A battery characteristic converter comprises an interface to a battery and to an electronic device to be powered with energy supplied by the battery. The interface to the battery and the interface to the electronic device are connected using a bidirectional voltage ratio converter. The bidirectional voltage ratio converter is controlled so that the characteristics at the interface to the electronic device are adapted to the electronic device, independently of the battery characteristics. Energy may flow to the electronic device to power the electronic device or from the electronic device to the battery to charge the battery, depending on a comparison of the characteristics at the interfaces.