A charging device for charging an electric bicycle includes a charger which is received in the trunk of a vehicle and electrically connected to the battery of the vehicle by a conductive wire. A wire extends from the charger and is detachably connected to the rechargeable battery of the electric bicycle which can be received in the trunk or carried on the vehicle by a bicycle carrier attached to the vehicle. The conductive wire has the first end connected to the charger and the second end having an adapter which is received in the cigarette lighter receptacle hole of the vehicle.