A power supply system comprising: a first power supply circuit including a direct-current battery string for direct-current power and an inverter that is configured to convert direct-current power output from the direct-current battery string to alternating-current power, the first power supply circuit being configured to output first alternating-current power with use of the direct-current battery string and the inverter; a second power supply circuit including an alternating-current battery string for alternating-current power, the second power supply circuit being configured to output second alternating-current power with use of the alternating-current battery string and without the use of an inverter; and a control device configured to control the first power supply circuit and the second power supply circuit, wherein: the alternating-current battery string and the direct-current battery string are configured such that power transfer is performed between the alternating-current battery string and the direct-current battery string; each of the alternating-current battery string and the direct-current battery string includes multiple battery circuit modules connected in series; each of the battery circuit modules includes a battery, an output terminal that outputs a voltage of the battery, a first switch connected to the output terminal and connected in parallel with the battery, and a second switch connected in series with the battery; each of the battery circuit modules is configured such that the voltage of the battery is applied to the output terminal when the first switch is in an electrically disconnected state and the second switch is in an electrically connected state; and the control device is configured to adjust a state of charge of each of the alternating-current battery string and the direct-current battery string by the power transfer between the alternating-current battery string and the direct-current battery string before performing requested energy management. a first power supply circuit including a direct-current battery string for direct-current power and an inverter that is configured to convert direct-current power output from the direct-current battery string to alternating-current power, the first power supply circuit being configured to output first alternating-current power with use of the direct-current battery string and the inverter; a second power supply circuit including an alternating-current battery string for alternating-current power, the second power supply circuit being configured to output second alternating-current power with use of the alternating-current battery string and without the use of an inverter; and a control device configured to control the first power supply circuit and the second power supply circuit, wherein: the alternating-current battery string and the direct-current battery string are configured such that power transfer is performed between the alternating-current battery string and the direct-current battery string; each of the alternating-current battery string and the direct-current battery string includes multiple battery circuit modules connected in series; each of the battery circuit modules includes a battery, an output terminal that outputs a voltage of the battery, a first switch connected to the output terminal and connected in parallel with the battery, and a second switch connected in series with the battery; each of the battery circuit modules is configured such that the voltage of the battery is applied to the output terminal when the first switch is in an electrically disconnected state and the second switch is in an electrically connected state; and the control device is configured to adjust a state of charge of each of the alternating-current battery string and the direct-current battery string by the power transfer between the alternating-current battery string and the direct-current battery string before performing requested energy management. the alternating-current battery string and the direct-current battery string are configured such that power transfer is performed between the alternating-current battery string and the direct-current battery string; each of the alternating-current battery string and the direct-current battery string includes multiple battery circuit modules connected in series; each of the battery circuit modules includes a battery, an output terminal that outputs a voltage of the battery, a first switch connected to the output terminal and connected in parallel with the battery, and a second switch connected in series with the battery; a battery, an output terminal that outputs a voltage of the battery, a first switch connected to the output terminal and connected in parallel with the battery, and a second switch connected in series with the battery; each of the battery circuit modules is configured such that the voltage of the battery is applied to the output terminal when the first switch is in an electrically disconnected state and the second switch is in an electrically connected state; and the control device is configured to adjust a state of charge of each of the alternating-current battery string and the direct-current battery string by the power transfer between the alternating-current battery string and the direct-current battery string before performing requested energy management.