see your parts list for a 13.6 KWH system and let's look at the cost
over a 10 year period.  List the charger/inverter  and the frame and
housing.

When you do you costing assume the system is used cycled daily.  Design in
enough margin so that tyou system still meets speciications after 10 years
of use.   Itmust still have 13.6 KWHafter 10 years of daily cycling.
  Yes, this can be done with LA.

You can get the initial cost way low but you can't run it for 10 years
without replacing all the batteries 3 or 4 times.   That is the problem is
lead-acid batteries, it is their very limited number of cycles.   You can
work out different designs.   If the goal is only low initial cost then you
will find you need a VERY frequent battery replacement schedule.   You can
greatly reduce the number of times you need to replace each cell over the
10 year period if you double the initial cost.

You can't claim LA is lower cost until you look at the total cost
of ownership, not just the up from cost.   It is possble to get  very low
up from cost or you can also "cheat" assume the system is only used for
backup power a few times a year.  But realistically you need to look at
costs of a system that is actually used over an extended period.


So, you have to make a spreadsheet or punch buttons on a calculator.A
LA cell is good for about 300 cycles to 50% discharge before it looses bout
1/2 it's capacity. SO Youfigure maybe we only go to 40% and extend this
is 400 cyccles and buy 2X as may calls so we still meet specs after 400
cyccles.Then you work out how many batteries you need using them to
only 40%of their rating and stating with 2X over capsity.  You are
"shocked" at the cost so you think about designing a yearly schedule where
you add a few batteries everyyears and remove a few every year, but maybe
you don't add and removethe same number, so long as you kee the same 13.6
KWH spaec.  Work this over a 10 year period.

The up front cost means nothing because you can make that very low but it
will cost you a LOT later. I doubt you can do $6,700 total cost over 10
years.



On Thu, May 16, 2019 at 12:03 PM Dave Cole  wrote:


https://www.wholesalesolar.com/blog/lead-acid-vs-lithium-batteries/

This solar company wrote up this analysis regarding Lead Acid vs Lithium
and generally recommend Lead Acid for off grid residential use.
I went through their analysis and the only problem I had with it is that
their lead acid batteries are over priced.
Which, if their Lithium batteries are priced right, means that Lead Acid
is by far the best way to go.

I think their numbers for a Crown Lead Acid bank was $2800.  I did some
numbers and figured I could create a deep cycle bank of the same
capacity for about $1800.
Making your own power wall or Lithium battery pack is certainly a
possibility, but as mentioned cell balancing circuity is required.

I have a sailboat and participate in several sailboat lists and the
overwhelming way to go for house power on a larger sailboat is to use 6V
golf cart batteries.
The cost per power stored is cheaper than using 12 volt batteries and
golf cart batteries are true deep cycle batteries which are commonly
available.
A lot of 12 volt deep cycle batteries are compromised designs.

Now if these batteries were in a mobile device, like a car, that would
be an entirely different comparison since weight is a big deal in a
mobile device.
But these are for a stationary application.

Regarding the power wall concept.  The idea of having 20+ KWHR of stored
energy in my house is a little daunting.
If a short circuit occurs and the batteries melt down, your house could
be gone.

I'd put the battery bank in an outbuilding.  If something shorts out and
the battery bank melts down, the little building may burn but my house
won't.

Dave



On 5/14/2019 2:11 PM, Kirk Wallace wrote:

On 5/14/19 9:33 AM, Dave Cole wrote:

I've been planning to put up an array on my roof.  But I have plenty
of space so I may do a ground level install.
It would be a lot easier to maintain.

FLA batteries seem to be the general recommendation for a constant
use residential install.

In my opinion, lead-acid batteries of any format are far inferior to
lithium. LA batteries need to be at full charge most of the time or
they will degrade and with good management will only last about 5
years. I ended up running my generator to charge my FLA batteries in
the eveni

Re: [Emc-users] How come....

[Dave Cole]

DC power contactors are available. They are used in Golf Carts, Fork 
Lifts etc.


But you are right, DC arcs are not easy to extinguish, and that can be a 
problem.


BTW, most electric forklifts are still using Lead Acid batteries and 
many have 5 year warranties on the batteries.

Most fork trucks are used at least 5 days a week.

Dave


On 5/17/2019 6:23 AM, Erik Christiansen wrote:

On 16.05.19 21:18, Nicklas Karlsson wrote:

...
I'd put the battery bank in an outbuilding.  If something shorts out and
the battery bank melts down, the little building may burn but my house
won't.

There certainly is a lot of power from a byttery and it could be a
little bit hard to turn off. You put a fuse at battery cable?

If local regulations do not require a HRC (High Rupture Capacity) fuse
between the battery bank and any connection to it, then it's an
invitation to disaster. A dc arc is much more difficult to extinguish,
because there are no zero crossings, and molten metal can end up flowing
on the floor.

Small HRC fuses are generally in ceramic tubes, and are sand-filled, to
quench the arc when the element fuses. The one I have on the desk beside
me is a 100 A with a 100 kA (100,000 A) arc rupture capacity, but it's
27x44x49 mm, and is overkill. Just 10 times AH rating seems to be normal,
i.e. 2000 A rupture capacity for a 200 AH bank. (The fault current will
be limited by battery internal resistance.)


I also think DC relays have to be a little bit different than AC
relays, used an ordinary AC relay for a few few days connected to a DC
voltage and even though two switches is connected in series it
sometimes make a buzzing sound then turned off.

Most relays and switches are marked with both AC and DC current ratings.
The DC rating is always much lower, due to the difficulty of rupturing a
DC arc. Rather than bother with maintenance/replacement due to contact
deterioration after many switching cycles, I prefer to switch DC loads
with MOSFETs - they're easy to parallel, as the inherently share.

Erik


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Re: [Emc-users] How come....

[Erik Christiansen]

On 16.05.19 21:18, Nicklas Karlsson wrote:
> > ...
> > I'd put the battery bank in an outbuilding.  If something shorts out and 
> > the battery bank melts down, the little building may burn but my house 
> > won't.
> 
> There certainly is a lot of power from a byttery and it could be a
> little bit hard to turn off. You put a fuse at battery cable?

If local regulations do not require a HRC (High Rupture Capacity) fuse
between the battery bank and any connection to it, then it's an
invitation to disaster. A dc arc is much more difficult to extinguish,
because there are no zero crossings, and molten metal can end up flowing
on the floor.

Small HRC fuses are generally in ceramic tubes, and are sand-filled, to
quench the arc when the element fuses. The one I have on the desk beside
me is a 100 A with a 100 kA (100,000 A) arc rupture capacity, but it's
27x44x49 mm, and is overkill. Just 10 times AH rating seems to be normal,
i.e. 2000 A rupture capacity for a 200 AH bank. (The fault current will
be limited by battery internal resistance.)

> I also think DC relays have to be a little bit different than AC
> relays, used an ordinary AC relay for a few few days connected to a DC
> voltage and even though two switches is connected in series it
> sometimes make a buzzing sound then turned off.

Most relays and switches are marked with both AC and DC current ratings.
The DC rating is always much lower, due to the difficulty of rupturing a
DC arc. Rather than bother with maintenance/replacement due to contact
deterioration after many switching cycles, I prefer to switch DC loads
with MOSFETs - they're easy to parallel, as the inherently share.

Erik


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Re: [Emc-users] How come....

[Erik Christiansen]

On 16.05.19 23:25, andy pugh wrote:
> On Thu, 16 May 2019 at 23:07, Chris Albertson 
> wrote:
> 
> 
> > ill never beat Tesla's price.  Even if you build a factory and mass
> > produce them
> 
> 
> So, let's turn that on its head. How can I run my cordless tools from Tesla
> cells...

IIRC, the individual cells¹ are around 3.2 or 3.4v, so 4 would make a
12v pack, 6 for 18v, etc. Since their form factor probably won't suit an
existing tool, it's either fabricate a new battery compartment, or run a
cable to a pack on your belt or the floor. (I was going to do the latter
with a small spare 12v lead acid battery, but in the end fitted an even
smaller one into the existing battery compartment. It's adequate for the
small jobs I use the cordless for.)

A 13.8v LA charger was easier to make out of a spare plugpack than would
be a Li-Ion charger. Might have to snoop fleabay.

Erik

¹ The ones which flew in the air, spewing flame and smoke, in one EV
  battery pack repurposing I saw on youtube. 


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Re: [Emc-users] How come....

[Chris Albertson]

  There are instructions all over Youtube for making battery packs from
generic LiPo cells.You need a 3D printer to make the case and then you
need to build a spot welder to wire the batteries together.  Soldering does
not work.

Back when I owned a sailboat some years ago I used to keep a cordless drill
on it and the battery technology was NoCad and the drill's performance was
horrible.  I bought two cordless drills before I figured out the battery
tech was not up to the task.   This was back in the NiCad days. So I
solved the problem by buying a corded drill and installing a 1000W inverter
on the boat connecting it to the boat's bank of lead acid cells (6 golf
cart batteries)  So I guess I had a Lead-Acid powered drill?   (and a lead
acid powered microwave oven too)

I'd never make a power tool battery pack but my reasonfor owning machine
tools is robots.So g=far I'm been using LiPo batteries that are
designed and sold for quad copter drones as (for obvious reasons) they seem
to have the best power to weight ratio and lowest cost per kilowatt hour.
But these batteries are like playing with gasoline but worse when they
design to burn, they continue to burn even if you toss it  in a bucket of
water.Those cylindrical cells (that are used in tools, cars and power
walls) are safer to use.I'm going to build a spot welder one day.

On Thu, May 16, 2019 at 3:27 PM andy pugh  wrote:

> On Thu, 16 May 2019 at 23:07, Chris Albertson 
> wrote:
>
>
> > ill never beat Tesla's price.  Even if you build a factory and mass
> > produce them
>
>
> So, let's turn that on its head. How can I run my cordless tools from Tesla
> cells...
>
> --
> atp
> "A motorcycle is a bicycle with a pandemonium attachment and is designed
> for the especial use of mechanical geniuses, daredevils and lunatics."
> — George Fitch, Atlanta Constitution Newspaper, 1916
>
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-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] How come....

[andy pugh]

On Thu, 16 May 2019 at 23:07, Chris Albertson 
wrote:


> ill never beat Tesla's price.  Even if you build a factory and mass
> produce them


So, let's turn that on its head. How can I run my cordless tools from Tesla
cells...

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is designed
for the especial use of mechanical geniuses, daredevils and lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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Re: [Emc-users] How come....

[Chris Albertson]

Let's see your parts list for a 13.6 KWH system and let's look at the cost
over a 10 year period.  List the charger/inverter  and the frame and
housing.

When you do you costing assume the system is used cycled daily.  Design in
enough margin so that tyou system still meets speciications after 10 years
of use.   Itmust still have 13.6 KWHafter 10 years of daily cycling.
 Yes, this can be done with LA.

You can get the initial cost way low but you can't run it for 10 years
without replacing all the batteries 3 or 4 times.   That is the problem is
lead-acid batteries, it is their very limited number of cycles.   You can
work out different designs.   If the goal is only low initial cost then you
will find you need a VERY frequent battery replacement schedule.   You can
greatly reduce the number of times you need to replace each cell over the
10 year period if you double the initial cost.

You can't claim LA is lower cost until you look at the total cost
of ownership, not just the up from cost.   It is possble to get  very low
up from cost or you can also "cheat" assume the system is only used for
backup power a few times a year.  But realistically you need to look at
costs of a system that is actually used over an extended period.


So, you have to make a spreadsheet or punch buttons on a calculator.A
LA cell is good for about 300 cycles to 50% discharge before it looses bout
1/2 it's capacity. SO Youfigure maybe we only go to 40% and extend this
is 400 cyccles and buy 2X as may calls so we still meet specs after 400
cyccles.Then you work out how many batteries you need using them to
only 40%of their rating and stating with 2X over capsity.  You are
"shocked" at the cost so you think about designing a yearly schedule where
you add a few batteries everyyears and remove a few every year, but maybe
you don't add and removethe same number, so long as you kee the same 13.6
KWH spaec.  Work this over a 10 year period.

The up front cost means nothing because you can make that very low but it
will cost you a LOT later. I doubt you can do $6,700 total cost over 10
years.



On Thu, May 16, 2019 at 12:03 PM Dave Cole  wrote:

> https://www.wholesalesolar.com/blog/lead-acid-vs-lithium-batteries/
>
> This solar company wrote up this analysis regarding Lead Acid vs Lithium
> and generally recommend Lead Acid for off grid residential use.
> I went through their analysis and the only problem I had with it is that
> their lead acid batteries are over priced.
> Which, if their Lithium batteries are priced right, means that Lead Acid
> is by far the best way to go.
>
> I think their numbers for a Crown Lead Acid bank was $2800.  I did some
> numbers and figured I could create a deep cycle bank of the same
> capacity for about $1800.
> Making your own power wall or Lithium battery pack is certainly a
> possibility, but as mentioned cell balancing circuity is required.
>
> I have a sailboat and participate in several sailboat lists and the
> overwhelming way to go for house power on a larger sailboat is to use 6V
> golf cart batteries.
> The cost per power stored is cheaper than using 12 volt batteries and
> golf cart batteries are true deep cycle batteries which are commonly
> available.
> A lot of 12 volt deep cycle batteries are compromised designs.
>
> Now if these batteries were in a mobile device, like a car, that would
> be an entirely different comparison since weight is a big deal in a
> mobile device.
> But these are for a stationary application.
>
> Regarding the power wall concept.  The idea of having 20+ KWHR of stored
> energy in my house is a little daunting.
> If a short circuit occurs and the batteries melt down, your house could
> be gone.
>
> I'd put the battery bank in an outbuilding.  If something shorts out and
> the battery bank melts down, the little building may burn but my house
> won't.
>
> Dave
>
>
>
> On 5/14/2019 2:11 PM, Kirk Wallace wrote:
> > On 5/14/19 9:33 AM, Dave Cole wrote:
> >> I've been planning to put up an array on my roof.  But I have plenty
> >> of space so I may do a ground level install.
> >> It would be a lot easier to maintain.
> >>
> >> FLA batteries seem to be the general recommendation for a constant
> >> use residential install.
> >
> > In my opinion, lead-acid batteries of any format are far inferior to
> > lithium. LA batteries need to be at full charge most of the time or
> > they will degrade and with good management will only last about 5
> > years. I ended up running my generator to charge my FLA batteries in
> > the evening if the solar had not brought them up during the day. So I
> > ran the generator most days. Lithium batteries don't like to be fully
> > charged so now I don't need to worry about topping up before I go to
> > bed. Lead-acid batteries typically have a cycle life in the hundreds
> > of cycles where lithium battery cycle life is in the thousands or
> > more, and end up being cheaper in the longer term. On the other hand,
> > Lith

Re: [Emc-users] How come....

[Chris Albertson]

How many tool batteries are needed to equal one Tesla Power Wall?

The biggest tool battery I have is the 18 volt ones for my skill saw.  I
think it is 5 AH.  So let's say 90 watt hours.

SO I can build a "Power Wall" if only I have 150 of these batteries.  They
cost $120 each  So I could build my own power wall for $18,000  or I could
buy one from Tesla for $6,700.

But if I build my own I'd need more than just 150 batteries.  I'd need
something like 150 chargers and a whopping big inverter to turn all that DC
into AC.  So let's say $20K   Even if I get the batteries for 1/2 price the
cost is to high

You will never beat Tesla's price.  Even if you build a factory and mass
produce them you can't beat their scale of operations,  They make 3 million
lithium cells per day in Nevada.  They control the entire process from raw
materials up.

On Tue, May 14, 2019 at 10:58 PM Gregg Eshelman via Emc-users <
emc-users@lists.sourceforge.net> wrote:

> One of these days I'm expecting to see someone build a power wall style
> installation that uses lithium ion power tool batteries plugged into
> sockets. Imagine a closet full of Ryobi ONE+ 18 volt batteries. Buy them
> used, old ones on clearance etc.

-- 

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] How come....

[Nicklas Karlsson]

> ...
> I'd put the battery bank in an outbuilding.  If something shorts out and 
> the battery bank melts down, the little building may burn but my house 
> won't.

There certainly is a lot of power from a byttery and it could be a little bit 
hard to turn off. You put a fuse at battery cable? I also think DC relays have 
to be a little bit different than AC relays, used an ordinary AC relay for a 
few few days connected to a DC voltage and even though two switches is 
connected in series it sometimes make a buzzing sound then turned off.


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Re: [Emc-users] How come....

[Dave Cole]

https://www.wholesalesolar.com/blog/lead-acid-vs-lithium-batteries/

This solar company wrote up this analysis regarding Lead Acid vs Lithium 
and generally recommend Lead Acid for off grid residential use.
I went through their analysis and the only problem I had with it is that 
their lead acid batteries are over priced.
Which, if their Lithium batteries are priced right, means that Lead Acid 
is by far the best way to go.


I think their numbers for a Crown Lead Acid bank was $2800.  I did some 
numbers and figured I could create a deep cycle bank of the same 
capacity for about $1800.
Making your own power wall or Lithium battery pack is certainly a 
possibility, but as mentioned cell balancing circuity is required.


I have a sailboat and participate in several sailboat lists and the 
overwhelming way to go for house power on a larger sailboat is to use 6V 
golf cart batteries.
The cost per power stored is cheaper than using 12 volt batteries and 
golf cart batteries are true deep cycle batteries which are commonly 
available.

A lot of 12 volt deep cycle batteries are compromised designs.

Now if these batteries were in a mobile device, like a car, that would 
be an entirely different comparison since weight is a big deal in a 
mobile device.

But these are for a stationary application.

Regarding the power wall concept.  The idea of having 20+ KWHR of stored 
energy in my house is a little daunting.
If a short circuit occurs and the batteries melt down, your house could 
be gone.


I'd put the battery bank in an outbuilding.  If something shorts out and 
the battery bank melts down, the little building may burn but my house 
won't.


Dave



On 5/14/2019 2:11 PM, Kirk Wallace wrote:

On 5/14/19 9:33 AM, Dave Cole wrote:
I've been planning to put up an array on my roof.  But I have plenty 
of space so I may do a ground level install.

It would be a lot easier to maintain.

FLA batteries seem to be the general recommendation for a constant 
use residential install.


In my opinion, lead-acid batteries of any format are far inferior to 
lithium. LA batteries need to be at full charge most of the time or 
they will degrade and with good management will only last about 5 
years. I ended up running my generator to charge my FLA batteries in 
the evening if the solar had not brought them up during the day. So I 
ran the generator most days. Lithium batteries don't like to be fully 
charged so now I don't need to worry about topping up before I go to 
bed. Lead-acid batteries typically have a cycle life in the hundreds 
of cycles where lithium battery cycle life is in the thousands or 
more, and end up being cheaper in the longer term. On the other hand, 
Lithium batteries are easy to kill if they are over or under charged, 
so a proper battery manager/protector/balancer is a must. Otherwise 
they have a wide charge range and don't mind be anywhere within that 
range. I have been using these with good success for a while:
https://kit.com/jehu/lithium-battery-sources-july-2018/1274926-johnson-controls-24- 


https://www.mobile-solarpower.com/solar-charge-controllers.html

(Epever 40 amp)



I've had chargers trash batteries when they failed.  I sure wouldn't 
want that to happen to $10K worth of Lithium batteries!


Weight isn't an issue.

Dave


... snipped to end


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Re: [Emc-users] How come....

[Gregg Eshelman via Emc-users]

One of these days I'm expecting to see someone build a power wall style 
installation that uses lithium ion power tool batteries plugged into sockets. 
Imagine a closet full of Ryobi ONE+ 18 volt batteries. Buy them used, old ones 
on clearance etc. The practical aspect is the ONE+ batteries have built in safe 
discharge control so they can be used in the old blue and orange tools, and 
Ryobi didn't have to include discharge control circuitry in every new green and 
black tool. The lithium ion ONE+ batteries do require a special charger that 
uses the 4th contact. Those chargers can also charge to 3 contact nickel 
cadmium batteries. I dunno why Ryobi skipped using nickle metal hydride.


On Tuesday, May 14, 2019, 12:01:47 PM MDT, Bruce Layne 
 wrote:  
 
 Great analysis, Chris.  There's no way I'd use any lead acid battery
technology in a new off-the-grid solar power system.

A friend of mine replaced his old lead acid batteries with a home brewed
Tesla Power Wall, built from the battery from a wrecked Tesla Model S
automobile.

Part 1 (23 minutes):
https://www.youtube.com/watch?v=qpPYkqpe-Ms

Part 2 (13 minutes):
https://www.youtube.com/watch?v=U3PM2Ndu0zg  
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Re: [Emc-users] How come.... Batteries

[Chris Albertson]

On Tue, May 14, 2019 at 10:54 AM Nicklas Karlsson <
nicklas.karlsso...@gmail.com> wrote:

>  I have done calculations there storage cost for generated energy where
> higher than buying new electricity.
>

I depends on if you have time  of use metering.Here where I live the
utilty price depends on the time of day.   It used to be power was cheapest
at night and highers in mid afternoon when all the airconditional loads
were active.But solar power has changed this and now power is chear
when the sun is out.

Batteries if they are cheap enough like the Tesla units can ppay for them
selfs if yo buy power when it is lowset and used it when the price is high.
   But you need very good quality batteries to break even.

One interresting solution is to use an electric car. Let's say you know
you nedd to drive to work in the moring.  But "work" is only 20 miles round
trip.   You can get there on a 10% charge.So you charge the car durring
the day and then use the car to power the house while beibg carfule to
leave about 10% still inthe battery so you can get to work in the moring.
This works if you already own an electric car.

lastly, in 10 to 20 years there will be an over supply of used electric car
batteries that are no longer suitable for use in tha car.   A dozen of
these used battries would be perfect for a house   Tesla is selling 500K
cars per year now and VW is building a factory to make 600K and Tesla is
planning a second factory.   We shall soon see over  a million per years.
Then in 10 years we will have that many old batteries to salvageevery
year.  They will be cheap

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] How come....

[Kirk Wallace]

On 5/14/19 9:33 AM, Dave Cole wrote:
I've been planning to put up an array on my roof.  But I have plenty of 
space so I may do a ground level install.

It would be a lot easier to maintain.

FLA batteries seem to be the general recommendation for a constant use 
residential install.


In my opinion, lead-acid batteries of any format are far inferior to 
lithium. LA batteries need to be at full charge most of the time or they 
will degrade and with good management will only last about 5 years. I 
ended up running my generator to charge my FLA batteries in the evening 
if the solar had not brought them up during the day. So I ran the 
generator most days. Lithium batteries don't like to be fully charged so 
now I don't need to worry about topping up before I go to bed. Lead-acid 
batteries typically have a cycle life in the hundreds of cycles where 
lithium battery cycle life is in the thousands or more, and end up being 
cheaper in the longer term. On the other hand, Lithium batteries are 
easy to kill if they are over or under charged, so a proper battery 
manager/protector/balancer is a must. Otherwise they have a wide charge 
range and don't mind be anywhere within that range. I have been using 
these with good success for a while:

https://kit.com/jehu/lithium-battery-sources-july-2018/1274926-johnson-controls-24-
https://www.mobile-solarpower.com/solar-charge-controllers.html

(Epever 40 amp)



I've had chargers trash batteries when they failed.  I sure wouldn't 
want that to happen to $10K worth of Lithium batteries!


Weight isn't an issue.

Dave


... snipped to end


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Re: [Emc-users] How come....

[Bruce Layne]

Great analysis, Chris.  There's no way I'd use any lead acid battery
technology in a new off-the-grid solar power system.

A friend of mine replaced his old lead acid batteries with a home brewed
Tesla Power Wall, built from the battery from a wrecked Tesla Model S
automobile.

Part 1 (23 minutes):
https://www.youtube.com/watch?v=qpPYkqpe-Ms

Part 2 (13 minutes):
https://www.youtube.com/watch?v=U3PM2Ndu0zg

For small solar powered devices, there are LiFePo4 batteries that are
sized to replace sealed lead acid batteries.  LiFePO4 technology is the
much safer form of lithium battery.  These sealed battery modules have
internal cell balancing, and some of them have under voltage and over
voltage protection.  A cheap imported DC to DC converter can be used in
lieu of a charge controller.  That makes it very easy to design a solar
power system.  For most applications, simply size the battery for the
maximum energy needed for use at night and cloudy days and then size the
solar panel to be sufficient for the desired charge time without being
so large that it can charge the battery at an excessive rate.  I just
got the components from Amazon to power a 100W amateur radio station
that's entirely off-the-grid.  Hopefully I'll get that built and tested
this week.





On 5/14/19 1:36 PM, Chris Albertson wrote:
> If you are building a battery-based power system and space and weight are
> not issues then what you should care about is the "total watt-hours per
> dollar".
>
> Here is an example,... You have a 100 amp-hour lead-acid battery at 12
> volts.  If it is lead-acid then you can only discharge to 50% if you want a
> reasonable lifetime.If it is a cheap batery it might last only 100
> charge cycles.   so 50% x 100 cycles x 100 amp-hours x 12 volts is 60 KWH.
>The cheap battery might cost $100 to you pay  $1.60 per KHW for battery
> power based on the replacement cost of the battery.  You can buy a higher
> quality battery for more money but your cost is going to be between $1 and
> $2. per KWH
>
> So the cost of the battery power is 4 to 8 times high than the cost of
> power from the utility company.
>
> But what if you buy higher quality batteries?
>
> A Tesla "Power Wall" cost $6,800 (They used to be $10K)  it is a 13 KW
> capacity and is good for more than 3,000 charge cycles and is actually
> warrantied for 10 years.   It is maintenance free for 10 years.   Use with
> a waentry you have an incentive to use it for the full 3,650 cycles.
> Lets assume you only cycle it 3,000 times. That is under 20 cets per
> KHW for battery power.  It is dramtically cheaper then lead acid.
>
> This is why Tesla is selling b'zillions fo power wall systems.   If you do
> care about space, these Power Wall units cn be mounted to an exterior wall
> and actually look attractive.
>
>
>
>
>
>
> On Tue, May 14, 2019 at 9:32 AM Dave Cole  wrote:
>
>> I've been planning to put up an array on my roof.  But I have plenty of
>> space so I may do a ground level install.
>> It would be a lot easier to maintain.
>>
>> FLA batteries seem to be the general recommendation for a constant use
>> residential install.
>>
>> I've had chargers trash batteries when they failed.  I sure wouldn't
>> want that to happen to $10K worth of Lithium batteries!
>>
>> Weight isn't an issue.
>>
>> Dave
>>
>>
>>
>> On 5/9/2019 10:37 PM, Erik Christiansen wrote:
>>> On 09.05.19 10:24, Dave Cole wrote:
 Erik,

 Do you have a blog going on your build?
>>> Now that's an idea. All I've started is the seeds of an article for
>>> "Owner Builder" magazine - the editor was interested when we last spoke.
>>>
 I'd be very interested in your solar and battery setup for your off-grid
 home.
>>> The existing home, from the 1950's & extended, only has a little 2 kW
>>> petrol generator. The new roof which will carry the solar arrays goes up
>>> in June, if the framing carpenters turn up on time. (Just off the phone
>>> to 'em half an hour ago.) There's 6 or 7 kW of equator-facing panels,
>>> but the west-facing hipped roof can only take 9 panels, so only 2.5 kW
>>> or so - but still enough to keep pace with a modest aircon.
>>>
>>> The best trick for allowing high power consumption straight from the
>>> arrays, yet limiting battery charge rate to permissible maximum, is to
>>> use a hybrid inverter - they're beginning to become more available now.
>>> The Redflow ZnBr battery has a limited max charge rate (44A), and pretty
>>> much any other does too, e.g. 20A/100AH of capacity for LiFePO4. The
>> hybrid
>>> inverter looks after that while delivering to load first.
>>>
>>> I like the Redflow, as it's a long-life unit, unkillable by 100%
>>> discharge. It does though need that once a fortnight to regenerate, so
>>> it can be handy to have another battery. For off-grid, just one 10 kWh
>>> battery is maybe enough for one occupant, but a second is great for
>>> visitors from the city. But the reflow is about A$14k (US$10k), so I've
>>> even been look

Re: [Emc-users] How come.... Batteries

[Nicklas Karlsson]

Redox flow batteries might be a cheaper alternative. It might be likely not all 
available charging cycles are used for a long lasting battery. 20 cent per kWh 
hour, price for electricity I found in USA is in the range 7 - 23 cents per 
kWh, with an array on roof storage cost might be if you are unlucky storage 
come cost close to bying electricity. I have done calculations there storage 
cost for generated energy where higher than buying new electricity.


On Tue, 14 May 2019 10:36:42 -0700
Chris Albertson  wrote:

> If you are building a battery-based power system and space and weight are
> not issues then what you should care about is the "total watt-hours per
> dollar".
> 
> Here is an example,... You have a 100 amp-hour lead-acid battery at 12
> volts.  If it is lead-acid then you can only discharge to 50% if you want a
> reasonable lifetime.If it is a cheap batery it might last only 100
> charge cycles.   so 50% x 100 cycles x 100 amp-hours x 12 volts is 60 KWH.
>The cheap battery might cost $100 to you pay  $1.60 per KHW for battery
> power based on the replacement cost of the battery.  You can buy a higher
> quality battery for more money but your cost is going to be between $1 and
> $2. per KWH
> 
> So the cost of the battery power is 4 to 8 times high than the cost of
> power from the utility company.
> 
> But what if you buy higher quality batteries?
> 
> A Tesla "Power Wall" cost $6,800 (They used to be $10K)  it is a 13 KW
> capacity and is good for more than 3,000 charge cycles and is actually
> warrantied for 10 years.   It is maintenance free for 10 years.   Use with
> a waentry you have an incentive to use it for the full 3,650 cycles.
> Lets assume you only cycle it 3,000 times. That is under 20 cets per
> KHW for battery power.  It is dramtically cheaper then lead acid.
> 
> This is why Tesla is selling b'zillions fo power wall systems.   If you do
> care about space, these Power Wall units cn be mounted to an exterior wall
> and actually look attractive.
> 
> 
> 
> 
> 
> 
> On Tue, May 14, 2019 at 9:32 AM Dave Cole  wrote:
> 
> > I've been planning to put up an array on my roof.  But I have plenty of
> > space so I may do a ground level install.
> > It would be a lot easier to maintain.
> >
> > FLA batteries seem to be the general recommendation for a constant use
> > residential install.
> >
> > I've had chargers trash batteries when they failed.  I sure wouldn't
> > want that to happen to $10K worth of Lithium batteries!
> >
> > Weight isn't an issue.
> >
> > Dave
> >
> >
> >
> > On 5/9/2019 10:37 PM, Erik Christiansen wrote:
> > > On 09.05.19 10:24, Dave Cole wrote:
> > >> Erik,
> > >>
> > >> Do you have a blog going on your build?
> > >
> > > Now that's an idea. All I've started is the seeds of an article for
> > > "Owner Builder" magazine - the editor was interested when we last spoke.
> > >
> > >> I'd be very interested in your solar and battery setup for your off-grid
> > >> home.
> > > The existing home, from the 1950's & extended, only has a little 2 kW
> > > petrol generator. The new roof which will carry the solar arrays goes up
> > > in June, if the framing carpenters turn up on time. (Just off the phone
> > > to 'em half an hour ago.) There's 6 or 7 kW of equator-facing panels,
> > > but the west-facing hipped roof can only take 9 panels, so only 2.5 kW
> > > or so - but still enough to keep pace with a modest aircon.
> > >
> > > The best trick for allowing high power consumption straight from the
> > > arrays, yet limiting battery charge rate to permissible maximum, is to
> > > use a hybrid inverter - they're beginning to become more available now.
> > > The Redflow ZnBr battery has a limited max charge rate (44A), and pretty
> > > much any other does too, e.g. 20A/100AH of capacity for LiFePO4. The
> > hybrid
> > > inverter looks after that while delivering to load first.
> > >
> > > I like the Redflow, as it's a long-life unit, unkillable by 100%
> > > discharge. It does though need that once a fortnight to regenerate, so
> > > it can be handy to have another battery. For off-grid, just one 10 kWh
> > > battery is maybe enough for one occupant, but a second is great for
> > > visitors from the city. But the reflow is about A$14k (US$10k), so I've
> > > even been looking at old technology like NiFe. They're also robust, but
> > > can drink a lot of distilled water, emit quite a bit of hydrogen, and
> > > put out a bit of mist. About 80% energy recovery is common for a lot of
> > > battery chemistries, these included. Li-Ion, or better LiFePO4, are
> > > better efficiency-wise, but cycle life on deep discharge is less. Do
> > > your machining in sunlight, and only run lights, computers, tv, and a
> > > microwaved egg sanger at night, then they'll do well enough, I reckon -
> > > certainly long enough for a better technology to reach a better price.
> > >
> > > We know from laptops that Li-Ion loses capacity with age. The ZnBr unit
> > > is claimed to retain ca

Re: [Emc-users] How come....

[Chris Albertson]

If you are building a battery-based power system and space and weight are
not issues then what you should care about is the "total watt-hours per
dollar".

Here is an example,... You have a 100 amp-hour lead-acid battery at 12
volts.  If it is lead-acid then you can only discharge to 50% if you want a
reasonable lifetime.If it is a cheap batery it might last only 100
charge cycles.   so 50% x 100 cycles x 100 amp-hours x 12 volts is 60 KWH.
   The cheap battery might cost $100 to you pay  $1.60 per KHW for battery
power based on the replacement cost of the battery.  You can buy a higher
quality battery for more money but your cost is going to be between $1 and
$2. per KWH

So the cost of the battery power is 4 to 8 times high than the cost of
power from the utility company.

But what if you buy higher quality batteries?

A Tesla "Power Wall" cost $6,800 (They used to be $10K)  it is a 13 KW
capacity and is good for more than 3,000 charge cycles and is actually
warrantied for 10 years.   It is maintenance free for 10 years.   Use with
a waentry you have an incentive to use it for the full 3,650 cycles.
Lets assume you only cycle it 3,000 times. That is under 20 cets per
KHW for battery power.  It is dramtically cheaper then lead acid.

This is why Tesla is selling b'zillions fo power wall systems.   If you do
care about space, these Power Wall units cn be mounted to an exterior wall
and actually look attractive.






On Tue, May 14, 2019 at 9:32 AM Dave Cole  wrote:

> I've been planning to put up an array on my roof.  But I have plenty of
> space so I may do a ground level install.
> It would be a lot easier to maintain.
>
> FLA batteries seem to be the general recommendation for a constant use
> residential install.
>
> I've had chargers trash batteries when they failed.  I sure wouldn't
> want that to happen to $10K worth of Lithium batteries!
>
> Weight isn't an issue.
>
> Dave
>
>
>
> On 5/9/2019 10:37 PM, Erik Christiansen wrote:
> > On 09.05.19 10:24, Dave Cole wrote:
> >> Erik,
> >>
> >> Do you have a blog going on your build?
> >
> > Now that's an idea. All I've started is the seeds of an article for
> > "Owner Builder" magazine - the editor was interested when we last spoke.
> >
> >> I'd be very interested in your solar and battery setup for your off-grid
> >> home.
> > The existing home, from the 1950's & extended, only has a little 2 kW
> > petrol generator. The new roof which will carry the solar arrays goes up
> > in June, if the framing carpenters turn up on time. (Just off the phone
> > to 'em half an hour ago.) There's 6 or 7 kW of equator-facing panels,
> > but the west-facing hipped roof can only take 9 panels, so only 2.5 kW
> > or so - but still enough to keep pace with a modest aircon.
> >
> > The best trick for allowing high power consumption straight from the
> > arrays, yet limiting battery charge rate to permissible maximum, is to
> > use a hybrid inverter - they're beginning to become more available now.
> > The Redflow ZnBr battery has a limited max charge rate (44A), and pretty
> > much any other does too, e.g. 20A/100AH of capacity for LiFePO4. The
> hybrid
> > inverter looks after that while delivering to load first.
> >
> > I like the Redflow, as it's a long-life unit, unkillable by 100%
> > discharge. It does though need that once a fortnight to regenerate, so
> > it can be handy to have another battery. For off-grid, just one 10 kWh
> > battery is maybe enough for one occupant, but a second is great for
> > visitors from the city. But the reflow is about A$14k (US$10k), so I've
> > even been looking at old technology like NiFe. They're also robust, but
> > can drink a lot of distilled water, emit quite a bit of hydrogen, and
> > put out a bit of mist. About 80% energy recovery is common for a lot of
> > battery chemistries, these included. Li-Ion, or better LiFePO4, are
> > better efficiency-wise, but cycle life on deep discharge is less. Do
> > your machining in sunlight, and only run lights, computers, tv, and a
> > microwaved egg sanger at night, then they'll do well enough, I reckon -
> > certainly long enough for a better technology to reach a better price.
> >
> > We know from laptops that Li-Ion loses capacity with age. The ZnBr unit
> > is claimed to retain capacity, just losing efficiency. If a few (cheap)
> > extra panels are put in the array(s), then that's pretty much covered.
> >
> > One thing - the hybrid inverter should have two MPPT string inputs - one
> > for each PV array, as their voltage at max power will never be equal,
> > given widely divergent orientation.
> >
> >> You must have a substantial setup to be able to run your AC off your
> battery
> >> bank.
> > I'm hoping to be able to get the roof up in time to qualify for a
> > current A$5k government rebate on batteries. Systems with only 6.3 kWh
> > battery capacity are selling well here for on-grid customers. I'd like
> > twice that, as without that, running the mill for hours after half a 

Re: [Emc-users] How come....

[Dave Cole]

I've been planning to put up an array on my roof.  But I have plenty of 
space so I may do a ground level install.

It would be a lot easier to maintain.

FLA batteries seem to be the general recommendation for a constant use 
residential install.


I've had chargers trash batteries when they failed.  I sure wouldn't 
want that to happen to $10K worth of Lithium batteries!


Weight isn't an issue.

Dave



On 5/9/2019 10:37 PM, Erik Christiansen wrote:

On 09.05.19 10:24, Dave Cole wrote:

Erik,

Do you have a blog going on your build?
  
Now that's an idea. All I've started is the seeds of an article for

"Owner Builder" magazine - the editor was interested when we last spoke.


I'd be very interested in your solar and battery setup for your off-grid
home.

The existing home, from the 1950's & extended, only has a little 2 kW
petrol generator. The new roof which will carry the solar arrays goes up
in June, if the framing carpenters turn up on time. (Just off the phone
to 'em half an hour ago.) There's 6 or 7 kW of equator-facing panels,
but the west-facing hipped roof can only take 9 panels, so only 2.5 kW
or so - but still enough to keep pace with a modest aircon.

The best trick for allowing high power consumption straight from the
arrays, yet limiting battery charge rate to permissible maximum, is to
use a hybrid inverter - they're beginning to become more available now.
The Redflow ZnBr battery has a limited max charge rate (44A), and pretty
much any other does too, e.g. 20A/100AH of capacity for LiFePO4. The hybrid
inverter looks after that while delivering to load first.

I like the Redflow, as it's a long-life unit, unkillable by 100%
discharge. It does though need that once a fortnight to regenerate, so
it can be handy to have another battery. For off-grid, just one 10 kWh
battery is maybe enough for one occupant, but a second is great for
visitors from the city. But the reflow is about A$14k (US$10k), so I've
even been looking at old technology like NiFe. They're also robust, but
can drink a lot of distilled water, emit quite a bit of hydrogen, and
put out a bit of mist. About 80% energy recovery is common for a lot of
battery chemistries, these included. Li-Ion, or better LiFePO4, are
better efficiency-wise, but cycle life on deep discharge is less. Do
your machining in sunlight, and only run lights, computers, tv, and a
microwaved egg sanger at night, then they'll do well enough, I reckon -
certainly long enough for a better technology to reach a better price.

We know from laptops that Li-Ion loses capacity with age. The ZnBr unit
is claimed to retain capacity, just losing efficiency. If a few (cheap)
extra panels are put in the array(s), then that's pretty much covered.

One thing - the hybrid inverter should have two MPPT string inputs - one
for each PV array, as their voltage at max power will never be equal,
given widely divergent orientation.


You must have a substantial setup to be able to run your AC off your battery
bank.

I'm hoping to be able to get the roof up in time to qualify for a
current A$5k government rebate on batteries. Systems with only 6.3 kWh
battery capacity are selling well here for on-grid customers. I'd like
twice that, as without that, running the mill for hours after half a week
of overcast winter days could mean arcing the generator up for a charging
burst. But a litre of petrol now and then is a darn sight cheaper than a
big battery.


What do you do for domestic water?  A deep well?

For 55 years it's just been rainwater tanks. I'll be putting in another
90,000 litres of tanks, to catch it when it does come. There'll be
nearly 400 m² of roof all up. (But yes, years ago in a big drought it
really was bathe the baby in a bucket of water, use that to wash her
clothes, then wash the lino floor with it, then put it on the few garden
plants you could keep going.) The concern is that a tight rain deficit
might be shaping up to be the new norm for SE Australia, not improving
at all while we go from the current 1°C warming, through 1.5°C maybe as
early as 2030, to 2°C a bit later. (Accelerated warming at the poles
does not bear looking at, unless you've had a stiff drink first.)

The neighbour had a drill rig in before easter, to drill for stock
water. It was expected around 70 feet down. I haven't heard the results.
That's a finite resource though, only buying limited time. Slabs of
India is hundreds of feet down now, and heading for a brick wall. More
roof, more tanks, and live on what precipitates is more viable for
longer.

Erik


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Re: [Emc-users] How come....

[Gene Heskett]

On Thursday 09 May 2019 11:10:03 pm Erik Christiansen wrote:

> On 09.05.19 09:16, Gene Heskett wrote:
> > Good thinking Erik. I suppose the next Q is how far down is it to
> > the water table?  And thats a job for a wind mill tower...  But you
> > knew that. What would be neat is a big remote switch rod running up
> > the tower to a clutch to disconnect the wheel from the pump jack
> > when the tank is full, and connect it to an alternator for battery
> > charging. A dog clutch could handle that as the normal water pump
> > fan doesn't turn that fast. About a 10x gear up to an alternator
> > ought to give some usable wattage for the batteries.
>
> Although a mill and a lathe help with maintaining a windmill, they're
> scarily expensive here in the 21st century, and susceptible to the
> increasing energy in our atmosphere. A high velocity microcell can
> wreak havoc in a small area, and Murphy can smell an expensive
> windmill at forty miles, I figure.
>
> The electrical engineer in me thinks an electric pump and a few more
> panels on the PV array are a darn sight less maintenance effort in the
> long run. Turned on only when there's good sun, the only required
> storage is in the water tank. (No extra battery cost.)
>
> There's over 200 Ha (nudging 500 acres) of eucalypt forest on site, so
> steady wind is a good bit less than right out in the open.
>
If you don't get some precip, those will be greasy firewood, waiting for 
the first lightning strike. Ashes in 20 minutes.
 
> > I spent a couple years of my early life on grandpa's farm in Madison
> > County Iowa, several miles "off grid" as that was long before the
> > R.E.A. It was just how it was in those days, a farmer was self
> > sufficient or starved.  We ate well, very well in fact. Big glass
> > single cell lead acid cells, about 5 gallon size, 10 of them gave us
> > a bit if light in the evenings, lights in the barn to milk the cows
> > by and ran the maytag washer after the put-miss-put backfired and
> > broke grandmas ankle, first electric washing machine in rural
> > Madison County by quite a few years. Yeah, that Madison County, made
> > famous 80 years later by Eastwood and Streep in Bridges. I was over
> > quite a few of those bridges in a team of horses drawn wagon back
> > then. A simpler, but not always easier time back then.
>
> There's quite a comparison between that "can-do or do without"
> upbringing and city kids now sitting indoors in a big house on a 300
> m² (0.074 acre) block with no back yard, playing video games and
> watching "Bluey", a serialised cartoon in which dogs play the roles of
> children playing in back yards, which the real children don't have. I
> don't see this "progress" progressing to a happy conclusion.

Neither do I, but I figure it will take rope and bullets to fix it.  I'm 
hoping I won't still be around.

> Wouldn't 
> trade my farm upbringing for modern childhood. (My father used to say
> "A good kite flies best in a headwind." Well it taught some resilience
> as well as what elbow grease could do, and where to find it.)

Amen.
>
> There's an old "32 Vdc" lighting generator somewhere in Dad's old
> shed. They must have had matching light globes back then.

Yes, often carbon filament, not very bright, and often radio reception 
killers.  I had a shirttail aunt who lived in the house next to the 
school in Redfield Ia.  Had a radio for the news but it was buzzy.  I 
went looking for the buzz when the first 4 transistor pocket radios came 
out.  Found it in a 15 watt, carbon filament bulb in the attic which had 
no switch to turn it off, so it was likely 35 years old then, but she 
wouldn't let me unscrew it.  I suppose it could still be burning and 
buzzing.  Hard to tell, they both passed in the next decade, and I've 
not been back to Redfield since 2007 when I stopped at our old home 
place I helped my stepfather build in '46 and intro'ed myself as the 
electrician that had wired the place on a used shoestring when I was 12 
years old.  The folks living there now got a kick out of that. They had 
finally rewired it with some yard sale stuff in about 2005.  Had 
somebody do it for them that is. 'sfunny how life makes you drive 20 
million miles and pull up in the same driveway 70 years later.

I was coming home from saying goodbye to my oldest daughter, who passed 
about 28 hours after I got home, and the wife had us packed and we got 
up the next morning and drove another 450 miles to her nieces dairy farm 
in New York. Got in about dark, had some eats, adjourned to a pair of 
couches in the basement, but was startled awake about 2 AM by somebody 
or something that wasn't there, but I could feel their presence. Gave 
up, recycled some water and went back to sleep. Up the next morning, my 
cellphone burped once them rang, normally theres no coverage there, 
answered it and it took 10 seconds of noise before the cell tower put 
enough power in it to get to me, its was my son-in-law, advising me that 
she ha

Re: [Emc-users] How come....

[Erik Christiansen]

On 09.05.19 09:16, Gene Heskett wrote:
> Good thinking Erik. I suppose the next Q is how far down is it to the 
> water table?  And thats a job for a wind mill tower...  But you knew 
> that. What would be neat is a big remote switch rod running up the tower 
> to a clutch to disconnect the wheel from the pump jack when the tank is 
> full, and connect it to an alternator for battery charging. A dog clutch 
> could handle that as the normal water pump fan doesn't turn that fast. 
> About a 10x gear up to an alternator ought to give some usable wattage 
> for the batteries.

Although a mill and a lathe help with maintaining a windmill, they're
scarily expensive here in the 21st century, and susceptible to the
increasing energy in our atmosphere. A high velocity microcell can wreak
havoc in a small area, and Murphy can smell an expensive windmill at
forty miles, I figure.

The electrical engineer in me thinks an electric pump and a few more
panels on the PV array are a darn sight less maintenance effort in the
long run. Turned on only when there's good sun, the only required
storage is in the water tank. (No extra battery cost.)

There's over 200 Ha (nudging 500 acres) of eucalypt forest on site, so
steady wind is a good bit less than right out in the open.

> I spent a couple years of my early life on grandpa's farm in Madison 
> County Iowa, several miles "off grid" as that was long before the R.E.A.  
> It was just how it was in those days, a farmer was self sufficient or 
> starved.  We ate well, very well in fact. Big glass single cell lead 
> acid cells, about 5 gallon size, 10 of them gave us a bit if light in 
> the evenings, lights in the barn to milk the cows by and ran the maytag 
> washer after the put-miss-put backfired and broke grandmas ankle, first 
> electric washing machine in rural Madison County by quite a few years.  
> Yeah, that Madison County, made famous 80 years later by Eastwood and 
> Streep in Bridges. I was over quite a few of those bridges in a team of 
> horses drawn wagon back then. A simpler, but not always easier time back 
> then.

There's quite a comparison between that "can-do or do without"
upbringing and city kids now sitting indoors in a big house on a 300 m²
(0.074 acre) block with no back yard, playing video games and watching
"Bluey", a serialised cartoon in which dogs play the roles of children
playing in back yards, which the real children don't have. I don't see
this "progress" progressing to a happy conclusion. Wouldn't trade my
farm upbringing for modern childhood. (My father used to say "A good
kite flies best in a headwind." Well it taught some resilience as well
as what elbow grease could do, and where to find it.)

There's an old "32 Vdc" lighting generator somewhere in Dad's old shed.
They must have had matching light globes back then.

Erik


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Re: [Emc-users] How come....

[Erik Christiansen]

On 09.05.19 10:24, Dave Cole wrote:
> 
> Erik,
> 
> Do you have a blog going on your build?
 
Now that's an idea. All I've started is the seeds of an article for
"Owner Builder" magazine - the editor was interested when we last spoke.

> I'd be very interested in your solar and battery setup for your off-grid
> home.

The existing home, from the 1950's & extended, only has a little 2 kW
petrol generator. The new roof which will carry the solar arrays goes up
in June, if the framing carpenters turn up on time. (Just off the phone
to 'em half an hour ago.) There's 6 or 7 kW of equator-facing panels,
but the west-facing hipped roof can only take 9 panels, so only 2.5 kW
or so - but still enough to keep pace with a modest aircon.

The best trick for allowing high power consumption straight from the
arrays, yet limiting battery charge rate to permissible maximum, is to
use a hybrid inverter - they're beginning to become more available now.
The Redflow ZnBr battery has a limited max charge rate (44A), and pretty
much any other does too, e.g. 20A/100AH of capacity for LiFePO4. The hybrid
inverter looks after that while delivering to load first.

I like the Redflow, as it's a long-life unit, unkillable by 100%
discharge. It does though need that once a fortnight to regenerate, so
it can be handy to have another battery. For off-grid, just one 10 kWh
battery is maybe enough for one occupant, but a second is great for
visitors from the city. But the reflow is about A$14k (US$10k), so I've
even been looking at old technology like NiFe. They're also robust, but
can drink a lot of distilled water, emit quite a bit of hydrogen, and
put out a bit of mist. About 80% energy recovery is common for a lot of
battery chemistries, these included. Li-Ion, or better LiFePO4, are
better efficiency-wise, but cycle life on deep discharge is less. Do
your machining in sunlight, and only run lights, computers, tv, and a
microwaved egg sanger at night, then they'll do well enough, I reckon -
certainly long enough for a better technology to reach a better price.

We know from laptops that Li-Ion loses capacity with age. The ZnBr unit
is claimed to retain capacity, just losing efficiency. If a few (cheap)
extra panels are put in the array(s), then that's pretty much covered.

One thing - the hybrid inverter should have two MPPT string inputs - one
for each PV array, as their voltage at max power will never be equal,
given widely divergent orientation.

> You must have a substantial setup to be able to run your AC off your battery
> bank.

I'm hoping to be able to get the roof up in time to qualify for a
current A$5k government rebate on batteries. Systems with only 6.3 kWh
battery capacity are selling well here for on-grid customers. I'd like
twice that, as without that, running the mill for hours after half a week
of overcast winter days could mean arcing the generator up for a charging
burst. But a litre of petrol now and then is a darn sight cheaper than a
big battery.

> What do you do for domestic water?  A deep well?

For 55 years it's just been rainwater tanks. I'll be putting in another
90,000 litres of tanks, to catch it when it does come. There'll be
nearly 400 m² of roof all up. (But yes, years ago in a big drought it
really was bathe the baby in a bucket of water, use that to wash her
clothes, then wash the lino floor with it, then put it on the few garden
plants you could keep going.) The concern is that a tight rain deficit
might be shaping up to be the new norm for SE Australia, not improving
at all while we go from the current 1°C warming, through 1.5°C maybe as
early as 2030, to 2°C a bit later. (Accelerated warming at the poles
does not bear looking at, unless you've had a stiff drink first.)

The neighbour had a drill rig in before easter, to drill for stock
water. It was expected around 70 feet down. I haven't heard the results.
That's a finite resource though, only buying limited time. Slabs of
India is hundreds of feet down now, and heading for a brick wall. More
roof, more tanks, and live on what precipitates is more viable for
longer.

Erik


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Re: [Emc-users] How come....

[Dave Cole]

Erik,

Do you have a blog going on your build?
I'd be very interested in your solar and battery setup for your off-grid 
home.


You must have a substantial setup to be able to run your AC off your 
battery bank.


What do you do for domestic water?  A deep well?

Dave


On 5/9/2019 5:17 AM, Erik Christiansen wrote:



Down under, the last dam/waterhole on the farm has dried up after a dry
autumn on top of the driest year in the 55 years we've been there. (245
mm rain last year, and many times that in evaporation rate.) Don't know
what the kangaroos and wombats are drinking.

But cloudless blue skies are OK for a retiree, so the off-grid build
proceeds - slowly. The slab is in. Waiting on carpenter availability and
pre-made wall frames & trusses. Our tax office has a nifty scheme where
old folk can raid up to $300k from their superannuation for a home
down-size, then put it back when the old home is sold. And being architect,
owner-builder, and lender keeps everything on a cooperative footing.
(Just watch the paperwork, though.)

Still had to get building surveyor approval when I redrew the roof to
take a west-facing solar array to power the aircon in the afternoon,
after the sun has slid off the north-facing array. Kinda essential on a
43°C day, when you're off-grid. (It's too late to recharge the battery
for the night after you've hammered it hard for late afternoon aircon.)

Erik


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Re: [Emc-users] How come....

[Gene Heskett]

On Thursday 09 May 2019 05:17:13 am Erik Christiansen wrote:

> On 09.05.19 09:58, Peter Blodow wrote:
> >  there has been no incoming mail since May 6th?
> > Peter
>
> I was about to facetiously venture "Perhaps because Gene's been busy
>
> over on debian-user?", but there was a whole thread on:
> >From emc-users-boun...@lists.sourceforge.net  Tue May  7 13:03:40
> > 2019
>
>  Subject:  Re: M52
>   Folder: cnc_linux_u8992
>
> but those 5 were all, AFAICT.
>
>
> Down under, the last dam/waterhole on the farm has dried up after a
> dry autumn on top of the driest year in the 55 years we've been there.
> (245 mm rain last year, and many times that in evaporation rate.)
> Don't know what the kangaroos and wombats are drinking.
>
> But cloudless blue skies are OK for a retiree, so the off-grid build
> proceeds - slowly. The slab is in. Waiting on carpenter availability
> and pre-made wall frames & trusses. Our tax office has a nifty scheme
> where old folk can raid up to $300k from their superannuation for a
> home down-size, then put it back when the old home is sold. And being
> architect, owner-builder, and lender keeps everything on a cooperative
> footing. (Just watch the paperwork, though.)
>
> Still had to get building surveyor approval when I redrew the roof to
> take a west-facing solar array to power the aircon in the afternoon,
> after the sun has slid off the north-facing array. Kinda essential on
> a 43°C day, when you're off-grid. (It's too late to recharge the
> battery for the night after you've hammered it hard for late afternoon
> aircon.)
>
> Erik

Good thinking Erik. I suppose the next Q is how far down is it to the 
water table?  And thats a job for a wind mill tower...  But you knew 
that. What would be neat is a big remote switch rod running up the tower 
to a clutch to disconnect the wheel from the pump jack when the tank is 
full, and connect it to an alternator for battery charging. A dog clutch 
could handle that as the normal water pump fan doesn't turn that fast. 
About a 10x gear up to an alternator ought to give some usable wattage 
for the batteries.

I spent a couple years of my early life on grandpa's farm in Madison 
County Iowa, several miles "off grid" as that was long before the R.E.A.  
It was just how it was in those days, a farmer was self sufficient or 
starved.  We ate well, very well in fact. Big glass single cell lead 
acid cells, about 5 gallon size, 10 of them gave us a bit if light in 
the evenings, lights in the barn to milk the cows by and ran the maytag 
washer after the put-miss-put backfired and broke grandmas ankle, first 
electric washing machine in rural Madison County by quite a few years.  
Yeah, that Madison County, made famous 80 years later by Eastwood and 
Streep in Bridges. I was over quite a few of those bridges in a team of 
horses drawn wagon back then. A simpler, but not always easier time back 
then.
>
> ___
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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Re: [Emc-users] How come....

[Gene Heskett]

On Thursday 09 May 2019 04:46:25 am Roland Jollivet wrote:

> Because no-one has posted anything?
>
> On Thu, 9 May 2019 at 10:17, Peter Blodow  wrote:
> >  there has been no incoming mail since May 6th?
> > Peter

I've been getting posts, although slow, about 14 since then.

I figure folks are just busy with the first warmer weather stuffs.

Like yesterday I had a fellow with a backhoe in and tore up my front yard 
from the water meter to the house, replaceing the whole roll of 40+ yo 
plastic pipe because I had more leaks, we found my fix from last 
Septembers dig was still good, but 3 more leaks beyond that including 
some rube goldberg stuff of copper and galvanized right out side the 
house and the galvanized was rotted out from galvanic.

Good thing the guy that did it has already passed or I'd have been 
tempted to beat him to death with it. Other than that it was a 
relatively quiet day, but I've got aches and pains in places I I'd 
forgotten about this morning from fetching the stuff they didn't bring 
and probably should have.

But now I've got all new stuff from the meter to about a foot below the 
shutoff just inside the basement.  We also found 30 feet of the gas line 
w/o damaging it, the french drain around the house and the gutter run we 
had to patch. But not the sewer, so we've still after 30 years, not a 
clue where it leaves. Building codes?  What building codes?, the city 
didn't have or didn't enforce them 40 years ago. Water and gas in the 
same ditch!. So we made some new ditch for part of it. Hopefully that 
will be the last of that for 40+ years, by which time it will be 
somebody else's headache.

The guy had quoted me a per hour, I think trying to scare me off, and 
asked for only 1/3rd of that when he was done. Blew me away. So I paid 
him the cash price and gave him an extra $70 with instructions that it 
was a tip for his helper that did all the shovel work. he did a lot of 
work the hoe couldn't reach and did it willingly. Good help is hard to 
find, and should be rewarded IMO.

A more productive day than usual around the coyote.den, my local 
domainname. 

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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Re: [Emc-users] How come....

[Erik Christiansen]

On 09.05.19 09:58, Peter Blodow wrote:
>  there has been no incoming mail since May 6th?
> Peter

I was about to facetiously venture "Perhaps because Gene's been busy
over on debian-user?", but there was a whole thread on:

>From emc-users-boun...@lists.sourceforge.net  Tue May  7 13:03:40 2019
 Subject:  Re: M52 
  Folder: cnc_linux_u8992

but those 5 were all, AFAICT.


Down under, the last dam/waterhole on the farm has dried up after a dry
autumn on top of the driest year in the 55 years we've been there. (245
mm rain last year, and many times that in evaporation rate.) Don't know
what the kangaroos and wombats are drinking.

But cloudless blue skies are OK for a retiree, so the off-grid build
proceeds - slowly. The slab is in. Waiting on carpenter availability and
pre-made wall frames & trusses. Our tax office has a nifty scheme where
old folk can raid up to $300k from their superannuation for a home
down-size, then put it back when the old home is sold. And being architect,
owner-builder, and lender keeps everything on a cooperative footing.
(Just watch the paperwork, though.)

Still had to get building surveyor approval when I redrew the roof to
take a west-facing solar array to power the aircon in the afternoon,
after the sun has slid off the north-facing array. Kinda essential on a
43°C day, when you're off-grid. (It's too late to recharge the battery
for the night after you've hammered it hard for late afternoon aircon.)

Erik


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Re: [Emc-users] How come....

[Leonardo Marsaglia]

Haha. It's good to ask anyway. A few months ago I got unsuscribed from the
list and don't know why.

El 9 may. 2019 07:36, "Roland Jollivet" 
escribió:

> Because no-one has posted anything?
>
> On Thu, 9 May 2019 at 10:17, Peter Blodow  wrote:
>
> >  there has been no incoming mail since May 6th?
> > Peter
> >
> >
> > ___
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> >
>
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[Emc-users] How come....

[Roland Jollivet]

Because no-one has posted anything?

On Thu, 9 May 2019 at 10:17, Peter Blodow  wrote:

>  there has been no incoming mail since May 6th?
> Peter
>
>
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>

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[Emc-users] How come....

[Peter Blodow]

 there has been no incoming mail since May 6th?
Peter


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