Patent ID: 8297391

Claim:
A power supply system provided with a plurality of power storage devices, comprising: a first voltage converting device arranged between a first power storage device and a load device for converting a voltage provided from said first power storage device and providing the converted voltage to said load device; a second voltage converting device arranged between a second power storage device and said load device for converting a voltage provided from said second power storage device and providing the converted voltage to said load device; and a control unit controlling said first and second voltage converting devices such that one of said first and second voltage converting devices operates and the other voltage converting device stops when a required power of the power supply system is smaller than a reference value, and controlling said first and second voltage converting devices such that both of said first and second voltage converting devices operate when said required power is equal to or larger than said reference value; wherein, when said required power is smaller than said reference value, said control unit stops the voltage converting device corresponding to one of said first and second power storage devices providing a lower output voltage than the other.