To provide a power supply system with a charge balancing function.

A power supply system includes a first charge storage. A series circuit with a number (n) of charge storage modules is connected between load terminals. A second charge storage includes load terminals. A charge transfer arrangement includes at least one charge transfer unit coupled between one of the charge storage modules and the load terminals of the second charge storage. The charge transfer arrangement is configured to transfer upon request electrical charge from the one charge storage module to the second charge storage.