Abstract: A battery is charged in a number of states, with a change from a third charge stage to a fourth charge stage (e.g., final stage) is executed when a battery voltage reaches a change voltage or when a charge time reaches an upper time limit, in order to inhibit the overcharging or undercharging of the battery. The upper time limit is set in response to a battery temperature detected at the end of a second charge stage. In addition, if the charge stage is changed to the fourth stage in response to a determination of whether the upper time limit has elapsed or not, a complete charge mode cycle is increased. At the fourth stage, a charge time calculated using a charge electricity quantity, a battery temperature and a charge mode of the first stage is set.

Abstract: A battery is charged in a number of states, with a change from a third charge stage to a fourth charge stage (e.g., final stage) is executed when a battery voltage reaches a change voltage or when a charge time reaches an upper time limit, in order to inhibit the overcharging or undercharging of the battery. The upper time limit is set in response to a battery temperature detected at the end of a second charge stage. In addition, if the charge stage is changed to the fourth stage in response to a determination of whether the upper time limit has elapsed or not, a complete charge mode cycle is increased. At the fourth stage, a charge time calculated using a charge electricity quantity, a battery temperature and a charge mode of the first stage is set.