Onboard charging apparatus

An onboard charging apparatus comprising:

• a rotating electric machine that generates electric power by being rotated by motive power supplied from an engine that is mounted to a vehicle or kinetic energy of the vehicle that is traveling;
• and
• a plurality of main electric-power storage apparatuses that store generated electric power outputted from an output terminal of the rotating electric machine, wherein:
• the 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 plurality of 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 the vehicle;
• and
• the onboard charging apparatus comprises:
• a connecting unit that selectively connects, by switching control, the output terminal and any of high potential side terminals of the plurality of main electric-power storage apparatuses;
• and
• a switching control unit that 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 plurality of main electric-power storage apparatuses, based on an output voltage of the output terminal.