EP0344258A1

EP0344258A1 - Intercell connection and method and apparatus for making connector

Info

Publication number: EP0344258A1
Application number: EP89900029A
Authority: EP
Inventors: James M. Shannon; John K. Shanon Sr.
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-23
Filing date: 1988-10-20
Publication date: 1989-12-06
Also published as: WO1989004065A1; AU2611088A; EP0344258A4

Abstract

An improved composite battery (10) and intercell connector (16) are disclosed. The intercell connector has a braided cable (28), preferably flat, between two terminal connectors (24,26) which are secured at its opposite ends, preferably by die-casting, to accommodate intercell movements in the composite battery. The intercell connector preferably has an inte gral flexible coating (38) over its entire outer surface. Also disclosed are a method and apparatus for manufacture of such intercell connectors.

Description

Title: INTERCELL CONNECTION AND METHOD AND APPARATUS FOR MAKING CONNECTOR

Field of the Invention

This invention is related generally to composite batteries having independent battery units connected in series to provide a desired size or voltage and, more particularly, to intercell connectors and inter-battery connectors for such composite batteries. The invention i also related to methods and apparatus for making such intercell and inter-battery connectors.

Background of the Invention

An example of the sort of composite battery to which this invention is applicable is an electric battery of th type commonly used m. industry to power lift trucks, golf carts, and electric cars. However, the invention is applicable to any battery which is constructed of an array of individual units, typically multi-cell units, joined together to form a large battery. Such composite battery is actually an array of discrete independent battery units

Each battery unit of such composite batteries include a set of positive plates and a set of negative plates. Th positive and negative plates are separated from each other by battery-plate separators. The positive plates are all affixed to one terminal and the negative plates are affixe to another. The terminals are usually post-like in shape.

These elements and an electrolyte are contained in a cell jar, typically made of rubber or plastic and sealed with a cover. The positive and negative terminals protrude through gasketed holes in the cover to provide means for external connections.

In forming a composite battery, such battery units ar usually arranged in a tray with the positive terminal of one battery unit next to the negative terminal of the adjacent battery unit. The positive and negative terminal are connected in series by intercell connectors, the array of battery units and intercell connectors forming the composite battery.

In the prior art, intercell connectors for composite batteries are usually molded from lead in the form of rigi bars. Such bars can provide excellent conductivity due to their substantial conductive cross-sections. Indeed, it i essential that intercell connectors of composite batteries used for lift trucks, golf carts, and the like have substantial conductive cross-sections; slender wires, thin

• sheets, or the like are insufficient and inappropriate for intercell connectors. Such molded constructions usually have a hole through each end, the holes typically being large enough to fit over the battery terminals and to accommodate, during assembly, variations in the center-to-center dimensions of the battery unit terminals to be connected. Then, with t intercell connector in place and the individual terminals protruding into the holes of the connector, the terminals and intercell connector are welded together, in a process called "lead-burning," to form a rigid one-piece assembly

("Center-to-center dimension" is used herein to refe to the spacing between the positive and negative terminal of adjacent battery units or, as hereafter seen, to the length of an intercell connector, used to connect such terminals, as measured between the centers of its termina connectors. )

There are many problems with such prior art composit battery structures, particularly with such intercell connectors. Some of the problems relate to difficulty in attachment to the battery units, while other problems relate to use of the product after attachment.

For one thing, lead burning is a difficult and time-consuming procedure. It requires that the holes in "the rigid connector bar be accurately positioned. A grea deal of training and skill are required to produce consistent, reliable attachments of intercell connectors with battery-unit terminals during the original construction of the battery array. This, of course, entails considerable cost.

Another problem is that in use the rigidity of such intercell connectors significantly magnifies the pressure on battery-unit covers and cover-to-terminal gaskets whic is caused by the shifting, flexing or relative movement o the composite battery and its individual battery units.

Shifting and relative movement of the individual unit jar is inherent in the operation of such composite batteries, due to vibration, twisting forces caused by the difficult of supporting such large and heavy battery arrays, therma expansion and contraction, chemical growth on positive plates, and other causes. Individual battery units may move up and down (vertical movement) , side to side (later movement) , and back and forth (longitudinal movement) wit respect to each other, particularly during movement of th vehicle which they power or on which they are supported.

These movements not only strain the seals between th battery terminals and cover and between the battery-unit cover and jar, they can apply strains and pressures on th welds between the battery plates and terminals inside the cell. Failure of the such internal welds can cause significant problems or even battery-unit failure. And, with external strains, electrolyte leakage can occur.

Another significant problem of such rigid intercell connectors relates to the difficulty in removing a single battery unit from the array. Removal of a single battery unit (jar) is often required for maintenance of the composite battery. Composite batteries of the prior art having intercell connectors which are welded onto the battery terminals typically require physical cutting of th intercell connectors from the terminals to remove a single battery unit. In some cases, such removal of the intercell connecto is carried out by use of a hollow drill. This leaves post on the battery units which are adjacent to the removed battery unit, and such posts can be used for connection of intercell connectors which extend to the terminals of the replacement battery unit. Such reconnection is again by welding. This entire procedure requires special tools, torches, and a skilled lead-welding technician. The procedure is time-consuming and messy. It is a potentiall dangerous procedure which cannot be performed by ordinary maintenance personnel.

Another problem with intercell connectors of the type described is that they are not readily insulated. The portions lead-burnt onto battery terminals, of course, mus be exposed for such procedures. In any event, insulating such intercell connectors is problematic. Furthermore, intercell connectors of the rigid type are very heavy.

Another somewhat similar intercell connector of the prior art includes a solid copper strap with lead lugs which are cast on each end of the copper strap and welded onto the adjacent battery terminals in the same manner as rigid lead connectors. Such intercell connectors offer very little vertical and virtually no lateral or longitudinal flexibility to accommodate relative movement of the battery units. Many of the problems of the previously described intercell connectors apply equally t these connectors. Removal of an individual battery unit connected by such connectors is carried out in the same manner as described above, with all the attendant disadvantages.

Another type of intercell connector, including one sold by a German company under the trademark "VARTA" and another by an American company under the trademark "DEKKA, is a "bolt-on" intercell connector which- includes a substantially rigid insulated copper cable of round cross section with conventional copper lugs affixed at each end, typically by crimping. The copper conductor is either of rope-lay or concentric-lay construction.

This construction allows minimal relative vertical movement of individual battery units and virtually no relative lateral or longitudinal movement unless the cabl of such intercell connector can be in the form of a loop. Since the vast majority of _^intercell connectors have a center-to-center dimension of less than six inches (15.24 cm), such loops are impossible or impractical, even if th were otherwise desirable on composite batteries.

This lack of relative movement is especially apparen in the case of the 2/0 gauge wire size required for many installations. Lateral or longitudinal motion is essentially impossible with such intercell connectors, fo various reasons including the fact that the crimped-on copper lugs lock the individual strands together, thus preventing them from flexing. Indeed, the locked strands of such wire act essentially like a solid, inflexible mas

Thus, there are long-standing unsolved problems with composite batteries of the prior art and, in particular, with the intercell connectors used in such composite batteries. There is a need for an intercell connector which overcomes such problems, combining some or all of th following characteristics: substantial cross-sectional size to allow sufficient current flow; accuracy and ease i connection to and disconnection from battery terminals; an flexibility in a variety of directions to accommodate the relative movements of adjacent battery units in composite batteries and eliminate the attendant stresses and strains on various parts of the composite battery.

Techniques and apparatus of the prior art for making intercell connectors fail to produce intercell connectors overcoming the problems described above. Among the many needs relating to methods and apparatu for manufacture of intercell connectors is to produce an intercell connector which, while flexible in various directions, has terminal connectors at its opposite ends with center-to-center spacing equal to the center-to-cente dimensions of the terminals (of adjacent battery units) to be connected. By making the center-to-center dimension of the intercell connector precisely match the dimension between terminals, the extent of battery-unit movement which may be accommodated by the intercell connector, to protect the battery units, can be maximized.

In forming intercell connectors, attachment of terminal connectors to a cable may be required. For many years attachment of a_. terminal connector to a cable has frequently been accomplished by die-casting lead terminals onto cable ends. The cable is held with pincher bars or the like, with the cable end protruding into a mold cavity.

With the cable in place and the mold closed, lead is injected into the cavity. If the cable s held securely in place, the injected lead surrounds the cable end and forms a terminal connector on the cable end.

One problem, however, is that the hydraulic pressure of the injected lead can move the cable — slightly or substantially, or even cause it to shoot out of the mold. Any movement problem whatever when such a method is being used to form terminal connectors on opposite ends of an intercell connector cable would result in intercell connectors of incorrect and/or inconsistent length. In th case of substantial movement^', insufficient electrical connection may even result.

In addition to the operational problems, inconsistent lengths in intercell connectors during their manufacture can cause difficulties, when insulating materials are to b applied, in proper and even application of such materials onto the intercell connector. This could occur if, during application of insulating materials, the intercell connector is supported at each end by close-fitting cores engaging and covering the electrical contact surfaces of its terminal connectors.

Such support would be to expose all other surfaces of the intercell connector such that they are ready for application of insulating material. In such position, drooping of the connector due to its being too long can cause.an uneven, perhaps even unacceptably uneven, application of insulating material, at least if a molding technique is used for application of an insulating material. It is important that the intercell connector no droop between its supporting ends. Consistent length will avoid this problem.

In addition to the need to provide an apparatus and method for consistently accurate manufacture of intercell connectors, it would be desirable to provide such an apparatus and method which could readily be adjusted for manufacture of intercell connectors of different lengths.

Objects of the Invention

It is an object of this invention to provide an improved composite battery overcoming shortcomings and problems of the prior art, including those mentioned above.

Another object of this invention is to provide an improved intercell connector for composite batteries. Another object of th s i.nventi.on i.s to provi.de a composite battery with substantially reduced levels of stress and strain, both inside the battery units and on th outside thereof, which are caused by relative movement of the battery units.

Another object of this invention is to provide an intercell connector having, at the same time, sufficient cross-sectional size to carry substantial current and sufficient flexibility to accommodate relative movements o the battery units forming the composite battery.

Another object of this invention is to provide a composite battery and an intercell connector which facilitate connection and disconnection of the intercell connector from the battery unit terminals.

Another object of this invention is to provide an intercell connector of very short length yet having sufficient flexibility in all directions to accommodate relative movements of the battery units of a composite battery.

Still another object of this invention is to provide an improved intercell connector which can safely accommodate the relative movements, of an adjacent pair of battery units connected by the intercell connector, in any direction.

Another object of this invention is to provide an improved intercell connector which is light in weight. Another object of this invention is to provide an improved method and improved apparatus for accurate manufacture of intercell terminals.

Another object of this invention is to provide a method and apparatus for making intercell connectors which provides connectors with center-to-center dimensions which are accurate and consistent. Another object of this invention is to provide an apparatus for manufacture of intercell connectors which ca be readily adjusted to accurately produce connectors of different lengths. Summarv of the Invention

This invention is an improved composite battery and intercell connector for such composite battery which overcome certain problems and shortcomings of the prior art, including those mentioned above. The invention also involves an improved method and apparatus for manufacture of intercell connectors for composite batteries.

The intercell connector of this invention includes a braided cable, most preferably a flat braided cable, extending between a pair of terminal connectors. The terminal connectors (preferably lead terminal connectors) are connected to the ends of the braided cable, preferabl by die-casting such terminal connectors directly onto the ends of the braided cable. The intercell connectors of this invention preferably extend along substantially straight lines.

The term "braided cable," as used herein, means that, viewed in cross-section along its length, the cable is a two-dimensional matrix of wire strands. Flat braided cabl has a greater number of strands along one direction than along the transverse direction.

We have found that because of the way in which flat braided cable is woven, its compression, extension, and flexing, in any direction, ^together allow the intercell connectors of this invention to accommodate substantial, otherwise destructive, relative movements of battery units of the composite battery of this invention, even when the intercell connectors are securely fixed to terminals at their opposite ends. This is in extreme contrast with the other elongated conductive members of intercell connectors of the prior art.

Even in short lengths, such as six inches (15.24 cm) or less as is typical for intercell connectors in composit batteries, and even when firmly secured at both ends, the intercell connectors, of this invention are compressible, extendable, and bendable in every direction even while firmly connected to terminals at both ends. Indeed, the intercell connector of this invention allows significantly improved vertical, horizontal, lateral, and longitudinal flexibility, including stretching, compressing and twisting, regardless of how short the connectors may be.

Such multi-direction flexibility is an important aspect of this invention, because we have found it to be sufficient to protect and extend the life of various structures of the battery units which together form the composite battery. While providing a capacity for substantial current flow, as is necessary, the intercell connector accommodates relative movement of the battery units forming the composite battery such that the structur and critical junctures of the battery units remain intact. And, while providing these advantages, the intercell connector may readily be connected and disconnected from battery terminals.

Another important aspect of this invention is the encapsulation of the intercell connector with an integral, homogenous jacket to electrically insulate it and protect it from corrosion. Such coating extends continuously over both the braided cable and the terminal connectors, leaving only the electrical contact surfaces of the terminal connectors uncovered. The coating, while integral over most of the intercell connector, is flexible enough to not interfere significantly with the flexibility provided by the braided cable. The coating may be a molded polyvinyl chloride coating.

The terminal connectors preferably may be bolted to the battery unit terminals, although other connection means are possible. When bolts or other connectors are used for attachment to the battery unit terminals, snap-on cover tabs, preferably formed integrally with of the insulating layer, may be used to electrically insulate such bolts or other connectors,

A variety of terminal-connector structures, for connection to battery-unit terminals, may be applied to the braided cable without departing from the spirit and scope of the invention. As noted above, it is highly preferred that the intercell connector of this invention have die-cast terminal connectors formed on each end of the braided cable. This is a simple form of connection with the fewest components. It also provides excellent conductivity, but in this case without the problems associated with intercell connector rigidity.

Another aspect of this invention, as noted above, is manufacture of the intercell connectors described above.

The method and apparatus for making such intercell connectors will now be described.

The method and apparatus of this invention represent substantial improvement in die-casting terminal connector onto cables. The method includes placing a substantially straight braided cable of given length onto a sectioned mold with opposite ends of the cable extending into space terminal-connector cavities, and then simultaneously casting terminal connectors onto each end of the cable. This method produces intercell connectors having consiste center-to-center dimensions (that is, the dimension from the center of one terminal connector to the other) .

Such simultaneous opposite-end casting rules out any significant inaccuracy in center-to-center dimensions. T casting step preferably includes injecting molten metal such as lead simultaneously into the two cavities under equal pressure. Even if there were slight movement of th cable, there will be virtually no deviation in the length of the intercell connectors from the intended length; slight movement of the cable end in an outward direction with respect to the cavity in which it is held would resu in a corresponding inward movement at the other end. In any event, such simultaneous equal-pressure die-casting a opposite ends of a straight length of cable removes the tendency for movement.

The two cavities are in spaced terminal-connector cavity blocks, the spacing of which is controlled to dictate the precise desired center-to-center dimension of 1 the intercell connector. And the intercell connector is made such precise desired length with the braided cable in its relaxed natural configuration, which means that after

_ mounting in the composite battery distortion to accommodat 5 any sort of relative movement of the battery units can readily occur.

Preferred examples of the method and apparatus of thi invention adjust the intended intercell connector length b ₁₀ placement of an appropriate spacer block between the terminal-connector cavity blocks. Such spacer blocks can easily be changed for manufacture of intercell connectors of different lengths.

Referring more specifically now to the structure of τ_5 the die-casting apparatus, the aforementioned pair of spaced terminal-connector cavity blocks have a pair of aligned lateral openings to receive the opposite ends of the cable. The die-casting apparatus also has means to support the terminal-connector cavity blocks at a selected ₀ spacing corresponding to the selected intercell connector length. In preferred embodiments, such means includes the aforementioned spacer block between the cavity blocks. Th die-casting apparatus also includes means for routing and injecting molten metal into the pair of cavity blocks at 5 the same time.

After the length of braided cable has terminal- connectors die-cast on its opposite ends, as described, th intercell connector being formed is stripped from the mold cavities. The mold cavities will have formed, among other ₀ things, inside contact surfaces on each of the terminal connectors; these are the surfaces which will contact the post-like terminals of the battery units, in a female-male relationshi .

After stripping the intercell connector from the mold, 5 the intercell connector is preferably then suspended in a second mold on mounting posts, the mounting posts contacting the intercell connectors only on such inside contact surfaces of the terminal connectors, and perhaps on similar opposite surfaces. Such second mold is used for casting a flexible insulating layer integrally over the terminal connectors and braided cable.

The casting of such flexible layer is carried out in generally the same manner as^" the metal casting of the terminal connectors. However, such second mold provides thin space all around the terminal connectors and the braided cable to allow formation of the integral insulati layer. The layer is preferably made of flexible plastic, such as polyvinyl chloride, or of rubber; however, a wide variety of flexible insulating materials can be used instead. The flexibility of the layer must be enough to allow the intercell connector flexibility which is an essential characteristic of this invention.

An alternative to coating by the mold and molding method described is dipping, for example, in polyvinyl chloride plastisol. In such dipping operation, the intercell connector would be supported only by the inside contact surfaces of its terminal connectors.

The apparatus used in the preferred method of formin an integral layer of insulating material on an intercell connector is a special mold. Such mold includes a pair o opposed cavity blocks each having an end space for one of the terminal connectors and- an adjoining lateral channel for that portion of the cable which extends from the terminal connector. The opposed cavity blocks are orient such that their respective lateral channels are aligned.

Mounting posts extend into each of the end spaces fo mating engagement with the inside contact surfaces of the terminal connectors. Such mounting posts are positioned, and the end spaces and lateral channels are shaped, to provide a continuous clearance around all portions of the intercell connector. Such mold also includes means, including•appropriate flow channels, for routing and injecting an insulating material which is flowable and congealable, such as a polyvinyl chloride plastisol, into the continuous clearance. Such flow channels preferably extend to each o the end spaces.

Such apparatus for forming an integral insulating layer on the intercell connector preferably includes a spacer block between the opposed cavity blocks. Such spacer block has a channel which is aligned with and continues the aligned lateral channels of the opposed cavity blocks.

Brief Description- of the Drawings

FIGURE 1 is a side sectional view of an intercell connector in accordance with this invention, shown in position to join adjacent battery units.

FIGURE 2 is a partially cutaway top view of the intercell connector of FIGURE 1.

FIGURE 3 is a side sectional view, taken along sectio 3-3 as indicated in FIGURE 4, of a molding apparatus used for simultaneous die-casting of terminal connectors on the opposite ends of a flat braided cable.

FIGURE 4 is a top view of FIGURE 3 with the top portion of the molding apparatus removed.

FIGURE 5 is a side sectional view, taken along sectio 5-5 as indicated in FIGURE 6, of a molding apparatus used for molding an integral insulating layer over substantiall all of the surface of the intercell connector.

FIGURE 6 is a top view of FIGURE 5 with the top portion of the molding apparatus removed.

FIGURE 7 is a fragmentary perspective view of another preferred intercell connector in accordance with this invention.

Detailed Descriptions of Preferred Embodiments

FIGURE 1 illustrates a composite battery 10, which includes adjacent battery units 12 and 14, and an intercell connector 16 in accordance with this invention.

Battery units 12 and 14 are positioned such that the negative terminal 18 of unit 12 is closely adjacent to the positive terminal 20 of unit 14. Terminals 18 and 20 project above covers 22 of battery units 12 and 14. Intercell connector 16 incl de^ first and second terminal connectors 24 and 26 which are in position for engagement with terminals 18 and 20, respectively.

Intercell connector 16 has a flat braided cable 28 which is preferably about 1 to 1-1/2 inches (25-38 mm) wi and about 1/8 to 3/8 inches (3.2-9.5 mm) thick. Braided cable 28 is preferably made of a great many fine tinned copper strands, as shown in FIGURE 2, braided to give substantial longitudinal compressibility and extendabilit

In cross-section along its length, flat braided cabl 28 is a two-dimensional matrix of such strands, such matr including a large number of strands adjacent to one anoth along the narrow dimension of cable 28 and a still larger number of strands adjacent to one another along the wide dimension of cable 28.

Braided cable 28 has first and second ends 30 and 32 which engage first and second terminal connectors 24 and 26, respectively. Cable ends 30 and 32 are attached to terminal connectors 24 and 26 by die-casting formation of such metal terminal connectors onto the ends of cable 28.

Terminal connectors 24 and 26 have screw holes 34 which are in alignment with, threaded screw holes 36 in terminals 18 and 20. Screws (not shown) are used to firm connect terminal connectors 24 and 26 to terminals 18 and 20. Intercell connector 16, including terminal connector 24 and 26 and braided cable 28, is encapsulated by an integral polyvinyl chloride plastisol coating 38. Coatin 38 extends continuously over the entire outside surface o intercell connector 16, leaving exposed only the inside contacts surfaces 40 which contact post-like terminals 18 and 20. FIGURES 3 and 4 illustrate the method and apparatus used for making the intercell connector shown in FIGURES and 2. More specifically, FIGURES 3 and 4 illustrate a first molding apparatus 42 used for die-casting first and second terminal connectors 24 and 26 onto cable ends 30 an 32, respectively.

Molding apparatus 42 includes a lower (or "ejector") portion 44 and an upper portion 46. Lower and upper portions 44 and 46 each include two sections; lower portio 44 includes sections 44a and 44b and upper portion 46 includes sections 46a and 46b. These pairs of sections are held together by bolts 48, while lower and upper portions 44 and 46 are held together by means not shown.

Molding apparatus 42 allows die-casting for several intercell connectors at one time. FIGURE 4 shows cavities for two intercell connectors. Thus, sections 44a and 46a form several terminal-connector cavities 50a, and sections 44b and 46b form corresponding terminal-connector cavities 50b. Extending from each pair of terminal-connector cavities 50a and 50b are lateral openings 52a and 52b which are in alignment with one another. Lateral openings 52a and 52b provide a, space for laying a flat braided cable piece 28, as shown in FIGURES 3 and 4.

. Secured between lower portions 44a and.44b and between upper portions 46a and 46b is a spacer block 54. Spacer block 54, which is secured by means of bolts 48, forms a channel 56 which extends and joins lateral openings 52a and 52b to further accommodate £he placement of braided cable piece 28. Spacer block 54 is selected from a group of spacer blocks (not shown) having differing thicknesses. By choosing the appropriate spacer block, the intercell connector will be formed with the precise intended length. Lower portions 44a and 44b form flow channels 58a and 58b which allow the flow of molten metal, preferably lead, to terminal-connector channels 58a and 58b. Flow channels 58a and 58b are branched to allow flow to cavities for production of a number of intercell connectors. Flow channels 58a and 58b join upstream at flow channel 60, and channels 60 and 58a and 58b are fed by a plunger through sprue 62. This provides simultaneous casting of opposed terminal-connectors 24 and 26 for each intercell connector being made. Such simultaneous casting, under equal pressure, minimizes or eliminates any movement of braided cable 28 during the die-casting operation. After the injection of molten metal and the hardenin thereof to form terminal connectors 24 and 26, ejector pi

64 serve to eject terminal connectors 24 and 26, and with them attached braided cable 28, from molding apparatus 42.

FIGURES 5 and 6 illustrate a second molding apparatu 66 which is used for molding integral plastic coating lay 38 onto intercell connector 16, specifically, onto termin connectors 24 and 26 and braided cable 28 therebetween. I many respects, as will be noted, second molding apparatus 66 is similar to first molding apparatus 42. Molding apparatus 66 has lower and upper portions 68 and 70, each of which is divided into two sections. Likewise, second molding apparatus 66 includes a spacer block 72 which may be selected from a group of blocks to accommodate an intercell connector of specific length. For each intercell connector 16 which is being coated molding apparatus 66 has a pair of end spaces 74 for receiving terminal connectors 24.and 26. Adjoining each end space 74 is a lateral channel 76 for receiving that portion of braided cable 28 which extends from the termina connector. Lateral channels 76 are aligned with each other. Spacer block 72 has a channel 78 which extends and joins lateral channels 76.

Mounting posts 80 extend into end spaces 74 and are shaped for mating engagement with inside contact surfaces 40 of terminal connectors 44 and 46. Likewise, downwardly extending mounting posts 79 are for joining surfaces 81. Mounting posts 80 and 81 are positioned, and end spaces 74 lateral channels 76, and spacer block channel 78 are shaped, to provide a continuous clearance 82 around all portions of intercell connector 16 once intercell connecto 16 is properly supported on mounting posts 80 and 81.

Second molding apparatus 66, like first molding apparatus 42, provides flow channels 84 extending to end spaces 74 to provide a means for routing and injecting a flowable insulating material into continuous clearance 82, A preferred material, as indicated above for integral coating layer 38 is a polyvinyl chloride plastisol.

After formation of coating layer 38 on intercell connector 16, ejector pins 86 eject intercell connector 16 from second molding apparatus 66 in much the same way as i first molding apparatus 42. FIGURE 7 illustrates another preferred intercell connector 90. Intercell connector 90 has a cap 92 which i integrally formed with coating layer 38 and movably secure to coating layer 38 by means of flexible hinge 94. Cap 92 is dimensioned to readily snap into engagement with recess 96. Thus, cap 92 serves to cover the screw (not shown) which is used for attachment of intercell connector 90 to battery terminal.

While the principles of this^"invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.

Claims

1WHAT IS CLAIMED:

1. In a composite battery of the. type having at leas 5 one pair of discrete battery units with a corresponding pair of adjacent terminals and an intercell connector electrically connecting the adjacent terminals of each suc pair of units, the improvement wherein the intercell connector comprises a substantially straight length of ^■*^-0 braided cable and first and second terminal connectors secured to the cable at opposite ends thereof.

2. The composite battery of claim 1 wherein the braided cable is flat braided cable of length less than 5 about 15.24 cm, said cable forming, in cross-section along its length, a two-dimensional matrix of wire strands.

3. The composite battery of claim 2 wherein the terminal connectors are removably attached to the 0 terminals.

4. The composite battery of claim 2 wherein the terminal connectors are die cast onto the opposite ends of the cable.

5. The composite battery of claim 2 comprising an insulating coating over the cable and the terminal connectors which is integral from one of the terminal connectors to the other.

6. In a method for making an intercell connector including attachment of a terminal connector to a cable by die-casting the terminal connector onto the cable end, the improvement comprising:

— placing a substantially straight braided cable of given length onto a sectioned mold with opposite ends of the cable extending respectively into spaced terminal-connector cavities; and

10 - casting terminal connectors simultaneously on the opposite ends of the cable, whereby the center-to-center length of the intercell connector will consistently match the lengths of other intercell connectors made by the same method.

15

7. The method of claim 6 wherein the casting step comprises injecting molten metal simultaneously into both of the cavities under equal pressure.

20

8. The method of claim 6 wherein the cavities are in spaced terminal-connector cavity blocks and including the preliminary step of adjusting to an intended intercell connector length by placement of an appropriate spacer block between the terminal-connector cavity blocks.

25

9. The method of claim 6 including the subsequent steps, of:

- stripping the intercell connector from the mold, the ~₀ terminal connectors having inside contact surfaces;

- suspending the intercell connector in a second mold on mounting posts, the mounting posts contacting the intercell connectors only on the inside contact surfaces of the terminal connectors; and 5 - casting a flexible insulating layer integrally over the terminal connectors and braided cable.

10. An adjustable molding apparatus for making a substantially straight intercell connector of selected length of the type having a comprising:

- a pair of terminal-connector cavity blocks having a respective pair of aligned lateral openings for receiving a cable;

- means to support the terminal-connector cavity block at a selected spacing corresponding to the selected intercell connector length; and

- means for routing and injecting molten metal into th pair of cavity blocks at the same time.