POWER SUPPLY SYSTEM

In a power supply system, a plurality of voltage converters have chargeable/dischargeable batteries connected to the respective primary sides and have respective secondary sides connected in parallel to each other. For each of the voltage converters, a voltage transformation rate is set such that the current measured by a primary side current measuring instrument is maintained within a first range between the discharge current maximum value of the batteries connected to the primary sides and the charge current maximum value of the batteries.