That really sucks I have puffed batts and while taking them apart I have punctured a cell and been able to throw it in my ammo box.

Lipos are very dangerous but if you treat them properly they are great.

What I do is do not balance charge. I just normal charge to about 95% of the pack ( about 4.15V/Cell) then let the pack sit while I charge the other ones. Then throw it on the balancer to finish charging very slowly.