RE: Hobbico LiFeSource for 50cc?
You have to find out the maximum current draw when going from one stop to the opposite stop. Contact the servo company. Multiply that by the maximum # of servos you really can cause that to happen. That would be your worst case amperes in a stunt. Your servo leads & any extensions may be too small to carry full current & allow full volts AT THE SERVO.
Especially be concerned about any " Y " servo setups.