A docking device for receiving a portable computer is disclosed. The docking device includes a device housing and a charging connector that is provided on a side surface of the device housing and is connected to a battery connector of a battery pack in order to charge the battery pack. The charging connector is connectable to the battery connector in a state where the battery pack and the device housing are disposed on the same plane. When the charging connector and the battery connector are in a connected state and the device housing is being moved to a position within a predetermined height from the plane, the connection state between the charging connector and the battery connector is maintained. When the device housing is being moved to a position that exceeds the predetermined height from the plane, the battery connector will be separated from the charging connector due to the weight of the battery pack.