Patent ID: 8823320

Claim:
A vehicle charging system, comprising: a drive battery for supplying power to a running motor of a vehicle; an auxiliary battery for supplying power to auxiliary equipment of the vehicle; and a drive battery charging device for charging the drive battery by receiving power from an external power source, wherein: the drive battery charging device comprises: a control section; and a power source circuit for supplying power to the control section; and the power source circuit comprises: a power converter which is connected to a plurality of power sources including the external power source, and supplies power from each of the plurality of power sources to the control section; and a switch for switching ON/OFF of a connection between each of the plurality of power sources and the power converter, wherein the control section detects amounts of power supplied from each of the plurality of power sources and selects at least one of the plurality of power sources as a power source to power the control section based on the detected amounts of power.