I've had excellent luck with 3s 1300mah and 2200 mah Turnigy batteries from Hobby King. My 7 lb Showtime runs with 4 2200's - 2 pair in series for 6s then parallel the pairs together for 4400mah. I just checked out Hobby Partz and their prices look as good, but with fixed price shipping ($4.95) for any size order it will be hard to beat them.