Method of charging battery pack and battery pack

A method of charging a battery pack that can prevent a battery or an external power source from being damaged due to a trickle charge current in order to improve battery safety, and the battery itself. The method of charging the battery pack includes determining (S1) whether a charge current exists, determining (S3) whether the charge current and a charge voltage are changed if determined that the charge current exists, determining (S4) whether the charge current is changed from a first current level to a second current level less than the first current level, and a present voltage level of the battery is less than a former voltage level if determined that the charge current and the charge voltage are changed, and maintaining (S5) the charge current at the second current level for a predetermined maintenance time if determined that the present voltage level of the battery is less than the former voltage level.