I have no issues with the Turnegy lipos. I have a lot of them, mostly the NanoTech, but I have the regular ones as well. I have found that if you over discharge them or try and charge them too quickly, they do tend to puff. For the price, I am happy with them. I have had 3 out of about 20 that I would not fly with. Weak cell. I use those to bench test. and fly the rest. Several people here like the Zippy's as well. Make sure that you have more than one and an effective way of charging them.