Method for counting charge and discharge cycle of smart battery

PURPOSE: A method for counting the charging/discharging cycle of a smart battery is provided to improve the calculating accuracy of the residual capacity of a battery by counting the charging/discharging cycle. CONSTITUTION: Determining whether or not the smart battery discharges is performed(301). If the smart battery is not in a discharge state, charging of the smart battery is performed(302). If the smart battery is in the discharge state, determining whether or not the discharge state is in a discharging interval(A,A') is performed(303). In cases the discharge state is in the discharging interval(A,A'), the number of passing is counted by 1(304); and, if otherwise, determining whether or not the discharge state is in a discharging interval(B,B') is performed(305). If the discharge state is in the discharging interval(B,B'), the number of passing is counted by 1(306); and, if otherwise, determining whether or not the discharge state is in a discharging interval(C,C') is performed(307). In cases the discharge state is in a discharging interval(C,C'), the number of passing is counted by 1(308). If the total number of passing reaches to a predetermined number of passing, counting the number of charging/discharging is performed(310).