EV Digest 4009
Topics covered in this issue include:
1) Re: DIY Controller
by Seth Allen <[EMAIL PROTECTED]>
2) Re: KISS AC EV Drive System
by Evan Tuer <[EMAIL PROTECTED]>
3) 300zx
by "Steve Clunn" <[EMAIL PROTECTED]>
4) Torque converters for DD EV's, Re: KISS AC EV Drive System
by jerry dycus <[EMAIL PROTECTED]>
5) Re: Blueprinting electric motors
by M Bianchi <[EMAIL PROTECTED]>
6) RE: One-Way Breaker
by "Bill Dennis" <[EMAIL PROTECTED]>
7) RE: 300zx
by "damon henry" <[EMAIL PROTECTED]>
8) Salvage Wire, was "Good wire"
by "Harry Houck" <[EMAIL PROTECTED]>
9) RE: One-Way Breaker
by Mark Farver <[EMAIL PROTECTED]>
10) Re: One-Way Breaker
by Evan Tuer <[EMAIL PROTECTED]>
11) Re: Multiple Powertool chargers as Ni Cad Pack charger
by Lee Hart <[EMAIL PROTECTED]>
12) RE: One-Way Breaker
by "Bill Dennis" <[EMAIL PROTECTED]>
13) Re: Blueprinting electric motors
by Lee Hart <[EMAIL PROTECTED]>
14) Re: "Good wire" ?
by Lee Hart <[EMAIL PROTECTED]>
15) Re: Multiple Powertool chargers as Ni Cad Pack charger
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
16) Re: 300zx
by David Dymaxion <[EMAIL PROTECTED]>
17) RE: One-Way Breaker
by <[EMAIL PROTECTED]>
18) Re: High Power Zener
by Lee Hart <[EMAIL PROTECTED]>
19) Re: One-Way Breaker
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Follow-up on Valence Li-Ion batteries in 12V size
by "Rich Rudman" <[EMAIL PROTECTED]>
21) Re: Follow-up on Valence Li-Ion batteries in 12V size
by "Rich Rudman" <[EMAIL PROTECTED]>
22) Re: Follow-up on Valence Li-Ion batteries in 12V size
by "Rich Rudman" <[EMAIL PROTECTED]>
23) Re: "very important that you allow the battery to gas"?
by "Rich Rudman" <[EMAIL PROTECTED]>
24) Re: "Good wire" ?
by "Rich Rudman" <[EMAIL PROTECTED]>
25) Re: Torque converters for DD EV's, Re: KISS AC EV Drive System
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
You can buy 144V and 156V AC systems for cars. That's what Solectria
Forces had. And I believe Electro Automotive will sell them to the
public as a dealer for Solectria. With lower voltage, performance is
modest. There is also the fact that several hundred Forces were built
so the system has the kinks ironed out. The system is for a small car
like a Geo, or perhaps something similar (I kind of like the new Chevy
Aveo).
New forktruck motors are sometimes AC and those operate around 72V.
Perhaps one per drive wheel for a car? I really don't know what the
performance potential of something like that is. Or maybe just buy the
forktruck motor as it might be properly wound for a low voltage AC
system. And probably rugged. I bet others, like Rod Hower and John
Wayland know a bit about these.
Seth
On Jan 6, 2005, at 10:59 PM, Mike Barber wrote:
I've been following this debate over AC motors very closely with much
interest. I am interested in building an AC EV. I initially learned
a lot from reading Victor's site - very well done, well documented CRX
conversion - nice job. I started thinking that I wanted my power
plant to be based on a siemens motor.
However, I started looking at the specs for these motors more closely,
and became a bit disenfranchised with them. It seems that Siemens
really designed these motors with large buses or boats in mind, not
smaller commuter BEVs. I say this because of the voltage and current
requirements. For example, the 1PV5135 motor has its peak voltage at
380V, and its peak current at 400A. You really can't get this kind of
power without having a battery pack that weighs more than around 2000
lbs - correct me if I'm wrong please. I base that number on using
exide orbitals - I've read they weigh 40 lbs? If they were putting
out 8V at 400A, you would need 48 batteries, which would weigh 1920
lbs.
Sure, you could probably use lithium ions to get more power density...
but you'd also have to get 400 amps out of them, so I assume you'd
have to parallel them up, and then you're talking about a lot of money
as well.
For me, I would like to make my own controller. I realize this is
quite an effort, but I would consider that enjoyable. Since I can't
even buy these motors without buying the ~$4500 Siemens controller
with it, it doesn't make sense to buy these motors.
What Lee is talking about is very interesting, because you can design
the motor around your power source. If I know that my pack will
consist of say 12 orbitals, I can assume then that my peak power
rating of the motor should be achieved at the peak power of the pack.
From other's posts, I am assuming that I can get 1000A from each
orbital for a short duration, and they would probably have an output
voltage of 6V (please correct me if this is wrong). I could then talk
to the guys at a motor shop, perhaps find a shop with an old 20hp
motor with a shorted stator, and get them to rewind it to have 80hp at
72V and 1000A.
From talking to the guys at a local motor shop, they estimated a
rewinding fee of $1000. Assuming I could get the original 20hp motor
with a shorted stator for free, I could have a nice AC motor matched
to my lightweight battery pack for under $1500 (I'm throwing some
extra in there for getting a new balanced rotor with nice bearings).
Considering the Siemens motors cost in the neighborhood of $3500, I'm
still doing pretty good, and I'm having someone else do the work -
it's still just money at this point, not endless hours of my time.
Granted, they won't be totally enclosed water cooled, but it sounds
like it's pretty easy to stick a fan on them and get good
performance.
Does what I'm saying have any major holes in it? Thanks again guys
for the good discussion.
Victor Tikhonov wrote:
Lee Hart wrote:
Victor Tikhonov wrote:
Sure, people do all kind of things. Lot of time for questionable
improvement (vs. buying a motor for the job) makes sense only
if that time worth little.
Or if you don't have the money.
Money is not relevant if the result cannot be achieved.
Of ciurse if the foal is "just do the best you can with
X dollars available" than *any* tiny improvement is better than
nothing and so you *always* achieve the goal to make something
better (and brag about it!).
If it would be that easy and effective, we'd see it being
done by now on regular basis. Why don't we?
Actually, you do! A city of any size has a shop that rebuilds motors.
I meand people on the list buying industrial AC motors and
rewinf/modify them the way you prescribe.
It's the same as car mechanics. You can change your own oil; the oil
and
filter is only $10 at Walmart. Or you can take it to the dealer, who
will charge you $50. Both have the same end result. Which do you want
to
save; time or money?
The big difference is amount of knowledge you need to do it
right (right means outcome worth the effort). For your analogy
if the oil cap can only be undone by writing special code and using
special equipment/process (this is what AC drive making involves),
very few would be capable of doing that no matter how much they want
to.
If one would know how much calculation and tweaking of inter-related
parameters is happening in design stage (a software for the matching
inverter involved too, it must contain a model for *that* motor),
one would drop this idea.
Victor, I think you are making it sound a lot harder than it really
is.
A plain old cheap off-the-shelf motor is going to be around 80%
efficiency. Or, you can buy an ultra-super state-of-the-art special
with
every trick known to science that is 90% efficient -- for 10 times the
price. Is 10% more efficiency worth 10 times the price? Probably not.
Well, you make it sound a lot easier than it is. Yes, this motor
will move your car. Move "good enough". If this is the goal, you
are right.
BAck to basics: corollas move people "good enough", no slower
than BMWs and Mercedeses which are x5 to x10 cost. Why people
buy those? They may be reacher than average on this list, but
no one throws money away for nothing.
And, if you are willing to do the work yourself and do some
experimenting, you can get half the efficiency gain (85%) for maybe
twice the cost of a cheap motor. To lots of people, that is a good
deal!
I'm not arguing that it is good deal, and would attempt it
if no alternatives I could afford would exist. So, as you said,
it is time vs money question, provided one is willing to accept
less than the/she wants.
If you shop for BMW and want it for $30k you have to decide
what gives if that is not possible. THey may offer it for $35k,
but offer Camry for $30k. In theory, you should not settle for
Camry since this is not what you really wanted. Drop the idea,
because having BMW for $30k is impossible.
IF you settle for Camry, then it doesn't matter what do you really
want in the first place, you're ready to accept "something" to move
you from A to B for under 30K. Nothing wrong with such compromise,
but my point is outcome of shopping has nothing to do with your
original shipping goal. Your efforts to achieve *your* goal yielded
nothing. And you accepted it.
Some won't. Some will.
I like this spirit, but from the engineering stand
point it is often just demonstration of ignorance.
Einstein said, "Imagination is more important than knowledge.
Knowledge
is limited. Imagination encircles the world." and "Knowledge of what
is
does not open the door directly to what should be. The only source of
knowledge is experience."
So, we do not want to rely on the "experts" that are building today's
motors to define what is possible. We need to do our own experiments,
and learn for ourselves. That is how new discoveries will be made!
Sure. If I only keep imagining something, I'd never drive.
When I started, I had 8" ADC in my CRX, Cirtii and 10 Trojan 27 TMH,
standard beginner's setup: http://metricmind.com/dc_honda/car.htm.
My goal was to drive EV. Not to have OEM grade EV, just EV.
Trust me, when I was done I was happiest in the city, I'd never
trade this poor CRX for latest Mercedes (even if from money
stand point Mercedes worth parts for 5 CRXes; didn't matter).
If my goal back then was to have AC EV with LiIon batteries,
I should have dropped this idea, because settling for less
(good enough), wasn't the goal. Whether original wish list was
realistic or not, is different issue.
Of course, in real life you must bend your wishes and *real* goals
aligning them with reality of your income, family, other unavoidable
aspects of life. How much to compromise original truly real goal
is up to you.
And up to those who will rewind that 60 Hz motor :-)
Victor
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--- Begin Message ---
On Wed, 05 Jan 2005 19:52:56 -0800, russco <[EMAIL PROTECTED]> wrote:
> About five years ago Lee posted a simplified AC drive system for an
> electric vehicle. No comments were given to Lee's idea. Instead of a
> complex vector control variable frequency AC drive, Lee's proposal was
> basically to use a rewound four pole induction motor, feed it with a six
> step inverter and use an automatic transmission. Upon examination, this
> approach should be easy to accomplish.
I too missed this proposed design, and would be very interested in it
and in your development.
However, for my own uses I would be unwilling to employ a torque
converter, and see one of the main benefits of an AC drive as having a
wide speed range with flat torque, so as to also eliminate the
gearbox.
I would be more practically interested in a "DIY EV" grade AC
inverter, with a minimal feature set, but able to work with normal
induction motors rewound for lower voltages and fitted with an
encoder, and configurable by the user to suit the motor and battery
pack.
Such things are available affordably for the forklift market but are
aimed at quite low voltage packs and power levels currently. The
Brusa AMC range was well suited to EVs but expensive, and again was
tailored to suit particular motors.
Regards
Evan
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--- Begin Message ---
I weighted the 26 Golf carted 300zx yesterday at the junk yard , 4,580 lbs ,
Its doing a little better , as the brakes are not scrubbing , .
Steve Clunn ,
--- End Message ---
--- Begin Message ---
Hi Evan and All,
--- Evan Tuer <[EMAIL PROTECTED]> wrote:
> On Wed, 05 Jan 2005 19:52:56 -0800, russco
> <[EMAIL PROTECTED]> wrote:
>
> > About five years ago Lee posted a simplified AC
> drive system for an
> > electric vehicle. No comments were given to Lee's
Since hydraulic torque converters multiply the
torque about 2.5-3 times, wouldn't it help a direct EV
drive make more torque while keeping amps down? And
allow a higher top speed?
Anyone know of a self contained one that could be
used for a series motor of about 50hp peak?
Or are they too costly?
Thanks,
jerry dycus
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--- Begin Message ---
This discussion on where to get improvements in efficiency reminds me of an
interview I did during the 1995 Tour de Sol:
:
Of particular interest to the EV discussion e-mail group is the Solar Bolt.
They achieved that 142 miles per charge record using 120V of Trojan batteries
(27 kWh), Advanced DC motor, and Curtis controller in a 1974 Fiat. (Sound
familiar?) They did this by getting the coefficient of drag down to 0.3 by
smoothing out the car's lines, keeping the air away from the underside of the
car with a front dam, reducing the frontal area, using low rolling resistance,
tubed tires, reworking the disk brakes calipers to make the pistons
>perfectly< round, and making the wheel camber > dead zero <. All this was to
get rid of every bit of friction they could find. The result is a 3394 pound
car that can be moved with one finger! Pretty impressive, even if you don't
notice that this is a > high school < team. ((This from a talk given by Roger
Titus of Bolton High School at the 1994 NESEA Sustainable Energy Conference.))
Bolton is entered in the 1995 ATdS.
:
Roger Titus, who is the advisor to the Solar Bolt, number 61, made the claim
last year that you could push their 3200 pound car on a level surface with one
finger. Well, today I did just that. Well, two fingers. I hooked them over
the bumper and (once the emergency brake was off) just pulled steadily and it
came along. The low rolling resistance is attributed to brakes that do not
drag. On a brake cylinder, you have a piston that is sealed with an rubber
ring. When the piston is pushed out, the rubber ring deforms slightly. If
the pistons and cylinder are truly round, the rubber ring will pull the back
and bring the brake pad with it, and thus not dragging on the brake disk. "On
your American and all your regular cars, they don't machine them fine enough.
So we took them out, made them truly round, and made them work," said Titus.
They also made the car, a 1974 Fiat X19, aerodynamic by making fiberglass
farings, so the air would not burble over bumps and around corners. A air dam
completely seals off the normal grill on the front of the car, a major source
of drag, according to Titus. Also, the hub caps are plane, flat pans, again
to cut drag. And the wheel wells are shaped so the air gets shot around the
tires; "the tires would act like a big windmill otherwise, that chew up a lot
of energy. The biggest gain is at the first impact that the air sees, and you
gain less as you go back on the car."
:
http://www.foveal.com/ATdS_Report_1995.txt
http://www.foveal.com/Tour_de_Sol_Reports.html
--
Mike Bianchi
Foveal Systems
973 822-2085 call to arrange Fax
[EMAIL PROTECTED]
http://www.AutoAuditorium.com
http://www.FovealMounts.com
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--- Begin Message ---
Evan Tuer wrote:
> What is the application, there might be a simpler way of doing it?
James Massey wrote:
> Simplest way would be a pair of diodes back-to-back with the fuse in one
leg
I've just been thinking out loud about safety issues for hybrid battery pack
systems, like the one Doug Hartley uses. I thought it might be a good idea
to guard against the possibility of the TS pack accidentally being at much
lower voltage than the PbA pack when they were connected and thus having the
PbA pack dump oodles of amps into the TS pack. For example, if the PbA pack
were fully charged to 158.4V (13.2 * 12) and the TS back were (for whatever
reason) discharged at 120V (3 * 40), then there'd be a 38.4V difference
between the packs. Assuming something like 5mOhm per 200Ah TS cell,
internal resistance would be .2 Ohms for the string. So the formula I =
38.4 / .2 yields an amperage of 192A into the string. Probably not fatal,
but I was just wondering if it was something to be guarded against, since
human errors do happen.
I had thought of the 2-diodes-and-a-fuse method, but in Doug Hartley's
design, there's already a diode controlling the amperage coming out of the
PbA pack, so I wasn't sure if putting one on the TS side would mess things
up.
Bill Dennis
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--- Begin Message ---
I don't know if you are looking to give this car a name or not, but if you
are my suggestion is
Porky Pig
Th th thaaaats all folks....
damon
From: "Steve Clunn" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: <ev@listproc.sjsu.edu>
Subject: 300zx
Date: Fri, 7 Jan 2005 09:20:09 -0500
I weighted the 26 Golf carted 300zx yesterday at the junk yard , 4,580 lbs
,
Its doing a little better , as the brakes are not scrubbing , .
Steve Clunn ,
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--- Begin Message ---
Want an eleven foot long battery cable? Find a BMW 325 in a junk yard.
The battery is in the trunk. An 11' copper cable runs inside the car to
the firewall. I'm not sure of the guage, but it's about half inch
diameter with the insulation. Battery post clamp at one end and a
battery POST at the other, both soldered on with a 10 guage wire too.
Very well made. Take the insulated clamp and very heavy grommet from the
firewall side. Cost at our local yards is $2 - $3.
-Harry in Fresno
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--- Begin Message ---
> I've just been thinking out loud about safety issues for hybrid battery pack
> systems, like the one Doug Hartley uses. I thought it might be a good idea
> to guard against the possibility of the TS pack accidentally being at much
> lower voltage than the PbA pack when they were connected and thus having the
> PbA pack dump oodles of amps into the TS pack. For example, if the PbA pack
Wouldn't it be easier to have a safety system that refuses to connect
the two packs together unless the voltages were within some predefined
limits? In this system no device would have to try and interrupt the
fault current.
Otherwise as someone else noted, a shunt and some simple comparators
could open a contactor. If a contactor is not foolproof enough Lee can
probably describe a crowbar circuit with an SCR shorting out the pack
and blowing the packs safety fuse.
Mark
--- End Message ---
--- Begin Message ---
On Fri, 7 Jan 2005 07:58:39 -0700, Bill Dennis <[EMAIL PROTECTED]> wrote:
> Evan Tuer wrote:
>
> > What is the application, there might be a simpler way of doing it?
>
> James Massey wrote:
>
> > Simplest way would be a pair of diodes back-to-back with the fuse in one
> leg
>
> I've just been thinking out loud about safety issues for hybrid battery pack
> systems, like the one Doug Hartley uses. I thought it might be a good idea
> to guard against the possibility of the TS pack accidentally being at much
> lower voltage than the PbA pack when they were connected and thus having the
> PbA pack dump oodles of amps into the TS pack. For example, if the PbA pack
> were fully charged to 158.4V (13.2 * 12) and the TS back were (for whatever
> reason) discharged at 120V (3 * 40), then there'd be a 38.4V difference
> between the packs. Assuming something like 5mOhm per 200Ah TS cell,
> internal resistance would be .2 Ohms for the string. So the formula I =
> 38.4 / .2 yields an amperage of 192A into the string. Probably not fatal,
> but I was just wondering if it was something to be guarded against, since
> human errors do happen.
>
> I had thought of the 2-diodes-and-a-fuse method, but in Doug Hartley's
> design, there's already a diode controlling the amperage coming out of the
> PbA pack, so I wasn't sure if putting one on the TS side would mess things
> up.
I was under the impression that in Doug's setup, it is not possible to
connect the packs directly together - the main couple is the big diode
feeding the controller from the lead-acid pack when the TS one sags
too low. And a small current bleed the other way. There should
definitely be a suitable fuse both ways, and there shouldn't be a way
of "accidentally" connecting them directly, if I understood it.
A more flexible way of doing this hybrid pack business, by the way, is
to connect the controller to the lead-acid pack primarily, and build a
simple current-mode-control PWM chopper to continuously supply 80A to
the lead-acid pack, with an upper limit of 13.8V per block obviously.
I also have 8 individual 3A power supplies which top up my AGM
batteries from the mains while the TS pack is recharging. The TS pack
is protected by a BMS to prevent under-voltage.
It is still far from ideal but lets me use my (too big and heavy) car
with the TS cells until the more suitable one is built.
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Lawrence Rhodes wrote:
> I've backed down from three strings of NiCads in the truck. Going
> one string in a recumbent motorcycle. I've seen some higher voltage
> drill gun chargers that might work. I think.
Just remember that 99% of consumer chargers are designed to be cheap,
cheap, and cheap. They have no interest or incentive to make them work
well. Most of these chargers will slowly murder your batteries.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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Evan Tuer wrote:
>I was under the impression that in Doug's setup, it is not possible to
>connect the packs directly together - the main couple is the big diode
>feeding the controller from the lead-acid pack when the TS one sags
>too low.
Hm, I thought that Doug's setup connected the two packs together at their
positive terminals, via a Schottky diode. Then the combined amps traveled
together from there to the controller. In that case, it seems like the PbA
could dump the amps into the TS pack if the two were connected when the TS
voltage was lower. Just to clarify I'm thinking of the situation where the
car is off and you've disconnected the two packs from each other for
whatever reason. Now, with the car still off, you go to connect them
together again.
Here's what Doug posted:
> Connect one polarity (say negative) of both packs directly together.
> Connect the positive of the AGM pack (through a 200A DC rated circuit
> breaker for protection and disconnect), to the anode of a large diode
> rated > to carry more than this current (ideally something like a low drop
> Schottky > 300A diode on a suitable heat sink).
> Connect the cathode end of the diode to the Li Ion pack positive.
Bill Dennis
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Victor Tikhonov wrote:
> If you're not cautioning other novices, thus making them repeat
> fruitless steps, you're wasting their time as well.
>
> If they *know* what the outcome will be but still want to try
> it just to learn something in process, this is different matter,
> perfectly fine, and should indeed be encouraged.
A key point to learning is that we learn more from our mistakes than
from our successes. But, too much failure is discouraging. So, we must
provide for both kinds of learning.
When I am teaching children how to use tools, I let them make lots of
mistakes. They have boundless enthusiasm and energy, and are inclined to
discount all my warnings on safety and the "right" way to do things.
Putting in a screw with a screwdriver is too hard; they want to pound it
in with a hammer!
After endlessly telling them not to do this (and having them not believe
me), I've finally discovered the way to do it. I'll tell them, "Most
people use a screwdriver. You can also pound it in with a hammer, but it
won't work very well". Most kids will ignore the screwdriver and go for
the hammer. And the board splits or the screw bends. Now, after their
failure, there is a "teachable moment". They come back, and NOW they are
motivated to learn the right way to do it.
Often, to take two steps forward, you have to take one step back.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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Ryan Stotts wrote:
> Is this wire actually "better" or is it just marketing?
> http://www.painlesswiring.com/wireterm.htm
Sounds like marketing lies. The "2750 deg.F" temperature rating is
obviously wrong. "Exceeds OE specifications" is meaningless unless they
tell you *which* specs.
Your best assurance for quality wire is to look for "UL", "CSA", "CE",
or other safety agency ratings right on the wire itself. These
temperature and voltage ratings have been independently tested and
confirmed.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
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I thought so. I'm just looking for a solution other than a variac &
stopwatch. Lawrence Rhodes......
----- Original Message -----
From: "Seth Allen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, January 06, 2005 5:21 PM
Subject: Re: Multiple Powertool chargers as Ni Cad Pack charger
Lawrence, are these BB600s? Because a starved electrolyte Ni-Cd charger is
not the right charger for these.
Seth
On Jan 6, 2005, at 7:45 PM, Lawrence Rhodes wrote:
I've backed down from three strings of NiCads in the truck. Going one
string in a recumbent motorcycle. I've seen some higher voltage drill
gun chargers that might work. I think. 5 aught to do it. Lawrence
Rhodes........
Lawrence Rhodes
Bassoon/Contrabassoon
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
[EMAIL PROTECTED]
415-821-3519
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--- Begin Message ---
Thanks Steve, that's a good data point. How much does each battery
weigh?
--- Steve Clunn <[EMAIL PROTECTED]> wrote:
> I weighted the 26 Golf carted 300zx yesterday at the junk yard ,
> 4,580 lbs ,
> Its doing a little better , as the brakes are not scrubbing , .
> Steve Clunn ,
=====
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--- Begin Message ---
If the PbA pack was supplying lots of current to the TS pack, the PBA pack
would be down to 12V/module or less and the TS cells voltage would rise
substantially while charging at significant current, so actually there would be
a low voltage difference and less current than you expected. If the system is
in an abnormal state of lower resting TS pack voltage than PbA pack voltage,
due to manipulation, tampering or failure of some kind, then charge the TS pack
separately first and correct the cause before resuming normal operation.
Regards,
Doug
>
> From: "Bill Dennis" <[EMAIL PROTECTED]>
> Date: 2005/01/07 Fri AM 09:58:39 EST
> To: ev@listproc.sjsu.edu
> Subject: RE: One-Way Breaker
>
> Evan Tuer wrote:
>
> > What is the application, there might be a simpler way of doing it?
>
> James Massey wrote:
>
> > Simplest way would be a pair of diodes back-to-back with the fuse in one
> leg
>
> I've just been thinking out loud about safety issues for hybrid battery pack
> systems, like the one Doug Hartley uses. I thought it might be a good idea
> to guard against the possibility of the TS pack accidentally being at much
> lower voltage than the PbA pack when they were connected and thus having the
> PbA pack dump oodles of amps into the TS pack. For example, if the PbA pack
> were fully charged to 158.4V (13.2 * 12) and the TS back were (for whatever
> reason) discharged at 120V (3 * 40), then there'd be a 38.4V difference
> between the packs. Assuming something like 5mOhm per 200Ah TS cell,
> internal resistance would be .2 Ohms for the string. So the formula I =
> 38.4 / .2 yields an amperage of 192A into the string. Probably not fatal,
> but I was just wondering if it was something to be guarded against, since
> human errors do happen.
>
> I had thought of the 2-diodes-and-a-fuse method, but in Doug Hartley's
> design, there's already a diode controlling the amperage coming out of the
> PbA pack, so I wasn't sure if putting one on the TS side would mess things
> up.
>
> Bill Dennis
>
>
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
> To protect a TS cell from over-voltage, can it be as simple as
> clamping a 1% 4.2V or 4.3V Zener dialog across the cell terminals?
Yes, in principle. But, real zeners aren't good enough. Zeners around
4.3v have a very soft threshold, large variations between devices, and
drift a lot with temperature. For example a 1N5336 4.3v 5% 5w zener
draws:
1ma at 3.0v
25ma at 3.6v
110ma at 4.0v
290ma at 4.3v
550ma at 4.5v
1100ma at 4.7v
Note that it still draws 25ma at 3.6v; so it would run down a fully
charged battery just from sitting for weeks. And the clamping action is
very soft, and would let the cell go over 4.3v even with only 290ma of
charging current.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
>
> Is there such a thing as a one-way breaker or fuse? It would let current
> flow freely in one direction, but allow only 20A in the other direction, for
> example.
There are polar relays that do this. Basically, it's a relay with a
magnet in its core, so it requires a particular polarity of current flow
to trip it. They are used in telco and instrumentation. For example, my
old Simpson analog multimeter had a circuit breaker for protection -- it
tripped at something like -50% or +200% of full scale reading (to keep
you from bending the meter needle).
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I don't see any problems with your numbers.
And a flaw is doing the mileage thing with just a few numbers. I have
very little hands on data with TS cells.
I don't know how far you can push them or what a Good, non damaging cycle
is.
On Yts and Orbitals... I am swimming in data.
----- Original Message -----
From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, January 05, 2005 12:02 PM
Subject: RE: Follow-up on Valence Li-Ion batteries in 12V size
> Rich, by my calculations, only around 165 miles for the pack size that you
> suggest (using the 250Wh/mile that you mention). The cells settle down to
> about 80% of their rated value after a small number of cycles, so you'd
soon
> get only 160Ah out of the 200Ah cells. Plus, you use only 80% DOD on
that,
> ending up with about 128 usable Ah out of each cell. Since 326 Volts is
> about 90 cells:
>
> 128Ah * 3.6V = 460.8Wh/cell
> 460Wh/cell * 90 cells = 41472Wh
>
> 41472Wh / 250Wh/mile = ~165 miles
>
> Also, 90 200Ah cells would weigh 1089 pounds, as compared to the 760
pounds
> of YT's. So the actual range difference isn't 10 times, but more like:
>
> (165 / 25) * (760 / 1089) = ~4.6 times the range
>
> If you were talking about 25 miles for 80% DOD on the YT's, then the 4.6
> number should be more in the ballpark--assuming I didn't make any math
> errors. To paraphrase Dan Quayle, "I stand by all my miscalculations."
:)
>
> Bill Dennis
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Rich Rudman
> Sent: Wednesday, January 05, 2005 12:30 PM
> To: ev@listproc.sjsu.edu
> Subject: Re: Follow-up on Valence Li-Ion batteries in 12V size
>
> $500 for a Yt??
> this is enough for 6 packs of Yts...
>
> It is not entirely clear that TS cells will do more than 500 cycles, with
EV
> loads on them.
> Until they do, Even with Ultra Caps, Victor......I am not sure what going
to
> TS will give me?
>
> Who has the the best Kilowatt/hour range numbers on thier TS pack????
>
> 200 amphrs or 326 should be 65Kwhr.
>
> What is the best the TS group has gotten.
>
> For reference ... a 228 volt 19 Orbital pack gets 6 Kwhr. 760 lbs for
about
> 25 miles.
> The 200 amp 326v TS pack should make 260 miles If both EVs can manage 250
> Whrs per mile.
>
> 10 times the range. Anybody have ANY real world EV range capabilites from
> TS???
>
> ----- Original Message -----
> From: "Tim Humphrey" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Wednesday, January 05, 2005 6:52 AM
> Subject: Re: Follow-up on Valence Li-Ion batteries in 12V size
>
>
> >
> > >
> > >> Philippe Borges wrote:
> > >>
> > >
> > >> ok TS 200Ah, let's choose... your car exemple and compare 326V Optima
> > >> pack
> > > with say about 300V TS pack.
> > >
> > >>pack price:
> > >>$3 500 | $30 000
> > >
> >
> > Philippe;
> >
> > That's not quite right.
> >
> > the pack you are quoting is a 200ah Ts pack compared to a 50ah YT pack
so
> > the price difference is more like.
> >
> >
> > $14,000 | $30,000
> >
> >
> > Plus IF (big IF) the TS cells last as long as they predict they will go
> > over half a million miles, and in the long run cost less than flooded
> > GC's.
> >
> > Plus what is it worth to never have to change whole battery pack again.
> >
> >
> > --
> >
> > Stay Charged!
> > Hump
> > "Whether you think you can or think you can't, you are right!" --Henry
> Ford
> >
>
>
>
--- End Message ---
--- Begin Message ---
Yea...
The Yts seam to not have come down in price much. I was getting Factory
Blems for $80 years ago.
The Orbitals XCD-34 are cheaper...
200 amp hours of Yts at 324v is a LOT of Yts...
Just think about all those Regs....Droool!.
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, January 05, 2005 11:37 AM
Subject: RE: Follow-up on Valence Li-Ion batteries in 12V size
> Rich Rudman [mailto:[EMAIL PROTECTED] wrote:
>
> > $500 for a Yt??
> > this is enough for 6 packs of Yts...
>
> Phillipe's figure of $3500 for a (50Ah) 324V string works out to just
> under $130 per YT, which is reasonable.
>
> Tim is suggesting that a fairer comparison would be a 200Ah 324V pack of
> YTs since the $30k pack of TS LiIon is 200Ah. 200Ah of YTs requires 4
> strings, and so Tim simply multiplied $3.5k x 4 = $14k; still the same
> $130 per YT (though I suspect that buying over 100 at a shot would allow
> a better price than this).
>
> Roger.
>
--- End Message ---
--- Begin Message ---
So you say you get 70 amp hours at 324 volts OK....
That's 22.680Kwhr.
That's a LOT of stored energy... I am impressed.
That would give me 90 miles in Goldie... Up from the 10 she now gets....
Also Victor, I am not looking for Drop Dead range, I am looking prudent
range with no damage. That's all.
The Orb tests I am doing are safe draw downs because I am not using 200 amp
loads and I have warning equipment and safties for prevent any battery from
going below 10 volts.
Cycle life??? This is what makes the difference If we can get 500 to 1000
cycles, Life gets really good. If it's less than 500 cycles.. Well Even lead
Acid AGM can do this...
At 2000 cycles that Valence is advertising ..... You can honestly expect 4x
the cycle life of Lead Acid. So spending 4x the cost is a safe bet. Getting
4 to 10 times the range and 4x cycle life
Is of course the Holy Grail.
With all these promises of range and cycle life, I just wanted to know
how far we have come in the last couple of years with the TS cells.
What kind of charge profile are you using now?
And what do your regs do. AKA how much of a BMS do you need to get 70
amphours out of a 90 amphour cell?
What are your amp limits to get long life...??
This kinda thing.
----- Original Message -----
From: "Victor Tikhonov" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, January 05, 2005 2:21 PM
Subject: Re: Follow-up on Valence Li-Ion batteries in 12V size
> Rich Rudman wrote:
>
> > $500 for a Yt??
> > this is enough for 6 packs of Yts...
> >
> > It is not entirely clear that TS cells will do more than 500 cycles,
with EV
> > loads on them.
>
> They will. Sorry, I can't tell you the number.
>
> > Until they do, Even with Ultra Caps, Victor......I am not sure what
going to
> > TS will give me?
>
> Until a BMS is ready it is only talk and no hard prove
> we all would like. If you want to be conservative, just
> coose not to believe in even 500 cycles.
>
> > Who has the the best Kilowatt/hour range numbers on thier TS pack????
>
> I use to record cumulative usage and dropped doing it about a week
> ago when damaged few cells (my mistake) and one failed
> (TS defect). So they are removed from service and Ah consumed
> from remaining cells, of course, is increased.
>
> > 200 amphrs or 326 should be 65Kwhr.
>
> Yes, but my cells are 90Ah (~70Ah actual).
> >
> > What is the best the TS group has gotten.
>
> Best what?
>
> > For reference ... a 228 volt 19 Orbital pack gets 6 Kwhr. 760 lbs for
about
> > 25 miles.
> > The 200 amp 326v TS pack should make 260 miles If both EVs can manage
250
> > Whrs per mile.
> >
> > 10 times the range. Anybody have ANY real world EV range capabilites
from
> > TS???
>
> I do daily driving and can only estimate range based on
> energy consumtion and that I supposedly have. To get real world
> number requires actually run the pack dead just to see this number,
> and no one is willing to subject their investment just to get
> one such number.
>
> I can tell you that my consumption is 1Ah/mile for 324V.
> With 70 real Ah it is 70 miles then, until drop dead condition.
> Sorry, I'm not going to test that, but you can trust this number.
>
> Note, 90Ah TS cells are undersized for a car.
> Note21. This applies only to sagging TS cells. 70Ah Kokam cells
> would be much better choice, but at 6x price tag I can't
> justify it.
>
> Victor
>
> > ----- Original Message -----
> > From: "Tim Humphrey" <[EMAIL PROTECTED]>
> > To: <ev@listproc.sjsu.edu>
> > Sent: Wednesday, January 05, 2005 6:52 AM
> > Subject: Re: Follow-up on Valence Li-Ion batteries in 12V size
> >
> >
> >
> >>>>Philippe Borges wrote:
> >>>>
> >>>
> >>>>ok TS 200Ah, let's choose... your car exemple and compare 326V Optima
> >>>>pack
> >>>
> >>>with say about 300V TS pack.
> >>>
> >>>
> >>>>pack price:
> >>>>$3 500 | $30 000
> >>>
> >>Philippe;
> >>
> >>That's not quite right.
> >>
> >>the pack you are quoting is a 200ah Ts pack compared to a 50ah YT pack
so
> >>the price difference is more like.
> >>
> >>
> >>$14,000 | $30,000
> >>
> >>
> >>Plus IF (big IF) the TS cells last as long as they predict they will go
> >>over half a million miles, and in the long run cost less than flooded
> >>GC's.
> >>
> >>Plus what is it worth to never have to change whole battery pack again.
> >>
> >>
> >>--
> >>
> >>Stay Charged!
> >>Hump
> >>"Whether you think you can or think you can't, you are right!" --Henry
> >
> > Ford
> >
>
--- End Message ---
--- Begin Message ---
On sealed AGM....
You can gas, but your should never Vent.
Big difference in concepts...
----- Original Message -----
From: "Ryan Stotts" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, January 05, 2005 12:28 PM
Subject: "very important that you allow the battery to gas"?
> "You may have heard of people trying to be clever and cut
> down on the water consumption, so they change their charger
> back to avoid the gassing state, don't do that. It is very
> important that you allow the battery to gas, vigorously, the
> gassing actually stirs this electrolyte. You will get long
> life and good capacity."
>
> http://geocities.com/brucedp/evbatt.html
>
--- End Message ---
--- Begin Message ---
2750 F
I am still laughing!!
copper melts at 1981 deg F Pure copper...Most alloys of Cu will melt at
less.
But the Idea of a Liquid copper conductor is rather intriguing.
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, January 07, 2005 11:05 AM
Subject: Re: "Good wire" ?
> Ryan Stotts wrote:
> > Is this wire actually "better" or is it just marketing?
> > http://www.painlesswiring.com/wireterm.htm
>
> Sounds like marketing lies. The "2750 deg.F" temperature rating is
> obviously wrong. "Exceeds OE specifications" is meaningless unless they
> tell you *which* specs.
>
> Your best assurance for quality wire is to look for "UL", "CSA", "CE",
> or other safety agency ratings right on the wire itself. These
> temperature and voltage ratings have been independently tested and
> confirmed.
> --
> "Never doubt that the work of a small group of thoughtful, committed
> citizens can change the world. Indeed, it's the only thing that ever
> has!" -- Margaret Mead
> --
> Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
>
--- End Message ---
--- Begin Message ---
jerry dycus wrote:
> Since hydraulic torque converters multiply the
> torque about 2.5-3 times, wouldn't it help a direct EV
> drive make more torque while keeping amps down? And
> allow a higher top speed?
> Anyone know of a self contained one that could be
> used for a series motor of about 50hp peak?
Yes; there are free-standing torque converter sold in all sizes. They
are used in various industrial machines.
What I haven't found is a free-standing torque converter that also has a
locking clutch. A torque converter is great while accellerating, but for
cruising you want to lock it to eliminate its losses.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
