Patent ID: 8556017

Claim:
A vehicular power supply system in which a power unit comprising an electrical condenser and at least one electrical component is disposed within a case, the interior of the case is partitioned into a first cooling air passage and a second cooling air passage, cooling air is supplied to the first and second cooling air passages by cooling air supply means, the electrical condenser is cooled by cooling air flowing through the first cooling air passage, and the at least one electrical component is cooled by cooling air flowing through the second cooling air passage, wherein a duct member integrally comprising an intake passage part and an exhaust passage part is provided at one end of the case, an outlet opening of the intake passage part is connected to the upstream end of the first cooling air passage, an inlet opening of the exhaust passage part is connected to the downstream end of the second cooling air passage, and the downstream end of the first cooling air passage and the upstream end of the second cooling air passage are connected via an intermediate duct at the other end of the case, and the at east one electrical component comprises an inverter and a DC-DC converter arranged side by side in the vehicle width direction, and heat sinks extending downward from lower faces of the inverter and the DC-DC converter face the second cooling air passage.