A storage battery system includes: electric storage units; and DC-DC converters each provided between one of the electric storage units and a DC bus. Each of the DC-DC converters includes: a voltage sensor for detecting a voltage value at a connection point between the DC bus and the DC-DC converter; a second obtainment unit which obtains voltage values detected by the voltage sensors of the other DC-DC converters; and a control unit which, when a difference value between a statistic of the voltage values obtained by the second obtainment unit and the voltage value detected by the voltage sensor is not less than a predetermined threshold value, changes the voltage value detected by the voltage sensor, and controls an amount of charge in and an amount of discharge from a corresponding one of the electric storage units to approximate the changed voltage value to a predetermined target value.