I had one of their 6s go bad after one run...Buy what you can afford, I fully understand that. For record i have destroyed 3 turnigy 3s batteries and i have 4 turnigy 4s LIHV batteries still sitting in an ammo can in my garage because something failed internally. If bought through hobbyking they expect you to eat the shipping cost even though they sent out a bad product.
Plugged it in the voltage metre and sent them photos. I got a new battery within a week and didnt have to send the old one in. Thought that was pretty good of them