A battery connection device includes a base end connector, a battery end connector and a waterproof rubber ring. The base end connector includes a base end terminal module. The base end terminal module is mounted to the base end connector. The base end connector has a ring-shaped holding groove. The holding groove surrounds the base end terminal module. The battery end connector is docked with the base end connector. The battery end connector includes a base plate, and a battery end terminal module mounted on the base plate. The base end terminal module is docked with the battery end terminal module. The waterproof rubber ring is mounted between the base end connector and the battery end connector.