Power tool charging system having battery reconditioning and battery capacity data updating functions

摘要

An improved charging system for preventing battery deterioration and for accurate indication of the remaining battery charge level includes an electric power tool (2) and a charger (1). The electric power tool (2) is provided with an internal rechargeable batteries (6) and a second controller (9). The charger (1) is provided with circuitry for charging, a microcomputer (19), and discharge circuitry which is comprised of a manually-operated battery refreshing button (25), a discharge relay (23) and a discharge resistor (24). Upon depression of the battery refreshing button (25), the microcomputer (19) causes the batteries (6) of the electric power tool (2) to be charged to a full level and discharged to a predetermined level twice. When the two-cycle operation of full charge and discharge is completed, the second controller (9) of the electric power tool (2) updates the remaining charge level of the batteries (6).