1) don't store the batteries fully charged over 12 hours
2) if storing for an extended period discharge to 6.6v for the pack
3) charge the batteries up right before you race
4) cycle the batteries once a month

If the above doesn't work and your packs still puff, buy new packs.

SMC is starting to get a negative reputation. Many racers have seen their packs "puff."

My advise is simple, buy thunderpower. They might have the occassional issue, but overall they seem to be better quality.

I wish SMC apologists would stop blaming the racers. I have seen many a local racer with both smc and thunderpower packs (same racer,) and guess which packs have puffed? The racers are obviously taking care of the batteries the same way. If the issue is that smc batteries need "special" instructions, what's the point? Buy thunderpower and be done with it.