Patent ID: 7880435

Claim:
A battery charger for charging a plurality of batteries, the battery charger comprising: a current source for supplying a source current; a plurality of bypass sections comprising first and second bypass sections; a plurality of sense sections comprising first and second sense sections; a feedback section for processing information from the plurality of sense sections; and a controller for modifying the source current based on the information from the feedback section, wherein: the first bypass section is adapted to couple to a first battery for diverting a first diverted current from the source current for clamping voltage across the first battery to a first clamp voltage; the second bypass section is adapted to couple to a second battery for diverting a second diverted current from the source current for clamping voltage across the second battery to a second clamp voltage; the first sense section is coupled to the first bypass section for determining at least one of the first diverted current and a first charge current coupled to the first battery; the second sense section is coupled to the second bypass section for determining at least one of the second diverted current and a second charge current coupled to the second battery; a plurality of temperature monitoring devices, wherein a first temperature monitoring device monitors a first temperature of the first battery at first predetermined time intervals, and a second temperature monitoring device monitors a second temperature of the second battery at second predetermined time intervals; and a plurality of PWM application sections for applying Pulse Width Modulation (PWM), wherein a first PWM application section is coupled to the first battery, and the first charge current is pulse-width modulated with a first temperature-dependent duty cycle (D 1 ) based on the first temperature obtained by the first temperature monitoring device, and a second PWM application section is coupled to the second battery, and the second charge current is pulse-width modulated with a second temperature-dependent duty cycle (D 2 ) based on the second temperature obtained by the second temperature monitoring device.