Thanks for the responses. I don't detect any heat at all right after coming off, even if practicing for 20 minutes straight. Was just considering getting some 2500mah 70C batteries since so little is drained during a heat (especially since the qualifiers are 6 minutes), but if the voltage starts to drop that quickly, I guess that won't be a good idea.

I would run the batteries down after the race, but I race weeknights and can't hang around for that long... nor do I think the employees want to hang out that late. Maybe I just need to get a charger with a better discharge rate.