A bidirectional two-phase chopper circuit boosts a voltage of direct-current power converted by an AC/DC converter to output it to a high-voltage battery and steps down a voltage of direct-current power being supplied to a low-voltage load unit from the high-voltage battery. A connector is connected to a quick charger supplying direct-current power. A connector is connected to a superquick charger supplying direct-current power having a higher voltage than that of the quick charger.