A charging circuit and method for charging a lithium-ion cell or battery at a charging voltage that is varied during the charging of the cell or battery from a selected minimum charging voltage to a predetermined maximum charging voltage. The charging circuit includes a transformer for transforming line voltage applied to the primary winding thereof to a lower AC secondary winding voltage, the transformer being selected to limit secondary winding output current when the charging voltage is not less than the selected minimum charging voltage to a value not exceeding a selected upper limit for the lithium-ion cell; a rectifier sub-circuit connected to the secondary winding of the transformer for rectifying the secondary winding voltage; and a charge-voltage regulator sub-circuit connected to the rectifier sub-circuit for receiving the rectified secondary winding voltage and providing an output charging voltage that is limited to the predetermined maximum charging voltage.