Stay away from the cheap China cells, they tend to bloat, there are differences between cells from 'branded' names and the 'cheap super good' names. I have seen too many failures from the China made batteries. They claim 20C but heat up when you pull 20C. Stick with brands like Polyquest, Thunder Power, Flight Power or Hyperion. They use good cells from Korean, the seemingly leading cell manufacturer is ENERLAND.