What is the best way to check the amp draw? And what should it be for the motor and battery combo? I'm wanting to get the 2100 15c lipo thunder power/2100 15c dymond modelsports or there is a 2200 12c from parkzone. Could you use 7.4 2 cell 2200 instead of 11.1 3 cell listed before and save weight and flying time? I'm using the 4200kv 400 can motor 20amp e-flite speed control as listed in the building manual, with the exception of the 12 tooth pinion instead of the 10 on the motor.