To reduce the charging time required for charging, there is provided a battery pack comprising a battery cell that supplies current to an electronic apparatus which is connected thereto or is charged by the supply of current from other power source, and a chargedischarge control section that controls the charging operation of the battery cell. The converter comprises m partial converters, each of the partial converters is composed of p units and each of these units is provided with nm switching circuits. The circuit further includes a device providing protection from electrostatic discharges which includes an integrated resistive device coupled between the input and output terminals.