Here in Australia there have been an increasing number of bad cell or damaged batteries from Hobby King.Warranty is available but they don't make it easy. I recently bought batteries from F3a Unlimited.They are a bit more expensive,but shipping cost is about the same and these were not only packed WELL but the service was excellent and the batteries the best I have seen both in condition on arrival but also in performance,they are light too.I have never used Thunder Power,can't justify the cost,but I have used Flight Power and the F3a are MUCH better. As they say "you pays your money and makes your choice"!!!
Other than a satisfied customer I have no connection with F3a Unlimited.
Dambuster.