U.S. Patent No. 7,556,056 for single point battery watering system with pivot float and ball valve.

The present invention relates to single point fluid supply systems for replenishing a liquid electrolyte in a plurality of battery cells simultaneously and in particular to a series of cell fill valves interconnected by a series of hoses and T-connections, one to each cell, each cell fill valve controlled by a ball in a seat in a single fill opening, the ball controlled by a float on a pivotable lever arm with an end finger which holds the ball up to admit water with the float down and allows the ball to lower onto the seat as the cell fills causing the float to rise to a shutoff level when the cell is filled to a desired level.