Patent ID: 7208915
Filing Date: 2007-04-24
Classification: H02J

Abstract:
1. A battery charger for charging a secondary cell, said charger comprising: a power supply configured to supply a charge current to said secondary cell; a controller including a current monitor which is configured to monitor a charge current being supplied to said cell and give a current signal indicative of the charge current; said controller configured to control said power supply for varying the charge current in accordance with said current signal from said current monitor; said controller calculating a current difference between a predetermined target current and the charge current being monitored, said controller generating a control signal of varying the charge current at a first charge current increasing rate when said current difference is out of a predetermined range, and varying the charge current at a second charge current increasing rate when said current difference is within said predetermined range, the first charge current increasing rate being set to be greater than the second charge current increasing rate; said controller generating said control signal repeatedly at predetermined intervals for varying the charge current.