Field of the invention

The present disclosure relates to an apparatus for assembling battery packs and a method for assembling battery packs.

Background

Batteries combine chemical and electrical elements. The chemical elements store electrical charge and need to be contained within the battery to ensure the battery operates effectively. In addition, the chemicals may be toxic or harmful to the environment, so there is a need to protect the chemical elements and ensure that the chemicals do not leak.

The electrical elements may also need to be protected, for example from water or from inadvertent contact by a user, for example to prevent short-circuiting of the battery. In addition, batteries generally need to be portable to fulfil their function of providing electrical power to systems where mains electricity may not be suitable.

Batteries are in general tailored to a specific purpose - for example their size, capacity and power output is selected to fulfil that specific purpose. This means, however, that a battery tailored for one specific purpose may not be suitable for another purpose, for example due to its size or capacity.

Summary of the invention

Aspects of the invention are as set out in the independent claims and optional features are set out in the dependent claims. Aspects of the invention may be provided in conjunction with each other and features of one aspect may be applied to other aspects.

Drawings

Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1A shows a cross-section through an example battery pack; Fig. 1 B shows an exploded view of a region of the cross-section of Fig. 1 A;

Fig. 2 shows an example apparatus for assembling battery packs in operation;

Fig. 3 shows an example apparatus for assembling battery packs in operation;

Fig. 4 shows an example flow process for assembling battery packs;

Fig. 5 shows an example apparatus for assembling battery packs in operation; and Fig. 6 shows a plurality of loaded cassettes forming part of an example apparatus for assembling battery packs

Fig. 7 shows another example apparatus for assembling battery packs in operation. Specific description

Embodiments of the disclosure relate to an apparatus for assembling battery packs that allows stacks of batteries to be quickly and easily loaded into a battery pack. The apparatus 200, for example as shown in Fig. 2, comprises a cassette 201 for holding a plurality of batteries 900 in at least one stack. It also comprises an aligner 210 arranged to hold the at least one stack of batteries in a configuration where a respective hole 105 of each battery 900 is aligned, and an indexer 205 arranged to release the aligned at least one stack of batteries 900 from the cassette 201 for assembly of the battery pack 100. Advantageously, such embodiments may allow battery packs 100 to be assembled quickly and more efficiently. Embodiments of the disclosure also allow different sized battery packs 100 to be quickly and easily assembled, thereby allowing a single battery pack assembly apparatus 200 to be customisable to manufacture battery pack assemblies 100 having differing numbers of batteries 900 for different purposes. Because battery packs 100 of the disclosure may be assembled bespoke for each intended purpose, the battery packs 100 can be assembled to fit the selected number of batteries needed and therefore may reduce the carbon footprint of the battery pack assembly 100 by reducing unnecessary packaging. An aspect of the disclosure provides an apparatus for assembling battery packs, such as the assembled battery pack 100 shown in Figs. 1A and 1 B. As shown in Fig. 1A, the assembled battery pack 100 comprises a stack of batteries held between a first plate 101 and a second plate 103. The battery pack assembly 100 provides an enclosure for the stack of batteries, for example a sealed enclosure such as a waterproof enclosure, to protect the batteries 900. Each battery 900 has a housing enclosing at least one battery cell. The housing is configured to protect the battery cell from damage. Each battery 900 forming the stack of batteries 900 may be modular so that any number of batteries 5 900 can be used to form the stack of batteries. For example, in example embodiments, each battery 900 is identical. A stack of batteries may comprise every battery 900 of the stack being in the same orientation, or may comprise selected batteries 900 of the stack being in different orientations. 0 Each battery 900 of the stack of batteries comprises at least one hole 105 extending therethrough, and in the example shown each battery 900 has four holes 105, each hole 105 at a respective corner of the battery 900. Each hole 105 extends in the same direction. Each hole 105 extends in a thickness direction through each battery 900, which is the smallest dimension of each battery 900. Each of the respective holes 105 of5 each battery are aligned so that the holes 105 of the batteries of the stack of batteries are aligned. First and second plates 101 , 103 are provided either side of the stack of batteries to sandwich the stack of batteries. The first plate 101 has a plurality of holes 102 matching the number of holes 105 in each battery 900. The second plate 103 also has a plurality of holes 104, also matching the number of holes 105 in each battery 900.0 The holes 105 of each battery 900 are aligned with the holes 102, 104 of the two plates 101 , 103.

A stud 1 10 extends through each hole 102 in the first plate 101 , through each set of aligned holes 105 of the stack of batteries, and through each hole 104 in the second5 plate 103, to couple the first and second plates 101 together and to clamp the batteries 900 of the stack of batteries between the two plates 101 , 103. The coupling arrangement can be seen in better detail in Fig. 1 B. The studs 1 10 may comprise, for example, a threaded bar and may comprise a head 1 1 1 at one end (with an outer diameter greater than the diameter of the hole 102 in the first plate 101 ) for engagement0 with the first plate 101 , and a nut 1 12 (with an outer diameter greater than the diameter of the hole 104 of the second plate 103) threaded onto the threaded bar at the other end for engagement with the second plate 103. Additionally or alternatively, each stud 1 10 may be integrated into one of the plates 101 , 103, for example each stud 1 10 may be integrated into the first plate 101.

Each plate 101 , 103 may be sprung to provide additional pressure to the stack of batteries. For example, each plate 101 , 103 may be slightly bowed in the middle to provide pressure to the middle of the stack of batteries when the two plates 101 , 103 are clamped together. For example, each plate 101 , 103 may be made from sprung steel.

An example apparatus 200 for assembling a battery pack, such as the battery pack assembly 100 shown in Figs. 1A and 1 B, is shown in Fig. 2. The apparatus 200 comprises a cassette 201 for holding a plurality of batteries 900 in at least one stack. In the example shown, the cassette 201 comprises a single stack of three batteries 900 although in other examples it will be understood that the cassette 201 can hold a plurality of stacks of batteries, and that each stack can vary in the number of batteries 900 it comprises.

The cassette 201 comprises an indexer 205 for releasing a stack of batteries 900 from the cassette 201. In the example shown, the indexer 205 comprises a plurality of fingers. The spacing of the fingers is selected based on the dimensions of each battery 900, for example so that a finger sits on either side of, and separates, each battery 900 of the stack of batteries. Each finger extends at least partially into the stack of batteries to separate at least two batteries 900. Each battery 900 of the stack of batteries has a long edge and a short edge. In the example shown the fingers of the indexer 205 separate the batteries 900 along their long edge, thus providing access to their short edge (which may comprise features of the battery 900 that are useful for access, such as terminals). It will be understood, however, that in other examples there may not be a finger between each battery 900 of a stack. For example, in some examples there may be a finger separating each stack of batteries. Each finger may comprise a non-friction coating to aid retraction. Each finger may be made from nylon or hardened steel, for example. The cassette 201 shown in Fig. 2 also comprises an aligner 210. In the examples shown, the aligner 210 comprises a set of tubes, but as will be described below, other types of aligner 210 may be used. A respective tube is provided for aligning each set of holes 105 of the batteries 900. For example, because the batteries 900 shown in the examples each have four holes 105, four tubes are provided. The batteries 900 are loaded into the cassette 201 such that the holes 105 of each respective battery are aligned. The tubes of the aligner 210 extend through the aligned sets of holes 105 to hold the batteries in an aligned stack in the cassette 201.

Each tube has an outer diameter smaller than the diameter of the holes 105 of each battery 900, and an inner diameter greater than that of each stud 1 10, so that each tube can fit over each stud 1 10 inside the hole 105 of each battery 900. As with the fingers of the indexer 205, each tube of the aligner 210 may comprise a non-friction coating to aid retraction. Each tube may be made from nylon or hardened steel, for example.

The aligner 210 is arranged to align the respective hole 105 of each battery 900 with the respective hole 105 of each of the other batteries 900 of the stack of batteries. The aligner 210 is therefore arranged to hold the stack of batteries 900 in a configuration where the respective holes 105 of each battery 900 are aligned. In the example shown, the aligner 210, for example each tube of the aligner 210, is arranged to extend through the respective hole 105 of each battery 900 to align the respective hole 105 of each battery 900 with the respective hole 105 of each of the other batteries 900 of the stack of batteries.

The aligner 210 is also configured to align the respective holes 105 of each battery 900 of the stack of batteries with a jig 300, for example as shown in Fig. 4. In the examples shown, the jig 300 comprises the first plate 101. The apparatus 200 is configured to align the respective hole 105 of each battery 900 of the stack of batteries with a respective location on the first plate 101.

As shown in Fig. 2, the first plate 101 comprises four studs 1 10 (one for each set of aligned holes 105) extending substantially vertically from the first plate 101. The studs 1 10 extending from the first plate 101 act as the jig 300. The aligner 210 is therefore configured to align the respective holes 105 of each battery 900 of the stack of batteries with the studs 1 10.

In the examples shown, the aligner 210 does this by aligning each of the tubes of the aligner 210 with the jig 300. The aligner 210 then slides each tube over each stud 1 10, as shown in Fig. 2, to align and locate the holes 105 of each battery with the studs 1 10.

The indexer 205 is arranged to release the stack of batteries onto the first plate 101. In the example shown, the apparatus is configured to release an aligned stack of batteries from the cassette 201 by operating at least one of the plurality of fingers. At least one of the fingers of the indexer 205 is configured to retract to release and drop a battery 900 over the studs 1 10 and onto the first plate 101 , so that the battery 900 is released in a configuration that is aligned with the first plate 101.

The indexer 205 is operable to release a selected number of batteries 900 from the cassette 201. For example, at least one of the plurality of fingers is arranged to count the number of batteries 900 released from the cassette 201. The indexer 205 may be computer operated, for example by a controller coupled to the indexer 205, and may be programmed to release differing numbers of batteries 900, for example depending on the intended use of the battery pack 100 being assembled. For example, the indexer 205 may be configured to operate a selected number of fingers to release a corresponding number of batteries 900 to form a stack of batteries of a selected height. Alternatively, each finger may be operated to release a respective stack of batteries.

Each tube of the aligner 210 is arranged to electrically insulate the stack of batteries from the stud 1 10. In some examples, such as that shown in Fig. 2, the aligner 210 is arranged to retract each tube from the aligned stack of batteries after the stack of batteries have been released from the cassette 201. However, in other examples, the aligner 210 is configured to leave each tube in the aligned and released stack of batteries. Due to the relative dimensions of each tube, stud 110 and hole 105, each tube is arranged to inhibit movement of each battery 105 of the stack of batteries relative to the stud 1 10. The apparatus 200 is also configured to align a location on the second plate 103, such as the holes 104 in the second plate 103, with the aligned holes 105 of the stack of batteries. For example, the aligner 210 is configured to align each hole 104 in the second plate 103 with the jig 300. For example, the aligner 210 is configured to align each hole 104 in the second plate 103 with a respective stud 1 10.

The apparatus 200 is configured to lower the second plate 103 onto the aligned stack of batteries. The apparatus 200 also comprises a tightener 500, as shown in Fig. 3, for mechanically coupling the second plate 103 to the first plate 101 via the studs 1 10. For example, the tightener 500 may comprise a torque wrench, and mechanically coupling the second plate 103 to the first plate 101 via the studs 1 10 may comprise tightening a nut 1 12 onto a threaded end of each stud 1 10 to a selected torque. In this way, the stack of batteries can be clamped between the first and second plates 101 , 103 to a selected pressure. Because the jig 300, in the example shown, comprises the first plate 101 and studs 1 10, the assembled battery pack 100 therefore comprises the jig 300.

The battery pack 100 is assembled by operating the apparatus 100 to align the stack of batteries with the jig 300 and release the stack of batteries onto the jig 300. Accordingly, another aspect of the disclosure provides a method for assembling battery packs, such as the battery pack 100 described above and as shown in Fig. 1.

In use, the stack of batteries are held in the cassette 201. The aligner 210 aligns the respective hole 105 of each battery 900 of the at least one stack of batteries in the cassette 201. In the example shown, the tubes of the aligner 210 align the respective hole 105 of each battery 900 of the stack of batteries in the cassette 201 with a jig 300. The jig 300 in the examples shown comprises a set of studs 100 extending from the first plate 101. The aligner 210 therefore aligns the respective hole 105 of each battery 900 with a location (in the example shown being the studs 1 10) on the first plate 101 , and aligning the respective hole 105 of each battery 900 of the stack of batteries with the jig 300 comprises aligning a respective set of holes 105 of the stack of batteries with a corresponding stud 1 10.

In the example shown, aligning a respective set of holes 105 of the stack of batteries with the jig 300 comprises sliding a respective tube over each stud 1 10 such that each stud 100 extends through a respective tube and the respective holes 105 of each battery 900 in the stack of batteries. The indexer 205 is operated to release the aligned stack of batteries from the cassette 201 for assembly of the battery pack 100. Operating the indexer 205 to release the stack of batteries from the cassette 201 comprises operating at least one of the plurality of fingers to release one of the stacks of batteries from the cassette 201. In this way, the 5 aligned stack of batteries are dropped onto the first plate 101 and over the studs 1 10 into the battery pack assembly 100. In some examples, at least one of the fingers of the indexer 205 counts the number of batteries 900 in the aligned stack of batteries 900 released from the cassette 201 and is operable to release a selected number of batteries 900 from the cassette 201 onto the first plate 101 and/or into the battery pack assembly 10 100.

In some examples, once the batteries 900 have been released from the cassette 201 , the tubes of the aligner 210 are removed from the battery pack assembly 100, however it will be understood that in other examples the tubes may be left in, for example to provide 15 additional electrical insulation between the batteries 900 and the studs 1 10, and/or to inhibit movement of the batteries 900 inside the battery pack assembly 100.

Once the stack of batteries has been released, the apparatus 200, for example the aligner 210, aligns a location on the second plate 103 with the aligned holes 105 of the

20 stack of batteries. In the example shown, aligning a location on the second plate 103 with the aligned holes 105 of the stack of batteries comprises aligning respective holes 104 in the second plate 103 with respective sets of aligned holes 105 of the stack of batteries. In the example shown, aligning respective holes 104 in the second plate 103 with respective sets of aligned holes 105 of the stack of batteries comprises aligning

25 each hole 104 in the second plate 103 with a respective stud 1 10 passing through each set of aligned holes 105 of the stack of batteries.

The second plate 103 is then released onto the stack of batteries, and the first plate 101 and the second plate 103 are mechanically coupled together via the studs 1 10 passing 30 through the aligned holes 105 of the stack of batteries to mechanically clamp the stack of batteries together. In the example shown, the tightener 500 is operated to fasten a respective nut 1 12 over a threaded end of each stud 1 10 to a selected torque. ln some examples, as shown in Fig. 4, the apparatus comprises a conveyor 400 for carrying components of the battery pack assembly 100 relative to the cassette 201. For example, the conveyor 400 is arranged to carry and position the jig 300 relative to the cassette 201. As noted above, the jig 300 may comprise the first plate 101 and/or the 5 studs 1 10 extending from the first plate 101. The conveyor 400 shown in Fig. 4 comprises a moving belt arranged to carry components of the battery pack assembly 100 along as the battery pack assembly 100 is being assembled. Of course, the conveyor 400 may take a number of different forms to fulfil a function of carrying components of the battery pack assembly 100 relative to the cassette 201. For example, the conveyor 10 may comprise a robotic arm.

In some examples the aligner 210 does not comprise tubes. For example, in some examples the aligner 210 comprises a set of locating cups that may each be seated on the end of a respective stud 1 10. The aligner 210 may be configured to align the 15 respective hole 105 of each battery 900 of the stack of batteries with a respective stud 1 10 by placing a portion of the stud 1 10 in the locating cup of the aligner 210.

In some examples, the studs 1 10 do not already extend from the first plate 101. In such examples, the aligner 210 may be configured to align each tube with a respective hole 20 102 on the first plate 101. Once each set of aligned holes 105 in the batteries 900 of the stack of batteries in the cassette 201 is aligned with the respective holes 102 in the first plate 101 , the stack of batteries may be released onto the first plate 101. The apparatus 200 may then be configured to insert a respective stud 1 10 through each set of aligned holes 102, 105.

25

Alternatively, the apparatus 200 may be configured to align the second plate 103 with the aligned stack of batteries released onto the first plate 101. For example, the jig 300 may comprise the first plate 101 and the second plate 103. For example, the aligner 210 may be arranged to align respective holes 104 in the second plate 103 with respective sets of 30 aligned holes 102 in the first plate 101 and aligned holes 105 through the stack of batteries. Once the holes 104 of the second plate 103 are aligned with the holes 105 of the stack of batteries and the holes 102 in the first plate 101 , the apparatus 200 may be configured to insert a respective stud 1 10 through each set of aligned holes 102, 104, 105 and then mechanically couple the first and second plates 101 , 103 together via the studs 1 10, for example using the fastener 500 described above.

In some examples, the aligner 210 may comprise the stud 1 10, and the jig 300 may comprise the first plate 101 and the holes 102 in the first plate 101. The aligner 210 may be configured to align each set of aligned holes 105 of the stack of batteries with a respective hole 102 in the first plate 101. In such examples, the cassette 201 may comprise a set of studs 1 10, for example each extending through a respective set of aligned holes 105 of the batteries 900 of the stack of batteries. The aligner 210 may be arranged to align the respective hole 105 of each battery 900 with the jig 300 by aligning each stud 1 10 with a respective hole 102 in the first plate 101. The aligner 210 may be configured to lower the studs 1 10 into the respective holes 102 in the first plate 101.

The aligner 210 may also be configured to align the second plate 103 with the aligned holes 105 of the batteries 900 of the stack of batteries and the holes 102 of the first plate 101 , for example by aligning the holes 104 in the second plate with the holes 105 of the batteries 900 and the holes 102 in the first plate 101. For example, if studs 1 10 are already extending through the aligned sets of holes 102, 105 then the aligner 210 may be configured to align the holes 104 of the second plate 103 with the studs 1 10.

An assembled battery pack 100 may comprise a plurality of stacks of batteries, for example, an assembled battery pack 100 may comprise two stacks of batteries side-by- side. As shown in Fig. 4, a plurality of stacks of batteries could be released side-by-side onto the first plate 101 , so that the assembled battery pack 100 comprises multiple stacks of batteries. For example, the apparatus 200 may comprise two or three cassettes 201 side-by-side, such as shown in Fig. 6. In other examples, each cassette 201 may be configured to hold a plurality of stacks side-by-side. Additionally or alternatively, because each cassette 201 may be operable to hold a plurality of stacks of batteries, the cassette 201 may be operate to release a first stack of batteries at a first location, for example on a first plate 101 , and release a second stack of batteries at a section location, for example adjacent to the first location on the first plate 101. Both stacks of batteries may be aligned via the aligner 210 in the same way as described above. In some examples, a stack of batteries held by the cassette 201 may be electrically coupled prior to release from the cassette 201. For example, the method of assembling a battery pack may comprise electrically coupling a stack of batteries held in the cassette 5 201 , and wherein releasing the stack of batteries from the cassette 201 comprises releasing the electrically coupled stack of batteries from the cassette 201. The stack of batteries may be electrically coupled via a bus bar 600, for example as shown in Fig 5. The bus bar 600 may electrically couple the batteries 900 of the stack of batteries along the short edge of the batteries 900.

0

In some examples, each battery 900 of the stack of batteries comprises at least two terminals, for example at least three terminals on their short edge. For example, two of the terminals may be arranged for electrically coupling the battery 900 to other batteries 900 of the stack of batteries and, if present, one of the terminals may be arranged for5 electrically coupling to at least one of a thermistor and a balancing harness. Each battery 900 of a stack may be stacked in the same orientation or in other orientations. For example, selected batteries 900 of the stack of batteries may be stacked upside down relative to the other batteries 900 of the stack (for example flipped like a pancake). For example, every alternate battery 900 of a stack may be arranged upside down0 relative to the other batteries 900 of the stack. Arranging the batteries 900 of the stack in this way may mean that the polarity of the terminals on the short edge alternates from side-to-side from battery 900 to battery 900 in the stack. For example, the terminals of the batteries 900 may alternate so that a terminal of a lower battery 900 has an opposite polarity to an adjacent terminal of an adjacent upper battery 900 along the same side of5 the short edge of the battery 900. This may be advantageous, for example, to more efficiently electrically couple the batteries 900 of the stack, for example with the bus bar 600.

To achieve this alternate stacking of the batteries 900, the batteries 900 may be stacked0 in alternate orientations in the same cassette 201 , or stacked in different orientations in different respective cassettes 201. For example, respective cassettes 201 may each comprise batteries 900 held in a particular orientation. For example, one cassette 201 may hold batteries 900 in one orientation and another cassette 201 may hold batteries 900 in another, alternate, orientation. For example, batteries 900 may be released from respective cassettes 201 (for example by a controller) in sequence to achieve the selected stacking orientation. For example, the apparatus 200 may be configured to move the jig 300 relative to the cassette 201 , or the cassette 201 relative to the jig 300, 5 so that a selected battery 900 can be released from the cassette 201 onto the jig 300 and into the battery pack assembly 100 to form a desired stacking orientation. In this way, the orientation of batteries 900 relative to each other in a stack of batteries may be selected to more efficiently electrically couple the batteries 900 of a stack of batteries together.

10

In the examples shown, the stack of batteries is released from the cassette 201 downwards, so that it drops onto the first plate 101 due to gravity. However, it will be understood that the cassette 201 may release the stack of batteries in any orientation. For example, the cassette 201 may be configured to raise a stack of batteries up from

15 underneath the first plate 101. For example, the conveyor 400 may have a gap for the cassette 201 to raise the stack of batteries through. The conveyor 400 may be configured to convey the first plate 101 onto the gap so that the first plate 101 is aligned with the batteries 900 of the stack of batteries in the cassette 201. Once aligned, the cassette 201 may be configured to raise the stack of batteries up and onto the conveyor

20 400.

In some examples, the battery pack assembly 100 may be assembled by adding components of the battery pack assembly 100 to the cassette 201. For example, the holes 102 of the first plate 101 may be aligned with the holes 105 of the stack of batteries

25 and the first plate 101 raised onto the cassette 201. The cassette 201 may already comprise the second plate 103 pre-loaded and aligned with the stack of batteries, so that the first plate 101 can be fastened onto the stack comprising the pre-loaded second plate 103. The first plate 101 may be fastened onto the stack in the cassette 201 , for example, by aligning respective studs 1 10 with respective holes 104 in the first plate 101 and

30 respective sets of aligned holes 105, 104 in the stack of batteries and second plate 103 and inserting the studs 1 10 through the respective sets of holes 104, 105 in the cassette 201. ln some examples the jig 300 comprises the first plate 101 and the holes 102 in the first plate and/or studs 1 10 extending from the first plate 101. Additionally or alternatively the jig may comprise studs 1 10 alone, or may comprise the second plate 103 and holes 104 in the second plate 103.

In some examples at least one of the plates 101 , 103, for example the first plate 101 , may be provided integrated into a base of an enclosure for the battery pack assembly 100. For example, a base of the battery pack assembly 100 may comprise a trough comprising the first plate 101 at a bottom thereof with studs 1 10 protruding from the first plate 101. The trough may be configured to be open or openable on one side for providing access to at least one side, for example the short side, of the stack of batteries inside the base. In such examples, the battery pack assembly 100 may also comprise a lid and/or wall sections for coupling with the base and the method of assembly may comprise placing the wall sections and/or the lid on the base section and coupling the sections together. For example, the lid section may couple to the second plate and thereby clamp a number of wall sections therebetween. In such examples, releasing an aligned stack of batteries from the cassette 201 may comprise placing the aligned stack of batteries into the base of the battery pack assembly 100. It will be understood from the above that the batteries 900 for assembling the battery pack assembly 100 may be manufactured so that they are pre-loaded into the cassette 201. For example, if the batteries 900 themselves are manufactured in a physical location, such as a country, that is different to where the back pack assemblies 100 themselves are assembled, the batteries 900 could be shipped pre-loaded onto the cassettes 201 which would result in efficiency gains in the assembly process and may reduce the amount of packaging involved in manufacturing the battery pack assemblies 100, thereby reducing the carbon footprint of the battery pack assembly 100.

Although in the above examples each plate 101 , 103 and each battery 900 comprises a plurality of holes 102, 104, 105, it will be understood that they may each only have one hole, and therefore that only one stud 1 10 may couple the plates 101 , 103 together to clamp the stack of batteries therebetween. Another example apparatus 700 for assembling a battery pack, such as the battery pack assembly 100 shown in Figs. 1A and 1 B, is shown in Fig. 7.

The apparatus 700 comprises a cassette 201 suspended above a conveyor 400. The cassette 201 comprises two opposing guides 203 extending in a height direction perpendicular to the conveyor 400 and extending the entire height of the cassette 201. Each guide 203 forms a wall of the cassette 201 , so that the cassette 201 has walls on two opposing sides and is open on the other two opposing sides. Two tubes forming an aligner 210 are arranged between the two guides 203 parallel to the two guides 203. In the example shown, the two tubes extend the height of the cassette 201 and are generally coterminous with the guides 203 that hold the tubes. The two tubes are made from a material having a low coefficient of friction, such as nylon or hardened steel.

One of the guides 203 also has two fingers forming an indexer 205. One finger is at the bottom end of one of the guides 203, and the other finger is roughly half-way up the same guide 203. The guides 203 also comprise an actuator (not shown) to actuate the fingers of the indexer 205. The two fingers are also made from a material having a low coefficient of friction, such as nylon or hardened steel. The cassette 201 in Fig. 7 holds two stacks of batteries between the two guides 203. Each stack of batteries comprises three batteries 900 stacked on top of each other. Each battery 900 of each stack of batteries has at least two holes 105 therethrough, as described above in relation to Figs. 1A and 1 B. The stacks of batteries are fed onto the cassette such that the two tubes forming the aligner 210 extend through the respective holes 105 of each battery 900 such that the batteries 900 of the stacks of batteries are held in place in the cassette 201 and aligned by the guides 203 on either side and by the tubes of the aligner 210 extending through the holes 105 of the batteries 900. The first and lowest stack of batteries is supported from falling out of the cassette 201 by the lowest finger of the indexer 205. The second stack of batteries is suspended above the first stack by the second finger of the indexer 205 half-way up the wall of one of the guides 203 of the cassette 201. Each stack of batteries is coupled together by a bus bar 600 on the edge (in this example being a short edge) away from the fingers of the indexer 205. A jig 300 is located below the cassette 201 on the conveyor 400. The jig 300 comprises the first plate 101 of the battery pack assembly 101 and two studs 1 10 extending substantially perpendicularly up from the first plate 101. The spacing between the two 5 tubes of the aligner 210 of the cassette 201 , and the spacing between the two studs 1 10 of the jig 300 are the same, such that the tubes of the aligner 210 can fit over the studs 1 10 of the jig 300.

The conveyor 400 is operable to carry and position the jig 300 relative to the cassette 10 201. The two tubes of the aligner 210 are arranged to hold the two stacks of batteries in a configuration where the respective hole 105 of each battery is aligned. The aligner 210 is configured to align the respective hole 105 of each battery 900 of the stack of batteries with the jig 300. The aligner 210 may be operable to do this, for example, by sensing the position of the jig 300 relative to the cassette 201 via a sensor (not shown), and sending 15 signals to a controller (not shown) to operate the conveyor 400 to position the jig 300 in the desired, aligned, position. The controller may be operable to control other components of the apparatus 700, such as the indexer 205, once the aligner 210 has aligned the batteries 900 of the stack of batteries with the jig 300. Additionally or alternatively, the cassette 201 itself may be positionable relative to the conveyor 400 (for 20 example in a direction transverse to a direction of movement of the conveyor 400).

The fingers of the indexer 205 are retractable through the guide 203, for example by operation of the optional actuator described above, for example in response to receiving command signals from a controller once the batteries 900 of the stack of batteries are

25 aligned with the jig 300. One finger of the indexer 205 may be operable at a time, for example so that the lower finger is operated first to release the lower stack of batteries but the upper stack of batteries is not released by the second, upper finger. In this way, the indexer 205 is arranged to release one aligned stack of batteries at a time from the cassette 201 for assembly of the battery pack 100. The cassette 201 is configured to

30 retract the tubes of the aligner 210 from the battery pack assembly once the stack of batteries has been released from the cassette 201.

In operation, a jig 300 comprising the first plate 101 and the studs 1 10 is loaded onto the conveyor 400. The batteries 900 are also loaded into the cassette 201 by sliding the batteries 900 onto the tubes of the aligner 210. The batteries 900 loaded in the cassette are separated into two stacks, and the fingers of the indexer 205 are operated to hold the stacks apart. The two stacks are then coupled together by the bus bars 600, so that the batteries of the first stack are coupled together by a first bus bar 600, and the batteries of the second stack are coupled together by a second bus bar 600. Of course, in other examples the batteries 900 may be coupled together by respective bus bars 600 prior to loading into the cassette 201. The conveyor 400 carries the jig 300 towards the cassette 201 such that the jig 300 is located under the cassette 201. The aligner 210 aligns with the studs 1 10 of the jig 300, and the cassette 201 is lowered down towards the jig 300 and the conveyor 400. The cassette 201 may be lowered down so that the studs 1 10 of the jig extend through the tubes of the aligner 210, and the base of the cassette 201 is in contact with the first plate 101 of the jig. In some examples the cassette 201 may be lowered only partially such that only a portion of the studs 1 10 of the jig 300 extend into the tubes of the aligner 210.

Once the cassette 201 is lowered such that the studs 1 10 of the jig 300 extend through the tubes of the aligner 210 in the cassette 201 , the lower finger of the indexer 205 is operated to release the lower stack of batteries from the cassette 201 onto the jig 300. The stack of batteries slides over the tubes of the aligner 205 and/or over the studs 1 10 of the jig 300 until the stack of batteries rests on the first plate 101 and the stack of batteries is released from the cassette 201. The cassette 201 and tubes of the aligner 210 are then retracted from the jig 300 such that the cassette 201 is once again suspended above the conveyor 400. The fingers of the indexer 205 are then operated so that the upper stack of batteries is dropped down to replace the deposited first stack of batteries. To do this, the lower finger of the indexer 205 remains in position blocking the end of the cassette 201 , and the upper finger of the indexer 205 is retracted, so that the upper stack of batteries can slide down the tubes of the aligner 210 inside the cassette 201.

The conveyor 400 then moves the jig 300 comprising the deposited batteries 900 along away from the cassette 201. A second plate 103 is aligned with and coupled to the studs 1 10 of the jig 300 to a selected torque to clamp the stack of batteries between the two plates 101 , 103. This may be using a tightener such as the tightener 500 shown in Fig. 3 and as described above. For example, the apparatus 700 may comprise a robotic arm 5 (not shown) that carries the second plate 103 relative to the jig 300 comprising the deposited stack of batteries, located the second plate 103 over the studs 1 10 of the jig 300, and lowers the second plate 103 onto and over the studs 110 until the second plate 103 rests on top of the deposited stack of batteries. A tightener, such as the tightener 500 shown in Fig. 3 and described above, may then place a respective nut 1 12 on each 10 stud 1 10 and tighten it to a selected torque. The robotic arm and/or tightener may be controlled by a controller, for example the same controller that may control the conveyor 400, the indexer 205 and the aligner 210. Additionally or alternatively the second plate 103 may be aligned with and coupled to the studs 110 by a user.

15 Although the cassette 201 described above in relation to Fig. 7 comprises two tubes forming the aligner 210, it will be understood that in other example the two tubes are not necessary. For example, the guides 203 acting as walls of the cassette 201 may act to align the batteries 900 such that their respective holes 105 are aligned. For example, the guides 203 may be arranged to provide a corner for a corresponding corner of each

20 respective battery 900 to abut and align with.

It will be appreciated from the discussion above that the embodiments shown in the Figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims. In the context of the

25 present disclosure other examples and variations of the apparatus and methods described herein will be apparent to a person of skill in the art. For example, the way the aligner 210 aligns with the jig 300 can be varied, or the order in which the cassette 201 releases the stack of batteries onto the plates 101 , 103 can be varied. Whether or not the studs 1 10 pass through the stack of batteries 900 before or after the second plate

30 103 is aligned with the stack of batteries can also be varied.

It will also be understood that the components and their functionality described in relation to one embodiment may be interchanged with that of another embodiment. For example, the features described above in relation to Fig. 7 (such as the cassette 201 , aligner 210 or indexer 205) may be replaced or provided by similar features (such as the cassette 201 , aligner 210 or indexer 205) described above in relation to the embodiments of any of the other Figures. Similarly, the jig 300 described above in relation to Fig. 7 may be provided in a different form, such as described above in relation to the embodiments of any of the other Figures, and accordingly the method of assembly described above in relation to Fig. 7 may be adapted or altered as appropriate to accommodate the different jig 300 and assembly process. In some examples, one or more memory elements can store data and/or program instructions used to implement the operations described herein. For example, embodiments of the disclosure provide tangible, non-transitory storage media comprising program instructions operable to program a processor to perform any one or more of the methods described and/or claimed herein and/or to provide data processing apparatus as described and/or claimed herein. For example, tangible, non-transitory storage media may comprise program instructions operable to program a processor to operate the cassette 201 , the conveyor 400, the aligner 210, the indexer 205 and the tightener 500 to assemble a battery pack assembly such as the battery pack assembly 100 described above.

The methods and apparatus outlined herein may be implemented using controllers and/or processors which may be provided by fixed logic such as assemblies of logic gates or programmable logic such as software and/or computer program instructions executed by a processor. For example, the cassette 201 , aligner 210, indexer 205, conveyor 400 and tightener 500 may be operable by a controller comprising a processor. The processor may be programmed to assemble the battery pack assembly 100 by operating the cassette 201 , aligner 210, indexer 205, conveyor 400 and tightener 500 in the manner described above. For example, the processor may be programmed to operate the tightener 500 to mechanically couple the first and second plates 101 , 103 via the studs 1 10 to a selected torque. Other kinds of programmable logic include programmable processors, programmable digital logic (e.g., a field programmable gate array (FPGA), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM)), an application specific integrated circuit, ASIC, or any other kind of digital logic, software, code, electronic instructions, flash memory, optical disks, CD-ROMs, DVD ROMs, magnetic or optical cards, other types of machine-readable mediums suitable for storing electronic instructions, or any suitable combination thereof.