摘要 |
A filler unit for automatically topping up a battery cell (14) includes a float vessel (16) for containing the liquid to be dispensed and a float valve assembly (34) for establishing a predetermined substantially constant head of liquid in the vessel (16). A baffle plate (40A) in the vessel (16) is spaced sufficiently close to a wall of the vessel (16) to define a capillary passage between the wall and the baffle plate (40A), with at least that surface of the baffle plate (40A) which defines the capillary passage being hydrophilic. In use, the replenishment water is able to flow from the vessel (16) to the cell (14) under gravity along a flowpath until such time as the water level in the cell (14) has risen to a desired level. This creates a pressure equilibrium in the flowpath which causes the flow from the vessel (16) to the cell (14) to cease automatically. |