EV Digest 4161
Topics covered in this issue include:
1) Peukerts for LI-Poly (was Re: Additional outside funding)
by "Myles Twete" <[EMAIL PROTECTED]>
2) Re: BB-600 NiCad Cells
by Michael Hurley <[EMAIL PROTECTED]>
3) Re: 4 wd at?
by mike golub <[EMAIL PROTECTED]>
4) Re: 4 wd at?
by "Christopher Robison" <[EMAIL PROTECTED]>
5) Re: BB-600 NiCad Cells
by "Philippe Borges" <[EMAIL PROTECTED]>
6) Re: BB-600 NiCad Cells
by Michael Hurley <[EMAIL PROTECTED]>
7) Re: Las Vegas NEDRA Wicked Watts Head Count
by "a.k. howard" <[EMAIL PROTECTED]>
8) Re: Las Vegas NEDRA Wicked Watts Head Count
by "Rich Rudman" <[EMAIL PROTECTED]>
9) Re: Datsun Minitruck Mania!
by "Rich Rudman" <[EMAIL PROTECTED]>
10) Re: 3 phase PM-long and heading OT
by "Rich Rudman" <[EMAIL PROTECTED]>
11) Re: Peukerts for LI-Poly (was Re: Additional outside funding)
by Victor Tikhonov <[EMAIL PROTECTED]>
12) Surplus BB600 nicads
by [EMAIL PROTECTED]
13) Re: EV digest 4160
by [EMAIL PROTECTED]
14) Re: nicads
by [EMAIL PROTECTED]
15) Re: 4 wd at?
by mike golub <[EMAIL PROTECTED]>
16) Re: Contactor Straight to Motor Test OK?
by "Patrick Maston" <[EMAIL PROTECTED]>
17) EVCC
by "Christopher Robison" <[EMAIL PROTECTED]>
18) RE: Regarding the Spirit and Purpose of NEDRA
by "Roger Stockton" <[EMAIL PROTECTED]>
19) Various Brush DC EV motors on Ebay
by Rod Hower <[EMAIL PROTECTED]>
20) Re: Contactor Straight to Motor Test OK?
by Electro Automotive <[EMAIL PROTECTED]>
--- Begin Message ---
For some reason, my earlier post didn't seem to make it out of the SJSU
server...so the latest post probably got lost in translation to
ya'all...anyway, I'm sending the first one, corrected with proper labeling
and some other cleanup-
Cliff asked:
> I think (anybody, please correct me if I am wrong) that Peukerts equation
is
> specific to lead acid batteries.
I doubt it...Peukert hypothesized and showed his equation to apply the the
batteries at the time in 1897---Nickel-Iron batteries were big then.
> batteries. At http://www.kokam.com/english/product/battery_main.html
> under SLB603870H, there is a zip file that charts information
> for their high capacity 1.5 amp-hr cell used in R/C planes.
> Using the Peukerts calc at
> http://www.geocities.com/hempev/Battery.html
>
> .5 C to 3C Peukert's exponent 1.04 and Peukert's capacity 1.58 amp-hrs
> 3C to 5C Peukert's exponent 1.07 and Peukert's capacity 1.67 amp-hrs
> 5C to 7 C Peukert's exponent 1.15 and Peukert's capacity 1.96 amp-hrs
> 7C to 10C Peukert's exponent 1.87 and Peukert's capacity 10.62 amp-hrs
> .5C to 10C Peukert's exponent 1.16 and Peukert's capacity 1.53 amp-hrs
>
> There seems to be pretty substantial differences. How accurate would this
be?
I looked at the data in Excel.
Your numbers look about right from the Peukert Exponents.
And the Peukert exponent does appear to change.
The Peukert model assumes that this holds:
C = k*I^n
or logC = n*logI +logk
I plotted the data as log(AH) vs log(Amps).
Interesting that it looks a lot like the power curve of a solar cell (I vs
V)---i.e. fairly constant, but decaying until the knee, and then drops like
a rock.
The knee of the AH vs I curve for this battery looks to be right about at
7C.
Now, according to Peukert,
log(capacity) = n * log(current) + k1
= n * log(current) + log(Io)
capacity = 10^(n * log(current) + log(Io))
= Io*I^n
I found that the following values generate a fairly good fit for the 0.5-7C
data:
n ~ - .046
k1 ~ 0.2
Io = 10^0.2 = 1.585amps
Current Capacity Model Predict Difference
C Ah Ah %
--------------------------------------------
0.5 1.6 1.61 0.39
3.0 1.49 1.48 -0.74
5.0 1.44 1.44 0.32
7.0 1.36 1.42 4.59
10.0 0.99 1.40 41.34
Below 7C, the capacity goes to hell anyway as seen in the forementioned
Peukert coefficient numbers, so this model (Peukert, I think...?) looks
pretty good for the LiPo.
Am I wrong, or isn't this model identical to the Peukert model?
-Myles Twete
--- End Message ---
--- Begin Message ---
At 3:25 PM -0500 on 3/7/05, Tim Humphrey wrote:
Please reply OFF-LIST if you would be interested in purchasing some never-
used military surplus BB-600 NiCad cells.
These are manufactured by Saft. They are flooded 34ah aircraft starting
battery individual cells.
3.3 lbs
1.2 volts
34 ah
772 amps discharge rate
How about a buck a cell, plus shipping, initial offering.
Reply off list.
I'm interested. How many do you have?
--
Auf wiedersehen!
______________________________________________________
"..Um..Something strange happened to me this morning."
"Was it a dream where you see yourself standing in
sort of Sun God robes on a pyramid with a thousand
naked women screaming and throwing little pickles
at you?"
"..No."
"Why am I the only person that has that dream?"
- Real Genius
--- End Message ---
--- Begin Message ---
Yes, it does get cold here, but not for long, and then
in the summer we've got sun all the time!
So the range of the batteries would be hurt by the
cold. I was thinking I'd still be ahead if I could
use the PbA batteries. I could leave the gas tank
attached, and run a webasto heater. Also several
inches of foam insulation might help.
Thanks
--- Frank Schmitt <[EMAIL PROTECTED]> wrote:
> Wilde Evolutions converted an old-school Land Rover
> to electric power.
> I don't know the exact story, but part or all of
> W.E. transformed
> itself into EVParts.com.
>
> The two downsides to AWD vehicles are additional
> driveline losses and
> additional weight (and in some cases, less room for
> batteries). But it
> can definitely be done.
>
> The trouble I think you might run into is that
> standard EV batteries
> (lead-acid) don't work very well in cold weather. So
> you're looking at
> either battery heaters or more exotic chemistries
> (I'm not sure which
> ones are cold-weather compatible, but I'd look at
> NiMH and LiIon).
>
> Googling for "Electric Vehicle Custom Conversions"
> (what EVCC stands
> for) brings up the following:
>
> Electric Vehicle Custom Conversions Larry Foster
> (818) 913-8579
>
> HTH,
>
> -Frank
>
> On Mar 7, 2005, at 12:27, mike golub wrote:
>
> > Hello
> > It kills me that I have to plug-in my car to keep
> it
> > warm, when I could be using that energy to charge
> the
> > batteries.
> >
> > 1-Has anyone converted either an AWD or 4wd
> vehicle to
> > electric?
> >
> > 2- does anyone have contact info for EA
> > JDM or EVCC adapter plates?
> >
> > 3-Are there cheaper ways to convert a car?
> > I don't think I need more than 35-45mph and a
> 30ish
> > range, perhaps even less range since we got 120v
> > plugins all over my city (fairbanks, ak)
> >
> > Thanks
> > Mike
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam? Yahoo! Mail has the best spam
> protection around
> > http://mail.yahoo.com
> >
> >
>
>
__________________________________
Celebrate Yahoo!'s 10th Birthday!
Yahoo! Netrospective: 100 Moments of the Web
http://birthday.yahoo.com/netrospective/
--- End Message ---
--- Begin Message ---
Unless you've got the money for the really exotic stuff, what you want for
the cold weather is nicad. (like, the Saft BB600 cells Tim Humphrey just
offered?) Nicads do very well in the cold.
Nick Viera did a 4wd Jeep Cherokee conversion. Check out www.driveev.com.
EVCC is no longer in business. Larry Foster passed away a year or two ago.
--chris
Frank Schmitt said:
> Wilde Evolutions converted an old-school Land Rover to electric power.
> I don't know the exact story, but part or all of W.E. transformed
> itself into EVParts.com.
>
> The two downsides to AWD vehicles are additional driveline losses and
> additional weight (and in some cases, less room for batteries). But it
> can definitely be done.
>
> The trouble I think you might run into is that standard EV batteries
> (lead-acid) don't work very well in cold weather. So you're looking at
> either battery heaters or more exotic chemistries (I'm not sure which
> ones are cold-weather compatible, but I'd look at NiMH and LiIon).
>
> Googling for "Electric Vehicle Custom Conversions" (what EVCC stands
> for) brings up the following:
>
> Electric Vehicle Custom Conversions Larry Foster (818) 913-8579
>
> HTH,
>
> -Frank
>
> On Mar 7, 2005, at 12:27, mike golub wrote:
>
>> Hello
>> It kills me that I have to plug-in my car to keep it
>> warm, when I could be using that energy to charge the
>> batteries.
>>
>> 1-Has anyone converted either an AWD or 4wd vehicle to
>> electric?
>>
>> 2- does anyone have contact info for EA
>> JDM or EVCC adapter plates?
>>
>> 3-Are there cheaper ways to convert a car?
>> I don't think I need more than 35-45mph and a 30ish
>> range, perhaps even less range since we got 120v
>> plugins all over my city (fairbanks, ak)
>>
>> Thanks
>> Mike
>>
>> __________________________________________________
>> Do You Yahoo!?
>> Tired of spam? Yahoo! Mail has the best spam protection around
>> http://mail.yahoo.com
>>
>>
>
>
--- End Message ---
--- Begin Message ---
i have +2000Amp capable Saft cells (50Ah/1C: CVH500), same type and usage
than marathon BB-600 (aircraft starting)
they are both high power low energy cells (40wh/kg compared to Saft EV
purpose 55wh/kg batteries)
Saft, like Marathon, make a lot of cells and batteries type for a lot of
usage :^)
The issue with this cells is watering, there is a special tool you
absolutely need to have correct level (watering is often and vital for cells
like BB-600 because they have tiny water reserve and high water consuption)
this is one for CVH500:
http://vehiculeselectriques.free.fr/images/SeringueSaft.jpg
the genuine 24V50Ah aircraft starting box open
http://vehiculeselectriques.free.fr/images/Aprilia%20Eproject%20001.jpg
a special made 13,2V box (for 24V box complement on an 37,2V electric
scooter)
http://vehiculeselectriques.free.fr/images/SaftCVH50504.jpg
i discharged and charged 2 days ago the 37,2V pack with a special Nicad/Nimh
algorythme charger, they are now sitting at 42.2V (1.38V/cells) waiting for
next hard discharge test :^)
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Christopher Robison" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, March 07, 2005 10:24 PM
Subject: Re: BB-600 NiCad Cells
> I thought that the BB600 Nicad cells were manufactured by Marathon, not
Saft.
>
> Saft makes Nicad cells and batteries that have higher energy density, but
> nowhere near the power density of the sintered-plate BB600s.
>
> On the other hand, I've heard that BB600 is actually a military
> designation, and not the real product name for the Marathon cells (which I
> think is something like "H-120" or similar) ... Are you saying that Saft
> has a sintered-plate cell product that is identical (i.e. 2000+ amps,
> etc)?
>
>
> --chris
>
>
>
>
> Tim Humphrey said:
> > Please reply OFF-LIST if you would be interested in purchasing some
never-
> > used military surplus BB-600 NiCad cells.
> >
> > These are manufactured by Saft. They are flooded 34ah aircraft starting
> > battery individual cells.
> >
> >
> > 3.3 lbs
> > 1.2 volts
> > 34 ah
> > 772 amps discharge rate
> >
> >
> > How about a buck a cell, plus shipping, initial offering.
> >
> > Reply off list.
> >
> >
> > -
> >
> > Stay Charged!
> > Hump
> > "Whether you think you can or think you can't, you are right!" --Henry
> > Ford
> >
> >
>
--- End Message ---
--- Begin Message ---
Oops. That was meant to be offlist. Grrr...
--
Auf wiedersehen!
______________________________________________________
"..Um..Something strange happened to me this morning."
"Was it a dream where you see yourself standing in
sort of Sun God robes on a pyramid with a thousand
naked women screaming and throwing little pickles
at you?"
"..No."
"Why am I the only person that has that dream?"
- Real Genius
--- End Message ---
--- Begin Message ---
From: Chip Gribben <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: <ev@listproc.sjsu.edu>
Subject: Re: Las Vegas NEDRA Wicked Watts Head Count
Date: Mon, 07 Mar 2005 09:50:10 -0500
That's cool Gadget!
So far, Brigham Young University will be there with their ultra capacitor
powered EV-1.
NEDRA VP, Brian Hall will be there with his record setting bikes.
Brent and Ken Singleton will be racing with their record setting electric
jr
dragster.
William Keuhl will be racing his NEDRA record breaking Pontiac Fiero.
I think Richard plans to race his RX7 but may have some battery issues with
it.
There are some folks flying in from California to spectate.
That's what I know off hand. We'll know more towards the end of March.
Chip Gribben
NEDRA Webmaster
http://www.nedra.com
I will be there, Regards, A.K. Howard, Las Vegas, NV
--- End Message ---
--- Begin Message ---
I would love to be there to have Goldie put on smoke show for the camera
crews...
but April is the middle of my Crazy season... I need to stay home and make
chargers.
Last year was January... one of the quietest months I have...
----- Original Message -----
From: "Reverend Gadget" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Sunday, March 06, 2005 11:17 AM
Subject: Re: Las Vegas NEDRA Wicked Watts Head Count
> Gadget will be there with camera and crew. we would
> like to get some footage to use in our upcoming pilot.
> I'd love to know who's going.
>
> Gadget
> --- Chip Gribben <[EMAIL PROTECTED]> wrote:
>
> > Hey everyone,
> >
> > There's been a lot of discussion about NEDRA classes
> > lately but now its time
> > to start doing some racing!
> >
> > Our NEDRA Season opener will be at Las Vegas April
> > 9. Just a month away.
> >
> > We need a head count of who is going.
> >
> > Please respond to Stan Hanel, Richard Furniss or
> > myself if you plan to race
> > or visit.
> >
> > [EMAIL PROTECTED]
> > [EMAIL PROTECTED]
> > [EMAIL PROTECTED]
> >
> > So dust off those battery caps and get on out to Las
> > Vegas April 9.
> >
> > Chip Gribben
> > NEDRA hat on
> > http://www.nedra.com
> >
> >
>
>
> =====
> visit my website at www.reverendgadget.com
>
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "John Wayland" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Saturday, March 05, 2005 6:26 PM
Subject: Re: Datsun Minitruck Mania!
> Hello to All,
>
> However, the s-t-r-e-t-c-h-e-d ADC
> 'XP1227' 8 inch motor, produces way more power than it's otherwise clone
brother the
> 'XP1263' only because the center section of the motor is longer, thus
larger field coils
> and a longer armature to interact with them.
>
> See Ya.....John Wayland
>
The longer motor has more torque per amp since the forces are acting on
longer armature windings.
But the XP-1263 and the XP 1227 have the same commutator, so the limit to
power generation is the same. What you can get the commutator to pass
without acring.
So... The smaller motor... can make as much power as the larger motor....If
the Current and voltage is the same. The 1227 can make a LOT more torque for
the same amperage.
So you get more force for the same current. I would love to have access to a
1227 for Dyno work. And record the actual torque and motor amps.
If you have a heavy EV...a 400 amp controller, and don't wish for super high
power levels... the 1227 is a good motor.
The 1263 is lighter,and can move the same power.... Better for Steet work.
The Stocker 8 inch EV motor or the Sparrow version has less comm bars, and
can take MUCH higher currents because there is More copper to use,and the
field turns are 12 instead of 14 turns on the 1263, This yields a motor of
less eff, More RPM and a much higher current survive level. The result is
the Stocker can make a LOT more RPM and therefore a lot more HP. But it
can't keep up with the XP motors in a tractor pull. You have to ask what
the working ranges are before you select a motor.
I am heading toward less and less torque off the line and RPM is the
holy grail for me right now. I have torque to spare, and no top end....
My motor in Goldie IS a XP-1263, and I shorted a pair orf comm bars testing
the Raptor series of controller for DCP. The current set up is a 37 bar comm
in a 14 turn case. This can move 900 amps to 4500 rpm. The stockers look
like I get 1000 amps to above 5500 rpm. If so.. this is a hand full of
tenths off my ET, and 5 to 8 mph at the lights. A good chunk of the 20 MPH I
am hunting for this year in Drag racing.
Got the Dyno to give some real numbers... incidentally .... the motor under
test is a 8 incher Sparrow , and the Generator is the Last 8" XP-1263 that
I got from ...Plasma boy himself.
Rough numbers... with say a %20 +- error bar for you numbers Geeks...
Expect the Error bars to drop rather significantly... as the week
progresses.
Once I get a clean plot that is repeatable... and the Cal points withing
%5, I will publish, or E-mail BMP files or the data files in Excell format.
Input power was 350 amps of 70 volts(96 volt batteries sagged to 70) for
24,500 watts input
Output power was:
45 ftlbs at 3000 rpm for 25.7 Hp and
19,172 watts shaft power
this yields a Efficiency of
%78.25
This number is withing the specs published by AvDC and Warp for thier like
designed motors. So my numbers meet the BS detector... and are in the Ball
park.
Brushes are set to the nuetral position... motor was run CCW. I have to dig
the set screws out of the fully Advanced CCW hole sets...
NO visable arcing on the motor under test!
Points of note, this yanked the Old T-Rex into WOT... as my numbers firmed
up as soon as the PWM went away and we had a Locked on controller.
The PWM noise is tweaking my RPM and torque readings. I went from a screen
full of 60Hz and 18Khz hash to solid lines, with some offsets. BIG
improvents.
And this yielded the first data set that I dare publish. This little fact
has got me to wondering how much Quiter the Zilla is than the T-rex...Ot's
pretty proud of his boxes....Leave it to his excompeditor... to find out how
much better.....
The battery pack is 96 volts of throw away Yellow tops... most are prototype
and cosmetic blems, that I yanked out of Goldie 2 years ago. Pretty poor
excuses for batteries. good enough for Dyno abuse.
Goldie with 13 fresh Orbs will be on this same motor by midweek...I hope.
-
--- End Message ---
--- Begin Message ---
Raymond, listers.. and Myles..
Steam hp is real HP... but how they measure it is not the same as Break Hp
as we all know it.
There is a Sales and 100 years of different ways of recording it.
If the Steam engine trully made only 1.5 Hp... or 1119 Watts. Getting 600
watts and not having the Steam engine stall out Would be a pretty good
conversion.
So... your tests of 2000 rpm and 13.2 volts and 55 amps = 726 watts at 2000
rpm. is about 2.56 ftlbs of torque on the alternator shaft with 100%
conversion.
So... if your alternator sucks 5 ftlbs off the Steam engine....you are going
to be lucky. So.. the basic math says that your alternator will stall the
steam engine.
This cleary is not happening... so the Steam engine has a LOT more hp when
running than the 1.5 that we are lead to believe.
Also ... should somebody need to use a AvDC 8 incher and a controller to
drive a alternator? I do have the dyno to measure the results.
A conversion that could be nice to have is 1 ft lbs is .3808 Horsepower at
2000 rpm. Or 284 watts mechanical.
This lets you play with your ratios.. The above numbers 5 ftlbs on the
alternator shaft is going to place 6 times that on the steam crankshaft...
if it's belted up to the 1:6 ratio.
That's 30 lbs of drag on the steam engine.
If the steam engine is rated at 1.5 Hp at 300 rpm....26.26 Ft lbs. you
still don't have enough to make the alternator spin and move the boat.
So I am guessing that the steam engine is making a LOT more power than it
seams.
----- Original Message -----
From: "Raymond Knight" <[EMAIL PROTECTED]>
To: "EV List" <[EMAIL PROTECTED]>
Sent: Saturday, March 05, 2005 5:31 AM
Subject: RE: 3 phase PM-long and heading OT
> When testing using my new test bench, a JBT5-P, the test parameters are to
> 13.2volts (SAE spec I believe). Meaning it puts out 55amps at 2000rpm at
> 13.2volts. It is also supposed to be temperature stabilized. Not sure what
> they mean by that though. I think they mean it is brought up closer to
> operating temperature before the test is done. Going through the test
cycle
> it checks for leaks, then tests regulators set point voltage, then checks
> turn on rpm, then full fields it at around 3000 rpm (usually I will an
extra
> 30% over test results here), then it brings it up to 6000 rpm and runs the
> test down to about 10amps. When it is done the alternator is usually too
hot
> too touch, about 125F, which is close to what it is in service. We
sometimes
> will do several repeated tests back to back to get the alternator to
150+F,
> which is right in line with service temperatures. Typically there will be
> about a 10% loss in the top end output doing it this way.
> When testing on my old test bench, I usually drag it down to about
14volts,
> unless the customer is looking then I full field it to 12volts, just to
> impress them. But my old bench only goes to 100amps unless I am using a
> separate hand clamp meter.
> The Ecoair comes rated at 240amps at 77F at 1650rpm, and 185amps at 200F
at
> 1650rpm. The 10478101's are rated the same way I rate my units.
> The Bosch I don't know about. There is a major trend going on like what
> Thermodyne did. I hate to say it but it is becoming the norm with
> starters/alternators/and batteries. Really poor marketing by my standards.
I
> look at it as the new school way of doing business. Where handshakes mean
> nothing, you will be told what ever you need to hear to make the sale, and
> there is tons of fine print involved. For 35years we have gone by
"Quality,
> Service, and Integrity". But since the ISO9000 crap came along, I have
been
> thinking of changing it as they are busily ruining the thought.
> As for real world tests, I am all for it. Some of it I know off hand, some
> of it I might know by a different phrase, and some it I won't have a clue
> how to do.
> The diodes are easy, typical button diodes have forward voltage drops of
0.7
> volts. The avalanche diodes are 0.5volts. Performance curves such as
> efficiency I cannot do. If you want output/rpm/at 13.2 or 26.4, no
problem.
> Internal resistance, I don't know. Which brings up a question from me, how
> do I test the internal resistance of a battery?
> Again you are welcome to take one of my alternators and test it yourself.
I
> would be interested in seeing the results. The more real world information
I
> get about what I am doing, the better.
> About the pulley ratios. Correct me if I am wrong here. An alternator sets
> the load according to how much power it needs to produce. So if it
requires
> 1.5hp to turn it, and you are spinning it at a 6 to 1 ratio, the larger
> pulley needs to be producing 6 times the 1.5hp, i.e. 9hp. Reversing this
if
> you were under driving it 3 to 1, then you would only need 1/3 the 1.5hp,
> i.e. .5hp. Correct? The more I think about this though, alternators
probably
> require very little HP, but lots of torque. Maybe we have always look at
it
> as HP because it has a fixed relationship to torque in an ICE. But with
your
> steam engine it is a different relationship? I say all this because I have
> seen many people try and make homemade generators with alternators, and
only
> succeed in stalling the motors, which is what I would have expected with
> your 1.5hp set up.
>
>
--- End Message ---
--- Begin Message ---
The knee and total loss of capacity beyond that (7C) is unrelated to
Peukert effect as we know it (gradual loss at higher rates, no knees).
Victor
Myles Twete wrote:
For some reason, my earlier post didn't seem to make it out of the SJSU
server...so the latest post probably got lost in translation to
ya'all...anyway, I'm sending the first one, corrected with proper labeling
and some other cleanup-
Cliff asked:
I think (anybody, please correct me if I am wrong) that Peukerts equation
is
specific to lead acid batteries.
I doubt it...Peukert hypothesized and showed his equation to apply the the
batteries at the time in 1897---Nickel-Iron batteries were big then.
batteries. At http://www.kokam.com/english/product/battery_main.html
under SLB603870H, there is a zip file that charts information
for their high capacity 1.5 amp-hr cell used in R/C planes.
Using the Peukerts calc at
http://www.geocities.com/hempev/Battery.html
.5 C to 3C Peukert's exponent 1.04 and Peukert's capacity 1.58 amp-hrs
3C to 5C Peukert's exponent 1.07 and Peukert's capacity 1.67 amp-hrs
5C to 7 C Peukert's exponent 1.15 and Peukert's capacity 1.96 amp-hrs
7C to 10C Peukert's exponent 1.87 and Peukert's capacity 10.62 amp-hrs
.5C to 10C Peukert's exponent 1.16 and Peukert's capacity 1.53 amp-hrs
There seems to be pretty substantial differences. How accurate would this
be?
I looked at the data in Excel.
Your numbers look about right from the Peukert Exponents.
And the Peukert exponent does appear to change.
The Peukert model assumes that this holds:
C = k*I^n
or logC = n*logI +logk
I plotted the data as log(AH) vs log(Amps).
Interesting that it looks a lot like the power curve of a solar cell (I vs
V)---i.e. fairly constant, but decaying until the knee, and then drops like
a rock.
The knee of the AH vs I curve for this battery looks to be right about at
7C.
Now, according to Peukert,
log(capacity) = n * log(current) + k1
= n * log(current) + log(Io)
capacity = 10^(n * log(current) + log(Io))
= Io*I^n
I found that the following values generate a fairly good fit for the 0.5-7C
data:
n ~ - .046
k1 ~ 0.2
Io = 10^0.2 = 1.585amps
Current Capacity Model Predict Difference
C Ah Ah %
--------------------------------------------
0.5 1.6 1.61 0.39
3.0 1.49 1.48 -0.74
5.0 1.44 1.44 0.32
7.0 1.36 1.42 4.59
10.0 0.99 1.40 41.34
Below 7C, the capacity goes to hell anyway as seen in the forementioned
Peukert coefficient numbers, so this model (Peukert, I think...?) looks
pretty good for the LiPo.
Am I wrong, or isn't this model identical to the Peukert model?
-Myles Twete
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Howdy Hump,
I'd be quite interested in asembling a pack of $1 BB600's, as my Karmann-Ghia
conversion will have easy pack access for watering. I'd be interested in @ 200
cells, plus some spares. Please keep me in the loop as you put this buy
together.
Thanks,
Jay Donnaway
Vancouver, WA
--- End Message ---
--- Begin Message ---
--- End Message ---
--- Begin Message ---
DOH! Stupid Reply Button.... unsend, ignore, pay no attention to that man
behind the curtain!!
-grin-
-Jay
--- End Message ---
--- Begin Message ---
why would someone collect all this valuable
information and then pass away with it?
Was Larry a one man show?
--- Christopher Robison <[EMAIL PROTECTED]>
wrote:
> Unless you've got the money for the really exotic
> stuff, what you want for
> the cold weather is nicad. (like, the Saft BB600
> cells Tim Humphrey just
> offered?) Nicads do very well in the cold.
>
> Nick Viera did a 4wd Jeep Cherokee conversion.
> Check out www.driveev.com.
>
> EVCC is no longer in business. Larry Foster passed
> away a year or two ago.
>
> --chris
>
>
>
> Frank Schmitt said:
> > Wilde Evolutions converted an old-school Land
> Rover to electric power.
> > I don't know the exact story, but part or all of
> W.E. transformed
> > itself into EVParts.com.
> >
> > The two downsides to AWD vehicles are additional
> driveline losses and
> > additional weight (and in some cases, less room
> for batteries). But it
> > can definitely be done.
> >
> > The trouble I think you might run into is that
> standard EV batteries
> > (lead-acid) don't work very well in cold weather.
> So you're looking at
> > either battery heaters or more exotic chemistries
> (I'm not sure which
> > ones are cold-weather compatible, but I'd look at
> NiMH and LiIon).
> >
> > Googling for "Electric Vehicle Custom Conversions"
> (what EVCC stands
> > for) brings up the following:
> >
> > Electric Vehicle Custom Conversions Larry Foster
> (818) 913-8579
> >
> > HTH,
> >
> > -Frank
> >
> > On Mar 7, 2005, at 12:27, mike golub wrote:
> >
> >> Hello
> >> It kills me that I have to plug-in my car to keep
> it
> >> warm, when I could be using that energy to charge
> the
> >> batteries.
> >>
> >> 1-Has anyone converted either an AWD or 4wd
> vehicle to
> >> electric?
> >>
> >> 2- does anyone have contact info for EA
> >> JDM or EVCC adapter plates?
> >>
> >> 3-Are there cheaper ways to convert a car?
> >> I don't think I need more than 35-45mph and a
> 30ish
> >> range, perhaps even less range since we got 120v
> >> plugins all over my city (fairbanks, ak)
> >>
> >> Thanks
> >> Mike
> >>
> >>
> __________________________________________________
> >> Do You Yahoo!?
> >> Tired of spam? Yahoo! Mail has the best spam
> protection around
> >> http://mail.yahoo.com
> >>
> >>
> >
> >
>
>
__________________________________
Celebrate Yahoo!'s 10th Birthday!
Yahoo! Netrospective: 100 Moments of the Web
http://birthday.yahoo.com/netrospective/
--- End Message ---
--- Begin Message ---
Thanks, Lee. My ammeter shunt is in the M- wire to the motor, so I'm
measuring motor amps. I checked the potbox and it's working normally.
I did all the diagnostic tests in the Curtis manual and it passed them
all. Before I installed the controller, I turned the controller
amperage limit all the way up per the Curtis manual (clockwise all the
way). The car starts out normally with the part-throttle growl and the
amps come up as the growl goes away, then it peaks at 200. It doesn't
matter what gear I'm in or what the motor rpm is, 200 is the limit.
Acceleration is real slow and it doesn't climb hills well. I guess the
meter could be wrong - I bought it from Electro Automotive along with
the shunt - both are new. If the meter is wrong and I'm actually
getting more amperage than I think, this thing is real DOG - much worse
that I expected: it's very slow.
Patrick
>>> [EMAIL PROTECTED] 3/7/05 3:33:19 PM >>>
Patrick Maston wrote:
> I'm only getting 200A at full throttle from my Curtis 1231C-8601
> to the motor on my 1981 Jet Electrica.
Where are you measuring current -- battery, or motor? And how are you
measuring it? Could your meter be wrong?
First, I'd see if the potbox is actually calling for full throttle.
Measure its resistance; it should change from 0 ohms to 5k ohms as the
throttle is moved from fully released (off) to fully depressed (full
power. The controller actually starts turning on at around 300 ohms,
and
is fully on over 4400 ohms.
Second, there is a current limit adjustment pot hidden behind one of
the
screws on the side of the case. It might be cranked all the way down,
and so be limiting your current.
Next, measure the actual voltage that you are getting across your
motor
at full throttle. You'll have to use a good quality meter for this, as
the voltage is very noisy! When the motor is a high rpm and the
throttle
is floored, you should see essentially full pack voltage (minus no
more
than 1-2 volts).
Finally, how is your motor geared? If geared to force motor rpm too
low,
then the controller never comes out of current limit. You may have 200
amps from the battery, but are delivering 400-500 amps to the motor
(at
reduced voltage). If this is the problem, shift or change your gear
ratio to let the motor spin up faster.
> I am considering wiring the contactor directly to the motor and
> closing the contactor momentarily to see how many amps I get with
> the controller out of the loop. Are there any potential problems
> in doing this?
LOTS of potential problems! The current won't be limited. If you close
that contactor with the motor stopped or at low rpm, it will draw some
frightening current (it easily could exceed 1000 amps). This can blow
fuses, weld contactors, rip out the motor coupling, break something in
the drive train, or overspeed the motor and destroy it. If the
controller is still in the circuit and you open that bypass contactor
when the motor is 500+amps, it can destroy the freewheel diodes in the
controller.
However, this is what is done in a contactor controller, and things
survive. The difference is that a contactor controller brings the
motor
up to speed in steps, so you don't hit it with full voltage until it
is
turning fast enough so the peak current won't be high enough to break
anything.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do the great deeds worth repeating
-- Ben Franklin, Poor Richard's Almanac
--
Lee A. Hart 814 8th Ave N Sartell MN 56377
leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
This is a story that Mark Farver knows more about than I do as he had some
involvment with Larry at one point, but suffice it to say it's a bit more
complex than that.
Maybe he can offer some comments...
--chris
mike golub said:
> why would someone collect all this valuable
> information and then pass away with it?
> Was Larry a one man show?
> --- Christopher Robison <[EMAIL PROTECTED]>
> wrote:
>> Unless you've got the money for the really exotic
>> stuff, what you want for
>> the cold weather is nicad. (like, the Saft BB600
>> cells Tim Humphrey just
>> offered?) Nicads do very well in the cold.
>>
>> Nick Viera did a 4wd Jeep Cherokee conversion.
>> Check out www.driveev.com.
>>
>> EVCC is no longer in business. Larry Foster passed
>> away a year or two ago.
>>
>> --chris
>>
>>
>>
>> Frank Schmitt said:
>> > Wilde Evolutions converted an old-school Land
>> Rover to electric power.
>> > I don't know the exact story, but part or all of
>> W.E. transformed
>> > itself into EVParts.com.
>> >
>> > The two downsides to AWD vehicles are additional
>> driveline losses and
>> > additional weight (and in some cases, less room
>> for batteries). But it
>> > can definitely be done.
>> >
>> > The trouble I think you might run into is that
>> standard EV batteries
>> > (lead-acid) don't work very well in cold weather.
>> So you're looking at
>> > either battery heaters or more exotic chemistries
>> (I'm not sure which
>> > ones are cold-weather compatible, but I'd look at
>> NiMH and LiIon).
>> >
>> > Googling for "Electric Vehicle Custom Conversions"
>> (what EVCC stands
>> > for) brings up the following:
>> >
>> > Electric Vehicle Custom Conversions Larry Foster
>> (818) 913-8579
>> >
>> > HTH,
>> >
>> > -Frank
>> >
>> > On Mar 7, 2005, at 12:27, mike golub wrote:
>> >
>> >> Hello
>> >> It kills me that I have to plug-in my car to keep
>> it
>> >> warm, when I could be using that energy to charge
>> the
>> >> batteries.
>> >>
>> >> 1-Has anyone converted either an AWD or 4wd
>> vehicle to
>> >> electric?
>> >>
>> >> 2- does anyone have contact info for EA
>> >> JDM or EVCC adapter plates?
>> >>
>> >> 3-Are there cheaper ways to convert a car?
>> >> I don't think I need more than 35-45mph and a
>> 30ish
>> >> range, perhaps even less range since we got 120v
>> >> plugins all over my city (fairbanks, ak)
>> >>
>> >> Thanks
>> >> Mike
>> >>
>> >>
>> __________________________________________________
>> >> Do You Yahoo!?
>> >> Tired of spam? Yahoo! Mail has the best spam
>> protection around
>> >> http://mail.yahoo.com
>> >>
>> >>
>> >
>> >
>>
>>
>
>
>
>
> __________________________________
> Celebrate Yahoo!'s 10th Birthday!
> Yahoo! Netrospective: 100 Moments of the Web
> http://birthday.yahoo.com/netrospective/
>
>
--- End Message ---
--- Begin Message ---
John Wayland [mailto:[EMAIL PROTECTED] wrote:
> The reason NEDRA exists, isn't to promote individuals, it's
> to promote EVs. Lately, the emphasis seems to be on how to
> reinvent NEDRA to accommodate 'winning' for those who seem
> fixated on beating the other guy or winning a prize.
My contributions to this thread are probably largely responsible for
this impression. My arguing in favour of some cost-related distinction
is not so much to 'accommodate winning' for those *competitors* who,
perish the thought, might consider winning as the logical goal of a
competition, but rather to encourage 'new blood' to enter EV racing.
Like it or not, one of the attractions for people to participate in any
competition is some probability of winning.
> but for the core NEDRA racers, we all understand that the
> most important aspect, is promoting the EV. We do this by
> dispelling the myth that EVs are dull, slow, and boring, and
> by mixing it up with muscle cars, rice burners, and drag
> machines as we demonstrate how powerful, quick, and fast EVs
> can be.
To be more precise, *you* do this. Very little 'mixing up' happens at
NEDRA events (I should probably say Woodburn, since that is the only
NEDRA event I've personally attended) between ICE and EV's because very
few of the present EV top-runners are quick enough to give any sort of
performance ICE competition. The Maniac Mazda vs Viper or Zombie vs 5L
Mustang, etc. 'exhibition' runs have definitely been crowd pleasers and
definitely make the point to the spectators of how powerful, quick, and
fast EVs can be.
However, NEDRA events (Woodburn) which are almost exclusively EV vs EV
(and even then often radically mismatched EV vs EV because there aren't
enough EVs in any given class to allow very many runs between
competitive vehicles before you end up with something like the
KillaCycle in one lane and an 18sec conversion in the other), are the
only time that many of these EVs make it to the track and end up being
of limited value for myth dispelling since there is little attraction to
draw spectators who are not already into EVs out.
If NEDRA's mission is to show the public how powerful, quick, and fast
EVs can be, then my suggestion is that perhaps they should be looking at
ways to attract more ICE-heads to their events. My suggestions for
doing this are to have more EV vs ICE competitions (not just fast ICE's,
but ICE's of similar performance ranges as the EVs, say anything from
18s to 12s machines), because, like it or not, the ICE sound is exciting
for spectators and gives them the clues to appreciate the performance
level of the EV, and to look at ways to attract more participants (such
as one or more new classes, etc. to try to offer more incentive for 'new
blood' to come out).
> It's easy to make a machine from orange
> board, duct tape, and hastily-made metal pieces that weighs
> next to nothing and doesn't even look like a 'car', then run
> it down the track to set a speed record.
'Easy' might not be the best word to use here. I think it would be far
easier to buy a dragster chassis and body 'off-the-shelf', or have one
made to order, and install an electric drivetrain than to build one from
the ground up. It comes back to that ugly word: money.
> When
> Dave Cloud says, "What makes a vehicle go faster is more
> money, not more voltage", I couldn't disagree more. What
> makes and EV quicker and faster, is years of dedication, long
> hours of often back-breaking labor, and most important of
> all, creativity!
There is no doubt that much hard work and creativity are required to
field a competitive EV, especially in the higher classes, however, there
is also little doubt that without the money to buy go fast parts such as
top of the line controllers and batteries, for instance, it becomes much
more difficult to achieve a given performance level.
I realise Rod's been busy with Gone Postal of late, but I also don't
think he's any less dedicated or hard-working than when Maniac Mazda was
eating Vipers at the track, and yet when Maniac Mazda lost its DCP
controllers and JCI Inspira pack not only did its performance plummet,
but it appears to be languishing somewhere. No amount of Rod's hard
work, dedication, and ingenuity is likely to return this EV to its
former glory (or beyond!) without money to replace the multiple DCP
controllers and to buy hi-pro batteries...
> As to those throwing stones at sponsorship, then claiming it
> was money that made the EV successful, I say rubbish.
That would be me mentioning sponsorship, and yes, I stand by what I
said. If I get sponsorship for my EV that allows me access to better
components, or the ability to use multiple motors or controllers, etc.,
then it will be more difficult for my competitors to match my
performance (unless I am really incompetent and also fail to learn from
my mistakes ;^).
Note, however, that I never said it was easy to get sponsorship; just
that the more money that one has to throw at their EV, the easier it is
to attain a given performance target.
> I believe that anyone can get sponsorship for their EV, but
> it certainly won't just get handed to you.
I would agree with the 'anyone' to a limited extent. What I said is
that 'everyone' can't get sponsorship, and what I mean is that all NEDRA
racers aren't likely to get sponsorship no matter how clean their
vehicles. At least not now, when the sponsors tend to be limited to
manufacturers of components used in EVs. Perhaps if EV racing ever
gathers enough spectator interest to be a worthwhile advertising venue,
then other sponsors might be attracted.
> You have to be
> unique in some regard (merely having a powerful and quick
> electric vehicle can not fill this requirement), you have
> to put pride and integrity into the vehicle to make it
> something a sponsor would feel good about having their name
> and products associated with, and then, well...you have to
> deliver!
It sounds a lot like the old adage about having to have money in order
to get money ;^>
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I just posted some PM brush motors that may be
suitable for various small EV projects like
scooters,
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3880153103
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3880151564&ssPageName=STRK:MESE:IT
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3880152268&ssPageName=STRK:MESE:IT
Items, 3880153103, 3880151564 and 3880152268
Thanks,
Rod
--- End Message ---
--- Begin Message ---
At 05:21 PM 3/7/05 -0800, you wrote:
Thanks, Lee. My ammeter shunt is in the M- wire to the motor, so I'm
measuring motor amps. I checked the potbox and it's working normally.
I did all the diagnostic tests in the Curtis manual and it passed them
all. Before I installed the controller, I turned the controller
amperage limit all the way up per the Curtis manual (clockwise all the
way). The car starts out normally with the part-throttle growl and the
amps come up as the growl goes away, then it peaks at 200. It doesn't
matter what gear I'm in or what the motor rpm is, 200 is the limit.
Acceleration is real slow and it doesn't climb hills well. I guess the
meter could be wrong - I bought it from Electro Automotive along with
the shunt - both are new. If the meter is wrong and I'm actually
getting more amperage than I think, this thing is real DOG - much worse
that I expected: it's very slow.
I don't think it's your gauge. We have had almost no problems with these
gauges. Also, if you were truly getting 500 amps and it was just a wrong
gauge, you should be getting good performance.
Shari Prange
Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989
http://www.electroauto.com [EMAIL PROTECTED]
Electric Car Conversion Kits * Components * Books * Videos * Since 1979
--- End Message ---
