Wow thanks for all the responses guys!

Well. I'm using the Venom 1200's. I do suck at soldering.. maybe I'm overheating them. It wouldn't surprise me in the least if that was the case.
I'm useing the Duratrax Ice Charger.. I have charged a lot of batteries with it.. never had problems till the 'homemade' packs started.

I'm doing them in Series. so if pack is facing me...
- -
+ + +

with a wire on the opposies sites of the bottom. (One on -, one on +) Which I 'think' is correct.

thenewguy821: care to take a stab with my last set so I don't ruin them all? =)