A power supply system includes a plurality of voltage sources, a switch circuit that switches between a state in which the plurality of voltage sources are connected in series and a state in which the plurality of voltage sources are connected in parallel, and a voltage control circuit that boosts an input voltage. The switch circuit connects the plurality of voltage sources in series, supplies an output of the plurality of serially connected voltage sources to an output node of the voltage control circuit, thereafter connects the plurality of voltage sources in parallel, and supplies outputs of the plurality of parallel-connected voltage sources to the voltage control circuit, and the voltage control circuit boosts voltages of the plurality of parallel-connected voltage sources.