CHARGER

A charger includes: a housing; a charging interface configured to be electrically connected to a first battery pack; a direct current power interface configured to be electrically connected to a second battery pack; and a drive assembly accommodated in the housing and configured to supply power to the charging interface. The drive assembly is electrically connected to the charging interface and the direct current power interface and is configured to transfer electric energy from the second battery pack to the first battery pack, the maximum output power of the drive assembly is greater than or equal to 2000 W, and the first battery pack and the second battery pack are detachably connected to the charger, so as to be detached and then mounted to a power tool and supply power to the power tool.