In a power supply system, a rechargeable battery module including a rechargeable battery and a conversion circuit is connectable to a power supply bus. A positive electrode and a negative electrode of the rechargeable battery are individually connected to a primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to a secondary-side terminal pair of the conversion circuit. The power supply system includes a bus voltage setting unit that sets a bus voltage requirement value which is a voltage required for the power supply bus and a control unit that controls an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module becomes the bus voltage requirement value. The bus voltage setting unit sets the bus voltage requirement value such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit.

In a power supply system, a rechargeable battery module including a rechargeable battery and a conversion circuit is connectable to a power supply bus. A positive electrode and a negative electrode of the rechargeable battery are individually connected to a primary-side terminal pair of the conversion circuit, and the rechargeable battery is serially connected to a secondary-side terminal pair of the conversion circuit. The power supply system includes a bus voltage setting unit that sets a bus voltage requirement value which is a voltage required for the power supply bus and a control unit that controls an output voltage of the conversion circuit such that an output voltage of the rechargeable battery module becomes the bus voltage requirement value. The bus voltage setting unit sets the bus voltage requirement value such that an output voltage of the conversion circuit becomes not more than a rated voltage of the conversion circuit.