A lid for a battery assembly

Abstract

A lid 100 for a battery assembly (700, Figure 7) for a vehicle (900, Figure 9) includes a central portion 102 positionable over one or more battery cells located within a battery frame 106 of the batt

Description

TECHNICAL FIELD The present disclosure relates to a lid for a battery assembly. Aspects of the invention relate to a lid, to a battery assembly, to a method of manufacturing a battery assembly and to a vehicle. BACKGROUND It is known to provide a battery assembly with a lid arranged to overlie a plurality of battery cells positioned within a battery frame of the battery assembly. The periphery of the lid is usually secured to the battery frame using a plurality of spaced apart fasteners which pass through apertures in the peripheral flange of the lid and are secured into the battery frame. A seal may be positioned between the periphery of the lid and the battery frame which is compressed when the lid and battery frame are secured together to keep the battery assembly watertight. The peripheral flange of the lid should therefore be appropriately sized so as to enable the seal to be compressed to the extent that a seal can be formed. However, other components, such as spacers, may be located on the battery frame which means that the battery frame should be wide enough to accommodate both the appropriately sized peripheral flange of the lid and the other components. As the external dimensions of the battery assembly are usually constrained by the battery assembly's location within the vehicle, it is sometimes necessary to increase the width of the battery frame to achieve the appropriate size for sealing purposes by reducing the internal dimensions of the battery frame instead of increasing the external dimensions. However, reducing the internal dimensions reduces the space available within the battery assembly for retaining battery cells. 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 Aspects and embodiments of the invention relate to a lid for a battery assembly, to a battery assembly, to a method of manufacturing a battery assembly and to a vehicle. According to an aspect of the present invention, there is provided a lid for a battery assembly for a vehicle, the lid comprising a central portion positionable over one or more battery cells located within a battery frame of the battery assembly and a first surface configured to abut a surface of the battery frame, wherein a section of the first surface comprises a first portion which extends away from the central portion by a first distance and a plurality of second portions which extend continuously away from the first portion at spaced apart locations by a second distance. The smaller first (“recessed”) portion relative to the second portion which extends beyond it, in a direction away from the central portion of the lid means that the peripheral flange is arranged such that the first portion is wide enough (as determined by the distance between central portion and edge of first portion of flange) to allow it to be seated on the battery frame such that it is immediately adjacent any structures on the battery frame such asspacers whilst the wider second portion provides a greater width of flange relative to the first portion and therefore increases the contact between the flange and the battery frame. This 1 means that the width of the underlying battery frame can be minimised because only the second portion is required to extend either side of the spacers. Minimising the width of the frame increases the internal space within the battery frame available for battery cells without increasing the overall (external) dimensions of the frame. According to an aspect of the present invention, there is provided a lid for a battery assembly for a vehicle, the lid comprising a central portion positionable over one or more battery cells located within a battery frame of the battery assembly and a peripheral flange configured to abut a surface of the battery frame, wherein a section of the peripheral flange comprises a first portion which extends away from the central portion by a first distance and a plurality of second portions which extend continuously away from the first portion at spaced apart locations by a second distance, and wherein the first distance is such that a continuous seal may be established along the entire section between the peripheral flange and the surface of the battery frame when the peripheral flange abuts the surface. The smaller first (“recessed”) portion relative to the second portion means that the peripheral flange is arranged such that the first portion is wide enough (as determined by the distance between central portion and edge of first portion of flange) to enable an underlying seal to be compressed to seal the battery assembly whilst accommodating adjacent structures on the battery frame such as spacers. This means that the width of the underlying battery frame can be minimised without the integrity of the seal being compromised. Minimising the width of the frame increases the internal space within the battery frame available for battery cells without increasing the overall (external) dimensions of the frame. The wider second portion provides more contact of the flange and the battery frame to further enhance the seal. Optionally, the first portion of the peripheral flange of the lid comprises an edge having a complementary profile to that of an adjacent component. Optionally, one or more of the adjacent component(s) comprises a spacer. Having a complementary profile to that of an adjacent component, such as a spacer, enables that portion of the flange to be positioned as close as possible to the component. This provides the possibility of applying the peripheral flange onto a narrower underlying part of the battery frame (e.g. side rail of the battery frame). This can mean that the internal dimensions of the battery assembly can be increased as narrower battery frame rails can be used, meaning that the internal dimensions of the battery frame can be commensurately increased which creates more space for accommodating battery cells. Optionally, each of the spaced apart locations of the second portions is positionable between two adjacent components when the peripheral flange abuts the surface. This arrangement increases the amount of surface area of the peripheral flange which is in contact with the underlying surface of the battery frame. This may assist in improving the quality of the seal between the lid and the battery frame. Optionally, one or both of the two adjacent components is a spacer. A spacer maintains the battery frame and an overlying component, such as but not limited to a load floor of a vehicle, at a fixed distance apart. Optionally, the lid comprises a shoulder portion between the central portion and the peripheral flange. The shoulder portion raises the central portion to a plane above the plane of the peripheral flange, thus 2 increasing the internal space within the battery assembly which enables more and / or larger battery cells to be accommodated within the battery frame. Optionally, the peripheral flange comprises a plurality of apertures for receiving fasteners for securing the peripheral flange to the surface of the battery frame. The plurality of apertures provides multiple fixing points for securing the flange to the battery frame. Optionally, the plurality of apertures are spaced apart from one another along the peripheral flange at a distance of between 40mm and 85mm, optionally 50mm to 70mm, optionally 65mm. In one or more embodiments, these example spacings ensure an even compression of the seal that underlies the peripheral flange when the lid is secured to the battery assembly. Optionally, the apertures are located at least partially in the second portion of the peripheral flange. This location allows the apertures to be formed in the widest part of the peripheral flange, meaning more of the flange material surrounds each aperture which helps improve seal quality due to more of the flange material being available to compress the underlying seal as compared to if the apertures were located entirely in the first portion. Optionally, a thickness of material forming the peripheral flange of the lid is 1 mm or less. Using a thickness of 1mm or less reduces the weight and cost of the component as compared to using a greater thickness of material. According to another aspect of the present invention, there is provided a battery assembly comprising a lid according to an aspect of the invention, and a battery frame. The aforementioned benefits of the lid are applicable to the battery assembly. Optionally, the battery assembly is a traction battery assembly. Traction battery assemblies may comprise a lid which is to be fitted around one or more components on the traction battery assembly frame and therefore the aforementioned benefits of the lid are applicable to traction battery assemblies. Optionally, the battery assembly comprises a sealing medium for sealing the lid of the battery assembly to the battery frame. The sealing medium prevents moisture ingress into the battery assembly. Optionally, the sealing medium is positioned between the peripheral flange and the surface of the of the battery frame. The gap between the peripheral flange and the surface of the battery frame may be vulnerable to moisture ingress. Positioning the sealing medium in this location prevents such moisture ingress through this gap. Optionally, the surface is a surface of a side rail of the battery frame. The side rail surface may be a convenient location on which to secure the lid of the battery assembly. According to another aspect of the present invention, there is provided a method of manufacturing a battery assembly, comprising sealing a lid according to an aspect of the present invention to a battery frame. The method provides a way of achieving a battery assembly having the benefits mentioned above in relation to the lid. According to another aspect of the present invention, there is provided a vehicle comprising a lid according to an aspect of the present invention, or a battery assembly according to an aspect of the present invention. The aforementioned benefits of the lid provide corresponding benefits to the vehicle. Optionally, the vehicle is a battery electric vehicle, a plug-in hybrid vehicle, or a mild hybrid vehicle. The vehicle battery assembly may be a primary or secondary energy source for vehicle propulsion. 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. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, 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. 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: Figure 1 shows a perspective view of a lid in accordance with an embodiment of the present invention; Figure 2 shows a plan view of the lid of Figure 1; Figure 3 shows a magnified view of a part of the peripheral flange of the lid shown in Figure 2 and illustrates a nominal boundary between a first portion and a second portion of the peripheral flange; Figure 4 shows a magnified view of a part of the peripheral flange of the lid shown in Figure 2 and illustrates the location of a sealing medium applied to the lid in an embodiment of the invention; Figure 5 shows a partial view of the lid shown in Figure 2, illustrating a part of the peripheral flange of the lid and adjacent central portion of the lid; Figure 6 shows an embodiment of a battery frame to which the lid shown in Figure 1 can be applied; Figure 7 shows a schematic illustration of a battery assembly in accordance with an embodiment of the present invention; Figure 8 shows a method of manufacturing a battery assembly in accordance with an embodiment of the invention; and Figure 9 shows a vehicle in accordance with an embodiment of the invention. DETAILED DESCRIPTION A lid in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figures 1 to 5. A battery frame to which the lid can be applied is described with 4 reference to Figure 6. A battery assembly in accordance with an embodiment of the invention shown in Figure 7, and a method of manufacturing a battery assembly in accordance with an embodiment of the invention is described with reference to Figure 8. Figure 9 illustrates a vehicle in which the battery assembly comprising the lid is installed. Figures 1 and 2 illustrate a lid 100 for a battery assembly for installation in a vehicle. In this embodiment, the lid 100 comprises a generally planar, rectangular metal sheet, formed from 1mm thick aluminum, which is pressed (stamped) during formation to define a central portion 102 which is bounded by a peripheral flange 104 which extends around the entire periphery of the central portion 102. In use, the peripheral flange 104 abuts a top surface 106a of a battery frame 106 (not shown on Figures 1 and 2). As will be described in more detail with reference to Figure. 3, the outermost edge of the peripheral flange 104 comprises a plurality of spaced apart recessed portions 204, indicated and more clearly visible on Figure 2. Also shown in Figure 2 is a sealing medium 202 which is applied to the underside of the peripheral flange 104, as will be described in more detail with reference to Figure 4. In the present embodiment, a rounded shoulder portion 110 is formed between the central portion 102 and the peripheral flange 104 during the stamping process. The rounded shoulder portion 110 comprises a first edge 110a and a second edge 110b, and the central portion 102 is contiguous with the first edge 110a of the shoulder portion 110. The shoulder portion 110 depends from the first edge 110a and curves outwardly and away from the first edge 110a to the second edge 110b. The second edge 110b is contiguous with the peripheral flange 104 which extends at approximately 90 degrees relative to a base of the shoulder portion 110 adjacent the second edge 110b such that the peripheral flange 104 is in a different but parallel plane relative to the plane of the central portion 102 of the lid 100, as can be seen in Figure 1. The provision of a lid 100 with a shoulder portion 110 between the central portion 102 and the peripheral flange 104 means that the plane of the central portion 102 can be spaced apart from that of the peripheral flange 104 thus creating a deeper lid 100 which allows the central portion 102 of the lid 100 to be raised above the battery frame 106 to which the lid 100 is applied. This arrangement increases the size of the underlying cavity 602 of the battery frame 106, thus increasing the space available within the cavity 602 for accommodating battery cells 702 (not visible in Figures 1 and 2, but shown in Figures 6 and 7). It will be appreciated that in embodiments of the invention (not illustrated) which do not comprise a shoulder portion between the central portion and the peripheral flange, the first portion of the peripheral flange of those embodiments may be contiguous with an edge of the central portion and may extend at a different angle to form the peripheral flange as compared to the present example. The central portion 102 of the lid 100 comprises a plurality of embossed regions 116 which are stamped into the sheet metal lid 100 during its formation to create regions 116 of the lid 100 which are raised on the uppermost surface of the lid 100, i.e. the outermost surface of the lid when the lid 100 is secured onto the battery frame 106. The boundary between each embossed region 116 and the substantially planar central portion 102 is defined by a shoulder 116a which bridges the distance between the embossed region 116 and the adjacent central portion 102. The embossed regions 116, including the shoulders 116a of each, provide the central portion 102 with additional strength and 5 rigidity due to the curved profile of the shoulder 116a of each embossed region 116, and this stiffens the component. The curved profile also reduces or eliminates mechanical stress concentrations in the lid 100 as compared to a sharp corner between the central portion 102 and the embossed regions 116. In one or more embodiments, embossed regions 116 may also be used to raise the height of localised regions of the lid 100 to accommodate components or features which are positioned under the lid 100 within a cavity 602 of the battery assembly 700 (not visible in Figures 1 and 2, but shown in Figures 6 and 7). These embossed regions 116 may take numerous forms and be of varying sizes and positions according to specific requirements, and therefore it is to be appreciated that the specific arrangement and form of the embossed regions 116 described and shown herein is not intended to be limiting. Figure 1 and Figure 2 show a plurality of positioning regions 118, 120 on central portion of the lid. These positioning regions are not features of the lid perse, in the present embodiment, but are an indication of the position at which assembly tools may be located for picking up and positioning the lid on the battery frame. Referring to Figure 3, the peripheral flange 104 of the lid comprises a first portion 104a which extends continuously around the entirety of the peripheral flange 104, and a plurality of second portions 104b each of which extend continuously away from the first portion 104a at spaced apart locations around the peripheral flange 104. A notional border 302 between the first portion 104a and the plurality of second portions 104b is illustrated in Figure 3. It is to be appreciated that this notional border 302 may be provided in different locations around the peripheral flange 104 and / or in different embodiments of the invention. As illustrated in Figure 3, the location of the notional border 302 in the present embodiment coincides with the location of apertures for receiving fasteners 114 which are used to secure the peripheral flange 104 of the lid 100 to the battery frame 106. This positioning of the fastener apertures relative to the notional border 302 allows pressure created by the fasteners 114 when they are tightened to be applied across both the first portion 104a and the second portion 104b to securely abut the peripheral flange 104 to the surface 106a of the battery frame 106. In the present embodiment, the first portion 104a of the peripheral flange 104 is contiguous with the second edge 110b of the shoulder portion 110 and extends at an angle of approximately 90 degrees relative to the shoulder portion 110 around the entire periphery of the central portion 102 by a first distance 302a, schematically shown on FIG. 3. This arrangement means that the peripheral flange 104 is in a substantially parallel plane to that of the central portion 102, but in a spaced apart arrangement, separated by the shoulder portion 110. However, in other embodiments which do not comprise a shoulder portion, the first portion 104a may extend away directly from an edge, or a notional edge, of the central portion 102. In such embodiments (not shown), the first distance 302a may be measured from the edge, or notional edge, of the central portion 102 to the notional border 302 of the peripheral flange 104. The second portions 104b of the peripheral flange 104 are defined by spaced apart regions 104b of the peripheral flange 104 which extend continuously away from the first portion 104a by a second distance 302b. As shown in the Figures, the outermost edge of the first portion 104a and inner edge of the second portions 104b are contiguous. The regions where the edges of the first portion 104a and second portions 104b meet may be curved, and / or may have a more angular profile. As can be seen in the Figures, this arrangement of the first portion 104a and spaced apart second portions 104b means that the peripheral edge of the first portion 104 located between two adjacent second portions 104b defines recessed portions 204 in the inner peripheral edge of the adjacent second portions. The plurality of recessed portions 204 formed by the spaces between each of the second portions 104b on the peripheral flange 104 is also shown on Figures 1 and 2. In this embodiment, the first distance 302a is approximately 11 mm, and the second distance 302b is approximately 16.5 mm, giving a total flange width (i.e. the total of the first distance and second distance) of 27.5 mm. It will be appreciated that in one or more other embodiments, the first distance 302a and / or second distance 302b may be different, for example, one or both of the first distance 302a and second distance 302b may be between 6mm and 20mm. The first distance 302a is such that a continuous seal may be established between the peripheral flange 104 and the surface 106a of the battery frame 106 when the peripheral flange 104 abuts the surface 106a. It will be appreciated that different first distances and second distances will commensurately affect the location of the notional border 302 between the first portion 104a and the second portion 104b. The relative size of each recessed portion 204 may vary between embodiments of the lid 100 and may depend on the size and / or shape of an adjacent component, such as a spacer 108. In the present example, each recessed portion 204 is adapted to fit around a spacer 108 which is fastened into a spacer aperture 606 in a side rail of the battery frame 106. As can be seen from Figures 3, 4 and 8, the recessed portion 204 curves commensurately with the curved profile of the spacer 108. This arrangement enables the recessed portions 204 of the peripheral flange 104 to be fitted onto the battery frame 106 closely around adjacent components such as spacers 108, without interfering with those components and whilst still providing a surface area of peripheral flange 104 which is capable of establishing a continuous seal between the peripheral flange 104 and the battery frame 106 when the peripheral flange 104 abuts the surface 106a of the battery frame 106. This can mean that if desired, the part of the battery frame to which the peripheral flange 104 is attached can be made narrower as compared to the width required to accommodate a planar edged peripheral flange that does not have recesses for accommodating adjacent components. This can provide the benefit of being able to reduce the overall dimensions of the battery frame, and thus the battery assembly, which may be useful if space forthe battery assembly is especially limited within the vehicle. Another benefit is that the internal dimension of the cavity of the battery frame can be increased without commensurately increasing the external dimensions of the battery assembly, since the width of the battery frame is reduced. By increasing the dimensions of the cavity, the space available for storing battery cells is also increased. As illustrated in Figure 4 (and also in Figure 2), in the present embodiment, a sealing medium 202 is positioned about the periphery of the lid 100 adjacent the shoulder portion 110. The sealing medium comprises a Room Temperatures Vulcanising (RTV) silicone sealant, such as but not limited to that provided under the trade mark Rimlex®, for example Rimlex 310™. It will be appreciated that other sealing medium compositions may be suitable. During assembly of the battery assembly, the sealing medium 202 is applied as a liquid which is sufficiently viscous enough to form a bead during application of the liquid. The bead of sealing medium 202 is applied in the region around and / or between the second edge 110b of the shoulder portion 110 of the lid 100 and notional boundary 302 of the first portion 104a of the peripheral flange 104. The liquid sealing medium 202 subsequently cures to form a resiliently deformable bead of sealing medium 202 along the first portion 104a of the peripheral flange 104. When the lid 100 is secured to the surface 106a of the battery frame 106, the sealing medium 202 is compressed by the peripheral flange 104 as the fasteners 114 are tightened into fastener apertures 608 in the battery frame 106, so as to seal the cavity 602 of the battery frame 106 against moisture ingress. In embodiments, equidistant spacing of the apertures 112 in the peripheral flange 104 ensures an even compression of the sealing medium 202 around the periphery of the lid 100. However, compression of the sealing medium 202 may still be achieved using irregular spacing of the apertures 112 and corresponding fasteners 114. Referring to Figure 5 (and also shown and described in relation to Figures 1 and 2), the peripheral flange 104 comprises a plurality of spaced apart apertures 112 for receiving fasteners 114 which can be secured into corresponding fastener apertures 608 on the battery frame 106, to secure the lid 100 onto the battery frame 106. The plurality of spaced apart apertures 112 are spaced approximately equidistance apart around the entire peripheral flange 104. In the present embodiment, the plurality of spaced part apertures are spaced apart at a distance of approximately 65mm. However, in one or more embodiments or vehicle environments, it may be necessary to use an alternative spacing in order to accommodate the spacers. The plurality of spaced apart apertures 112 are positioned so that they each bridge the first portion 104a and the second portion 104b of the peripheral flange 104, as shown on Figure 3 and Figure 4, for example. This positioning ensures that both the first portion 104a and the second portion 104b of the peripheral flange 104 are securely pressed against the underlying battery frame 106 when the fasteners 114 are secured through the spaced apart apertures 112 and into the corresponding fastener apertures 608 in the battery frame 106 when the lid 100 is fastened to the battery frame 106. It will be appreciated that in one or more other embodiments, the spaced apart apertures 112 may be positioned in the first portion 104a alone, and may still be able to securely press the entirety of the peripheral flange 104 to the surface 106a of the battery frame 106. Figure 6 illustrates a battery frame 106 to which the lid 100 is attached when the battery assembly is constructed. The battery frame 106 comprises a part of the battery assembly 700 and comprises a cavity 602 which is configured to retain battery cells (not visible on Figure 6). The cavity 602 is defined by a combination of the battery frame 106 which forms an enclosing wall of the cavity 602, and a base plate 604 which forms the base of the cavity 602. The lid 106 forms an upper boundary of the cavity 602 when the lid 106 is secured to the battery frame 106, as schematically illustrated in Figure 7. The battery frame 106 comprises a plurality of spacer apertures 606 which are spaced apart on an upper planar surface 106a of the battery frame. The spacer apertures 606 are positioned towards the lateral, i.e. outermost, edge, of the planar surface 106a. The spacer apertures 606 are configured to receive a spacer 108 for maintaining a fixed distance between the battery frame 106 and an overlying component, such as a vehicle body panel. It will be appreciated that in other embodiments, other components may be substituted for the spacers 108 shown in the present Figures. The upper planar surface 106a also comprises a plurality of spaced apart fastener apertures 608 which are positioned towards the medial, i.e. innermost, edge of the planar surface 106a. The fastener apertures are configured to receive fasteners 114 which secure the peripheral flange 104 of the lid 100 to the battery frame 106. In use, the central portion 102 of the lid 100 is positioned over the battery cells 702 and the battery frame 106 which surrounds them to form the battery assembly 700 which is schematically illustrated in FIG. 7. Accordingly, the lid 100 is sized and shaped during manufacturing so as to conform to the size and shape of the battery frame 106 component of the battery assembly 700. It will therefore be appreciated that in one or more other embodiments, the lid 100 may be provided in a different size, shape, material and / or configuration to that described herein, depending on the size and shape of the battery frame to which it will be secured. Figure 7 schematically illustrates a battery assembly 700 according to an embodiment of the Invention. During assembly of the battery assembly 700, the peripheral flange 104 abuts a surface 106a of the battery frame 106 such that the lid 100 rests on the surface 106a of the battery frame 106 to form the upper boundary of the cavity 602 of the battery frame 106. The central portion 102 of the lid 100 overlies battery cells 702 which are retained securely in the cavity 602. Figure 8 illustrates an example method of manufacturing a battery assembly 800 in accordance with an embodiment of the present invention. Although the example method of manufacturing a battery assembly 800 depicts a particular sequence of steps, the sequence may be altered without departing from the scope of the present disclosure. For example, some of the steps depicted may be performed in parallel or in a different sequence that does not materially affect the method of manufacturing a battery assembly 800. As another example, the step of shaping the peripheral flange of the lid of the battery assembly to define the first and second portions may be performed in the order set out below, or in a different order, such as during the step of cutting the aluminum sheet to a predetermined size. It will also be appreciated that not necessarily all steps involved in manufacturing the battery assembly are described. For example, the particular wiring arrangements for the battery assembly are not described, but will be within the scope of understanding of the skilled person. Similarly, the particular location of installation of the battery assembly is not described, since the installation location may vary depending on the constraints of the vehicle to which it is being fitted. In an embodiment of a method of manufacturing a battery assembly 800 according to the present invention, a sheet of 1mm thick aluminum is cut 802 to a predetermined size to fit over a battery frame 106 to form a lid 100 of the battery assembly 700. The cutting step 802 may also comprise selectively cutting the peripheral edge of the aluminum sheet to define recessed portions 204 in the peripheral edge of the sheet. These recessed portions 204 will form part of the first portions 104a of a peripheral flange 104 once production of the lid 100 is complete. Second portions 104b of the peripheral flange 104 are defined by regions of aluminum sheet remaining in the peripheral flange 104 either side of the recessed portions 204, and extending laterally beyond the first region to a peripheral edge of the peripheral flange 104. The cut aluminum sheet is stamped or embossed 804 to define a peripheral flange 104 around the periphery of the lid 100 for positioning the lid onto a surface 106a, such as a side rail of the battery frame 106. The peripheral flange 104 may be in the same plane as the remaining, more central part of the lid 100, or may be in a different plane to the remaining, more central part 102 of the lid 100, as shown in the Figures. The embossing step 804 may also comprise stamping one or more embossed regions 116 into the lid 100 to provide the lid 100 with increased rigidity. Once the peripheral flange 104 of the lid 100 has been formed, a plurality of apertures 112 are cut at spaced apart intervals around the peripheral flange 104, in step 806. These spaced apart apertures 112 are for receiving fasteners 114 to fasten the lid 100 to the battery frame 106 during assembly of the battery assembly 700. If the recessed portions 204 have not already been cut during the cutting step 802, then these are formed in step 806 to define the first portions 104a and second portions 104b of the peripheral flange 104 as described above by cutting recesses 204 out of regions of the peripheral flange 104 at intervals coinciding with the position of components such as spacers 108 which will be applied to the battery frame 106 during assembly of the battery assembly. In step 808, a sealing medium 202 is applied around the entirety of the peripheral flange 104 in the region which bridges the flange and the more central portion of the lid 100. The sealing medium 202 is applied as a bead of viscous liquid which subsequently cures to form a dry, compressible sealing bead 202 around the peripheral flange 104. In step 810, a plurality of battery cells 702 are installed in a cavity 602 of the battery frame 106. In step 812, a spacer 108 is fastened into each spacer aperture 606 on the battery frame 106 to maintain a predetermined fixed distance between the battery frame 106 and an overlying component. The overlying component may be a load floor, for example. In step 814, the lid 100 is positioned on the battery frame such that the peripheral flange 104 is seated on a surface 106a of the battery frame 106, and the recessed portions 204 of the peripheral flange 104 are positioned adjacent a medial side of each of the spacers 108 secured into the battery frame 106. The medial side of each of the spacers is the side closest to the cavity 602 of the battery frame 106. The second portions 104b of the peripheral flange 104 extend between the spacers 108. The plurality of apertures 112 on the peripheral flange 104 are aligned with the corresponding plurality of fastener apertures 608 on the battery frame. In step 816, the lid 100 is secured to the battery frame 106 by securing a fastener 114 through each of the plurality of apertures 112 on the peripheral flange 104 and into a corresponding fastener aperture 608 on the battery frame 106. Securing the fasteners 114 into the fastener apertures 608 causes the peripheral flange 104 of the lid 100 to be pressed against the surface of battery frame 106a. As the peripheral flange 104 is pressed against the surface of battery frame 106a, the underlying sealing medium 202 is also compressed, thus sealing the battery frame and preventing moisture ingress into the cavity 602 of the battery frame 106 in which the battery cells 702 are located. Figure 9 shows a vehicle 900 comprising the battery assembly which includes the lid 100. The battery assembly may be secured to the load floor of the vehicle 900. 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.

Claims

1. A lid (100) for a battery assembly (700) for a vehicle (900), the lid (100) comprising a central portion (102) positionable over one or more battery cells located within a battery frame (106) of the battery assembly (700) and a peripheral flange (104) configured to abut a surface (106a) of the battery frame (106), wherein a section of the peripheral flange (104) comprises a first portion (104a) which extends away from the central portion (102) by a first distance (302a) and a plurality of second portions (104b) which extend continuously away from the first portion (104a) at spaced apart locations by a second distance (302b), and wherein the first distance (302a) is such that a continuous seal may be established along the entire section between the peripheral flange (104) and the surface (106a) of the battery frame (106) when the peripheral flange (106) abuts the surface (106a).

2. A lid (100) according to claim 1, wherein the first portion (104a) and, optionally, at least part of the second portion (104b), comprises an edge having a complementary profile to that of an adjacent component.

3. A lid (100) as claimed in claim 2, wherein each of the spaced apart locations of the second portions (104b) is positionable between two adjacent components when the peripheral flange (104) abuts the surface (106a), optionally wherein one or both of the two adjacent components is a spacer (108).

4. A lid (100) as claimed in any preceding claim, wherein the lid (100) comprises a shoulder portion (110) between the central portion (102) and the peripheral flange (104).

5. A lid (100) as claimed in any preceding claim, wherein the peripheral flange (104) comprises a plurality of apertures (112) for receiving fasteners (114) for securing the peripheral flange (104) to the surface (106a) of the battery frame (106).

6. A lid (100) as claimed in claim 5, wherein the plurality of apertures (112) are spaced apart from one another along the peripheral flange (104) at a distance of between 40mm and 85mm, optionally 50mm to 70mm, optionally 65mm.

7. A lid (100) as claimed in claim 5 or claim 6, wherein the plurality of apertures (112) are located at least partially in the second portion (104b) of the peripheral flange (104).

8. A lid (100) as claimed in any preceding claim, wherein a thickness of material forming the peripheral flange (104) of the lid (100) is 1mm or less.

9. A battery assembly (700) comprising a lid (100) according to any preceding claim, and a battery frame (106).

10. A battery assembly (700) according to claim 9, wherein the battery assembly (700) is a traction battery assembly.

11. A battery assembly (700) as claimed in claim 9 or claim 10, comprising a sealing medium (202) for sealing the lid (100) of the battery assembly (700) to the battery frame (106).5 12. A battery assembly (700) as claimed in claim 11, wherein the sealing medium (202) is positionedbetween the peripheral flange (104) and a surface (106a) of the of the battery frame (106).

13. A battery assembly (700) as claimed in claim 12, wherein the surface (106a) is a surface of a side rail of the battery frame (106).1014. A method (800) of manufacturing a battery assembly, comprising sealing the lid (100) of any of claims 1 to 9 to a battery frame (106).

15. A vehicle (900) comprising the lid (100) of any of claims 1 to 9, or the battery assembly (700) of 15 any of claims 10 to 13.

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