The method is disclosed of controlling a switch circuit which includes a first switching unit configured to switch between energy accumulation and energy release in a coil, and second switching units configured to connect or disconnect a plurality of corresponding storage batteries with the coil. The method comprises a first step of performing an operation to switch on the first switching unit and to switch off the second switching units; and a second step of performing an operation to switch off the first switching unit and to switch on only one of the second switching units.