Maintaining proper water level in your battery will keep it running efficiently and at a power level to meet the needs of a demanding locomotive environment. The system consists of automatic shut-off valves, interconnected with tubing, that replace the existing vent caps. A quick coupling allows the system to be connected to a water supply. Once connected, water flows into each cell until it reaches the correct level. A flow indicator built into the water supply tells the operator when filling has been completed.