A charger circuit for providing a charging current and voltage to a battery includes a power delivery unit and a capacitive power conversion circuit. The power delivery unit converts an input power to a DC voltage and current. The capacitive power conversion circuit includes a conversion switch circuit including plural conversion switches and being coupled with one or plural conversion capacitors, a regulation switch, and a conversion control circuit. In a current scaled-up charging mode, the DC current is regulated, and the conversion control circuit controls the connection of the plural conversion capacitors such that the charging current is scaled-up of the DC current substantially by a predetermined current scale-up factor. In a constant voltage linear charging mode, the conversion control circuit linearly controls the regulation switch to regulate the level of the charging voltage to a predetermined constant voltage level.