A battery charger controller is coupled to DC output terminals of an AC-DC (or
DC-DC) adapter containing an AC-DC (or DC-DC) converter. A controlled current flow
path between input and output terminals of the battery charger controller circuit
is controlled to provide a substantially constant current to charge the battery
to a nominal battery voltage. When a constant voltage output of the said adapter
transitions to a value that limits available charging current to a value less than
programmed constant charging current, current flow drive for the controlled current
flow path is increased for a limited time interval. Thereafter, the controlled
current flow path gradually reduces charging current as the battery voltage remains
at its nominal battery voltage until the charge is complete or otherwise terminated.
