Vehicle power supply device

Abstract

In this vehicle power supply device, a power storage unit (3) comprises a plurality of switches (SW1-SW4) that selectively switch between serial connection or parallel connection of a plurality of capacitors (C1-C3), and a voltage detection unit that measures the voltage across both ends of each of the plurality of capacitors (C1-C3). When a voltage detection unit (30) detects, as the voltage across both ends, a prescribed voltage at which at least one capacitor of the plurality of capacitors (C1-C3) is incapable of discharging further, a control unit (4) controls the plurality of switches (SW1-SW4) to connect in parallel, and thereby distributes the residual charge of at least one among the plurality of capacitors (C1-C3) to another capacitor, making it possible to supply power again to the load without charging again.