# [EVDL] Flooded NiCad



## EVDL List (Jul 27, 2007)

When looking at specs for flooded NiCad batteries I notice that the amp-hour
capacity is listed as C/5 instead of the usual C/20 of lead acid batteries.
I know how to estimate the C/1 for lead acid based on the C/20.

Is there a similar conversion for flooded NiCads?

Do they exhibit the Peurkert effect and need to be adjusted?

Barry Oppenheim
New Hope, PA


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## EVDL List (Jul 27, 2007)

> When looking at specs for flooded NiCad batteries I notice that the
> amp-hour
> capacity is listed as C/5 instead of the usual C/20 of lead acid
> batteries.
> I know how to estimate the C/1 for lead acid based on the C/20.
>

They list C/5 because there isn't much difference between C/5 and C/20 on
nicads. Isn't a whole lot of difference between 1C and C/5 on most
flooded nicads either, qa little bit different due to internal resitance,
but not much..

Peukert is a guestimate intended for Lead-Acids only.


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## EVDL List (Jul 27, 2007)

> Barry Oppenheim wrote:
> > When looking at specs for flooded NiCad batteries I notice that the amp-hour
> > capacity is listed as C/5 instead of the usual C/20 of lead acid batteries.
> > I know how to estimate the C/1 for lead acid based on the C/20.
> ...


----------



## EVDL List (Jul 27, 2007)

>
>
> The Peukert effect for nicads is usually small enough that it can be
> ignored, at least for 1-hour and slower discharge rates. The C/5 and C20
> amphour capacities are almost the same. They use C/5 because it's faster
> to test.
>
> With lead-acid, the Peukert effect is significant. Manufacturers want to
> brag about the highest capacity possible, so they use the C/20 rate.
> It's the longest you can get away with and be able to complete a test
> cycle per day (it leaves just 4 hours for charging).


A number of deep cycle lead acid batteries for off-grid power use actually
give a C/100 rate... actually more useful than a C/20 for that particular
use, but... also useful for sounding like a bigger battery.

I love Ni-Cad's. If only I could find some for my EV.... I have 24 volts at
180AH for backup for the house and they have a very stiff voltage compared
to lead acid.... I'd love a NiCad bank for the truck  But I'm not sure
where I'd even be able to find a bank of them -- a new bank of 122AH 120V
Nickle irons would be $8,400, and weight 1100lbs.... pretty comparable on
the weight and performance to a 120 volt bank of T-105's I imagine. But
three to four times the price. And at least four times the lifetime?
NiCad's are even more expensive than Nickel Iron's, as far as I know, though
with better energy to weight ratio.

Z

>
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in -- Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>

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## EVDL List (Jul 27, 2007)

http://www.sbsbattery.com/subpage_index.php?_subp_=152
For anyone who wants to look at lots and lots of performance graphs of
flooded NiCad batteries....

And lots of other industrial batteries, as well.

Z





> Zeke Yewdall <[email protected]> wrote:
> 
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Can they be bought by John Doe and not Boeing? If so do you you know of any
distributors?

Barry Oppenheim

-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf
Of Zeke Yewdall
Sent: Wednesday, July 16, 2008 12:57 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Flooded NiCad


http://www.sbsbattery.com/subpage_index.php?_subp_=152
For anyone who wants to look at lots and lots of performance graphs of
flooded NiCad batteries....

And lots of other industrial batteries, as well.

Z





> Zeke Yewdall <[email protected]> wrote:
> 
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

I'm not sure, but I'm kind of interested in at least finding prices (I have
a feeling it'll make me feel like lithium prices are low). I haven't
contacted them yet to inquire on where you buy them though.

Z

On Wed, Jul 16, 2008 at 11:55 AM, Barry Oppenheim <
[email protected]> wrote:

> Can they be bought by John Doe and not Boeing? If so do you you know of
> any
> distributors?
>
> Barry Oppenheim
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf
> Of Zeke Yewdall
> Sent: Wednesday, July 16, 2008 12:57 PM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] Flooded NiCad
>
>
> http://www.sbsbattery.com/subpage_index.php?_subp_=152
> For anyone who wants to look at lots and lots of performance graphs of
> flooded NiCad batteries....
>
> And lots of other industrial batteries, as well.
>
> Z
>
>
>
>


> Zeke Yewdall <[email protected]> wrote:
> >
> > >
> > >
> ...


----------



## EVDL List (Jul 27, 2007)

> Can they be bought by John Doe and not Boeing? If so do you you know of
> any
> distributors?
>

Just so you're clear on this, these batteries weigh about the same as
Lead-Acid for the same basic performance/range. That is assuming you go
with the Fiber cells, The pocket plates cells weigh almost twice as much.

For example a 120V pack of KFM-120P will produce about the same 1 hr
output as a 120V pack of T-105 cells (at 100% DoD for each).
The KFM pack would weigh 1276lbs, the T-105s = 1260lbs

Their only significant advantages are a potentially longer life and the
fact that they don't mind 100% DoD or being left in a partially charged
state for long periods of time.

You're going to pay a premium for those advantages.

Granted they should last 4-5 times as long as lead-acids, but if they cost
4-5 times as much, that's no real advantage.
Plus NiCads generally require more frequent watering than PbA and tend to
have a lower energy efficiency, so your whs per mile will go up (higher
fuel -electricity- costs)

These kinds of NiCads make sense if you can get a supper deal on them, but
I'm not sure they are worth it if you have to pay retail.


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## EVDL List (Jul 27, 2007)

And... cold weather performance may be significantly better, for those of us
without garages to park inside in the winter in the snowy weather...
whether that's worth 5 to 10 times the price....



> Peter VanDerWal <[email protected]> wrote:
> 
> > > Can they be bought by John Doe and not Boeing? If so do you you know of
> > > any
> ...


----------



## EVDL List (Jul 27, 2007)

For those guys still wanting NiMh chemistry, Nilar is now distributing their
NiMh through http://www.pluginconversions.com/ for EV applications. Not
sure if I missed this being mentioned. But they claim not to have a patent
issue with Chevron.



> Zeke Yewdall <[email protected]> wrote:
> 
> > And... cold weather performance may be significantly better, for those of
> > us
> ...


----------



## EVDL List (Jul 27, 2007)

They are only 9AH for their battery bank, so that's how they get around it.
It's only the larger than 12AH or so NiMH that infringe on the Chevron
patent, to my understanding.

Z



> Marty Mercer <[email protected]> wrote:
> 
> > For those guys still wanting NiMh chemistry, Nilar is now distributing
> > their
> ...


----------



## EVDL List (Jul 27, 2007)

> They are only 9AH for their battery bank, so that's how they get around
> it.
> It's only the larger than 12AH or so NiMH that infringe on the Chevron
> patent, to my understanding.
>

It's not a patent infringement, it's a license infringement. You can't
build NiMH without a license from Chevron, the terms of the license vary
but generally you are not allowed to build any batteries larger than 10-12
AH.
Some of the licensing agreements specifically prohibit making batteries
for electric vehicles.


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## EVDL List (Jul 27, 2007)

Man, I hate Chevron.... 



> Peter VanDerWal <[email protected]> wrote:
> 
> > > They are only 9AH for their battery bank, so that's how they get around
> > > it.
> ...


----------



## EVDL List (Jul 27, 2007)

they're doing it? <shrugs>



> Zeke Yewdall <[email protected]> wrote:
> 
> > Man, I hate Chevron....
> >
> ...


----------



## EVDL List (Jul 27, 2007)

you can hear Kurt Jensen from Nilar stumble through questions about the
patent issues. He's suppose to be their expert. Not the best speaker to
represent the company.

http://stadium.weblogsinc.com/autobloggreen/audiointerviews/EVS23-kurt-jensen.MP3



> Zeke Yewdall <[email protected]> wrote:
> 
> > Man, I hate Chevron....
> >
> ...


----------



## EVDL List (Jul 27, 2007)

My understanding is that even though the energy densities are similar, more
energy is "available" from flooded NiCads since they can be discharged to a
greater DOD without affecting battery life cycles.

Example:
Assume 25 mile range desired, 300 watts/mile
Energy needed = 25 * 300 = 7500 W

Available energy per battery = V * amp-hours * DOD

To obtain this with T-105 (6v, 225amp-hours C/20, 63lbs):
----convert C/20 to C/1 225 * .57 = 128 amp-hour at C/1 discharge rate
----for DOD most people recommend not going past 50% to often in order to
maintain battery longevity
----available energy = 6V * 128 amp-hour * .50 = 384 W-hr for each battery
----#bats = 7500W/384W =19.5 so twenty batteries
----#weight = 20 * 63lbs = 1260lbs
----#volts = 20 * 6V = 120V

To obtain this with NiCad Saft 4076(24V, 36Ah C/1, 83lbs)
----DOD can be 80%+ without affecting number of cycles
----available energy = 24V * 36Ah *.80 = 691 W-hr for each battery
----#bats = 7500W/691W = 10.8 so eleven batteries
----#weight = 11 * 83lbs = 913 lbs
----#volts = 11 * 24 = 264V (so to run a 132V system you would have two
parallel strings of batteries or one string of parallel batteries)

So you have a 1260lb 120V system vs a 913 lb 132V system (which should
probably be a 996 lb 142V system to divide the batteries into two equal size
strings).
If I'm misinformed please let me know.

Barry Oppenheim
New Hope, PA



-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf
Of Peter VanDerWal
Sent: Wednesday, July 16, 2008 7:57 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Flooded NiCad


> Can they be bought by John Doe and not Boeing? If so do you you know of
> any
> distributors?
>

Just so you're clear on this, these batteries weigh about the same as
Lead-Acid for the same basic performance/range. That is assuming you go
with the Fiber cells, The pocket plates cells weigh almost twice as much.

For example a 120V pack of KFM-120P will produce about the same 1 hr
output as a 120V pack of T-105 cells (at 100% DoD for each).
The KFM pack would weigh 1276lbs, the T-105s = 1260lbs

Their only significant advantages are a potentially longer life and the
fact that they don't mind 100% DoD or being left in a partially charged
state for long periods of time.

You're going to pay a premium for those advantages.

Granted they should last 4-5 times as long as lead-acids, but if they cost
4-5 times as much, that's no real advantage.
Plus NiCads generally require more frequent watering than PbA and tend to
have a lower energy efficiency, so your whs per mile will go up (higher
fuel -electricity- costs)

These kinds of NiCads make sense if you can get a supper deal on them, but
I'm not sure they are worth it if you have to pay retail.


_______________________________________________
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For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


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## EVDL List (Jul 27, 2007)

The right to License of course coming from owning the patent.
Unlike copyright, Patents have a limited life of 20 years.
I first saw NiMH about eight years ago.
Allowing a 3 year lead time from the granting of the patent to production 
that would make them in the eleventh year of the patent.
9 to go.
Tom Meyers

)SNIP(
> Man, I hate Chevron.... 
)SNIP(
>> > It's only the larger than 12AH or so NiMH that infringe on the Chevron
>> > patent, to my understanding.

>> It's not a patent infringement, it's a license infringement. You can't
>> build NiMH without a license from Chevron, the terms of the license vary
>> but generally you are not allowed to build any batteries larger than 
>> 10-12
>> AH.
>> Some of the licensing agreements specifically prohibit making batteries
>> for electric vehicles.


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----------



## EVDL List (Jul 27, 2007)

As I understand it, their current patent runs out in 7 years (2015)

> The right to License of course coming from owning the patent.
> Unlike copyright, Patents have a limited life of 20 years.
> I first saw NiMH about eight years ago.
> Allowing a 3 year lead time from the granting of the patent to production
> that would make them in the eleventh year of the patent.
> 9 to go.
> Tom Meyers
>
> )SNIP(
>> Man, I hate Chevron.... 
> )SNIP(
>>> > It's only the larger than 12AH or so NiMH that infringe on the
>>> Chevron
>>> > patent, to my understanding.
>
>>> It's not a patent infringement, it's a license infringement. You can't
>>> build NiMH without a license from Chevron, the terms of the license
>>> vary
>>> but generally you are not allowed to build any batteries larger than
>>> 10-12
>>> AH.
>>> Some of the licensing agreements specifically prohibit making batteries
>>> for electric vehicles.
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
>



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## EVDL List (Jul 27, 2007)

Saft has EV size NiMh batteries listed on their site (6 -12 v, 34- 200Ah).
http://www.saftbatteries.com/Technologies_Nickel_NiMH_329/Default.aspx

Barry Oppenheim
New Hope, PA

-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf
Of Zeke Yewdall
Sent: Wednesday, July 16, 2008 6:02 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Flooded NiCad


They are only 9AH for their battery bank, so that's how they get around it.
It's only the larger than 12AH or so NiMH that infringe on the Chevron
patent, to my understanding.

Z



> Marty Mercer <[email protected]> wrote:
> 
> > For those guys still wanting NiMh chemistry, Nilar is now distributing
> > their
> ...


----------



## EVDL List (Jul 27, 2007)

I wonder if they can sell them in the US?

On Wed, Jul 16, 2008 at 5:47 PM, Barry Oppenheim <[email protected]>


> wrote:
> 
> > Saft has EV size NiMh batteries listed on their site (6 -12 v, 34- 200Ah).
> > http://www.saftbatteries.com/Technologies_Nickel_NiMH_329/Default.aspx
> ...


----------



## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

Where did you find used ones?

Z



> shred <[email protected]> wrote:
> 
> >
> > I bought some used Saft NiMH water cooled batteries and love them.
> ...


----------



## EVDL List (Jul 27, 2007)

There are some practical advantages to NiCd batteries that aren't 
immediately apparent. 

1. They are very sturdy and handle overcharge and overdischarge much better 
than lead batteries. They LIKE to gas, and Saft explicitly says that you 
can reverse cells with little damage (though they say "don't make a habit of 
it").

2. You can store them in any state of charge. They don't sulfate like lead 
batteries do when stored partly charged or flat.

3. They lose very little capacity at low temperatures. 

4. Their operating voltage is very stable, declining only slightly 
(appreciably less voltage slope than lead's discharge curve), until it falls 
off the cliff as the battery approaches flat. 

5. Many of them *do* have significantly better specific energy than lead 
batteries. This is not true of the BB-600 aircraft (?) batteries that some 
EVers use; they're about equal to lead in this regard. However, Saft's EV 
batteries (very hard to get now, alas) have a specific energy of 55 Wh/kg, 
compared to 28-36 Wh/kg for typical lead deep cycle batteries.

6. Life is excellent. Cycle life of 1500-3500 cycles and calendar life of 5-
20 years is not uncommon. 

The negatives:

1. Lower charge efficiency, 80-85% compared to lead's 90-95%.

2. They don't like heat. They lose cycle life if operated at ambient 
temperatures over about 95 deg F for too long or too often. NiCd batteries 
are outstanding for EVs in cool northern areas, however.

3. They require relatively specialized charging gear. Their chargers aren't 
as common as lead battery chargers, and they're usually more expensive 
(partly because NiCds aren't a commodity item like lead batteries, nor are 
the chargers).

4. They're expensive! This is again partly because of their non-commodity 
status; EV size NiCd batteries are produced in very limited quantities. 
However, as I understand it (please correct this if I err) cadmium is also 
not a very plentiful element, and this contributes to their cost. Finally, 
Saft NiCd batteries are (or were) produced in Europe, and the value of the 
US dollar against the Euro works against us for dollar pricing.

5. Some specific Saft NiCd batteries (type STM5-*MR[E]) can be ruined by 
excessive current on discharge. You absolutely have to adhere to the 
published limits on current and duration (and for certain production runs, 
be even more restrictive than that).

6. Cadmium is a heavy metal and the EU has fairly strict regulations which 
(as I understand it) make NiCds very difficult to manufacture in Europe and 
/ or for European sale.

-----

My opinion, and I think Bill Dube' will agree with this (he uses them in his 
Wabbit) : Except for the fact that they're flooded and require watering, 
NiCd batteries are about as hassle-free for EV use as you can get, providing 
that you use them within their specifications and limitations (as you 
obviously must with ANY battery). 

NiMH batteries eliminate the cadmium issues (cost and regulation) and 
they're even better for specific energy. They've proven themselves well in 
RAV4-EV use, with several such vehicles pasing 100,000 miles on the original 
battery. 

But they are not available in EV sizes.

For some years, NiCd batteries were reasonable substitutes for NiMH EV 
batteries. Now, alas, theyre becoming nearly as hard to obtain.

David Roden
EVDL Administrator
http://www.evdl.org/



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For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

On Wed, 16 Jul 2008 14:35:01 -0700, "Marty Mercer" <[email protected]>


> wrote:
> 
> >For those guys still wanting NiMh chemistry, Nilar is now distributing their
> >NiMh through http://www.pluginconversions.com/ for EV applications. Not
> ...


----------



## EVDL List (Jul 27, 2007)

"They require relatively specialized charging gear"

Is a PFC20/30 an acceptable charger?

Barry Oppenheim
New Hope, PA

-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf
Of EVDL Administrator
Sent: Wednesday, July 16, 2008 9:14 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Flooded NiCad


There are some practical advantages to NiCd batteries that aren't
immediately apparent.

1. They are very sturdy and handle overcharge and overdischarge much better
than lead batteries. They LIKE to gas, and Saft explicitly says that you
can reverse cells with little damage (though they say "don't make a habit of
it").

2. You can store them in any state of charge. They don't sulfate like lead
batteries do when stored partly charged or flat.

3. They lose very little capacity at low temperatures.

4. Their operating voltage is very stable, declining only slightly
(appreciably less voltage slope than lead's discharge curve), until it falls
off the cliff as the battery approaches flat.

5. Many of them *do* have significantly better specific energy than lead
batteries. This is not true of the BB-600 aircraft (?) batteries that some
EVers use; they're about equal to lead in this regard. However, Saft's EV
batteries (very hard to get now, alas) have a specific energy of 55 Wh/kg,
compared to 28-36 Wh/kg for typical lead deep cycle batteries.

6. Life is excellent. Cycle life of 1500-3500 cycles and calendar life of
5-
20 years is not uncommon.

The negatives:

1. Lower charge efficiency, 80-85% compared to lead's 90-95%.

2. They don't like heat. They lose cycle life if operated at ambient
temperatures over about 95 deg F for too long or too often. NiCd batteries
are outstanding for EVs in cool northern areas, however.

3. They require relatively specialized charging gear. Their chargers aren't
as common as lead battery chargers, and they're usually more expensive
(partly because NiCds aren't a commodity item like lead batteries, nor are
the chargers).

4. They're expensive! This is again partly because of their non-commodity
status; EV size NiCd batteries are produced in very limited quantities.
However, as I understand it (please correct this if I err) cadmium is also
not a very plentiful element, and this contributes to their cost. Finally,
Saft NiCd batteries are (or were) produced in Europe, and the value of the
US dollar against the Euro works against us for dollar pricing.

5. Some specific Saft NiCd batteries (type STM5-*MR[E]) can be ruined by
excessive current on discharge. You absolutely have to adhere to the
published limits on current and duration (and for certain production runs,
be even more restrictive than that).

6. Cadmium is a heavy metal and the EU has fairly strict regulations which
(as I understand it) make NiCds very difficult to manufacture in Europe and
/ or for European sale.

-----

My opinion, and I think Bill Dube' will agree with this (he uses them in his
Wabbit) : Except for the fact that they're flooded and require watering,
NiCd batteries are about as hassle-free for EV use as you can get, providing
that you use them within their specifications and limitations (as you
obviously must with ANY battery).

NiMH batteries eliminate the cadmium issues (cost and regulation) and
they're even better for specific energy. They've proven themselves well in
RAV4-EV use, with several such vehicles pasing 100,000 miles on the original
battery.

But they are not available in EV sizes.

For some years, NiCd batteries were reasonable substitutes for NiMH EV
batteries. Now, alas, theyre becoming nearly as hard to obtain.

David Roden
EVDL Administrator
http://www.evdl.org/



_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


No virus found in this incoming message.
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9:56 AM


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----------



## EVDL List (Jul 27, 2007)

> Barry Oppenheim wrote:
> > "They require relatively specialized charging gear"
> >
> > Is a PFC20/30 an acceptable charger?
> ...


----------



## EVDL List (Jul 27, 2007)

> On 17 Jul 2008 at 10:40, Christopher Zach wrote:
> 
> > An Elec-trak's "dumb as toast" ferro-resonant transformer is just fine
> > to be honest.
> ...


----------



## EVDL List (Jul 27, 2007)

> Peter VanDerWal wrote:
> >> They are only 9AH for their battery bank, so that's how they get around
> >> it.
> 
> ...


----------



## EVDL List (Jul 27, 2007)

> On 17 Jul 2008 at 9:55, Barry Oppenheim wrote:
> 
> > "They require relatively specialized charging gear"
> >
> ...


----------



## EVDL List (Jul 27, 2007)

> EVDL Administrator wrote:
> > On 17 Jul 2008 at 10:40, Christopher Zach wrote:
> >
> >> An Elec-trak's "dumb as toast" ferro-resonant transformer is just fine
> ...


----------



## EVDL List (Jul 27, 2007)

> On 17 Jul 2008 at 12:27, Christopher Zach wrote:
> 
> > I would love a set of STM5-100's for the Prizm. Of course I need 50 of
> > them.......
> ...


----------



## EVDL List (Jul 27, 2007)

> EVDL Administrator wrote:
> > On 17 Jul 2008 at 12:27, Christopher Zach wrote:
> >
> >> I would love a set of STM5-100's for the Prizm. Of course I need 50 of
> ...


----------



## EVDL List (Jul 27, 2007)

>Although there is at least one Elec-trak owner
>who managed to squeeze 6 ST5-180's into an Elec-trak
>in place of the
>T105's and charges with the on-board charger.

Zack, 
That might have been me,
http://picasaweb.google.com/rodnhower/ElecTrak
My ET is sitting by the storage shed and hasn't been
used for awhile, I have to much other stuff going on.
I threw the ET charger in the recycle bin soon after
purchasing the tractor. I've always used a TEVan
charger on my ET and golf cart,
http://picasaweb.google.com/rodnhower/ElectricVehicle/photo#5186514997314813890
Which has 8 STM-180 batteries.
They've been in there for 10 years now and I only
watered them once (the electrolyte goes well above the
minimum fill line still). The TEVan charger was
designed for a 180V or 30 battery pack and is no
smarter than a Rudman charger on my golf cart. I
babysit the charge cycle and watch for a peak voltage
before shutting it off. It takes less than half the
time to charge as drive since the TEVan charger puts
out 55 amps at this voltage. All of the batteries are
still within about 50mV or less. My charge cycle is
similar to the Prius, I almost never overcharge and
probably only put in less than 100% (instead of 130%
to get full capacity). I also have several BB-600's
that I want to try out at 72Vdc, just to hot rod the
golf cart, but other projects leave little time for
this.
Rod


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