POWER SUPPLY SYSTEM FOR VEHICLE

The present invention provides an automotive electric power supply system that suppresses deterioration in service life of a first electricity storage apparatus and enables electric power that is generated by an alternator to be changed significantly so as to enable increases in a charging rate of the first electricity storage apparatus, and enable regeneration of vehicle braking energy and improvements in vehicle fuel consumption to be achieved. A first DC/DC converter is connected to a higher-voltage output terminal of a rectifier by means of alternator wiring, and a battery that supplies electric power to a load is connected to the first DC/DC converter. A second DC/DC converter is connected to the higher-voltage output terminal of the rectifier by means of alternator wiring, and an electrical double-layer capacitor is connected to the second DC/DC converter.