Get the most from a "spec" NiCD pack ?
 

A few months ago I began racing in a "spec" touring car class that includes hand out 2000Mah NiCD batteries (6 cell 7.2V). It has been a while since I really tried to get the most from these packs and have been struggling at each event. These are low grade, sport, NiCD batteries .... however it seems to me that others may be getting more from their batteries than I do (run time and punch). Anyway, I was curious if someone could help refresh my memory on the best way to charge and discharge. Thanks.

U got pm

In general nicads need to be discharged all the way every time, right after your run. Not familiar with that battery, but I would suggest discharging at 20 amps, maybe more. At least with the 1200-1700 Sanyo nicads I used back in the day, discharging them at a high rate increased voltage under load after a few cycles. What was called pushing or training. Which is where matching cells started I believe, so you could discharge hard without damaging weaker cells.

And the higher you charge them, the better the punch will be as well. Suggest a 6 amp charge, try to have them peak about 10-15 minutes before the race, then repeak at 8 amps right before hitting the track. Or higher at the risk of reduced run time and battery life, but more punch.

Store them discharged. Some would dead short them before charging, but I think that depended on which nicad. I discharged to 0.5 volt per cell with good results.

Of course with all of this weak cells do not survive. If I remember correctly back in the day my battery matcher would start with 5 cycles to train them before matching, and some didn't survive. But the ones that did performed much better. So I guess if you can't open the packs to rematch you might have to lower the amperage some, but at least be sure to discharge them all the way every time.
Good luck!

Very helpful info .... Thanks !

I was always told never to discharge nicads past .7v per cell, due to cell reversal (polarity flips-creates a short). Nimh (up to GP3700) were able to be stored with a dead short prior to the IB cells that showed up. When the IB Cells took over people started to dead short and were not able to get batteries back to charge. Follow this link to learn more about batteries.

Hope this helps,
Cesar