An omnipotent Li-Ion battery charger with multi-mode
controlled techniques is proposed in this paper. When
charger charges battery, the proposed techniques solve
battery polarity problems. Beside, utilizing variable current
source to control three-stage charging mode is safe. The
maximum efficiency of the proposed charger is about 79%.
The omnipotent charger can provide the output voltage from
2.2V to 4.2V precisely. The proposed charger provides
applications greatly and conveniently.