Provided is a battery charger. The battery charger comprises a power converter, an input power connector, and an output power connector. The input power connector is configured to be connected to a power source such that the input power connector is arranged between the power converter and the power source. The output power connector is configured to be connected to an electronic device such that the output power connector is arranged between the power converter and the electronic device. The battery charger further includes a power control relay configured to connect the power converter to the input power connector. The battery charger further includes a timer device configured to disconnect the power converter from the input power connector after a predetermined amount of time has elapsed.