Patent ID: 7556056

Claim:
A single point fluid supply system for replenishing a liquid electrolyte in a plurality of battery cells simultaneously, the system comprising: plurality of cell fill valves interconnected by tubing and T-connections to a battery cell fluid supply flowing at any of a range of pressures through the system, one of the cell fill valves to each battery cell, each of the cell fill valves comprising a single fill opening controlled by a ball in a seat, a lever arm pivotable about a pivot point, the lever arm comprising a float on a first end of a pivot arm and an end finger on a second end of the pivot arm, the lever arm controlling the ball in the seat, the finger pointing upwardly with the float in a first downward position when the battery cell fluid level is low in a battery cell, the upward pointing finger thereby holding the ball up off the seat to admit a flow of battery cell fluid into the cell and the finger lowering as the float is lifted by battery cell fluid as the battery cell is filling until the battery cell is filled to a valve shutoff level and the finger is sufficiently low to lower the ball onto the seat to stop the flow of battery cell fluid into the battery cell, a first battery fluid retainer chamber formed around and under the bottom of the T-connection surrounded by a retainer wall extending above the bottom of the T-connection where the battery fluid enters the battery from a bottom opening of a vertical tube portion of the T-connection, and a second battery fluid retainer chamber above the ball and seat adjacent to the outside of the retainer wall, the first and second retainers communicating with each other over the wall, so that the battery fluid flows through the first chamber into the second chamber when the ball is elevated from the seat, and the retainer chambers retain some battery fluid up to the level of the wall after the battery cell reaches the shutoff level and the ball closes on the seat and the battery fluid in the chambers serve to function as a water seal to prevent gas from migrating up out of the battery cell to eliminate a potential hazard of a flame in one battery cell spreading to other battery cells via flammable gas in the tubing connecting the cells, and further comprising at least one vent passage above the second fluid chamber communicating between the second fluid retainer chamber and external air to vent any battery cell gases from the second chamber and prevent the battery cell gases from entering the first chamber and thereby prevent the battery gases from entering the T-connect and prevent gas pressure buildup in the battery cell.