VEHICLE POWER-SUPPLY DEVICE

A power supply device for a vehicle includes a power storage device (4), a connector (34) to which a power cable can be connected from outside of the vehicle, an inverter (2) for operating a rotating electric machine, a coil (L1; L2; L12) provided separately from a stator coil of the rotating electric machine, and a connection switching unit (3; 3A; 3B; 3C) switching connection relations among the power storage device, the connector, the inverter, and the coil. In a first operation mode, the connection switching unit sets the connection relation such that electric power from the power storage device is supplied to the inverter and the rotating electric machine can be driven without using the coil, and in a second operation mode, the connection switching unit sets the connection relation such that the coil and the inverter are used to constitute a voltage conversion circuit and voltage conversion can be performed between a voltage of the connector and a voltage of the power storage device.