Abstract: A vehicle electric power supply apparatus includes first and second power sources connected in parallel to each other; a DC-DC converter connected between the first and second power sources; a switch connected in parallel to the DC-DC converter and connected between the first and second power sources; an opening and closing unit that is operable to open and close the switch; and a control unit that controls the DC-DC converter and the opening and closing unit. When an internal combustion engine is stopped, the control unit sets the switch to be OFF using the opening and closing unit, and the control unit causes the second power source to be discharged and the first power source to be charged until the output voltage of the second power source reaches a first voltage by electric power supply from the second power source to the first power source via the DC-DC converter.

Abstract: A vehicle electric power supply apparatus includes first and second power sources connected in parallel to each other; a DC-DC converter connected between the first and second power sources; a switch connected in parallel to the DC-DC converter and connected between the first and second power sources; an opening and closing unit that is operable to open and close the switch; and a control unit that controls the DC-DC converter and the opening and closing unit. When an internal combustion engine is stopped, the control unit sets the switch to be OFF using the opening and closing unit, and the control unit causes the second power source to be discharged and the first power source to be charged until the output voltage of the second power source reaches a first voltage by electric power supply from the second power source to the first power source via the DC-DC converter.