REDUNDANT POWER SUPPLY SYSTEM

The redundant power supply system, in which a predetermined power is supplied via a first DC-DC converter (DDC) to a first battery and a first load of a primary system and the predetermined power is supplied via a second DDC to a second battery and a second load of a secondary system independent of the primary system, includes: a first switching element interposed between the second DDC and the second battery; a first diode which is connected in parallel to the first switching element and performs rectification in a direction from the second battery toward the second DDC; and a control section which turns off the first switching element when the second battery is in a first state where a stored power amount thereof is not smaller than a predetermined first threshold value, and turns on the first switching element when a state other than the first state is assumed.