A combination including a battery pack and a battery charger operable to
supply a charging current to the battery pack. The battery pack includes
a plurality of battery cells having a lithium-based chemistry and a
present state of charge. The battery pack also includes a battery
microcontroller that is 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. The battery charger includes a charger
microcontroller that is operable to receive the battery cell present
state of charge measurements from the battery microcontroller. The
charger microcontroller is also operable to supply the charging current
to the battery pack in pulses, wherein each pulse includes a first time
interval where charging current is being supplied to the battery and a
second time interval where charging current is being suspended from the
battery.