I have an sjm 400 v2 helicopter with a 30 amp speed control, 4000 mah 3 cell lipo 15c continuous, and a small 3950 kv outrunner motor. When I hover it for about 10 seconds it starts to lose power and I have to land. Then, once I wait for 30 sec. it gets full power again for another short flight. Obviously the battery is fine because I can keep getting the short flights; the battery is brand new and I charge it with the balacer. Could it be the speed control? There is no radio interferance because I have the dx7.