Electric Vehicle Project
Replacing the pack
March 2003, 2002
Updated September 2004

Well, life in EV-land is going fairly well. The Prizm's pack ran for a few months (it was 9 years old), then failed in October of 2002. Rather than replace the pack, I dropped it and checked the batteries.

A total of ten batteries had failed out of 50. Eight had lost one cell, one had lost two cells, and one had basically exploded. This explains why the range fell thru the floor; only one string was operational.

So I replaced the 10 batteries with 10 used batteries and closed the pack up. Range went back to 25 miles, but was still somewhat shakey. The pack lasted most of the winter before dropping once again to only 10 miles, then five.

Apparently another battery had blown.

So I bit the bullet and spent a total of $2,500 on batteries for the car. 52 "nearly new" Genesis batteries are currently being charged in the driveway. I expect to replace the pack this weekend, assuming good weather. Which is just in time, the pack (what is left of it) can barely generate 25kw of power. Which is barely enough to make it to the train station and back.

I hope these batteries are good. Because if they blow up I will not be happy :-)

Postfix:

I installed the pack in March of 2003. Boy what a difference; the car ran for 30 miles without a problem. Charged fast with the MagneCharger; put about 6,000 miles on the pack in a year.

And totally blew the pack up. What happened was that I was able to drive the car even up to Hagerstown MD (with a stop along the way in Frederick) which was a 45 mile drive. In the fall the pack started dropping range seriously. It went from 35 to 25 to 20 miles tops. Over the winter I only took it 15 miles or so, but I noticed that the pack would start out strong and once I hit 300 volts at 60 amps (around 12 miles) the pack would fall to 250 volts like a *ROCK* within 5 miles.

This spring I took the pack down and replaced it again. I looked at the old batteries; they looked fine but what happened is they were out of water. This made the electrolyte *very* strong, which gave incredible power. However when they ran out of electrolyte, they crashed like bricks.

I put in 20cc of water per cell using a syringe that pressed aganst the battery vent tops. The run time went up a bit for capacity, but more importantly the batteries didn't drop like bricks. My guess is that I wound up drying the pack out by charging too fast and too high a voltage using the MagneCharger. 375 volts and 18 amps rate was enough to toast the pack.

Lesson learned.

Chris Zach