Patent ID: 7378819

Claim:
A method of charging one or more battery cells of a battery pack coupled to a battery charging apparatus, comprising: providing said battery pack as a replaceable battery pack of an information handling system coupled to said battery charging apparatus; receiving a charging current in said battery pack from said battery charging apparatus, said charging current having a first current value that is the full value of charging current provided to said battery pack by said battery charging apparatus; adjusting the duty cycle of said charging current after it is received in said battery pack to produce a pulsed pre-charging current having a second current value, said second current value being less than said first current value; and charging said one or more battery cells of said battery pack by first entering a pre-charging mode when a voltage of said one or more battery cells of said battery pack is below a low voltage threshold by controlling the duty cycle of said charging current after it is received in said battery pack from said battery charging apparatus to limit the level of said pulsed pre-charging current to said second current value that is lower than said first current value provided by said battery charging apparatus, and then entering a full charge mode when a voltage of said one or more battery cells of said battery pack reaches said low voltage threshold by increasing the duty cycle of said charging current after it is received in said battery pack from said battery charging apparatus to a higher duty cycle to allow said charging current from said battery charging apparatus having said first current value to be provided to said battery pack until said one or more battery cells are fully charged; wherein a duty cycle of said charging current is represented by t 1 /(t 1 +t 2 ), with t 1 representing time that current is on and t 2 representing time that current is off such that a duty cycle of 100% provides said full value of said charging current from said battery charging apparatus to said one or more battery cells, and such that a duty cycle of 0% stops flow of said charging current from said battery charging apparatus to said one or more battery cells.