Abstract: A battery charging device for charging a battery with power drawn via a wall plug includes a full-wave rectifier of four diodes, two first metal-oxide varistors (MOVs), and a capacitor. The two MOVs are connected in parallel with the lower diodes of the bridge. The capacitor is arranged to electrically couple the anodes of the lower diode to a chassis ground of the device. This configuration allows for isolation voltage (hi-pot) testing to be performed with the MOVs in place.