There is provided a power supply for a vehicle, including a generator, a lead battery, an electric storage device that is connected in parallel to the lead battery and to the generator, a starter circuit that has a capacitor and a starter and is connected in parallel to the lead battery and to the generator, and at least two switches of a first switch connected in series to the lead battery, a second switch connected in series to the power supply, and a third switch connected in series to the starter circuit.