Patent attributes
In an onboard charging apparatus, a plurality of main electric-power storage apparatuses are connected in series to one another. A main electric-power storage apparatus on a lowest potential side of the main electric-power storage apparatuses is a lowest potential electric-power storage apparatus. The lowest potential electric-power storage apparatus has a nominal voltage that is set to 12 V, and supplies electric power to an electrical component mounted to a vehicle. In the onboard charging apparatus, a connecting unit selectively connects, by switching control, the output terminal and any of high potential side terminals of the main electric-power storage apparatuses. A switching control unit controls switching of the connecting unit to switch the high potential side terminal selected as a connection destination of the output terminal among the high potential side terminals of the main electric-power storage apparatuses, based on an output voltage of the output terminal.