Working prPerfect Steerable Transfer Cartiple----KPX battery power rail car transport mold trolley 20 ton This kind of KPX battery power rail car transport mold trolley 20 ton is powered by battery, The battery is installed in the car, and supply DC electricity to the control system, which makes the car start, stop, go forward, back forward and so on.It is consist of battery, motor, reducer, cart frame, electric appliance, etc.