POWER SUPPLY DEVICE FOR VEHICLE AND CONTROL METHOD FOR THE SAME

The power supply device includes a low voltage battery, a high voltage battery, a starter generator, a DC-DC converter, a changeover switch, and a controller. When an abnormality or a failure has occurred in the DC-DC converter, the controller controls the changeover switch to connect the starter generator to the other battery without via the DC-DC converter and controls the output of the starter generator corresponding to the connected other battery.