Vehicle battery pack sealing

Abstract

A vehicle battery pack sealing cover 47 comprising: a coplanar perimeter 49 configured to provide a mating surface (53, Fig. 4B) for a sealing interface (55, Fig. B) with a vehicle battery pack 15 cas

Description

30 01 £6 TECHNICAL FIELD The present disclosure relates to vehicle battery pack sealing. Aspects of the invention relate to a vehicle battery pack and a vehicle. 5 BACKGROUND Vehicles which use a large battery pack to provide increased range during electric or hybrid driving typically locate this battery pack under the vehicle floor. Large battery packs are known to extend under the occupant’s seating space. This can either reduce the space available to occupants or lead to raised rooflines. Changes 10 to the structure of battery packs to increase occupant space can be challenging without increasing the risk of the battery packs being ineffectively sealed. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION 15 Aspects and embodiments of the invention provide a vehicle battery pack and a vehicle as claimed in the appended claims. According to an aspect of the present invention there is provided a vehicle battery pack according to claim 1. Also disclosed herein is a vehicle battery pack comprising: a battery pack casing defining a cavity for receiving battery cells; at least two sets of one or more battery cells received within the cavity defined by the battery pack casing, wherein the at least two sets are separated such that a free volume is formed therebetween; and a vehicle battery pack sealing cover comprising: a coplanar perimeter configured to provide a mating surface for a coplanar sealing interface with the battery pack casing; and at least one integrally formed depression dimensioned to accommodate at least one foot compartment in a vehicle floor. The vehicle battery pack 25 sealing cover is sealed to the battery pack casing along the co-planer sealing interface, closing the cavity defined by the battery pack casing, and the at least one integrally formed depression is located within the free volume. The sealing interface is an interface between the vehicle battery pack sealing cover and the casing of the 30 vehicle battery pack at which there is sealing to provide a barrier to ingress of water, dust, or other contaminants into the vehicle battery pack. The sealing interface is formed between respective mating surfaces of the vehicle battery pack sealing cover and the casing of the vehicle battery pack. The coplanar perimeter of the vehicle battery pack sealing cover provides one of the mating surfaces. Accordingly, this mating surface is a coplanar mating surface. 35 The coplanar perimeter, and thus mating surface, and the integrally formed depression cooperate to enable improved occupant comfort without compromising the aerodynamic performance of the vehicle and with a low risk of ineffective battery pack sealing. 30 01 £6 The vehicle battery pack sealing cover may be a sealing cover for a vehicle battery pack in which at least two sets of one or more battery cells are separated such that a free volume is formed therebetween for accommodating the at least one integrally formed depression of the sealing cover. 5 Optionally, a depth of the at least one integrally formed depression is at least 100 mm, which may contribute to a meaningful extension of leg room for an occupant’s comfort. A base of the at least one integrally formed depression is offset from a plane of the coplanar perimeter. A plane of the base of the at least one integrally formed depression may be displaced and / or rotated with respect to 10 the plane of the coplanar perimeter. The base of the at least one integrally formed depression may comprise a surface which is parallel to the plane of the coplanar perimeter. The base of the at least one integrally formed depression may be planar or may comprise one or more relief elements having depths less than a depth of the at least one integrally formed depression. In either case, this 15 accommodates an undisrupted and undivided foot compartment, providing more freedom for an occupant to position their feet however best suits their comfort. A shortest dimension of the base of the at least one integrally formed depression may be at least 350 mm, which accommodates a foot compartment to suit a large range of foot / shoe sizes. Optionally, the at least one integrally formed depression extends across a centreline of the vehicle battery pack sealing cover. This accommodates a shared foot compartment for all occupants in a common seating row. The at least one integrally formed depression may furthermore extend uninterrupted across a centreline of the vehicle battery pack sealing cover. The at least one integrally formed depression may furthermore span 25 a majority of a width of the vehicle battery pack sealing cover. Optionally, the at least one integrally formed depression may span a majority of a width of the vehicle battery pack sealing cover to accommodate adjacent foot compartments. 30 Also disclosed herein a vehicle comprising the vehicle battery pack sealing cover. A vehicle floor may overlie the vehicle battery pack sealing cover and comprise at least one depression collocated with the at least one integrally formed depression of the vehicle battery pack sealing cover to form the at least one foot compartment for vehicle occupants. 35 Optionally, the coplanar perimeter of the vehicle battery pack sealing cover corresponds to a perimeter of the battery pack casing. Optionally, the free volume spans a full width of the cavity defined by the battery pack casing. This 40 accommodates a foot compartment that spans the full width of the battery pack casing, enabling a shared foot compartment for all occupants in a common seating row. 30 01 £6 A depth of the cavity defined by the battery pack casing is greater than a depth of the at least one integrally formed depression of the vehicle battery pack sealing cover and one or more current conducting connections between the at least two sets of one or more battery cells are arranged to pass through a gap between the at 5 least one integrally formed depression of the vehicle battery pack sealing cover and a base of the cavity defined by the battery pack casing. Advantageously, the current conducting connections can therefore remain with the closed cavity and, since they therefore do not cross the boundary of the cavity they do not contribute to any increased risk of ineffective sealing in respect of the battery pack. 10 The vehicle battery pack sealing cover and the battery pack casing are configured to form, in combination, a single closed cavity. The at least two sets of one or more battery cells are received within the single closed cavity. Advantageously, the use of a single closed cavity reduces the amount of pressure management systems / devices that need to be employed and, since such systems and devices inherently involve locations at which the boundary of the cavity is crossed, the risk of ineffective sealing in respect of the battery pack is 15 correspondingly reduced. According to a further aspect of the invention, there is provided a vehicle comprising the vehicle battery pack. A vehicle floor may overlie the vehicle battery pack sealing cover and comprise at least one depression collocated with the at least one integrally formed depression of the vehicle battery pack sealing cover to form the at least one foot compartment for vehicle occupants. Also disclosed herein is a vehicle battery pack sealing cover comprising: a coplanar mating surface for a coplanar sealing interface with a casing of a vehicle battery pack; and at least one integrally formed depression 25 dimensioned to accommodate at least one foot compartment in a vehicle floor. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination 30 that falls within the scope of the appended claims. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination that falls within the scope of the appended claims, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. 35 BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG 1 illustrates an example of a vehicle; 40 FIGs 2A to 2C illustrate examples of a vehicles with different roof and floor configurations; FIG 3 schematically illustrates an exploded-view of an example battery pack; FIGs 4A and 4B illustrate an example of a battery pack; FIGs 5A and 5B illustrate another example of a battery pack; FIGs 6A and 6B illustrate another example of a battery pack; FIGs 7A and 7B illustrate another example of a battery pack; 5 FIGs 8A and 8B illustrate another example of a battery pack; and FIG 9 illustrates an example of a vehicle including a battery pack. DETAILED DESCRIPTION A vehicle 1 in accordance with an embodiment of the present invention is described herein with reference to 10 the accompanying FIG 1. In some, but not necessarily all examples, the vehicle 1 is a passenger vehicle, also referred to as a passenger car or as an automobile. In other examples, embodiments of the invention can be implemented for other applications, such as commercial vehicles. FIG 1 is a front perspective view and illustrates a longitudinal x-axis between the front and rear of the vehicle 15 1 representing a centreline, an orthogonal lateral y-axis between left and right lateral sides of the vehicle 1, and a vertical z-axis. A forward / fore direction typically faced by a driver’s seat is in the negative x-direction; rearward / aft is +x. A rightward direction as seen from the driver’s seat is in the positive y-direction; leftward is -y. These are a first lateral direction and a second lateral direction. FIG 2A illustrates an example of an occupant 3 seated in a vehicle 1. The occupant’s seating position involves a high hip point (‘H-point’) 11 relative to the vehicle floor 7, which provides a comfortable amount of leg room. To provide the occupant 3 with sufficient head room, the vehicle 1 has a high roof line 9. The high roof line 9 compromises the aerodynamic performance of the vehicle 1. 25 FIG 2B illustrates an example in which the seating position is lowered, for example by moving the seat 5 closer to the vehicle floor 7, in order to enable a lower roof line 9’ while still providing sufficient head room for the occupant 3. The lower seating position involves a low H-point 11 which reduces leg room and associated levels of comfort for the occupant 3. 30 FIG 2C illustrates an example in which a foot compartment 13 is sunken or recessed into the vehicle floor 7. The foot compartment 13 permits a lowering of the occupant’s heel and knee, raising the occupant’s effective H-point 11 without raising the seat 5. Accordingly, the roof line 9’ can remain low. The provision of a foot compartment 13 therefore improves occupant comfort without compromising the aerodynamic performance of the vehicle 1. 35 However, if the vehicle 1 comprises a traction battery, the battery pack 15 will typically be located under the vehicle floor 7, extending laterally (in Y) at least substantially from sill to sill and longitudinally (in X) at least substantially between front and rear axles. Accordingly, the battery pack 15 is redesigned to accommodate one or more foot compartments 13. 40 30 01 £6 30 01 £6 FIG 3 schematically illustrates an exploded-view of a battery pack 15 for a vehicle 1 according to an embodiment of the invention. The battery pack 15 comprises a battery pack casing 17, sometimes alternatively known as the battery frame, 5 and battery cells 37. The battery pack casing 17 defines a cavity 35 for receiving the battery cells 37. The battery pack casing 35 has a base 19 and side walls 21 extending from the base 19. The cavity 35 is defined by the base 19 and side walls 21. The cavity 35 has an opening defined by the free edges 23 of the side walls 21. The free edges 23 of the side walls 21 all lie in a common plane. In some but not necessarily all examples, a flange 25 extends from the free edges 23 of the side walls 21. The free edges 23 of the side walls 21 or the 10 flange 25, if present, define a perimeter 27 of the battery pack casing 17. The perimeter 27 is a coplanar perimeter. The battery cells 37 may be bonded directly into the battery pack casing 17 or a number of the battery cells 37 may be bonded together into a cell stack or a module of these cell stacks, which are then bonded into the 15 battery pack casing 17. As illustrated, the battery pack 15 has a split arrangement of battery cells 37. The battery cells 37 are arranged into at least two sets 39, 41 of one or more battery cells 37. Each set 39, 41 comprises one or more battery cells 37, cell stacks, or modules. In the battery pack 15 the at least two sets 39, 41 are separated such that a free volume 45 is formed between each set 39, 41. The free volume 45 is dimensioned to accommodate at least one foot compartment 13. In some but not necessarily all examples, the free volume 45 spans a full width of the cavity 35 defined by the 25 battery pack casing 17. The at least two sets 39, 41 of one or more battery cells 37 are separated in the longitudinal dimension (in X). In some but not necessarily all examples, the free volume 45 extends over a full depth of the cavity 35. In other examples, it extends down (-Z) from at least the opening to the cavity 35 to a depth of at least one horizontal (XY) layer of the battery cells 37, though it will be appreciated that at least one other layer of battery cells 37 may extend underneath the free volume 45. 30 The at least two sets 39, 41 of one or more battery cells 37 function as a single battery pack 15 and therefore one or more current conducting connections 43 are provided between the at least two sets 39, 41 of one or more battery cells 37. The one or more current conducting connections 43 may traverse the free volume 45 separating the sets 39, 41 of one or more battery cells 37. The one or more current conducting connections 35 43 can be in the form of a busbar or busbars. The busbars are generally made of copper, aluminium or other alloys. The battery pack 15 comprises a battery pack sealing cover 47. The battery pack sealing cover 47 is configured to close the cavity 35 defined by the battery pack casing 17 and seal the battery pack 15 to prevent or at least 40 reduce ingress of water, dust, or other contaminants. The battery pack sealing cover 47 comprises a coplanar perimeter 49. The coplanar perimeter 49 provides a mating surface 53 for a coplanar sealing interface 55 with the battery pack casing 17, as can be seen in, for example, FIG 4B. 5 In some but not necessarily all examples, the coplanar perimeter 49 of the battery pack sealing cover 47 corresponds to the perimeter 27 of the battery pack casing 17. That is, the two perimeters 47, 27 have matching geometries. The perimeter 27 of the battery pack casing 17 provides the other mating surface 29 for the coplanar sealing interface 55 between the battery pack sealing cover 47 and the battery pack casing 17. The sealing between the two mating surfaces 53, 27 may be effected through any suitable means such as a gasket 10 57 as can be seen in, for example, FIG 4B. The gasket 57 may be dispensed as a viscous liquid and formed in place. The gasket may be made from, for example, a Silane-modified polymer sealant. The sealing interface 55 being coplanar reduces how tightly toleranced each of the battery pack casing 17 and the battery pack sealing cover 47 have to be in order to provide an effective seal. Accordingly, this design of 15 the battery pack 15 has a low risk of ineffective sealing. The battery pack sealing cover 47 also comprises at least one integrally formed depression 59 dimensioned to accommodate at least one foot compartment 13 in the vehicle floor 7. In examples in which the battery pack sealing cover 47 comprises multiple integrally formed depressions 59, each integrally formed depressions 59 may accommodate one or more foot compartments 13. In the assembled battery pack 15, the at least one integrally formed depression 59 is located within the free volume 45 between two sets 39, 41 of one or more battery cells 37. 25 The at least one integrally formed depression 59 is formed within the coplanar perimeter 49 of the battery pack sealing cover 47 and therefore has no influence on the sealing interface 47. The at least one integrally formed depression 59 does not need to be formed with tight tolerances in order to ensure effective sealing. In some but not necessarily all examples, a base 61 of the at least one integrally formed depression 59 is 30 offset from a plane 51 of the coplanar perimeter 49. The base 61 of the at least one integrally formed depression 59 is out-of-plane with respect to the coplanar perimeter 49. It will be appreciated, however, that, while not illustrated, the battery pack casing 17 may define a cavity 35 too shallow to receive the full depth of the layer or layers of battery cells 37 or may define no cavity 35 at all. In such examples, the battery pack sealing cover 47 may extend upwards (+Z) from its coplanar perimeter 49 to provide, respectively, extra depth 35 to the cavity 35 or the cavity 35 in its entirety. In such examples, the battery pack sealing cover 47 and the battery pack casing 17 define, in combination, a closed cavity which contains the battery cells 37. In such examples, a base 61 of an integrally formed depression 59 could feasibly be coplanar with the perimeter 49 of the battery pack sealing cover 47. 40 In some but not necessarily all examples, a depth (in Z) of the at least one integrally formed depression 59 is at least 100 mm. In examples, the depth of the at least one integrally formed depression 59 can be 110 mm, 6 30 01 £6 30 01 £6 115 mm, 120 mm, or the like. This accommodates a floor compartment 13 with a depth of at least 100 mm with respect to the surrounding level of the vehicle floor 7. It will be appreciated that, if for example a gap is provided between the level of the surrounding floor 7 and the level of the coplanar perimeter 49 of the battery pack sealing cover 47, then the floor compartment 13 can have a greater depth than the at least one integrally 5 formed depression 59. For illustration: if the integrally formed depression has a depth of 115 mm and there is a 30 mm gap between the floor 7and the level of the coplanar perimeter 49 of the battery pack sealing cover 47, as may be the case in at least some examples, then a foot compartment 13 with a depth of 145 mm can be accommodated. The occupant’s effective H-point 11 can accordingly be raised by at least the depth of the floor compartment 13 (e.g., at least 100 mm) without affecting an occupant’s posture and without a need to 10 raise the vehicle’s roof line 9’. In some but not necessarily all examples, the battery pack sealing cover 47 and the battery pack casing 17 are configured to form, in combination, a single closed cavity, within which the at least two sets 39, 41 of one or more battery cells 37 are arranged. This implies that a gap 67 is formed between the base 19 of the battery 15 pack casing 17 and the at least one integrally formed depression 59, as can be seen in the example of FIG 4B, such that a portion of the cavity 35 containing a first set 39 of one or more battery cells 37 is not closed off from a portion of the cavity 35 containing the second set 41 of one or more battery cells 37. A depth (in Z) of the cavity 35 is therefore greater than the depth (in Z) of the at least one integrally formed depression 59. An advantage of the battery pack 15 comprising a single closed cavity is that pressure management with just one pressure release vent 31 configured to release excess pressure from the closed cavity during abnormal conditions such as thermal runaway (also known as a safety valve or pressure relief valve) and, optionally, just one pressure equalisation valve 33 configured to enable the pressure inside the closed cavity to equalise with ambient pressure regardless of temperature, altitude, and the like (also known as an ambient breather) is possible. This reduces the risk of ineffective sealing in respect of the battery pack 15 as it minimises the 25 number of points at which the boundary of the cavity 35 can be crossed. It will however be appreciated that a battery pack 15 comprising a single closed cavity is not limited to just one pressure release vent 31 and just one pressure equalisation valve 33. In some but not necessarily all examples, a longitudinal dimension (in X) of the base 61 is at least 350 mm to 30 accommodate a large range of foot / shoe sizes, and in most cases avoid a tight fit between the feet / shoes and the floor compartment 13. In some examples the base 61 may be angled ratherthan flat and in those examples, the longitudinal dimension refers to the dimension which is most longitudinal. The longitudinal dimension may be the shortest dimension of the base 61. For example, the lateral dimension 35 (in Y) of the base 61 may be longer than the longitudinal dimension. In some but not necessarily all examples, the at least one integrally formed depressions 59 spans a majority of a width (in Y) of the battery pack sealing cover 47. This enables the at least one integrally formed depression 59 to accommodate adjacent foot compartments 13 for multiple vehicle occupants 3 sitting in a seating row or to accommodate an extended, continuous foot compartment 13 for multiple vehicle occupants 3 sitting in a seating row. In the latter example, 40 an integrally formed depression 59 extends across a longitudinal centreline 69 of the battery pack 15 providing an uninterrupted channel spanning a majority of a width of the battery pack sealing cover 47. 30 01 £6 FIGS 4A to 8B illustrate examples of the battery pack 15 which has been described in relation to FIG 3, particularly examples exhibiting differences in the depressions 59 formed in their sealing covers 47. 5 FIG 4A illustrates a plan view of an example battery pack 15 in which view the battery pack casing 35 and the battery cells 37 are obscured by the battery pack sealing cover 47. FIG 4B illustrates a cross-sectional view along the centreline 69 of the same example battery pack 15. In this example the plane 63 of the base 61 of the at least one integrally formed depression 59 is offset from 10 the plane 51 of the coplanar perimeter 49. The base 61 of the at least one integrally formed depression 59 comprises a surface which is parallel to and displaced vertically (in Z) from the plane 51 of the coplanar perimeter 49. In this example, a depth of the cavity 35 in which the battery cells 37 are contained is greater than a depth of 15 the at least one integrally formed depression 59 of the battery pack sealing cover 47. The gap 67 between the at least one integrally formed depression 59 and the base {ref27] of the cavity 35 is sufficient to accommodate the one or more current conducting connections 43. The one or more current conducting connections 43 pass through the gap 67. The gap 67 could be approximately 30 mm deep (in Z) to accommodate busbars, but it will be appreciated that this depth is tuneable to whatever form and dimensions the one or more current conducting connections 43 take. For instance, the gap 67 can be enlarged to accommodate cables connecting two sets 39, 41 of one or more battery cells 37. FIG 5A illustrates a plan view of another example battery pack 15 in which view the battery pack casing 35 and the battery cells 37 are obscured by the battery pack sealing cover 47. FIG 5B illustrates a cross-sectional 25 view along the centreline 69 of the same example battery pack 15. This example differs from the one illustrated in FIGS 4A and 4B in that the plane 63 of the base 61 of the at least one integrally formed depression 59 is rotated with respect to from the plane 51 of the coplanar perimeter 49. The at least one integrally formed depression 59 is deeper at its rear than its front. While this reduces the 30 extent to which an occupant’s forefoot may be lowered, it does not necessarily reduce the extent to which the occupant’s heel and knee and knee may be lowered and therefore can facilitate raising of the occupant’s effective H-point 11 to the same extent as the example of FIGS 4A and 4B. In this example the front of the base 61 of the at least one integrally formed depression 59 is still displaced 35 vertically from the plane 51 of the coplanar perimeter 49; however, it will be appreciated that the base 61 of the at least one integrally formed depression 59 may be angled such that the front edge of the base is coplanar with the coplanar perimeter 49. The at least one integrally formed depression 59 may therefore have a triangular profile in cross section. 40 In all other respects, this example is the same as the example of FIGS 4A and 4B. 30 01 £6 FIG 6A illustrates a plan view of another example battery pack 15 in which view the battery pack casing 35 and the battery cells 37 are obscured by the battery pack sealing cover 47. FIG 6B illustrates a cross-sectional view along the centreline 69 of the same example battery pack 15. 5 This example differs from the one illustrated in FIGS 4A and 4B in that the base 61 of the at least one integrally formed depression 59, rather than consisting of a planar surface, comprises one or more relief elements 65. The one or more relief elements 65 are raised or indented features on a surface of the base 61 such as ribs, as illustrated, or grooves. The depths of one or more relief elements 65 are less than the depth of the at least one integrally formed depression 59. Their function is to stiffen the base 61 without significantly reducing the 10 depth of the foot compartment 13 that can be accommodated. It will be appreciated that one or more relief elements 65 may also be provided on angled bases 61 such as that illustrated in the example of FIGS 5A and 5B. 15 In all other respects, this example is the same as the example of FIGS 4A and 4B. FIG 7A illustrates a plan view of another example battery pack 15 in which view the battery pack casing 35 and the battery cells 37 are obscured by the battery pack sealing cover 47. FIG 7B illustrates a cross-sectional view along the centreline 69 of the same example battery pack 15. In this example, the battery cells 37 are arranged into three sets 39, 41,71 of one or more battery cells 37 and the battery pack sealing cover 47 comprises two integrally formed depressions 59_1,59_2 which are located in the respective free volumes 45_1, 45_2 between the sets 39, 41, 71. The second integrally formed depression 59_2 accommodates a foot compartment for occupants of a further row of seating. It will be 25 appreciated that the battery cells 37 may be split into still further sets and still further integrally formed depressions 59 may be provided in order to accommodate foot compartments for still further rows of seating. Although both integrally formed depressions 59_1, 59_2 are illustrated as having the same geometry as the example of FIGs 4A and 4B, it will be appreciated that they may have any of the geometries previously 30 described. It will also be appreciated that they may have different geometries to one another. It will also be appreciated that their bases 61 may also comprises one or more relief element 65 as in the example of FIGs 6A and 6B. In all other respects, this example is the same as the example of FIGS 4A and 4B. 35 FIG 8A illustrates a plan view of another example battery pack 15 in which view the battery pack casing 35 and the battery cells 37 are obscured by the battery pack sealing cover 47. FIG 8B illustrates a cross-sectional view along the lateral line 73 of the same example battery pack 15. 40 This example differs from the one illustrated in FIGS 4A and 4B in that, rather than extending uninterrupted across the centreline 69 of the battery pack sealing cover 47, two integrally formed depressions 59_3, 59_4 9 30 01 £6 are provided on either side of the centreline 69, accommodating a foot compartment 13 for an occupant 3 on a left side of the vehicle 1 and a foot compartment 13 for an occupant 3 on a right side of the vehicle 1 respectively. 5 Although both integrally formed depressions 59_3, 59_4 are illustrated as having the same geometry as the example of FIGs 4A and 4B, it will be appreciated that they may have any of the geometries previously described. It will also be appreciated that they may have different geometries to one another. It will also be appreciated that their bases 61 may also comprises one or more relief element 65 as in the example of FIGs 6A and 6B. It will also be appreciated that one or more further rows of integrally formed depressions 59_3, 10 59_4 may be provided as in the example of FIGs 7A and 7B. In all other respects, this example is the same as the example of FIGS 4A and 4B. The battery pack sealing cover 47 can be fabricated from sheet metal such as sheet aluminium or sheet mild 15 steel or any other material which is capable of closing a Faraday cage around the battery cells 37 in conjunction with the battery pack casing 17. Superplastic forming may be used to shape the sheet metal into the battery pack sealing cover 47. The superplastic forming can comprise a blow forming step. Superplastic forming can achieve very steep draft angles and tight corner radii for the at least one integrally formed depression 59 to maximise the volume of the foot compartment 13 that can be accommodated. Alternatively, hot form quenching offers less steep draft angles and less tight fillet radii at a lower cost and cold forming provides a still lower cost option but requires large draft angles and generous fillet radii to allow material to flow. FIG 9 schematically illustrates a cross section through a vehicle 1 comprising the battery pack 15. The vehicle floor 7 overlies the battery pack sealing cover 47 and comprises at least one depression 75 which is collocated 25 with the at least one integrally formed depression 59 of the battery pack sealing cover 47 and forms the at least one foot compartment 13 for a vehicle occupant 3. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. 30 Features described in the preceding description may be used in combinations other than the combinations explicitly described. Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether 35 described or not.

Claims

1. A vehicle battery pack sealing cover comprising:a coplanar perimeter configured to provide a mating surface for a coplanar sealing interface with a casing of a vehicle battery pack; andat least one integrally formed depression dimensioned to accommodate at least one foot compartment in a vehicle floor.

2. The vehicle battery pack sealing cover according to claim 1, wherein a depth of the at least one integrally formed depression is at least 100 mm.

3. The vehicle battery pack sealing cover according to claim 1 or claim 2, wherein a base of the at least one integrally formed depression is offset from a plane of the coplanar perimeter.

4. The vehicle battery pack sealing cover according to claim 3, wherein the base of the at least one integrally formed depression is planar or comprises one or more relief elements having depths less than a depth of the at least one integrally formed depression.

5. The vehicle battery pack sealing cover according to any of claims 3 to 4, wherein a shortest dimension of the base of the at least one integrally formed depression is at least 350 mm.

6. The vehicle battery pack sealing cover according to any preceding claim, wherein the at least one integrally formed depression extends across a centreline of the vehicle battery pack sealing cover.

7. The vehicle battery pack sealing cover according to claim 6, wherein the at least one integrally formed depression spans a majority of a width of the vehicle battery pack sealing cover.

8. A vehicle battery pack comprising:a battery pack casing defining a cavity for receiving battery cells;at least two sets of one or more battery cells received within the cavity defined by the battery pack casing, wherein the at least two sets are separated such that a free volume is formed therebetween; andthe vehicle battery pack sealing cover according to any preceding claim, wherein the vehicle battery pack sealing cover is sealed to the battery pack casing along the co-planer sealing interface, closing the cavity defined by the battery pack casing, and the at least one integrally formed depression is located within the free volume.

9. The vehicle battery pack according to claim 8, wherein the free volume spans a full width of the cavity defined by the battery pack casing.

10. The vehicle battery pack according to claim 8 or claim 9, wherein a depth of the cavity defined by the battery pack casing is greater than a depth of the at least one integrally formed depression of the vehicle battery pack sealing cover, and wherein one or more current conducting connections between the at least two11sets of one or more battery cells are arranged to pass through a gap between the at least one integrally formed depression of the vehicle battery pack sealing cover and a base of the cavity defined by the battery pack casing.5 11. The vehicle battery pack according to any of claims 8 to 10, wherein the vehicle battery pack sealingcover and the battery pack casing are configured to form, in combination, a single closed cavity.

12. The vehicle battery pack according to any of claims 8 to 11, wherein the coplanar perimeter of the vehicle battery pack sealing cover corresponds to a perimeter of the battery pack casing.1013. A vehicle comprising the vehicle battery pack sealing cover according to any of claims 1 to 7 or the vehicle battery pack according to any of claims 8 to 12.

14. The vehicle according to claim 13, wherein a vehicle floor overlies the vehicle battery pack sealing 15 cover and comprises at least one depression collocated with the at least one integrally formed depression of the vehicle battery pack sealing cover and forming the at least one foot compartment for vehicle occupants.Amendments to the Claims have been filed as follows30 01 £6CLAIMS1. A vehicle battery pack comprising:a battery pack casing defining a cavity for receiving battery cells;at least two sets of one or more battery cells received within the cavity defined by the battery pack 5 casing, wherein the at least two sets are separated such that a free volume is formed therebetween; anda vehicle battery pack sealing cover comprising:a coplanar perimeter configured to provide a mating surface for a coplanar sealing interface with the battery pack casing; andat least one integrally formed depression dimensioned to accommodate at least one 10 foot compartment in a vehicle floor,wherein the vehicle battery pack sealing cover is sealed to the battery pack casing along the coplaner sealing interface, closing the cavity defined by the battery pack casing, and the at least one integrally formed depression is located within the free volume, andwherein a depth of the cavity defined by the battery pack casing is greater than a depth of the at least 15 one integrally formed depression of the vehicle battery pack sealing cover, and wherein one or more current conducting connections between the at least two sets of one or more battery cells are arranged to pass through a gap between the at least one integrally formed depression of the vehicle battery pack sealing cover and a base of the cavity defined by the battery pack casing.

2. The vehicle battery pack according to claim 1, wherein the depth of the at least one integrally formed depression is at least 100 mm.

3. The vehicle battery pack according to claim 1 or claim 2, wherein a base of the at least one integrally formed depression is offset from a plane of the coplanar perimeter.

4. The vehicle battery pack according to claim 3, wherein the base of the at least one integrally formed depression is planar or comprises one or more relief elements having depths less than a depth of the at least one integrally formed depression.30 5. The vehicle battery pack according to claim 3 or 4, wherein a shortest dimension of the base of theat least one integrally formed depression is at least 350 mm.

6. The vehicle battery pack according to any preceding claim, wherein the at least one integrally formed depression extends across a centreline of the vehicle battery pack sealing cover.

357. The vehicle battery pack according to claim 6, wherein the at least one integrally formed depression spans a majority of a width of the vehicle battery pack sealing cover.

8. The vehicle battery pack according to any preceding claim, wherein the free volume spans a full 40 width of the cavity defined by the battery pack casing.

9. The vehicle battery pack according to any preceding claim, wherein the vehicle battery pack sealing cover and the battery pack casing are configured to form, in combination, a single closed cavity.5 10. The vehicle battery pack according to any preceding claim, wherein the coplanar perimeter of thevehicle battery pack sealing cover corresponds to a perimeter of the battery pack casing.

11. A vehicle comprising the vehicle battery pack according to any preceding claim.10 12. The vehicle according to claim 11, wherein a vehicle floor overlies the vehicle battery pack sealingcover and comprises at least one depression collocated with the at least one integrally formed depression of the vehicle battery pack sealing cover and forming the at least one foot compartment for vehicle occupants.30 01 26o

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