Design and implementation of lithium-ion/lithium-polymer battery charger with impedance compensation

In this paper, an impedance-compensated battery charger is presented to increase the effective capacity of the lithium-ion/lithium-polymer battery. The proposed charger adopts a pulsating current source associated with a pulsating voltage detector to dynamically estimate compensated impedance of battery. With this approach, the discharge-time is extended 12% and the overall battery capacitor is increased 10%. The experimental results based on a lithium-ion battery charger with 11.4V/2.4Ah battery capacity verify these significant improvements.