# [EVDL] Lithium for an Elec-Trak?



## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> 
> > So the question is what kind of BMS would be best? The charger takes the
> > batteries to 42 volts at 20a, then tapers down to 2a at 44 and .5a at 45
> ...


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## EVDL List (Jul 27, 2007)

> Christopher Zach <[email protected]>wrote:
> 
> > I would like to try something small in the lithium world before blowing
> > $15k to put 100 100ah cells in my S10 truck. And if it catches fire I
> ...


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## EVDL List (Jul 27, 2007)

On 10/17/2011 5:18 PM, Chris Tromley wrote:
>


> Christopher Zach<[email protected]>wrote:
> >
> >> I would like to try something small in the lithium world before blowing
> >> $15k to put 100 100ah cells in my S10 truck. And if it catches fire I
> ...


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## EVDL List (Jul 27, 2007)

Hi Christopher, I recently did something similar to a E15. 

I found a pretty clean E-15 and decided to do my long desired lithium
pack/portable power and backup off grid inverter setup. In the end I
literally squeezed 24 of my oldish TS 90 ahr cells under the seat for 180
ahr at 38.4V nominal. These are the same size as the current 100s. It was a
very tight fit. The E-15 lost some weight (200 lbs) by doing that, but the
60 lb inverter helped being it back up a bit. 

I chose 2P12S in order to avoid overvoltaging the PM motors on the mowing
deck. I haven't rebuilt that deck yet so I'm still mowing using my lead acid
E-20, I'm hoping the lithium's full voltage of 40V will not overload the
deck mower. I also pushed the voltage in order to have a high enough voltage
to run the "48V" 4400W 120/240V inverter that I put under the front which
will run down to 36V. The inverter allows me to run my full shop and well
pump off the tractor when the power goes out, though I do turn off electric
heat to save the limited 7 kWhr of energy available in the tractor. For
longer outages the shops rooftop solar array can charge the batteries AC
coupled through microinveters and the Magnum inverter, though not at full
power due to "grid instability" errors.

As for regulators, the ones I currently like (Manzanita/Rudmans of course,
disclaimer I do work with them) were a bit pricey for me and not sitting
paid for in my shop. So I passed on the MM regs and went with the EV power
ones that I've used before and had extras. My opinion is that they have poor
environmental protection (the vias corrode through due to no back
protection) and some static sensitive issues requiring careful installation,
but overall I think the design is more reliable than the miniBMS units that
I also have here and were mentioned in this thread. The EVpower units
regulate at 3.6V, and don't mind going higher during equalize so long as I
keep cells well under the 4.1V fault level. I normally charge off solar to
3.65V average with a regulator that I made that ties into the error loop,
but I also have used the built in Electrak charger and I remember it's
finish voltage was not a problem. 

If anyone is curious to see pictures, I have them on my Google+ account but
they are not fully public. If you "follow" me I can add you to my EV circle
so you can see them. 



-----
-Otmar-

914 EV, California Poppy, Zilla research vehicle. 
http://evcl.com/914/

The Zilla factory is at:
http://manzanitamicro.com/

Zilla Support is still at: 
http://cafeelectric.com/Ssupport.php
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Lithium-for-an-Elec-Trak-tp3912607p3914308.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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