A charger adapted to charge either one of a first battery pack and a second battery pack. The first battery pack and the second battery pack have respectively a first interface and a second interface being substantially different from each other. The charger includes a housing having a receiving area in which the first battery pack and the second battery pack can be selectively received in such a way that the first battery pack is accommodated in a first region and the second battery pack is accommodated in a second region. The receiving area is at least partially defined by the first region partially overlapping the second region. The charger according to the invention is adapted to charge more than one type of battery pack, which saves cost and space needed for two separate chargers.