EV Digest 4350
Topics covered in this issue include:
1) test
by Nick Viera <[EMAIL PROTECTED]>
2) Re: TS Cells and Temperature
by "Doug Hartley" <[EMAIL PROTECTED]>
3) Re: Flexible instrumentation
by "Peter VanDerWal" <[EMAIL PROTECTED]>
4) Re: List and attachments
by "David Roden" <[EMAIL PROTECTED]>
5) RE: controller electric noise
by "Peter VanDerWal" <[EMAIL PROTECTED]>
6) Re: pulling a original prestolite from an Renault
by Tony McCormick <[EMAIL PROTECTED]>
7) Re: Charging and Peukert effect question
by "Joe Smalley" <[EMAIL PROTECTED]>
8) Re: Home made charge question
by "Joe Smalley" <[EMAIL PROTECTED]>
9) Re: FL EAA & Grassroots EV Rally Pictures
by Doug Weathers <[EMAIL PROTECTED]>
10) Re: Charging and Peukert effect question
by "Paulcompton" <[EMAIL PROTECTED]>
11) Re: newbie intro
by [EMAIL PROTECTED]
12) GP3300 Ultimate Racing Battery?
by David Dymaxion <[EMAIL PROTECTED]>
13) Re: test
by "Dave" <[EMAIL PROTECTED]>
14) Re: "eBay hype" or innovation?
by Neon John <[EMAIL PROTECTED]>
15) Sam's batteries
by "Mark Hanson" <[EMAIL PROTECTED]>
16) RE: The EClubman is registered
by "Mark Fowler" <[EMAIL PROTECTED]>
17) Re: Home made charge question (where?)
by mike golub <[EMAIL PROTECTED]>
18) Re: Charging and Peukert effect question
by Nick <[EMAIL PROTECTED]>
19) Re: Static buildup on EVs
by "David C. Navas" <[EMAIL PROTECTED]>
20) Re: TS Cells and Temperature
by =?ISO-8859-1?Q?Jukka_J=E4rvinen?= <[EMAIL PROTECTED]>
21) Re: Static buildup on EVs
by "Dave" <[EMAIL PROTECTED]>
22) Re: Static buildup on EVs
by David Dymaxion <[EMAIL PROTECTED]>
23) cruise control?
by mike golub <[EMAIL PROTECTED]>
24) Fwd: Re: Home made charge question (where?)
by Dave Cover <[EMAIL PROTECTED]>
25) Re: cruise control?
by Ryan Stotts <[EMAIL PROTECTED]>
26) Re: cruise control?
by Matt Holthausen <[EMAIL PROTECTED]>
27) GE Ecomagination: For Business, Green is Green(From the green car congress)
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
28) Bans on Motorized Scooters Increasing - Yahoo! News
by Ken Trough <[EMAIL PROTECTED]>
29) RE: An update regarding my JeepEV
by "Roger Stockton" <[EMAIL PROTECTED]>
--- Begin Message ---
?
--
-Nick
http://Go.DriveEV.com/
1988 Jeep Cherokee 4x4 EV
---------------------------
--- End Message ---
--- Begin Message ---
Bill,
The "capacity" is depleted mostly because the cell voltage is lower at lower
temperature, requiring more current draw by the motor controller to get a
given speed/power output to the motor. I would say that if the cells are
warm when you are discharging them, that is what counts. You have to allow
enough time for the mass of the cells to warm up again all through, before
driving.
Best Regards,
Doug
----- Original Message -----
From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 3:11 PM
Subject: TS Cells and Temperature
If I park my EV outside in the cold all day while at work, do I need to
keep
the TS cells warm the whole time, or can I just let them get cold and then
warm them up at some period of time before they're needed? In other
words,
does getting cold when not in use deplete capacity, or is capacity
depleted
only when cold cells are actually used? Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
Most modern laptops can suspend to disk (often called hibernate), where
they write the current memory contents to the disk and shutdown. Using
flash memory disks, these could boot rapidly (10-15 seconds maybe)
Many modern laptops have a standby mode where they shutdown everything but
memory and registers.
Maqny laptop CPUs have power savings modes where they reduce clock speed,
etc. and can drastically reduce power consumption (while also lowering
performance).
My Fujitsu Stylistic LT-P600 has a 35 whr battery. When set to maximize
battery life it can run for upto 6-8 hrs. When in standby it will maintain
the memory for well over a week and return to full operation in 7 seconds.
This would be quicker, but it waits to spin up the hard drive.
I made a few assumptions that, for the sake of brevity, I didn't elaborate
on.
These are my assumptions:
Since most people don't charge their vehicle and then wait a week to drive
it, I assumed that the EV would be driven within 24 hours of charging,
this seems typical of most people on this list.
An EV with a Lead-Acid batttery pack having a usuable, at EV power levels,
capacity of 12,500 watt hours.
Said EV has a maximum range of 50 miles with a typical power consuption of
250 watt hours per mile.
Said EV is typically driven 30 miles per day.
This 30 mile trip typically takes 45 minutes.
The onboard computer draws 12 watts (roughly twice as much as my Fujitsu
Stylistic LT-P600) during this 45 minutes and draws a further 3.5 watts
during the rest of the day (when the vehicle isn't charging).
This means the theoretical reduction in range (at 100% DOD) is approx 250
feet.
Since people typically don't drive to 100% DOD, unless they want to murder
their batteries, the difference between a reduction in range of 6 inches
or 250 feet is lower than the noise floor and irrelevent. In fact under
realistic driving conditions, it's probably unmeasureable.
In order to be concise I attempted to answer this question in a couple lines.
<sigh> Apparently I will have to abandon my attempts at brevity and
instead write long winded disertations when I answer questions in the
future.
>>> Will this fancy display reduce range?
>
> Peter VanDerWal wrote:
>> Sure, it will reduce your range by as much as 6 inches.
>
> Well, it would be a lot more than than. But everything hinges on exactly
> how much power it is consuming.
>
> Using my previous email, suppose this display is part of a computer that
> draws (say) 2.5 amps at 12 = 30 watts. Suppose your EV has a pack of 16
> Optimas (16 x 300 watthours = 4800 watthours total). Further, let's say
> your range is 30 miles on a charge, and you typically drive for one
> hour. Then the fancy display uses 30wh/4800wh = 0.625% of your power and
> reduces your range by 0.19 miles. Still not much -- but WAY more than 6
> inches! :-)
>
> As I said, the real problem is how much it consumes when parked. You'd
> have to keep such a computer off when parked, or it would murder your
> batteries fairly soon.
> --
> "The two most common elements in the universe
> are hydrogen and stupidity." -- Harlan Ellison
> --
> Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
>
>
--- End Message ---
--- Begin Message ---
The SJSU list gurus tell me that the attachment detatcher has been
temporarily turned off for debugging. It seems that something was causing
it to periodically snarf up too much processor time, resulting in listproc
restarts. They are working on the problem. In the meantime, they're
routing all messages through a virus checker.
Stay tuned for further bulletins.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- End Message ---
--- Begin Message ---
> 15000 Hz has a wavelength of several miles, so you couldn't "tune" the
> cable
> lengths to a specific fraction of a wavlength to minimize their
> effectiveness as antennae - at least not at that frequency.
>
Except that we are talking about a SQUARE wave, an enormously powerful one
at that. A squarewave is effectively made up of numerous sinewaves of
different frequencies.
Normally after about the tenth harmonic, these sinewaves have dropped off
to the point where they are insignificant compared to the original wave.
When you have a really powerful squarewave, it seems to me that some of
these "insignificant" harmonics will be powerful enough to cause problems.
--- End Message ---
--- Begin Message ---
Great, thanks I'll give it a try.
Tony
"Welcome to the dawn of a new error"
http://www.notebene.net/philosophy.html
Tony McCormick wrote:
I haven't posted anything to this list in a long time, but I have a
question that I figure only this audience can help me with.
I smoked my 48volt prestolite motor the other day on the way home and
now I've gotten to the last steps of pulling it out to be replaceed
with a ADC 8". Only, I could use some tips on pulling the motor, I
have unbolted the obvious stuff on the adapter plate and the carriage,
but it seems to still be connected at the shaft. I don't what to
'pry' it apart unless that's what you are supposed to do (cars are
like that sometimes). I can see two set screws in the 1/2" gap
between the adapter plate and the tranny that go into the collar. I
suspect that is the culprit, but they seem virtually impossible to
get to with out some kind of special, long square head tool.
Anyone do a replacement on an old Electric Leopard? Ideas?
--- End Message ---
--- Begin Message ---
Peukert's effect is caused by the impedance of the battery rising as the
ampere-hours are removed from the battery. When the impedance gets high
enough that the battery cannot supply the load enough voltage, the battery
is considered dead. If the load is removed for a period of time and the load
reattached, the battery will power the load for a short additional time
because diffusion reduces the impedance temporarily.
When you recharge a battery, it heats up slightly because the terminal
voltage is slightly higher than the open terminal voltage (14 V on charge
vice 13 V open circuit). The same thing happens on discharge because the
loaded voltage is lower than the open terminal voltage (11 V on discharge
vice 12 V open circuit). The heating effect is prominent at high amperages,
both on charge and discharge.
The Coulombic overcharge (ampere hours in minus ampere hours out)
dissociates the water into hydrogen and oxygen. In an AGM, they are
recombined into water (giving off heat) and recycled. In flooded cells
without recombination, the hydrogen and oxygen are vented. Water needs to be
replaced to keep the plates from being exposed. A chronically overcharged
battery pack will consume a lot of water.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Nick" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 12:46 PM
Subject: Charging and Peukert effect question
> I am confused:
> I have T-105 (equivalent) batteries in my truck...
> Warning: all of these figures are very approximate, and just used for
> this example!
> If I have a constant discharge rate of say 100 amps, I should get about
> 110-120ah out of my batteries.
> On the other hand, if I discharge at about 10 amps, I should get about
> 220 ah out of these batteries.
> In both cases, the batteries are discharged to about 100 percent of
> capacity.
> My question is:
> When I recharge them, am I going to put ~220ah back into the batteries
> in both cases, or am I going to only put 110-120ah back in after the
> 100amp discharge and 220ah after the 10amp discharge? I realize that in
> either case I will have to put somewhat more amp hours back into the
> battery than I took out, but that's beside the point (I think).
> I guess I am wondering where the extra amp hours are going when the
> Peukert effect kicks in.
>
> Nick
>
--- End Message ---
--- Begin Message ---
I would say the ripple VOLTAGE is the important factor to life of an AGM. As
long as the terminal voltage stays under the gassing voltage, no permanent
damage is done.
I agree that the ripple CURRENT causes unnecessary heating of the battery.
Sometimes you want the heat.
PFC chargers have a lot of CURRENT ripple at full load and almost none at
light loads near end of charge when it becomes important.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 11:15 AM
Subject: RE: Home made charge question
> Lee Hart [mailto:[EMAIL PROTECTED] wrote:
>
> > Philip Marino wrote:
> > > I've read that the batteries are better off if you add some
> > > capacitance (a few big electrolytics) to the output of this kind of
> > > charger (right after the bridge). Is this really true?
> >
> > No. 99% of all battery chargers have little or no filter
> > capacitors. The ones that do have them to protect the charger
> > -- the batteries themselves don't care.
>
> I'll use one of Lee's own "it depends" here ;^>
>
> What Lee says may be true for flooded lead acid, however, sealed lead
> acid batteries most definitely do care about the ripple current and
> voltage. Several manufacturers specify an upper bound on the amount of
> ripple the charger is allowed to subject the battery to.
>
> Among other things, ripple on the output of a battery charger causes
> unnecessary heating in the battery.
>
> Cheers,
>
> Roger.
>
--- End Message ---
--- Begin Message ---
On May 7, 2005, at 8:27 PM, Shawn Waggoner wrote:
Hey Everyone,
I got the pictures posted from the EV Rally here in Fl last weekend.
They
are on the Florida EAA website under "Photo Album" --> "Events
Gallery" -->
"EV Rally April 2005" ( http://www.floridaeaa.org )
Thanks for posting the pictures. I can't get enough of looking at EVs,
always looking for ideas and inspiration.
I would like more information on the three-wheeled Lambo replica owned
by Tom (the last picture in the gallery). What kit is that? What are
its specs? Is it in the EVAlbum? I wasn't able to find it there.
Thanks,
--
Shawn M. Waggoner
Florida Electric Auto Assoc.
http://www.floridaeaa.org
Custom Honda Electric Motorcycle 72V
--
Doug Weathers
Bend, OR, USA
http://learn-something.blogsite.org
--- End Message ---
--- Begin Message ---
-- Original message --
From: "Nick" <[EMAIL PROTECTED]>
To: <[email protected]>
Date: Monday 9 May 2005 23:45:04
Subject: Re: Charging and Peukert effect question
> Thanks for the excellent answer! I am still wondering why I can't get at
> the remaining Amp hours, but I suspect the answer would be a little more
> technical than I really care to get into. I do feel better now though; I
> was thinking that at higher discharge rates, I would have to put much
> more energy back into the battery to recharge, which would fly in the
> face of efficiency!
When you discharge a lead acid battery you form Lead sulphate which is an
insulator. The higher the rate of discharge, the more likely the reaction is to
take place at the surface of the plates, insulating them. You can in effect
lock up capacity inside the plates. This is why batteries like the Optima,
which has very thin plates, suffers less from the effect. The surface area to
volume ration is much higher.
Paul Compton
www.sciroccoev.co.uk
www.morini-mania.co.uk
___________________________________________
--- End Message ---
--- Begin Message ---
<<<My ruminations so far, for my project are as follows: the donor car
would be my '93 2-door Explorer. (is physically sound and good
condition) My intention is to convert it to front wheel drive,
connecting the drive motor directly to the transfer case. The transfer
case has two "speeds" 1:1 and 2:1. Most usage will be in town, so the
2:1 gear should suffice. When I do decide to take this vehicle out of
town, I believe the 1:1 gear should work out. There's no serious
hill-climbing ability needed. Replace the conventional rear axle and
differential with a "straight" axle from another front wheel drive
vehicle. The contemplated system would be 120 volts DC.>>>
Hi Tom - Is the transfer case one that you can "shift on the fly"? If so, then
you have something akin to the Holy Grail of direct drive systems (actually
just "no tranny")! An Explorer may be a bit on the heavy side, but if you
already own it, like it, and "know it" (not in the Biblical way), then stick
with it. Have you scoped out places to mount the pack?
Some points:
- How much money and time will I allot to this project? Always expect to spend
more than you think!
- How far/fast/quickly do I want to go/accelerate? Speed and range cost money,
simple as that!
- What technical skills do I have - mechanical, structural [welding and forming
parts], and electrical? Skills cut costs.
- Am I willing to install used/surplus items? Widens your money-saving options
if you can scrounge.
- KW output needed to equal original performance is about half the ICE's peak
HP, but usually with a lower top speed (don't need to go *that* fast anyway).
- Will you drain the pack by 80% in less than 1hr of driving? If not, flooded GC
batteries are a good choice; if yes, consider Optimas/Orbitals/Intimidators (or,
if you have plenty of dough, maybe NiCds?)
Think it out on paper (heck, post stuff here) and then look at what's available
locally before you have to start adding in all kinds of shipping costs.
--- End Message ---
--- Begin Message ---
Disclaimer: I have no finanical interest in the success or failure of
the makers of the GP3300 batteries.
Naturally I now can't find the web page that has the graphs I'm
quoting from, but at least I saved the graphs.
One graph shows the GP3300 battery has an average discharge voltage
of about 1.05 volts at 50 amps, going for aout 230 seconds before
hitting 0.9 volts.
The 2nd graph shows about a 0.87 average voltage , and 112 seconds
before hitting 0.6 V cutoff for a 100 amp discharge. It stays above
0.9 V for 42 seconds, and above 0.8 V for 91 seconds. The battery
weighs only 65 grams (= 0.065 kg)!
0.9 V * 100 Amps = 90 W
90 W / 0.065 kg = 1.4 kW/kg (!)
It amazed me, too, that 100 A * 112 seconds / (3600 seconds / hr) =
3.1 Ahr, for a 3.3 Ahr battery being driven very hard!
Wow, Kokam (http://www.kokam.com/english/product/battery03.html#2)
says their cells will do 1 kW/kg, as does Saft for their high power
lithiums. The best Nicads I know about (Sanyo N3000CR) are about 1
kw/kg. The Kokams do hold alot more energy (more range), about 3
times as much, and prices for similar amounts of power are similar.
For comparison, an Optima or Orbital will do about 10 kW / 18 kg =
0.56 kw/kg.
So a pack of 28 Orbitals will do about 280 kW ~ 280 rwhp. The same
weight in GP3300 batteries would have 700 rwhp! The GP3300 would also
have almost no peukert effect and triple the range.
More disclaimers: This equivalent weight pack would be about $55k at
full retail price (or have a 28 Orbital power equivalent pack, half
the weight and "only" $25k). I don't know how long the batteries
would last at these kinds of currents. I don't know how hard it would
be to parallel 20 to 30 strings of these cells.
__________________________________
Do you Yahoo!?
Yahoo! Mail - Helps protect you from nasty viruses.
http://promotions.yahoo.com/new_mail
--- End Message ---
--- Begin Message ---
5 by 5, Nick
David C. Wilker Jr. USAF (RET)
Children need love, especially when they do not deserve it.
- Harold S.
Hulbert
----- Original Message -----
From: "Nick Viera" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 8:56 PM
Subject: test
?
--
-Nick
http://Go.DriveEV.com/
1988 Jeep Cherokee 4x4 EV
---------------------------
--- End Message ---
--- Begin Message ---
On Mon, 9 May 2005 15:58:56 -0700, "Lawrence Rhodes" <[EMAIL PROTECTED]>
wrote:
>I remember that an EVent in Vancouver mentioned battery revival. Any word
>from that EVent that it worked. LR......
I've done some lab testing on the pulse type desulfator. I tested the
Battery Minder version on a Group 27 deep cycle battery that had been
laying around in my recycle pile for a couple of years. After several
cycles to stabilize the "before" capacity it measured 27ah on my
discharge tester.
After 24 hours of pulsing it measured 45 ah. After two weeks it
measured 85ah. Rated capacity is 105ah nominal. I tested at 5 amps,
the 20 hour rate.
What was interesting was that if I cycled the battery occasionally and
kept it on charge in the intervals the capacity held up. But if I
took the charger off and let the battery sit "fully charged" even for
a few days, the capacity would drop by half. Another week of pulsing
would bring it back mostly.
That battery is now one of my shop batteries and sits with the Battery
Minder attached all the time. It passes the 500 amp carbon pile
discharge with no problems. I'd guess the battery is >7 years old and
spent its first 3 years in my motorhome at the hands of an abusive
constant voltage charger that gassed it badly.
John
>----- Original Message -----
>From: <[EMAIL PROTECTED]>
>To: "EV Discussion List" <[email protected]>
>Sent: Monday, May 09, 2005 1:24 PM
>Subject: "eBay hype" or innovation?
>
>
>> More pulse charging or something new? Found this on eBay, but I'd be
>> suspect of
>> any "battery revival" technology:
>>
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7514789483
>>
>
---
John De Armond
[EMAIL PROTECTED]
http://www.johngsbbq.com
Cleveland, Occupied TN
--- End Message ---
--- Begin Message ---
Hi,
One of my 20 batteries cell vented under me and a cop pulled me over, said I
was going too slow when I stopped on the side of the road. Anyway, Sam's
initially said they had no warranty but when I mentioned I saw on the EVLIST a
12 month warranty, they gave me a FREE battery and said that it's *not*
prorated, if a battery fails within a year, they will replace for free. Since
they charge a $7 core charge, it's best to come up in your pick-up to the side
(where they work on the tires) and deposit the batteries 1st and then by the
new one's. If you call ahead, they'll have them sitting near the register for
pickup on a roll-cart.
Mark in Roanoke
www.solectrol.com
--- End Message ---
--- Begin Message ---
Hi Ben,
Contact your local RTA and ask them a few questions.
Will you need an engineer's certificate for your conversion, or simply a
blue slip?
(I used Peter Smith Engineering in Camden - a good bloke that now
understands a bit about electric cars :-)
There are NSW RTA rules that cover mounting and ventilating the
batteries, being able to manually shut down the electrical system from
the drivers seat, and making sure that any modifications you make to the
car don't affect important things like brakes, steering or seat belts.
Ask them if you can get a copy.
While building my car, I found that people usually responded to my
requests in one of two ways.
The first group (the majority) were quite interested about the whole EV
concept and would go out of their way to help, often giving cheaper
prices, extra parts or helpful advice.
The second group (only a few - thankfully) considered the whole thing to
be too hard, and weren't much help at all.
Mark
-----Original Message-----
From: Ben Haines [mailto:[EMAIL PROTECTED]
Sent: Saturday, 7 May 2005 11:42 PM
To: [email protected]
Subject: RE: The EClubman is registered
Would you be willing to give me any tips with when dealing with sydney's
RTA? I too live in sydney and I am in the process of a conversion now
and I have been trying to get some responses from the rTA but so far no
luck.
Thanks
Ben
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Fowler
Sent: Friday, 6 May 2005 1:42 PM
To: [email protected]
Subject: The EClubman is registered
Hi all,
Just a quick note to let you know that my electric PRB Clubman is now
registered and ready to drive the streets of Sydney.
He he - it only took two years :-)
It's not finished yet, of course, but is finished enough for the RTA to
let me drive it on the road.
Mark Fowler
--- End Message ---
--- Begin Message ---
Where did you post this?
--- Joe Smalley <[EMAIL PROTECTED]> wrote:
> I would say the ripple VOLTAGE is the important
> factor to life of an AGM. As
> long as the terminal voltage stays under the gassing
> voltage, no permanent
> damage is done.
>
> I agree that the ripple CURRENT causes unnecessary
> heating of the battery.
> Sometimes you want the heat.
>
> PFC chargers have a lot of CURRENT ripple at full
> load and almost none at
> light loads near end of charge when it becomes
> important.
>
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
>
> ----- Original Message -----
> From: "Roger Stockton" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Monday, May 09, 2005 11:15 AM
> Subject: RE: Home made charge question
>
>
> > Lee Hart [mailto:[EMAIL PROTECTED] wrote:
> >
> > > Philip Marino wrote:
> > > > I've read that the batteries are better off if
> you add some
> > > > capacitance (a few big electrolytics) to the
> output of this kind of
> > > > charger (right after the bridge). Is this
> really true?
> > >
> > > No. 99% of all battery chargers have little or
> no filter
> > > capacitors. The ones that do have them to
> protect the charger
> > > -- the batteries themselves don't care.
> >
> > I'll use one of Lee's own "it depends" here ;^>
> >
> > What Lee says may be true for flooded lead acid,
> however, sealed lead
> > acid batteries most definitely do care about the
> ripple current and
> > voltage. Several manufacturers specify an upper
> bound on the amount of
> > ripple the charger is allowed to subject the
> battery to.
> >
> > Among other things, ripple on the output of a
> battery charger causes
> > unnecessary heating in the battery.
> >
> > Cheers,
> >
> > Roger.
> >
>
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Thanks for all the great answers. That's what I love about this list: I
get to learn all about this stuff from people who can explain it very
well in a way that is easy to understand!
Nick
Joe Smalley wrote:
Peukert's effect is caused by the impedance of the battery rising as the
ampere-hours are removed from the battery. When the impedance gets high
enough that the battery cannot supply the load enough voltage, the battery
is considered dead. If the load is removed for a period of time and the load
reattached, the battery will power the load for a short additional time
because diffusion reduces the impedance temporarily.
When you recharge a battery, it heats up slightly because the terminal
voltage is slightly higher than the open terminal voltage (14 V on charge
vice 13 V open circuit). The same thing happens on discharge because the
loaded voltage is lower than the open terminal voltage (11 V on discharge
vice 12 V open circuit). The heating effect is prominent at high amperages,
both on charge and discharge.
The Coulombic overcharge (ampere hours in minus ampere hours out)
dissociates the water into hydrogen and oxygen. In an AGM, they are
recombined into water (giving off heat) and recycled. In flooded cells
without recombination, the hydrogen and oxygen are vented. Water needs to be
replaced to keep the plates from being exposed. A chronically overcharged
battery pack will consume a lot of water.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Nick" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 12:46 PM
Subject: Charging and Peukert effect question
I am confused:
I have T-105 (equivalent) batteries in my truck...
Warning: all of these figures are very approximate, and just used for
this example!
If I have a constant discharge rate of say 100 amps, I should get about
110-120ah out of my batteries.
On the other hand, if I discharge at about 10 amps, I should get about
220 ah out of these batteries.
In both cases, the batteries are discharged to about 100 percent of
capacity.
My question is:
When I recharge them, am I going to put ~220ah back into the batteries
in both cases, or am I going to only put 110-120ah back in after the
100amp discharge and 220ah after the 10amp discharge? I realize that in
either case I will have to put somewhat more amp hours back into the
battery than I took out, but that's beside the point (I think).
I guess I am wondering where the extra amp hours are going when the
Peukert effect kicks in.
Nick
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--- In [EMAIL PROTECTED], Bob Bath <[EMAIL PROTECTED]> wrote:
> Just curious, all;
> As an ICE, my Civic would shock me in certain times
[...]
> Now as an EV, I get shocked the WHOLE year.
My Sentra does this to me 100% of the time as an ICE.
I've gotten used to using clothed parts of my body to close
doors. It's one of my reasons for wanting to convert a Saturn.
Anyway, my understanding is that this is due to the type of
tires you are using. Not aware of the details, but perhaps
this will point you in the right direction.
-Dave
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Hi all.
If you have just basic insulation for the cells, like 10 mm thick
urethane, you will get 10 celsius drop in the box in 12 hours. This is
when cells are 40 celsius after driving. You will have still operation
temperature available next morning.
This test was done when outside was -35 celsius.
Biggest problem will occure IF the temperature difference among cells is
too high. 15 celsius difference can end up over 40 ah difference in one
cycle if no BMS is used. You might ruin several cells by over discharging.
This test was done during weekend. Friday vehicle was parked with no
temperaure management. saturday the difference among the cells was
already 10 celsius. Charging was done during saturday and cell voltages
were quite even and when voltage level was reached charging stopped. NO
temperature compansation enabled in BMS. Sunday was a bit warmer day.
only -15 celsius. monday vehicle was driven until 8 corner and side
cells from all 34 sagged under 2 V. Temperature rose in middle less than
in corners but the capasity in corners were about 40 ah less.
Cells were charged up to specs in 20 Celsius after sitting one full day
in lab. All cells showed the capasity before test. So driving colder
pack and stopping before damage is done you should get away nicely. I
see monster in the big difference in cell temps across the pack. With
out BMS problems will occure. In worst case even flames if trying to
charge with reversed cells.
If TS cells are in around 10 celsius you can use them but with only
limited power. If system is designed correctly it will not be a problem.
Ucaps can compensate the power loss but best and simplest way is to keep
cells up 18 to 20 celsius all the time. If insulation is done well pack
will keep its temperature nicely even if vehicle is parked off grid
several days. In this case take care that the air inside the box is
circulated and the temp difference is not getting too great.
If grid is connected to vehicle BMS can maintain the temperature.
-Jukka
fevt.com
Doug Hartley wrote:
Bill,
The "capacity" is depleted mostly because the cell voltage is lower at
lower temperature, requiring more current draw by the motor controller
to get a given speed/power output to the motor. I would say that if
the cells are warm when you are discharging them, that is what counts.
You have to allow enough time for the mass of the cells to warm up again
all through, before driving.
Best Regards,
Doug
----- Original Message ----- From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 3:11 PM
Subject: TS Cells and Temperature
If I park my EV outside in the cold all day while at work, do I need
to keep
the TS cells warm the whole time, or can I just let them get cold and
then
warm them up at some period of time before they're needed? In other
words,
does getting cold when not in use deplete capacity, or is capacity
depleted
only when cold cells are actually used? Thanks.
Bill Dennis
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You might try an anti-static strap. It attaches to the chassis at the rear,
and hangs down far enough to contact the roadway.
David C. Wilker Jr. USAF (RET)
Children need love, especially when they do not deserve it.
- Harold S.
Hulbert
----- Original Message -----
From: "Bob Bath" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, May 09, 2005 4:18 PM
Subject: Static buildup on EVs
Just curious, all;
As an ICE, my Civic would shock me in certain times
of the year. Needless to say, it's quite the
aerodynamic shape, and as it cuts through dry air,
that makes sense.
Now as an EV, I get shocked the WHOLE year. It's
not a nasty zap, just a normal static discharge as I
shut the door. I can't remember the VoltsRabbit doing
that.
Any bright ideas why it happens? Floating pack in
both, so...?
'92 Honda Civic sedan, 144V
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering
wheel? Are you saving any gas for your kids?
Yahoo! Mail
Stay connected, organized, and protected. Take the tour:
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It may not be that the car is electric. On some of my cars I would
get shocked almost every time I exited and sometimes on entering
(sometimes with an audible "snap!" and a centimeter long spark). Utah
is very dry, I didn't have this problem in California. I've learned
to touch the car metal with my elbow (fewer nerves and less pain). I
just take it as a good sign that I am meant to finish my conversion
and drive electric.
I'm also careful to touch body metal before fueling my gasoline cars.
--- Bob Bath <[EMAIL PROTECTED]> wrote:
> Just curious, all;
> As an ICE, my Civic would shock me in certain times
> of the year. Needless to say, it's quite the
> aerodynamic shape, and as it cuts through dry air,
> that makes sense.
> Now as an EV, I get shocked the WHOLE year. It's
> not a nasty zap, just a normal static discharge as I
> shut the door. I can't remember the VoltsRabbit doing
> that.
> Any bright ideas why it happens? Floating pack in
> both, so...?
>
> '92 Honda Civic sedan, 144V
Discover Yahoo!
Find restaurants, movies, travel and more fun for the weekend. Check it out!
http://discover.yahoo.com/weekend.html
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Is there any cruise control on EV's?
__________________________________
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http://promotions.yahoo.com/new_mail
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--- mike golub <[EMAIL PROTECTED]> wrote:
>
> Where did you post this?
I get to the the list through Yahoo, I'm not familiar with the SJSU side of
things. I uploaded the
file to Yahoo but I'll try and figure out how to post it to SJSU too.
Dave Cover
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mike golub wrote:
> Is there any cruise control on EV's?
It's listed as a "future feature" for the Hairball in the Zilla manual.
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It would be easy to rig up an existing cruise control mechanism for an
ICE to your controller potbox, provided you had a vacuum source.
Matthew Holthausen
On May 10, 2005, at 1:34 PM, mike golub wrote:
Is there any cruise control on EV's?
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Yahoo! Mail - You care about security. So do we.
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Maybe this is the time to contact GE. I have a GE motor and controller in
my EV. They have been doing this for a long time. Maybe where the big auto
manufacturers won't GE will. LR>......
General Electric Chairman and CEO Jeff Immelt today announced
"ecomagination," an aggressive GE initiative to bring to market new clean
energy technologies.
Ecomagination is GE's commitment to address challenges such as the need
for cleaner, more efficient sources of energy, reduced emissions and
abundant sources of clean water. And we plan to make money doing it.
Increasingly for business, "green" is green.
Ecomagination is about the future. We will focus our unique energy,
technology, manufacturing and infrastructure capabilities to develop
tomorrow's solutions such as solar energy, hybrid locomotives, fuel cells,
lower-emission aircraft engines, lighter and stronger materials, efficient
lighting and water purification technology.
We are going to solve tough customer and global problems and make money
doing it.
Under the program, GE will:
a.. Double investment in clean technology R&D to $1.5 billion annually by
2010, up from $700 million in 2004.
b.. Introduce more ecomagination products each year. GE plans to double
its revenues from products and services that provide significant and
measurable environmental performance advantages to customers from $10
billion in 2004 to at least $20 billion in 2010 with more aggressive targets
thereafter.
These products include renewable sources of energy such as wind and solar,
technologies and materials that make energy production and consumption more
efficient, cleaner and more efficient transportation technologies, and
products and services that conserve or purify water.
c.. Reduce its greenhouse gas (GHG) emissions and improve its energy
efficiency. In addition to helping customers meet their environmental goals,
GE has committed to reduce its GHG emissions 1% by 2012 and the intensity
of its GHG emissions 30% by 2008 (both compared to 2004). Based on the
company's projected growth, GE's GHG emissions would have risen 40% by 2012
without further action.
d.. Keep the public informed. GE pledges to publicly report its progress
in meeting these goals.
GE is already one of the world's largest producers of wind turbines and is
heavily involved in solar power.
GE has initially identified 17 products that meet its ecomagination criteria
in areas such as electrical production, transportation, consumer and
industrial, and infrastructure.
Its current transportation ecomagination-class products are large scale:
railroads and aircraft.
a.. Transportation Rail
a.. Evolution Series
b.. Hybrid locomotive
b.. Transportation Aircraft
a.. GEnx aircraft engine
b.. GE90-115B aircraft engine
c.. LM2500+ marine engine
GE also has one of the leading research projects on advancing hydrogen as a
transportation fuel. GE's research focuses on the production, distribution,
storage and use of hydrogen.
Resources:
a.. The GE ecomagination website
b.. Webcast archive of Immelt speech
c.. Worldchanging Perspective: Inside GE's Power Play
Lawrence Rhodes
Bassoon/Contrabassoon
Reedmaker
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
[EMAIL PROTECTED]
415-821-3519
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http://news.yahoo.com/s/ap/no_room_to_zoom
FYI
-Ken Trough
Admin - V is for Voltage Magazine
http://visforvoltage.com
AIM - ktrough
FAX/voice message - 206-339-VOLT (8658)
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Nick Viera [mailto:[EMAIL PROTECTED] wrote:
> The specific charge cycle we are discussing here took
> exactly 10 kWh in on the AC side from start to finish,
> and I had gone 11.2 miles since the last charge cycle.
OK. Let's assume your PFCxx charger achieved 90% efficiency (since Rich
often mentions >90%); then (at least) 9kWh went into the pack, which
suggests something like 47-50Ah removed from the pack (accounting
roughly for the charge inefficiency).
> > and your pack of 8VGCs
>
> They are Trojan T-875s, not US Batteries.
OK. I used "8VGCs" as a generic reference to 8V golf car (GC) flooded
batteries, not as a reference to the US8VGC product specifically.
> I have the voltage set to 195 volts
> (~2.43 volts per cell * 80 cells).
Sounds good, provided your batteries are at about 26.7C (80F). Given
that your charger is going into thermal cutback within 3-5min of
operation, is it possible that your batteries are somewhat warmer than
80F while charging? If so, you will need to lower the charge voltage,
and this could help the current taper off.
> Every time I've monitored
> voltage while charging, I do see the voltage slowly come up to
> about 194.2 volts, at which point the charger timer kicks in.
> By the time the blue LED is flashing at it's medium speed, the
> voltage will have hit 195, where it stays for the duration of
> the charge.
Sounds like the PFCxx is operating as designed.
> The current does
> taper off, but it takes recycling the charger on/off/on at least once
> before it has had enough time to taper into the 2 amp range.
Since you don't know how much you are taking out of the batteries, it
will be difficult to determine if you are fully charging them or not.
If you can get the current to taper to about 2A, this is a reassuring
sign. But, without knowing how long it takes to get there or what was
removed from the batteries it is difficult to know if you are delivering
adequate overcharge or not.
Your hydrometer is your friend ;^> Every cell better be at least 1.275,
and preferably at least 1.290 when measured a few hours after charge
completion.
Cheers,
Roger.
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