A power supply system comprising: a chargeable and dischargeable first power storage device having one potential terminal, an other potential terminal, and a first chargeable voltage range; a chargeable and dischargeable second power storage device having one potential terminal, an other potential terminal, and a second chargeable voltage range lower than the first chargeable voltage range; a multiphase motor having a star-connected multiphase stator windings (120a, 120b, 120c) with a neutral point, the multiphase motor working to generate torque when the star-connected multiphase stator windings are energized, the neutral point being electrically connected with the one potential terminal of the second power storage device; a multiphase inverter including a plurality of switching elements (130a to 130f) connected with each other in bridge configuration to provide a high-side direct-current terminal and a low-side direct-current terminal, the high-side DC terminal being electrically connected with the one potential terminal of the first power storage device, the low-side DC terminal being electrically connected with the other potential terminal of the first power storage device, any one of the high-side and low-side DC terminals being electrically connected with the other potential terminal of the second power storage device; a switch having a control terminal and connected between the second power storage device and the neutral point; and a controller electrically connected with the plurality of switching elements (130a to 130f) and the control terminal of the switch, the controller working to turn on the switch and switch the plurality of switching elements on and off during the multiphase motor being activated to thereby: convert a voltage of the first power storage device into a multiphase alternating-current voltage so as to supply the multiphase AC voltage to the multiphase motor; and boost the voltage of the second power storage device to charge the first power storage device by the boosted voltage, the controller working to turn on the switch and switch the plurality of switching elements (130a to 130f) on and off during the multiphase motor being inactivated to thereby boost the voltage of the second power storage device to charge the first power storage device by the boosted voltage, the controller working to: maintain the switch on when a voltage charged in the first power storage device is lower than a threshold voltage; and turn off the switch when the voltage charged in the first power storage device is equal to or higher than the threshold voltage. a chargeable and dischargeable first power storage device having one potential terminal, an other potential terminal, and a first chargeable voltage range; a chargeable and dischargeable second power storage device having one potential terminal, an other potential terminal, and a second chargeable voltage range lower than the first chargeable voltage range; a multiphase motor having a star-connected multiphase stator windings (120a, 120b, 120c) with a neutral point, the multiphase motor working to generate torque when the star-connected multiphase stator windings are energized, the neutral point being electrically connected with the one potential terminal of the second power storage device; a multiphase inverter including a plurality of switching elements (130a to 130f) connected with each other in bridge configuration to provide a high-side direct-current terminal and a low-side direct-current terminal, the high-side DC terminal being electrically connected with the one potential terminal of the first power storage device, the low-side DC terminal being electrically connected with the other potential terminal of the first power storage device, any one of the high-side and low-side DC terminals being electrically connected with the other potential terminal of the second power storage device; a switch having a control terminal and connected between the second power storage device and the neutral point; and a controller electrically connected with the plurality of switching elements (130a to 130f) and the control terminal of the switch, the controller working to turn on the switch and switch the plurality of switching elements on and off during the multiphase motor being activated to thereby: convert a voltage of the first power storage device into a multiphase alternating-current voltage so as to supply the multiphase AC voltage to the multiphase motor; and boost the voltage of the second power storage device to charge the first power storage device by the boosted voltage, convert a voltage of the first power storage device into a multiphase alternating-current voltage so as to supply the multiphase AC voltage to the multiphase motor; and boost the voltage of the second power storage device to charge the first power storage device by the boosted voltage, maintain the switch on when a voltage charged in the first power storage device is lower than a threshold voltage; and turn off the switch when the voltage charged in the first power storage device is equal to or higher than the threshold voltage.