# Voltage questions



## major (Apr 4, 2008)

Markijohn said:


> Background:
> I have a vehicle I acquired from my undergraduate college. If anyone is familiar with the Formula Lightning racing series from the early 2000's, it is one of those cars (I will post pics and a build thread at some point). The vehicle uses the motor out of the Chrysler EPIC minivan. This was an EV Chrysler did around that time. Somehow my school acquired the motor and controller from Chrysler, this was before my time. This motor is an AC motor. They got away from the Chrysler controller and went with a controller from Flux Vector (who since sold their company elsewhere). This controller and motor combo used 350V when we ran it back in the day. We had 28 yellow tops that supplied the voltage. I have all of these batteries, but they are at least 10 years old and have not been used in at least 4. I believe the spec on the controller is 200-400 VDC for operation.
> 
> Question:
> ...


A full power DC/DC boost converter is a bad idea.

The Volt battery at ~16kWh is more than the original 28 Optimas would have delivered by a long shot. What's wrong with that 

What do you intend to do with this racer?


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## Markijohn (Feb 7, 2014)

By far better than the Optima, I know. And I assumed as much on the converter. 

Ideally - drive it! I am looking to license it in NC and be able to drive it into work. Work unfortunately is 25ish miles one way and on a military base and I'm thinking they won't install a charger for me. The ultimate goal was 100 mile range, but $ is the biggest factor, as w/ any project.

Outside of just driving to and from work on a single charge, I would like to take it to the track, possibly do some autocross or anything. Not looking to set records, just have fun w/ it.


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## McRat (Jul 10, 2012)

If the AGM's were stored charged, they might be usable. Probably not though.


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## Markijohn (Feb 7, 2014)

I was thinking about trying to build a desulfator and going to town on them, but that will take a very long time, and is it really worth it? I'd rather upgrade. I would def. not be able to drive to work and back on those lead acids.


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## McRat (Jul 10, 2012)

Markijohn said:


> I was thinking about trying to build a desulfator and going to town on them, but that will take a very long time, and is it really worth it? I'd rather upgrade. I would def. not be able to drive to work and back on those lead acids.


Check voltage on batteries. If <11.9vdc, forgettabouttit...


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## Markijohn (Feb 7, 2014)

McRat said:


> Check voltage on batteries. If <11.9vdc, forgettabouttit...


Yea, most are bad. Some are decent enough to throw in my boat or use as tailgating power!


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## PStechPaul (May 1, 2012)

Lead batteries are good for tractors. Are these the 75 A-h 60 pound batteries like this:
http://d26maze4pb6to3.cloudfront.net/optimabatteries/4713/4583/5068/YELLOWTOP_Full_Specs_Sheet.pdf

If you were closer, I'd be interested in maybe 20 of these for a small tractor project, although 1200 pounds might be too much for what I have now. If you plan to be in the Baltimore, MD vicinity anytime in the next few months, I'd be willing to take some off your hands.

I am working on a DC-DC converter good for about 1000-2000 watts that should run on 48V battery packs. That would be enough for my tractor with four batteries. It should give about 3000 W-h (maybe 1500 usable) but that should provide 2 HP for an hour, which is plenty.

If my converter is successful, several of them could be connected in series/parallel to get higher power. I think they can be built for $50-$100 each so you might be able to get 15kW from a smaller lithium pack, maybe 15 x 200 A-h or 10 kW-h which would give you maybe 30 miles range at 300 W-h/mile. You probably need twice that, but the converters might give you more options than a 250-350 VDC battery pack.

I was at the KOA in Boone, NC in September 2012 and I've also been to the Outer Banks several times. A pretty long drive but some beautiful country.


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## RIPPERTON (Jan 26, 2010)

1994-2004
230kmh with in race battery swaps. !!!!!!
Jesus you yanks are good at keeping secrets

http://www.youtube.com/watch?v=F6qjJWFRrlI


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## Markijohn (Feb 7, 2014)

PStechPaul said:


> Lead batteries are good for tractors. Are these the 75 A-h 60 pound batteries like this:
> http://d26maze4pb6to3.cloudfront.net/optimabatteries/4713/4583/5068/YELLOWTOP_Full_Specs_Sheet.pdf
> 
> If you were closer, I'd be interested in maybe 20 of these for a small tractor project, although 1200 pounds might be too much for what I have now. If you plan to be in the Baltimore, MD vicinity anytime in the next few months, I'd be willing to take some off your hands.


They are the 75 AH, 60LB batteries, but are 10 years old. Not sure they're good for more than some simple around the house tasks (we used these recently for our wedding on the beach, gave power to the DJ during the ceremony). I don't foresee a trip to Maryland in the near future, but will probably have these things for a while.



> I am working on a DC-DC converter good for about 1000-2000 watts that should run on 48V battery packs. That would be enough for my tractor with four batteries. It should give about 3000 W-h (maybe 1500 usable) but that should provide 2 HP for an hour, which is plenty.
> 
> If my converter is successful, several of them could be connected in series/parallel to get higher power. I think they can be built for $50-$100 each so you might be able to get 15kW from a smaller lithium pack, maybe 15 x 200 A-h or 10 kW-h which would give you maybe 30 miles range at 300 W-h/mile. You probably need twice that, but the converters might give you more options than a 250-350 VDC battery pack.


I will need to sit down and calculate total power consumption and peak draw to see what power requirements I'd need out of a converter. I believe just getting the $ to buy enough batteries is probably my best option.



> I was at the KOA in Boone, NC in September 2012 and I've also been to the Outer Banks several times. A pretty long drive but some beautiful country.


I'm sitting in the Outer Banks as I type! My wife's parents had never been here, so we drove up yesterday. We got engaged on Jockeys Ridge 3 years this Tuesday.


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## Markijohn (Feb 7, 2014)

RIPPERTON said:


> 1994-2004
> 230kmh with in race battery swaps. !!!!!!
> Jesus you yanks are good at keeping secrets
> 
> http://www.youtube.com/watch?v=F6qjJWFRrlI


Awesome find! I've never searched for the series on YouTube. That is Ohio State's car (we were Ohio University), they would always win because they had a TON of money to play with. OU had a much smaller budget to work with. 

Unsure if it's true, but I heard that OSU blew up their motor a day before the race, had a helicopter fly their motor back to campus, rebuild it, and flew it back in. Yea, they had money!

Here are some of my own videos I took back when I had our car running:

http://www.youtube.com/watch?v=f0dr8MzJOHY

http://www.youtube.com/watch?v=DLBdtqBTZoU


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