POWER SYSTEM FOR VEHICLE

The purpose of the present invention is to provide a power supply system for a vehicle, which can prevent the residual amount of a high-voltage battery from being significantly reduced without being informed by a user. In order to solve the problem, the power supply system is provided with: a voltage converter for connecting a low-voltage circuit in which a low-voltage battery is provided and a high-voltage circuit in which a high-voltage battery is provided; a charge control unit for performing auxiliary charge control that operates the voltage converter and charges the low-voltage battery with power in the high-voltage circuit; the BCM is used for receiving an opening operation or a closing operation performed by a user; and an auxiliary charging time point setting unit for setting an auxiliary charging time point. When the engine stop time does not reach the auxiliary charging permission period, the charging control unit performs auxiliary charging control at the auxiliary charging timing set by the auxili