A vehicle power supply apparatus includes first and second power supply systems, an electrical conduction path, a switch, and a switch controller. The first power supply system includes a first electrical energy accumulator and an electric load. The second power supply system includes a generator and a second electrical energy accumulator. The switch is configured to be controlled to a turn-on state and a turn-off state. The turn-on state includes coupling the electric load and the second electrical energy accumulator to each other, and the turn-off state includes isolating them from each other. The switch controller controls the switch to the turn-on state on the condition that the generator has an abnormality, and afterwards controls the switch to the turn-off state.