Single point watering apparatus for lead-acid battery

The present invention is directed to a single point watering system for use with a lead-acid battery having a plurality of battery cell access ports. The system comprises a plurality of refill valves and a plurality of refill valves and a manifold having (i) a water feed tube with at least one external port and a plurality of outlets each communicating with one of the plurality of refill valves, and (ii) at least one passageway housing a flame arrestor to permit the discharge of gases from the battery cells to the surrounding environment only through the flame arrestor. The manifold is removably and sealably mountable to the battery so that each refill valve is in fluid communication with one of the battery cell access ports.

BACKGROUND OF THE INVENTION

The present invention relates generally to single point watering (SPW) systems. More particularly, the invention relates to an improved SPW system specially adapted for use with a particular class or style of lead-acid battery known in the art as a “deep cycle” battery.

Deep cycle batteries, widely used in boats and RVs, are ideal candidates for SPW maintenance. These batteries are commonly used to provide boats and RVs with “house power” for various accessories, including trolling motors, pumps, lighting and instruments. Deep cycle batteries are special 6 cell (12 volt) monoblocs, based on flooded, lead-acid technology, distinct from gel cell or absorbed glass mat technologies. Many boaters and RV owners prefer the flooded cell batteries to the alternatives. They have lower initial cost; they produce more amp hours of energy per pound; they use lower cost chargers; and they are more tolerant of overcharging. However, water is lost from the electrolyte in these batteries due to evaporation and electrolysis, and must be replaced periodically. As a result, a significant disadvantage of flooded cell batteries is that they require regular watering to maintain performance. This can be a significant problem. Batteries are frequently mounted in locations difficult to access, such as the bilge of a boat, or in small compartments that make it difficult to accurately add water manually. As a result, they often do not receive the regular watering they require, which can shorten batter life and weaken performance. If a practical SPW system were available for this class of batteries, it would prove valuable to a large number of boaters and RV owners.

Installing an SPW system on a deep cycle battery has heretofore been considered impractical. Cells are very closely spaced, and the battery cell vent openings are small in diameter, making individual SPW refill valves, designed for industrial use, too big and bulky to mount in deep cycle battery cells. With a cell spacing of 1 ⅝ in., there is not enough room to connect tubing to individual refill valves, even if they could fit into the small vent openings. In addition, multiple batteries are often used, with separate mounting arrangements and locations, making installation of an SPW system even more difficult, where control of water supply pressure, or residual water in the tubing could cause problems such as overfilling. A practical SPW system for this application would have to function reliably, independent of battery location and free of tightly controlled water supply pressure. Ideally, the vehicle operator could fill the batteries from a remote location, for example, in a boat while standing on the deck. The water should be supplied directly from a portable bottle of distilled water, or an easily accessed container of distilled water stored on the vehicle. Users will have a choice of water supply systems, such as a gravity fill or a small hand pump for a direct fill from a distilled water container, or a built-in electric pump, such as an inexpensive centrifugal pump, to provide push button battery watering.

What is needed, therefore, is an SPW system adapted particularly for use with the marine deep cycle class of lead-acid batteries.

SUMMARY OF THE INVENTION

The present invention is directed to a single point watering system for use with a lead-acid battery having a plurality of battery cell access ports. The system comprises a plurality of refill valves and a plurality of refill valves and a manifold having (i) a water feed tube with at least one external port and a plurality of outlets each communicating with one of the plurality of refill valves, and (ii) at least one passageway housing a flame arrestor to permit the discharge of gases from the battery cells to the surrounding environment only through the flame arrestor. The manifold is removably and sealably mountable to the battery so that each refill valve is in fluid communication with one of the battery cell access ports.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

I have found that the battery refill valve disclosed in U.S. Pat. No. 6,227,229 can be readily modified to provide a practical marine deep cycle battery SPW system. The entire disclosure of U.S. Pat. No. 6,227,229 is hereby incorporated by reference. This valve controls the flow of water into a battery cell by means of a displacer responsive to liquid level in the cell. This valve is unique in the SPW field in that it is sensitive to a very small displacement force over a wide range of operating water supply pressures. This enables the valve to be controlled by a small displacer which can fit into the small vent opening common to the marine deep cycle battery, and still allow a wide range of water supply pressures to be used. A wide range of input water operating pressure is important to provide a wide range of water supply options.

The term “deep cycle battery” as used herein refers to a special configuration of monobloc battery. They are 12 volt (six cell) monobloc batteries that are within the standard battery size designations: Group 24, Group 27 and Group 31. These batteries have certain similarities in the size and location of their cell vent port openings. Batteries in each of the Groups 24, 27 and 31 all have cell vent port openings of a nominal ¾ inch diameter. Also, the six openings in each battery share a common centerline and are grouped into two subsets of three cells each. The openings within the gangs of three are spaced a nominal 1 ⅝ inch apart. The two subsets are spaced differently between the Group 24, 27 and 31 size batteries. Typically, in deep cycle batteries, each cell vent port opening is designed to receive a venting cap which press fits into the opening. Normally these caps are ganged together in a single integral structure of three. The closure assembly includes a common passageway for cell gases to vent to atmosphere. Each battery has two closure/vent assemblies, each one press fit into three cell openings. The closures are spaced together most closely on the Group 24 size batteries and farthest apart on the Group 31 size batteries.

As described below in accordance with the preferred embodiment, three automatic shut-off refill valves are housed in a structure which replaces the normal closure used on Group 24, 27 and 31 batteries. Two manifolds per battery are therefore required. They are joined together on each battery by a short section of tubing of length appropriate for the particular Group.

In the preferred embodiments described below, the normal cap or closure assembly is replaced by a valve-manifold assembly. The manifold sits above the battery cover with the valve body of each refill valve housed within. The manifold must provide a path for water to flow into the cell during the refill cycle and for the gases to leave the cells and vent to atmosphere whenever the gas pressure exceeds ambient (atmospheric pressure). The manifold must also seal the cell opening so that electrolyte does not leak onto the battery top due to tilting and sloshing. The manifold must also allow the valve displacer to communicate with the electrolyte and the valve to control the electrolyte level. The manifold therefore includes three bosses which extend from the bottom of the manifold to press fit into the cell vent port openings to provide and maintain a tight seal and attachment under normal shock, vibration and handling loads. Each boss on the manifold has an inside diameter sufficient to allow a displacer to communicate with the valve body in the manifold and the electrolyte within the cell, as well as space for water to flow into the cell and gasses to flow from the cell into the manifold.

FIG. 1illustrates an array of three deep cycle batteries10, each having six battery cell access ports arranged linearly across the top of the battery. This set of six ports is, as described above, two subsets of three ports arranged end to end. While the spacing between the access ports in the subsets is uniform throughout the marine deep cycle battery class (at 1 ⅝ in.), the spacing between the two port subsets may vary (typically from 1 ⅝ in. to 2 ⅞ in.). As a result, each battery10is provided with two separate valve-manifold assemblies12, which are joined by intra battery connecting tubes14. The SPW system also includes a water supply tube16and inter battery connecting tubes18. Further, structural details of the valve-manifold assembly12are illustrated inFIGS. 2–5. The valve includes a valve body or cartridge20with an inlet21and valve stem23, and an acuator comprising displacer top22and displacer bottom24. The manifold includes a base26and cover28. A pair of flame arrestors30, in the form of porous plastic disks, are also part of the assembly.

The details of valve cartridge20and displacer22,24are more fully disclosed in U.S. Pat. No. 6,227,229 which is incorporated herein by reference. The individual valve cartridges20each are positional in an enclosure in the manifold defined by cartridge well32in the base26and a cartridge canister34in the cover28. The flame arrestors30are press fit into passageways or arrestor receptacles36where they abut shoulder38at a level just below gas vent ports40.

The manifold base26is provided with upstanding annular flanges42, each of which defines an individual valve cartridge well32. A plurality of spacers or small pins44are formed in the base26, preferably along the inside perimeter of flanges42, and a plurality of openings or slots46are formed in flanges42, as well. The pins44support the cartridges20in spaced relation from base26so that, in combination with slots46, passageways are provided for the flow of water from the refill valves into the battery cells and the flow of gases from the battery cells into receptacles34. The gases collecting in receptacles34then pass through the flame arrestors30and out of the manifold through vent ports40.

Base26is also provided with baffles48and sloping surfaces50. Thus, any water from a valve cartridge20or electrolyte from the battery cell that finds its way into gas receptacles34is easily redirected back into the battery cells.

Finally, base26is also provided with a plurality of manifold skirts or bosses51which are sized and positioned for press fit insertion into the battery cell access ports. In this manner, the valve-manifold assembly is sealably mounted to the battery with each of the refill valves' displacers positioned within one of the battery cells. Water is, therefore, delivered to the battery cells via the valve-manifold assemblies12and gases developing in and/or displaced from the cells are discharged to the surrounding environment through the valve-manifold assemblies12, as well.

Manifold cover28includes a longitudinally extending water feed tube52having four external ports, preferably two end ports54and two intermediate ports56. Bosses58extend from feed tube52into each valve cartridge canister34forming internal ports58for the delivery of water to each valve cartridge20. The internal size and configuration of the cartridge canisters34together with the bosses58are adapted to receive the individual valve cartridges20in press fit relationship to form a leak tight seal at the cartridge inlet21. The manifold cover28also preferably includes one or more projecting keys60which assure the proper orientation of the valve cartridges20in canisters34.

After the valve cartridges20and flame arrestors30are properly positioned within manifold cover28, the base26is ultrasonically welded or otherwise joined in a leak tight manner to the cover, and the displacer top22and bottom24are snap fit onto the valve cartridge stem23. At this point, the valve-manifold assembly is complete and it may be easily mounted to the top of a deep cycle battery10.

To finish the SPW system installation, the remaining access ports on the battery10, and on any other batteries in the array, are also fitted with a valve-manifold assembly12, and intra battery tubes14and inter battery tubes18, along with a water supply tube16are fitted onto the various external ports54and56, as needed. A barbed fitting or extension59may be conveniently employed for connecting tubes14,16and18to the manifold. All unused external ports are fitted with plugs62, and the entire SPW installation is complete. By using single barb connectors, as illustrated, and using flexible ¼ in. I.D. PVC tubing, the connections are effected simply by sliding the end of the tubes over the barb connectors, and no clamps or wire ties are required. This, too, simplifies the installation and reduces the entire associated costs.

As illustrated inFIGS. 6 and 7, during the water filling cycle the displacers24are low and water from the feed tube52, passes through valve cartridge20and into the battery cell. At the same time, gases displaced from the cells enter gas receptacles34and pass out of the manifold through arrestors30and vent ports40. When the displacers rise, the refill valves automatically close as the electrolyte level in each cell reaches the predetermined set point.

FIG. 8illustrates one other version of deep cycle battery70having a threaded vent port opening72. When used with this form of deep cycle battery an externally threaded adaptor74is first assembled to the vent port opening. Adaptor74has a smooth cylindrical internal surface76which cooperates with the manifold skirt51to provide a press fit, leak tight seal between the manifold assembly12and the battery.

It will be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be covered by the appended claims.