Apparatus and method with active balancing circuit and active balancing algorithm for charging and discharging secondary batteries connected in series

An active balancing control apparatus and method with an active balancing algorithm to charge and discharge a plurality of batteries connected in series. The active balancing control apparatus may be designed to simultaneously charge and discharge a plurality of batteries, connected in series and having different charge/discharge characteristics, using an active balancing circuit. The apparatus may perform switching to achieve balancing of each of the batteries so that all the batteries may be charged at a maximum voltage.