Battery lid fastener, battery back and method of securing a lid to a battery pack

Abstract

A fastener for an electric vehicle (EV) battery pack lid is provided. The fastener includes an elongated body having first and second opposite ends, and upper and lower surfaces extending between the first and second ends. First and second legs extend from the first and second ends, respectively. First and second retaining features are disposed at terminal ends of the first and second legs, respectively. The first and second retaining features are insertable through openings in a battery pack lid and corresponding openings in a battery pack housing. The first and second retaining features are engageable with a surface of the housing or lid to clamp the lid to the housing. A battery pack for an electric vehicle including the fastener and a method of securing a lid to an electric vehicle battery pack using the fastener are also provided.

Description

BATTERY LID FASTENERCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 63 / 536,967, filed September 7, 2023, the disclosure of which is incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The disclosure generally relates to battery packs for electric vehicles (EVs) and, more specifically, to fasteners for securing a lid / cap to a battery pack.BACKGROUND OF THE INVENTION

[0003] An electric vehicle utilizes a battery pack including a plurality of battery cells to store and provide a source of power to drive the vehicle. The battery cells are contained within a housing of the battery pack. EV battery packs typically have a removable lid / cap that covers over and closes an opening to the internal space within the housing of the battery pack. On average, about 80 fasteners are necessary to secure the lid / cap onto the battery pack housing in order to enclose the battery cells of the battery pack within the housing. At the same time, in conjunction with a seal (gasket or similar), the lid / cap seals the battery pack. In order to provide an adequate leakproof seal from the external environment (including moisture, dust, etc.), the lid / cap should compress the seal against a surface of the battery housing such that the seal is sandwiched between the lid / cap and the housing. Conventionally, the fasteners used to fix the lid / cap to the battery pack and to compress the seal are bolts. However, installation cycle time and cost are both concerns with the use of bolts to mount the lid / cap onto the battery pack housing. Therefore, a need exists for a quicker, easier, and less costly fastener for securing a lid / cap to a battery pack.BRIEF SUMMARY

[0004] An improved fastener for an electric vehicle (EV) battery pack lid is provided. The fastener includes an elongated body having first and second opposite ends, and upper and lower surfaces extending between the first and second ends. A first leg extends from the first end, and a second leg extends from the second end. A first retaining feature is disposed at a terminal end of the first leg, and a second retaining feature is disposed at a terminal end of the second leg. The first retaining feature is configured to be insertable through a first opening in a battery pack lid and a corresponding first opening in a battery pack housing and is configured to be engageable with a surface of the battery pack housing or a surface of thebattery pack lid. The second retaining feature is configured to be insertable through a second opening in a battery pack lid and a corresponding second opening in a battery pack housing and is configured to be engageable with a surface of the battery pack housing or a surface of the battery pack lid. When the first and second retaining features are engaged with the surface of the battery pack housing or the surface of the battery pack lid, the first and second retaining features clamp the battery pack lid to the battery pack housing.

[0005] In specific embodiments, each of the first and second retaining features is a flexible, elastic element including a pair of inwardly facing projections, with each projection including a clip face and a chamfer.

[0006] In specific embodiments, each of the first and second retaining features includes a release tab.

[0007] In specific embodiments, the elongated body includes at least one resilient member projecting away from the lower surface.

[0008] In certain embodiments, each resilient member is a cantilevered tab extending parallel to the first and second legs.

[0009] In certain embodiments, each resilient member includes at least one prong at a terminal end thereof.

[0010] In certain embodiments, the fastener includes two of the resilient members.

[0011] In certain embodiments, the resilient member is a single flexible strap connected between the first and second ends of the elongated body.

[0012] In certain embodiments, each resilient member is a cantilevered tab extending perpendicular to the first and second legs.

[0013] In particular embodiments, each resilient member extends from a side of the elongated body between the first and second ends.

[0014] In specific embodiments, the elongated body, the first and second legs, and the first and second retaining features are all part of a one-piece element formed by bending portions of a metal piece.

[0015] A battery pack for an electric vehicle (EV) is also provided. The battery pack includes a housing defining an internal chamber and having an opening providing access to the internal chamber. A plurality of battery cells are disposed in the internal chamber. A seal is disposed around the perimeter of the opening. A lid covers over the opening and sandwiches the seal between the housing and the lid. The battery pack further includes a first opening in the lid and a corresponding first opening in the housing, and a second opening in the lid and a corresponding second opening in the housing. The battery pack further includes a fastener as described in the preceding paragraphs. The fastener is insertable through the first opening in the lid and the corresponding first opening in the housing, and also is insertable through the second opening in the lid and the corresponding second opening in the housing. Thefastener is engageable with the first and second openings in the housing or the lid to clamp the lid to the housing and to compress the seal between the lid and housing.

[0016] In specific embodiments, the first and second openings in the lid have a circular shape, an oval shape, or a polygonal shape.

[0017] In specific embodiments, the first opening in the lid and the corresponding first opening in the battery pack housing have a complementary circular, oval, or polygonal shape, and the second opening in the lid and the corresponding second opening in the battery pack housing have a complementary circular, oval, or polygonal shape.

[0018] In specific embodiments, the corresponding first and second openings in the battery pack housing are each a cutout in an outer edge of the battery pack housing.

[0019] In certain embodiments, each cutout includes a straight surface.

[0020] A method of securing a lid to an electric vehicle (EV) battery pack is also provided. The method includes disposing the lid on a housing of the battery pack to cover a compartment opening in the housing. The lid includes a first opening and the housing includes a corresponding first opening, and the lid further includes a second opening and the housing further includes a corresponding second opening. A fastener as described in the preceding paragraphs is preassembled on the lid such that said first retaining feature of the fastener is inserted into the first opening in the lid and said second retaining feature of the fastener is inserted into the second opening in the lid. The method further includes aligning the first opening in the lid with the corresponding first opening in the housing, and aligning the second opening in the lid with the corresponding second opening in the housing. The method further includes pushing the fastener towards the lid to insert said first retaining feature into the corresponding first opening in the housing thereby engaging said first retaining feature with a surface of the housing adjacent the corresponding first opening, and to insert said second retaining feature into the corresponding second opening in the housing thereby engaging said second retaining feature with a surface of the housing adjacent the corresponding second opening. Engagement of the first and second retaining features with the housing clamps the lid to the housing.

[0021] In specific embodiments, the method further includes disposing a seal between the housing and the lid, wherein clamping the lid to the housing with the fastener compresses the seal between the lid and housing.

[0022] In other embodiments, the method includes providing a fastener as described in the preceding paragraphs. The method further includes disposing the lid on a housing of the battery pack to cover an opening in the housing. The method further includes inserting the first retaining feature of the fastener through a first opening in the lid and a corresponding first opening in the housing. The method further includes inserting the second retaining feature of the fastener through a second opening in the lid and a corresponding secondopening in the housing. The method further includes engaging the first retaining feature with a surface of the housing adjacent the corresponding first opening or a surface of the lid adjacent the first opening. The method further includes engaging the second retaining feature with a surface of the housing adjacent the corresponding second opening or a surface of the lid adjacent the second opening. Engagement of the first and second retaining features with the housing or lid clamps the lid to the housing.

[0023] In specific embodiments, the first and second retaining features are inserted simultaneously.DESCRIPTION OF THE DRAWINGS

[0024] Various advantages and aspects of this disclosure may be understood in view of the following detailed description when considered in connection with the accompanying drawings, wherein:

[0025] Figure 1 is a perspective view of a fastener in accordance with some embodiments of the disclosure, for securing a battery pack lid to a housing of a battery pack;

[0026] Figure 2 is a perspective view of a fastener in accordance with other embodiments of the disclosure;

[0027] Figure 3 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure;

[0028] Figure 4 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure;

[0029] Figure 5 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure;

[0030] Figure 6 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure;

[0031] Figure 7 is a perspective view of the fastener securing the lid to the battery pack housing and compressing a seal between the lid and the battery pack housing;

[0032] Figure 8 is a schematic illustration of a method of securing the lid to the battery pack, using the fastener;

[0033] Figure 9 is a side view of the fastener securing the lid to the battery pack;

[0034] Figure 10 is a plan view of the fastener securing the lid to the battery pack;

[0035] Figure 11 is a sectional view of the fastener securing the lid to the battery pack;

[0036] Figure 12 is a perspective view of the fastener securing the lid to the battery pack in accordance with other embodiments of the disclosure;

[0037] Figure 13 is a perspective view of the fastener securing the lid to the battery pack in accordance with some embodiments of the disclosure;

[0038] Figure 14 is a perspective view of the fastener securing the lid to the battery pack in accordance with other embodiments of the disclosure;

[0039] Figure 15 is a schematic illustration of a method of releasing the fastener from the lid and battery pack housing;

[0040] Figure 16 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure; and

[0041] Figure 17 is a perspective view of a fastener in accordance with yet other embodiments of the disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0042] A fastener for an electric vehicle (EV) battery pack lid is provided. Referring to Figures 1 -17, wherein like numerals indicate corresponding parts throughout the several views, the fastener is illustrated and generally designated at 10. The fastener 10 elastically deforms to provide a clamping force that secures a lid / cap / cover onto a battery pack housing as described in more detail below. The fastener 10 is also quickly assembled onto the lid and battery back housing, thereby reducing cycle time for securing the lid on the battery pack. Certain features of the fastener 10 are functional, but can be implemented in different aesthetic configurations.

[0043] The fastener 10 includes an elongated body 12 having a first end 14, an opposite second end 16, an upper surface 18 and lower surface 20 extending between the first and second ends, and first and second lateral sides 22, 24 extending between the first and second ends. A first leg 26 extends from the first end 14 of the body 12, and a second leg 28 extends from the second end 16 of the body. The body 12 thereby forms a crown between prongs that are formed by the first and second legs 26, 28. The body 12 may be substantially longer than the length of either of the legs 26, 28, such as at least approximately twice the length of one of the legs. The body 12 may also be wider than either of the legs 26, 28. The first and second legs 26, 28 each extend at an angle from the body 12 that preferably may be approximately a 90-degree angle, but may be slightly more or slightly less than 90 degrees, such as by way of example only, an 80-degree angle. A first retaining feature 30 is disposed at and connected to a terminal end 32 of the first leg 26. Likewise, a second retaining feature 34 is disposed at and connected to a terminal end 36 of the second leg 28. The first and second retaining features 30, 34 are respectively connected to the terminal ends 32, 36 of the first and second legs 26, 28 by a bend that provides resiliency and may be a near 180-degree bend. As such, each of the first and second retaining features 30, 34 is a flexible, elastic element that can be flexed from its resting position and that is urged towards and / or capable of returning to its resting position. Each retaining feature 30, 34 may have the same or similar construction, and particularly may each include a pair of inwardlyfacing projections 38. Each projection 38 has a clip face 40 and a chamfer 42. Each projection 38 may be generally triangular in shape. Each retaining feature 30, 34 also may have a release tab 44. As described in more detail below, the chamfer 42 and clip face 40 allow the retaining features 30, 34 to be snapped into a locked / engaged position, and the release tab 44 allows the retaining features 30, 34 to be unlocked and released from engagement.

[0044] The fastener 10 further includes at least one resilient member 46 that projects away from the lower surface 20 of the body 12. As shown in Figure 3, in one embodiment the fastener 10 include two resilient members 46, and each resilient member 46 is a cantilevered spring tab that extends parallel to the first and second legs 26, 28 and towards a middle portion of the body 12. In other words, each resilient member 46 is generally parallel to the lateral sides 22, 24 of the body 12. Each resilient member 46 may be formed by cutting three sides of a quadrilateral shape in the body 12 and bending the cut portion along the fourth side that remains connected to the body. Thus, cut-out holes may be present in the body 12 adjacent to each resilient member 46. The width of the body 12 allows for the resilient member(s) 46 to be formed within the boundary of the body 12. Further, one of the resilient members 46 is proximate the first end 14, and the other resilient member 46 is proximate the second end 16. In this embodiment, a cross bar (not numbered) extends across the middle portion of the body 12 between the two resilient members 46. In an alternative embodiment of the fastener 1 10 shown in Figure 2, the cross bar is not present between the resilient members 146. In another alternative embodiment shown in Figure 3, the fastener 210 includes only one resilient member 246 having a similar construction as the resilient members 46, 146 but being disposed at one side of the body 212, for example proximate the first end 214. In yet another alternative embodiment of the fastener 310 shown in Figure 4, the resilient member 346 is a single flexible strap connected between the first and second ends 314, 316 of the elongated body 312. In this embodiment, the resilient member 346 has a bent shape including two legs 348 extending at an angle from the lower surface of the body 312 and a single foot 350 connecting the legs. In another similar embodiment of the fastener 410 shown in Figure 5, the resilient member 446 is an integral portion of the body 412 and forms the entirety or a near entirety of the body between the first and second ends 414, 416. In this embodiment, the resilient member 446 is a curved and / or wave-like strip of material similar to a leaf spring. In yet another alternative embodiment of the fastener 510 shown in Figure 6, each resilient member 546 is a cantilevered tab extending perpendicular (transverse) to the first and second legs 526, 528, respectively, such that one resilient member 546 extends from the first lateral side 522 and the other resilient member 546 extends from the second lateral side 524. In this manner, the resilient members 546 resemble wings. In other similar embodiments (not shown), the resilient members may becantilevered tabs extending perpendicular to the first and second legs, but in contrast to the embodiment in Figure 6, these resilient members extend inwardly from the sides rather than extending outwardly away from the sides. As described in more detail below, the resilient members 46, 146, 246, 346, 446, 546 provide a clamping load that aids in maintaining the retaining features 30, 34, 130, 134, 230, 234, 330, 334, 430, 434, 530, 534 in the locked / engaged position.

[0045] In yet other embodiments as shown in Figure 16, the fastener 710 includes one or more prongs 772 in the form pointed tips. The prongs 772 are disposed at the terminal end of each resilient member 746. The prongs 772 thereby form a fork at the terminal end of each resilient member 746. When the fastener 710 is installed as described in more detail below, the prongs 772 dig into the surface of the two components that are fastened together to allow for the conducting of electricity between the two components, and thereby ground the two components together. The tension of the resilient members 746 against the surface of the components maintains the connection of the prongs 772 with the components. The two components may be, for example, two shell halves that when put together close an internal volume between the shells. More specifically, the two shells may be a housing body and a lid, wherein the prongs 772 provide an electrical connection between the housing and the lid. A similar but alternative fastener 810 is shown in Figure 17, wherein the resilient members 846 have a curved shape and the prongs 872 face towards the ends 814, 816 of the fastener 810 and away from a center of the fastener. In contrast, the resilient members 772 of the fastener 710 are generally flat, and the prongs 772 face toward the center of the fastener 710.

[0046] With specific reference now to Figures 7-12, the fastener 10 secures a lid / cap 52 that covers over an opening to an internal chamber within a battery pack housing 54 in which a plurality of battery cells are contained. In order to sufficiently seal the internal chamber of the battery pack, a seal 56 such as a gasket or similar is disposed around the perimeter of the opening that is covered by the lid. The seal 56 is thus sandwiched between the lid 52 and the housing 54 when the lid is placed over the opening in the housing. The lid 52 includes a first opening 58 that is spaced from but proximate to an outer edge 60 of the lid. The housing 54 includes a corresponding first opening 62 that is spaced from but proximate to an outer edge 64 of the housing. By “corresponding” it is meant that these two openings 58, 62 are complementary, i.e. when the lid 52 is properly aligned with the housing 54, the two openings 58, 62 are in alignment and the two openings 58, 62 preferably have the same or nearly the same size and / or shape. Likewise, the lid 52 further includes a second opening 66 that is spaced from but proximate to the outer edge 60 of the lid, and the housing 54 includes a corresponding second opening 68 that is spaced from but proximate to the outer edge 64 ofthe housing. In some embodiments, the first and second openings 58, 66 in the lid may have a circular or oval shape.

[0047] In some embodiments, the two first openings 58, 62 each may have a circular or oval shape. Further, the first opening 58 in the lid 52 and the corresponding first opening 62 in the battery pack housing 54 may have a complementary circular or oval shape (of the same or different size), and the second opening 66 in the lid 52 and the corresponding second opening 68 in the battery pack housing 54 may have a complementary circular or oval shape of the same or similar size as the two first openings 58, 62. Alternatively, the two openings 58, 66 in the lid 52 may have a circular shape, and the two openings 62, 68 in the battery pack housing 54 may have an oval or oval-like (e.g., stadium) shape. In yet another embodiment shown in Figure 12, the corresponding first and second openings 662, 668 in the battery pack housing 654 are each a cutout in the outer edge 664 of the battery pack housing. Particularly, each cutout includes a straight surface 670 adjacent to which the retaining features engage as described below. Furthermore, the first openings need not be the same size or same shape as the second openings, and the first and second openings may alternatively have a polygonal shape such as but not limited to a square shape, a rectangular shape, a triangular shape, or other polygonal shape.

[0048] To install the fastener 10, the first leg 26 and first retaining feature 30 are inserted into and through the first opening 58 in the lid 52 and the corresponding first opening 62 in the housing 54. Likewise and preferably but not necessarily simultaneously, the second leg 28 and second retaining feature 34 are inserted into and through the second opening 66 in the lid 52 and the corresponding second opening 68 in the housing 54. Alternatively, the fastener 10 may be preassembled / preinstalled onto the lid 52 such that the first retaining feature 30 is inserted into the first opening 58 in the lid 52 and the second retaining feature 34 is inserted into the second opening 66 in the lid 52. In this case, once the lid 52 is placed on the housing 54, the fastener 10 is pushed towards the surface of the lid 52 to insert the first retaining feature 30 through the corresponding first opening 62 in the housing 54 and to insert the second retaining feature 32 through the corresponding second opening 68 in the housing 54. The fastener 10 is inserted through the first openings 58, 62 and second openings 66, 68 to a point at which the first retaining feature 30 and second retaining feature 34 contacts and is engaged with an underside surface of the housing 54, i.e. a surface that is opposite the surface on which the lid 52 is disposed. More particularly, as the first and second legs 26, 28 are inserted into the respective openings, the chamfers 42 of the projections 38 contact the edges of the openings, pushing the legs 26, 28 outwardly due to the resiliency imparted by the bend at the connection of the legs and the retaining features 30, 34. At a certain depth of the legs 26, 28 in the openings, the chamfers 42 pass by the edges of the corresponding openings 62, 68 in the battery pack housing 54, which allowsthe legs 26, 28 to elastically flex back inwardly towards the body 12 such that the clip faces 40 of the projections 38 move into engagement with the underside surface of the battery pack housing 54 adjacent the corresponding openings 62, 68. Further, in this configuration, the resilient members 46 are urged into engagement with the upper surface (not numbered) of the lid 52. The resilient members 46 provide a clamping force that is exerted against the lid 52 and pushes the body 12 of the fastener 10 in a direction away from the lid such that the clamping force pulls the clip faces 40 into urged engagement with the underside surface of the battery pack housing 54 as shown especially in Figures 10 and 11. As such, by a translation movement of the fastener 10 relative to the lid 52, the first retaining feature 30 is urged into engagement with a surface of the battery pack housing adjacent the corresponding first opening 62, and the second retaining feature 34 is urged into engagement with a surface of the battery pack housing adjacent the corresponding second opening 68. This translational movement fixes the fastener 10 into a locked / engaged position as shown in Figures 7 and 9-12. The mechanical stress on the fastener 10 in the locked / engaged position caused by the clamping force exerted by the resilient members 46 may be primarily at the connection between the resilient members 46 and the body 12, as well as at the terminal ends 32, 36 of the legs 26, 28 and the clip faces 40. Further, the fastener 10 applies a clamping force on the lid 52 that compresses the seal 56 against the housing 54 and ensures that the seal 56 provides a tight seal that prevents gases, liquids, and debris from entering the internal chamber within the housing 54. Furthermore, the clamping force / stress on the fastener 10 resists other outside forces from loosening the clamp, such as vibration, internal pressure within the battery pack housing, etc.

[0049] In some embodiments shown in Figure 13, the fastener 10 may be installed from the top in a direction from the lid 52 to the battery pack housing 54. In other embodiments shown in Figure 14, the fastener 10 may be installed from the bottom in a direction from the battery pack housing 54 to the lid 52. In these embodiments, the resilient members 46 contact the underside surface of the battery pack housing 54, and the clip faces 40 of the retaining features 30, 34 engage the upper surface of the lid 52 adjacent the openings 58, 66.

[0050] Turning to Figure 15, to remove the fastener 10 from the lid 52 and battery pack housing 54, a tool such as a flathead screwdriver or similar can be used. Particularly, the tool may be forced against the release tab 44 of one or both retaining features 30, 34 to bend the legs 26, 28 at the body 12 and push the retaining features outward to move the clip faces 40 away from the underside of the battery pack housing 54 and into the openings. The outward force exerted by the resilient members 46 also aid in moving the chamfers 42 out of contact with the edges of the openings once the clip faces 40 are completely within the boundaries of the openings. In this disengaged configuration, the fastener 10 may be raised away from the lid 52 to pull the legs 26, 28 out of the openings.

[0051] Preferably, the fastener 10 may be formed of a metal or metal alloy as described above. However, it should be understood that the fastener may be formed of other materials such as a plastic or other similarly suitable material. Alternatively, the fastener may be a hybrid formed partially of metal and partially of plastic. Further, in some embodiments, the fastener 10 may be formed as an integral, one-piece construction. Additionally, in particular embodiments, the parts of the fastener 10 may all be part of a one-piece element formed by bending portions of a single metal section.

[0052] Furthermore, while the fastener 10 has been described as fastening / securing a lid to a battery pack, it should be understood that the fastener is not limited to this application and may be applied to other applications, such as fastening one panel to another panel or fastening a panel to an extruded profile, or even other applications requiring one part (not necessarily a panel) to be fastened to another part (not necessarily a panel). Also, the fastener may be applied to applications other than vehicular applications, such as in energy storage applications in which battery packs are utilized but the battery packs are stationary. In addition, the fastener may be used to fasten closed a box which contains electric or electronic components other than a battery pack.

[0053] It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, different, special, and / or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

[0054] Further, any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and / or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range “of from 0.1 to 0.9” may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and / or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language whichdefines or modifies a range, such as “at least,” “greater than,” “less than,” “no more than,” and the like, it is to be understood that such language includes subranges and / or an upper or lower limit. As another example, a range of “at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and / or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range “of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1 , which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

Claims

CLAIMS1 . A fastener for an electric vehicle (EV) battery pack lid, the fastener comprising: an elongated body having first and second opposite ends, and upper and lower surfaces extending between said first and second ends; a first leg extending from said first end; a second leg extending from said second end; a first retaining feature at a terminal end of said first leg; a second retaining feature at a terminal end of said second leg; wherein said first retaining feature is configured to be insertable through a first opening in a battery pack lid and a corresponding first opening in a battery pack housing and is configured to be engageable with a surface of the battery pack housing or a surface of the battery pack lid; wherein said second retaining feature is configured to be insertable through a second opening in a battery pack lid and a corresponding second opening in a battery pack housing and is configured to be engageable with a surface of the battery pack housing or a surface of the battery pack lid; wherein when said first and second retaining features are engaged with the surface of the battery pack housing or the surface of the battery pack lid, said first and second retaining features clamp the battery pack lid to the battery pack housing.

2. The fastener of claim 1 , wherein each of said first and second retaining features is a flexible, elastic element including a pair of inwardly facing projections, each projection including a clip face and a chamfer.

3. The fastener of claim 1 , wherein each of said first and second retaining features includes a release tab.

4. The fastener of claim 1 , wherein said elongated body includes at least one resilient member projecting away from said lower surface.

5. The fastener of claim 4, wherein each said resilient member is a cantilevered tab extending parallel to said first and second legs.

6. The fastener of claim 4, wherein each said resilient member includes at least one prong at a terminal end thereof.

7. The fastener of claim 4, including two said resilient members.

8. The fastener of claim 4, wherein said resilient member is a single flexible strap connected between said first and second ends of said elongated body.

9. The fastener of claim 4, wherein each said resilient member is a cantilevered tab extending perpendicular to said first and second legs.

10. The fastener of claim 9, wherein each said resilient member extends from a side of said elongated body between said first and second ends.11 . The fastener of claim 1 , wherein said elongated body, said first and second legs, and said first and second retaining features are all part of a one-piece element formed by bending portions of a metal piece.

12. A battery pack for an electric vehicle (EV), the battery pack comprising: a housing defining an internal chamber and having an opening providing access to the internal chamber; a plurality of battery cells disposed in the internal chamber; a seal disposed around the perimeter of the opening; a lid that covers over the opening and sandwiches the seal between the housing and the lid; a first opening in the lid and a corresponding first opening in the housing; a second opening in the lid and a corresponding second opening in the housing; and the fastener of claim 1 ; wherein the fastener is insertable through said first opening in the lid and said corresponding first opening in the housing and also insertable through said second opening in the lid and said corresponding second opening in the housing, and engageable with said first and second openings in the housing or the lid to clamp the lid to the housing and to compress the seal between the lid and housing.

13. The battery pack of claim 12, wherein said first and second openings in the lid have a circular, an oval shape, or a polygonal shape.

14. The battery pack of claim 12, wherein: said first opening in the lid and said corresponding first opening in the battery pack housing have a complementary circular, oval, or polygonal shape; andsaid second opening in the lid and said corresponding second opening in the battery pack housing have a complementary circular, oval, or polygonal shape.

15. The battery pack of claim 12, wherein said corresponding first and second openings in the battery pack housing are each a cutout in an outer edge of the battery pack housing.

16. The battery pack of claim 15, wherein each said cutout includes a straight surface.

17. A method of securing a lid to an electric vehicle (EV) battery pack, the method comprising: disposing the lid on a housing of the battery pack to cover a compartment opening in the housing, wherein the lid includes a first opening and the housing includes a corresponding first opening, the lid further includes a second opening and the housing further includes a corresponding second opening, and the fastener of claim 1 is preassembled on the lid such that said first retaining feature of the fastener is inserted into the first opening in the lid and said second retaining feature of the fastener is inserted into the second opening in the lid; aligning the first opening in the lid with the corresponding first opening in the housing, and aligning the second opening in the lid with the corresponding second opening in the housing; pushing the fastener towards the lid to insert said first retaining feature into the corresponding first opening in the housing thereby engaging said first retaining feature with a surface of the housing adjacent the corresponding first opening, and to insert said second retaining feature into the corresponding second opening in the housing thereby engaging said second retaining feature with a surface of the housing adjacent the corresponding second opening; wherein engagement of said first and second retaining features with the housing clamps the lid to the housing.

18. The method of claim 17, further including the step of disposing a seal between the housing and the lid, wherein clamping the lid to the housing with the fastener compresses the seal between the lid and the housing.

19. A method of securing a lid to an electric vehicle (EV) battery pack, the method comprising: providing the fastener of claim 1 ;disposing the lid on a housing of the battery pack to cover a compartment opening in the housing; inserting said first retaining feature of the fastener through a first opening in the lid and a corresponding first opening in the housing; inserting said second retaining feature of the fastener through a second opening in the lid and a corresponding second opening in the housing; engaging said first retaining feature with a surface of the housing adjacent the corresponding first opening or a surface of the lid adjacent the first opening; engaging said second retaining feature with a surface of the housing adjacent the corresponding second opening or a surface of the lid adjacent the second opening; wherein engagement of said first and second retaining features with the housing or lid clamps the lid to the housing.

20. The method of claim 19, wherein said first and second retaining features are inserted simultaneously.

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