Power supply apparatus and utilizing same electric vehicle

A power supply apparatus for a vehicle, comprising: a first battery unit (10); a second battery unit (60) for a lower voltage than the first battery unit (10), an inverting circuit (30a), a voltage of the first battery unit (10) through switches (24a, 24b) inputs a smoothing capacitor (31) connected in parallel between the first battery unit (10) and the inverter (30a) is provided; a DC-DC converter (50) is provided between the smoothing capacitor (31) and the second battery unit (60) to electrical energy in the first battery unit (10) or the smoothing capacitor (31) is stored, to supply the second battery unit (60) spannungszuwandeln, and electrical energy which is stored in the second battery unit (60), spannungszuwandeln for the supply of the smoothing capacitor (31); an electronic control unit (80) the DC-DC converter (50) before starting the power supply to the inverter circuit (30a) so / that regulates the switches (24a, 24b) are closed after the smoothing capacitor (31) to a voltage within a ...