Patent Application
20190189997
This invention relates generally to a lead acid battery and, in particular, to a cell connecting assembly for a lead acid battery.
Conventionally, a lead-acid battery has a housing with a plurality of cells, each generating approximately 2.1 volts, connected in series to provide a desired battery voltage. For example, six cells generally form a 12 V battery. In an even cell number battery wherein cells are connected in series, the battery has two terminal posts positioned near the same edge. The arrangement results in terminals arranged near the same edge of the battery because of the series connection locations alternating from front to back for each series connected cell. To explain in more detail, each cell includes a number of positive and negative plates, each plate having a tab rising from its top and positioned off-center. The plates are stacked in an alternating fashion, so that all the tabs for plates of the same polarity are lined up with each other, but not with the tabs of the opposite polarity plates. Separators are provided between each plate in order to prevent direct physical contact between plates of opposite polarity. Both the positive and negative plates are connected at the top by separate cast-on-straps that are welded to the tabs. One strap connects the plates of one polarity near the front of the housing and another strap connects the plates of opposite polarity near the back of the housing. Adjacent cells are connected in series to each other by vertical extensions connected to the straps, known as flags or tombstones, that are welded to each other though openings in the housing.
When an odd number of cells is required for the desired voltage, connecting the cells in the customary manner described above results in the terminal posts being positioned near opposite corners of the battery. This creates problems in manufacturing and presents problems with existing venting and valve systems.
A lead acid battery comprises a plurality of cells provided in an odd number arrangement greater than one in only a single row, a plurality of outer cell connectors connecting the plurality of cells to provide a single series electrical current path, and a pair of inner cell connectors. Each cell has a plurality of plates of differing polarity. Each of the outer cell connectors is positioned in an alternating manner on opposite sides of a longitudinal centerline of the plurality of cells. The plurality of outer cell connectors include a plurality of flags positioned on opposite sides of the longitudinal centerline of the plurality of cells. The inner cell connectors are connected to each other along the longitudinal centerline of the plurality of cells.
The invention will now be described by way of example with reference to the accompanying figures, of which:
As shown in
As shown in
An interior of the housing 10 is divided into N substantially equal cell cavities by a plurality of Nā1 partitions 19 substantially parallel to the end walls 12, 14. The height of the partitions 19 is substantially equal to the height of the four outer walls 12, 14, 16a, 16b. As shown, the housing 10 includes a plurality of cells 20 and of partitions 19 and, in particular, seven cells 20 and six partitions 19. However, one skilled in the art should appreciate that for the implementation of this invention the number of cells 20, N, can be any odd integer greater than one.
The housing 10 can be made from a heat moldable plastic resin or any suitable non-conductive material resistant to sulfuric acid and known to those of ordinary skill in the art.
As shown in
Each plate 22 is formed as a grid with perforations extending from one planar surface to an opposite planar surface thereof. Each surface on the positive plate 22a is coated with a positive active material which also fills the grid perforations. Each surface of the negative plate 22b is coated with a negative active material which fills the grid perforations. The grid forms a framework and current collector for the plates and is typically made substantially of lead. However, one skilled in the art should appreciate that any compatible arrangement of materials suitable for this framework and collecting of the current to a tab may be employed.
Each separator 24 is a porous electrical insulator substantially impervious to the electrolyte and resistant to electrochemical oxidation. The electrolyte is commonly a solution of water (H2O), sulfuric acid (H2SO4) and possibly various additives. When interposed between two adjacent positive and negative plates 22a, 22b, the separator 24 prevents electrical contact between adjacent plates 22a, 22b while providing minimal restriction to movement of ions (H3O+, HSO4ā) and water molecules (H2O). Separators can be made from various materials including micro-porous polyethylene, matted substantially glass fibers, phenolic sheet, certain rubber materials, expanded PTFE or any suitable non-conductive porous material known in the art.
The positive and negative active materials generally begin as a paste of lead oxide (PbO or lead (II) oxide), lead, water and sulfuric acid. Other ingredients in may include fibers or red lead (Pb3O4) in positive plates. Negative recipes may include fibers, barium sulfate (BaSO4), lignins, or various forms of carbon. Through processes of curing and electrical formation, the materials are converted substantially to lead dioxide (PbO2 or lead (IV) oxide) in the case of positive plates or lead sponge (Pb) in the case of negative electrodes. However, one skilled in the art should appreciate that other known starting ingredients or conversion methods may be used.
In the shown embodiment, the plurality of partitions 19 are used to separate each cell cavity 20 from adjacent cell cavities 20. The partition 19 is generally made from the same material as the housing and is often molded with the housing as a single piece. Any suitable material capable of substantially blocking ion flow between cells and allowing a series electrical connection to be made through it may be used by those skilled in the art.
As shown in
As shown in
In the shown embodiment, the pair of terminal posts 52 include a positive terminal post 52a and a negative terminal post 52b positioned at opposite ends of the lead acid battery 1. In particular, the positive terminal post 52a is positioned at a first end along a first side of the housing 10, while the negative terminal post 52b is positioned a second end, opposite the first end, along the same edge of the housing 10.
Each terminal post 52 includes a post section 54 and a cell connecting body 56. The post section 54 in the shown embodiment is an elongated tubular body having a blunt end 54a opposite the cell connecting body 54b, 56. The post section 54 extends substantially orthogonal with respect to the cell connecting body 56. In particular, in the shown embodiment, the post section 54 is positioned adjacent and connects to the cell connecting body 56. However, in other embodiments the post section 54 may extend from the cell connecting body 56. The cell connecting body 56 is a flat planar body having a cell connecting surface 57 disposed on a lower surface thereof. In the shown embodiment, all the tips of the plate tabs 23 that are aligned with the cell connecting body 56 penetrate the cell connecting surface 57 and are at least partially fused together (see
As shown in the
Now, with reference to
The strap 72 is an elongated body extending along horizontal plane along a longitudinal length of lead acid battery 1. The strap 72 includes a cell connecting surface 73 disposed on a lower surface thereof. In the shown embodiment, all the tips of the plate tabs 23 that are aligned with the strap 72 penetrate the cell connecting surface 73 and are at least partially fused together (see
Now, positioning of various components of the cell connecting assembly 50 will be described in detail with reference to
A first pair of outer cell connectors 60 are aligned with each other, such that each strap 62 is linearly aligned with the other and the pair of flags 64 face each other. Next a second pair of outer cell connectors 60 positioned opposite the first pair of outer cell connectors 60 and aligned with each other. Each strap 62 of the second pair of outer cell connectors 60 is linearly aligned with the other, and the pair of flags 64 face each other. Next, the pair of inner cell connectors 70 are positioned between the first pair of outer cell connectors 60 and the second pair of outer cell connectors 60. The straps 72 are offset from each other, with one strap 72 aligned with the strap 62 from the first pair of outer cell connectors 60, and another strap 72 aligned with the strap 62 of the second pair of outer cell connectors 60. The pair of flags 64 face each other in a substantial center between the pair of straps 72.
A first terminal post 52 is disposed on one side of the pair of inner cell connectors 70, while a second terminal post 52 is positioned on an opposite side of the pair of inner cell connectors 70. The first terminal post is positioned opposite the first pair of the outer cell connectors 60 and aligned with the second pair of outer cell connectors 60. The second terminal is positioned adjacent to and aligned with the second pair of outer cell connectors 60.
Now, assembly of the lead acid battery 1 will now be describe in detail with reference to
As for positioning, the plurality of positive plates 22a and plurality of negative plates 22b are positioned in the housing 10. Each positive plate 22a and negative plate 22b is separated from each other by the separator 24, and an electrolyte is disposed with an electrolyte receiving space 26. Each cell 20 is separated from each other by the divider 19.
Next, the cell connecting assembly 50 is positioned in the housing 10 on top of the cell 20, with the terminal posts 52 connect with cells 20 at opposite ends of the lead acid battery 1. The plurality of outer cell connectors 60 and pair of inner cell connectors 70 also connecting with cells 20.
The assembly consisting of the straps 72, flags 74, links 76 and posts 52 is cast and simultaneously welded to the proper plate tabs 23. Proper plate polarity must be maintained throughout the final series circuit. In the diagrammed embodiment the straps 72 with notched ends are intended to be welded to positive plates 22a and the opposite straps to negative plates 22b. It should be clear to those skilled in the art that other methods of polarity marking are acceptable. It should be clear to those skilled in the art that visible polarity markings are for the benefit of human observers and not strictly necessary for the workings of the battery. Holes are punched through the container partitions so that every opposed pair of flags will be centered over a hole after the assembly is stuffed into the housing. Electrical connections between opposing flags are made through the holes by a welding or similar process.
Next, the cover 30 connects with the housing 10 and encloses the cells 20.
Electrolyte is added. The battery is electrically formed. The electrolyte levels or strength may be adjusted and the battery is closed up. It should be understood by those skilled in the art that several variations are possible. Formation of the plates could occur prior to assembly. Formation of the assembled elements could occur prior to stuffing them into the housing. In these manufacturing variations, the responsibility of filling the battery with electrolyte could shift to the end user after sale.
The terms and expressions which are employed in this specification are used as terms of description and not of limitation. Mirrored or rotated configurations are equally functional. There is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof. It is recognized that various modifications are possible within the invention described and claimed herein.
This application is a continuation of co-pending U.S. patent application Ser. No. 15/214,959, filed on Jul. 20, 2016.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15214959 | Jul 2016 | US |
| Child | 16281280 | US |
