Patent ID: 7425816

Claim:
A combination comprising: a battery pack including a first battery terminal, a second battery terminal, a plurality of battery cells, each of the battery cells having a lithium-based chemistry and a present state of charge, the battery cells being coupled to at least one of the first battery terminal and the second battery terminal, and a battery microcontroller coupled to at least one of the first battery terminal and the second battery terminal, the microcontroller being operable to measure the present state of charge of at least one of the battery cells to produce battery cell present state of charge measurements; and a battery charger operable to supply a charging current to the battery pack, the battery charger including a first charger terminal configured to couple to at least one of the first battery terminal and the second battery terminal, the first charger terminal configured to supply charging current to the battery pack, a second charger terminal configured to couple to at least one of the first battery terminal and the second battery terminal, and a charger microcontroller coupled to the second charger terminal and operable to receive the battery cell present state of charge measurements from the battery microcontroller, the charger microcontroller also operable to supply the charging current to the battery pack in pulses, wherein each pulse includes a first time interval in which charging current is being supplied to the battery pack and a second time interval in which supply of charging current to the battery pack is suspended, the microcontroller being further operable to modify the first time interval of a pulse based at least in part on the battery cell present state of charge measurements received from the battery microcontroller.