the ignition battery needs to be separate from the receiver and its battery. you put a switch between the ignition battery and the ignition unit. Just like you put a switch between the receiver battery and the receiver. When you go to fly you turn on both switches. this keeps the ignition fron introducing noise into the receiver. You use exactly the same type of switch. When the switch is ON you are ready to fly. With the switches in the off position, you use the charge jack to check voltage and charge the battery.