Patent ID: 7535195
Filing Date: 2009-05-19
Classification: H01M,H02J,Y02E

Abstract:
1. A method of charging a battery and powering a load, comprising: setting a first variable to represent a maximum source current available from a power source; setting a second variable to represent a maximum rate of charge for the battery; employing a state machine to calculate a first battery charging control signal that indicates a first current value that represents a maximum charging current for the battery based upon the first variable and the second variable; employing the state machine to calculate a second battery charging control signal that indicates a second current value that represents a threshold load current based upon the first variable and the second variable; supplying a current to the load via a power supply circuit; and supplying an actual charging current to the battery by providing the first battery charging control signal and the second battery charging control signal to the power supply circuit, wherein the actual charging current is based, at least in part, on a sensed magnitude of the load current such that if the load current is less than the threshold load current, the actual charging current is not greater than the maximum charging current; and such that if the load current is greater than the threshold load current, the actual charging current is not greater than the difference between the maximum source current and the load current.