Abstract: A battery pack (12) comprises current sensor (28) for sensing the charge current through a battery cell (26), and generating a DC voltage which is sensed by a charger (14). The charger can then provide an output current that satisfies both the need for a constant charge current through the battery cell or cells, and the varying current demand of a load (10). Additionally, the battery pack may include a switch (34) for removing the current sensor from the discharge path of the battery cell or cells and the load when the battery pack is not connected to the charger.