Abstract: A water-refill plug for automatically filling and refilling the cells of the battery has a housing forming a valve seat, and forming an upper and lower guides above and below the valve seat. A float is movable vertically in the housing below the seat in one of the cells of the battery. A valve body vertically movable independently of the float body has upper and lower end vertically slidable in the upper and lower guides. A magnetically attractable or repellable element or permanent magnet is provided on one of the bodies. Another permanent magnetic on the other of the bodies exerts a force via the element or magnet so the valve body is moved by the float body.

Abstract: Water refilling plug for automatically filling and refilling the cells of a battery, comprising a valve body which is operated by a float and which closes the valve when the battery cell is full in order to terminate the refilling operation, wherein there is a permanent-magnet force between the valve body and the float, the movement of the float being transmitted to the valve body by said permanent-magnet force.