CN220042097U - Battery pack - Google Patents

Abstract

The utility model relates to the technical field of batteries, in particular to a battery pack, which comprises a box body and a box cover, wherein the box cover is connected to the top opening of the box body, the box cover comprises a cover plate body and a maintenance cover plate, a heat exchange flow channel is arranged in the cover plate body and can be used as an upper heat exchange plate, the cover plate body is provided with a maintenance window which penetrates through in the thickness direction, the position of the maintenance window corresponds to the position of an electric bin of the box body, and the maintenance cover plate is detachably connected to the cover plate body and seals the maintenance window. Through the structural design, the box cover can be conveniently and locally disassembled, namely, the electric parts in the electric bin are exposed out of the maintenance window by disassembling the maintenance cover plate, so that the electric parts are convenient to overhaul or maintain, the box cover or other related structures are not easily damaged due to the disassembling operation, and particularly, the heat exchange flow channel of the box cover is not easily damaged.

Description

Battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery pack.

Background

In the design scheme of the existing battery pack, the box cover is integrally covered on the box body, and when electric components in an electric bin of the box body are required to be overhauled or maintained, the box cover is required to be integrally detached, so that the detachment difficulty is high, the efficiency is low, and the box cover or related structures are easy to damage. In particular, when the liquid cooling plate is used as the case cover, the above-described detaching operation is liable to damage the structure of the liquid cooling plate such as the flow path.

Disclosure of Invention

It is a primary object of the present utility model to overcome at least one of the above-mentioned drawbacks of the prior art and to provide a battery pack that facilitates the repair or maintenance of electrical components and avoids damaging the case cover as a result.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

according to one aspect of the present utility model, there is provided a battery pack including a case and a case cover connected to a top opening of the case, the case cover including a cover body having a heat exchange flow passage therein to be used as an upper heat exchange plate, and a service cover removably connected to the cover body and closing the service window, the cover body being provided with a service window penetrating in a thickness direction thereof at a position corresponding to a position of an electrical compartment of the case.

According to the technical scheme, the battery pack provided by the utility model has the advantages and positive effects that:

the battery pack comprises a box body and a box cover, wherein the box cover is provided with a heat exchange flow channel and can be used as an upper heat exchange plate, the box cover comprises a cover plate body and a maintenance cover plate, the cover plate body is provided with a maintenance window, the maintenance window corresponds to an electric bin of the box body, and the maintenance cover plate is detachably connected to the cover plate body and seals the maintenance window. Through the structural design, the box cover can be conveniently and locally disassembled, namely, the electric parts in the electric bin are exposed out of the maintenance window by disassembling the maintenance cover plate, so that the electric parts are convenient to overhaul or maintain, the box cover or other related structures are not easily damaged due to the disassembling operation, and particularly, the heat exchange flow channel of the box cover is not easily damaged.

Drawings

Various objects, features and advantages of the present utility model will become more apparent from the following detailed description of the preferred embodiments of the utility model, when taken in conjunction with the accompanying drawings. The drawings are merely exemplary illustrations of the utility model and are not necessarily drawn to scale. In the drawings, like reference numerals refer to the same or similar parts throughout. Wherein:

fig. 1 is a schematic perspective view of a battery pack according to an exemplary embodiment;

fig. 2 is an exploded perspective view of the battery pack shown in fig. 1;

FIG. 3 is an enlarged schematic view of portion A of FIG. 2;

fig. 4 is a partial cross-sectional view of the battery pack shown in fig. 1;

fig. 5 is a plan view schematically showing a lid body of the battery pack shown in fig. 1;

fig. 6 is a schematic perspective view of a battery pack according to another exemplary embodiment;

fig. 7 is a schematic perspective view of a battery pack according to still another exemplary embodiment;

fig. 8 is a plan view schematically showing a cap plate body of the battery pack shown in fig. 7;

fig. 9 is a schematic perspective view of a battery pack according to still another exemplary embodiment.

The reference numerals are explained as follows:

100. a case;

110. an electrical bin;

200. a case cover;

201. a heat exchange section;

202. a liquid inlet section and a liquid outlet section;

210. a cover plate body;

211. a maintenance window;

2111. mounting steps;

212. a bridge portion;

213. a first projection;

220. maintaining the cover plate;

230. a sealing gasket;

240. a connecting piece;

300. a liquid inlet and outlet joint;

400. a lower heat exchange plate;

410. a second projection;

D1. spacing;

D2. spacing;

D3. spacing;

w1, width;

w2, width;

x, a first direction;

y. second direction.

Detailed Description

Exemplary embodiments that embody features and advantages of the present utility model are described in detail in the following description. It will be understood that the utility model is capable of various modifications in various embodiments, all without departing from the scope of the utility model, and that the description and drawings are intended to be illustrative in nature and not to be limiting.

In the following description of various exemplary embodiments of the utility model, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various exemplary structures, systems, and steps in which aspects of the utility model may be practiced. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps may be utilized and structural and functional modifications may be made without departing from the scope of the present utility model. Moreover, although the terms "over," "between," "within," and the like may be used in this description to describe various exemplary features and elements of the utility model, these terms are used herein for convenience only, e.g., in terms of the orientation of the examples depicted in the drawings. Nothing in this specification should be construed as requiring a particular three-dimensional orientation of the structure in order to fall within the scope of the utility model.

Referring to fig. 1, a schematic perspective view of a battery pack according to the present utility model is representatively illustrated. In this exemplary embodiment, the battery pack according to the present utility model is described as being applied to a vehicle-mounted battery. Those skilled in the art will readily appreciate that many modifications, additions, substitutions, deletions, or other changes may be made to the specific embodiments described below in order to adapt the relevant designs of the present utility model to other types of battery devices, and such changes remain within the principles of the battery packs presented herein.

As shown in fig. 1, in an embodiment of the present utility model, a battery pack according to the present utility model includes a case 100 and a case cover 200. Referring to fig. 2 to 5 in combination, an exploded perspective view of the battery pack is representatively illustrated in fig. 2, in which the three-dimensional structure of the service cover 220 separated from the cover body 210 is specifically illustrated; an enlarged schematic view of portion a of fig. 2 is representatively illustrated in fig. 3; a partial cross-sectional view of the battery pack is representatively illustrated in fig. 4; a plan view schematic of the cover body 210 is representatively illustrated in fig. 5. The structure, connection manner and functional relationship of the main components of the battery pack according to the present utility model will be described in detail with reference to the above drawings.

As shown in fig. 1 and 2, in an embodiment of the present utility model, the cover 200 is connected to the top opening of the case 100, and the cover 200 includes a cover body 210 and a repair cover 220. Specifically, the cover plate body 210 has a heat exchange flow channel therein and can be used as an upper heat exchange plate, and the cover plate body 210 is provided with a maintenance window 211 penetrating in the thickness direction, the position of the maintenance window 211 corresponds to the position of the electrical cabinet 110 of the box 100, and the maintenance cover plate 220 is detachably connected to the cover plate body 210 and seals the maintenance window 211. Through the above structural design, the cover 200 can be conveniently and partially disassembled, namely, the electric components in the electric bin 110 are exposed out of the maintenance window 211 by disassembling the maintenance cover 220, so that the electric components are convenient to overhaul or maintain, the cover 200 or other related structures are not easy to damage due to the disassembling operation, and particularly, the heat exchange flow channel of the cover 200 is not easy to damage.

As shown in fig. 2, in an embodiment of the present utility model, a gasket 230 may be disposed between the service cover 220 and the cover body 210. Through the above structural design, the sealing performance between the maintenance cover plate 220 and the cover plate body 210 can be enhanced by using the sealing gasket 230, and the sealing performance of the battery pack is ensured.

As shown in fig. 3 and 4, in an embodiment of the present utility model, the inner wall of the maintenance window 211 may be provided with a mounting step 2111. Also, the service cover 220 may be accommodated in the service window 211, and the service cover 220 is detachably coupled to the mounting step 2111. Through the above structural design, the present utility model can facilitate the assembly of the repair cover 220 on the cover body 210.

As shown in fig. 2 to 4, based on the structural design that the mounting step 2111 is provided on the inner wall of the maintenance window 211, in an embodiment of the present utility model, the maintenance cover 220 and the cover body 210 may be detachably connected via the connector 240, and the connector 240 is inserted through the maintenance cover 220 and the mounting step 2111, and the connector 240 is, for example, but not limited to, a bolt or a rivet. Through the above structural design, the present utility model can further optimize the convenience of assembling and disassembling the maintenance cover 220 and the cover body 210.

As shown in fig. 3 and 4, based on the structural design that the installation step 2111 is provided on the inner wall of the service window 211, in an embodiment of the present utility model, when the gasket 230 is provided between the service cover 220 and the cover body 210, the gasket 230 may be located between the bottom surface of the service cover 220 and the top surface of the installation step 2111. Through the above structural design, the present utility model can further facilitate the arrangement of the sealing gasket 230, and further optimize the sealing performance between the repair cover 220 and the cover body 210.

As shown in fig. 5, in an embodiment of the present utility model, the electrical bins 110 and the battery bins of the case 100 may be arranged along the first direction X, and the maintenance window 211 may be located at one end of the cover plate body 210 along the first direction X. On this basis, the heat exchange flow channel of the cover plate body 210 may include a heat exchange section 201 and a liquid inlet and outlet section 202, where the position of the heat exchange section 201 corresponds to that of the battery compartment, one end of the liquid inlet and outlet section 202 is connected to the heat exchange section 201, and the other end of the liquid inlet and outlet section 202 is connected to the liquid inlet and outlet connector 300. Through the structural design, the heat exchange function of the battery accommodated in the battery compartment can be guaranteed by the heat exchange section 201 of the heat exchange flow channel, and meanwhile, the connection between the heat exchange section 201 and the liquid inlet and outlet connector 300 is realized by the liquid inlet and outlet section 202, so that the circulation of heat exchange media is facilitated.

As shown in fig. 5, the heat exchange flow channel based on the cover plate body 210 includes a heat exchange section 201 and a liquid inlet and outlet section 202, and in an embodiment of the utility model, a distance D1 between the maintenance window 211 and the heat exchange section 201 along the first direction X may be greater than or equal to 6mm, for example, 6mm, 7mm, 8mm, etc. Through the structural design, a reasonable space is reserved between the maintenance window 211 and the heat exchange section 201, so that the heat exchange flow channel of the cover plate body 210 is prevented from being damaged easily in the process of disassembling and assembling the maintenance cover plate 220 due to the fact that the distance D1 is too small. In some embodiments, the distance D1 between the maintenance window 211 and the heat exchange section 201 along the first direction X may also be less than 6mm, for example, 5.95mm, but is not limited to this embodiment.

As shown in fig. 5, based on the structural design that the distance D1 between the maintenance window 211 and the heat exchange section 201 along the first direction X is greater than or equal to 6mm, in an embodiment of the present utility model, when the maintenance cover 220 is connected to the maintenance window 211 of the case cover 200 through the bolts, the distance D1 may be further greater than or equal to 10mm, so that a sufficient space can be provided for screwing and disassembling the bolts.

As shown in fig. 5, in an embodiment of the utility model, along the first direction X, a distance D2 between a side of the maintenance window 211 facing away from the heat exchange section 201 and an edge of the adjacent cover plate body 210 in the first direction X may be greater than a width of a frame of the box 100. Through the above structural design, the present utility model can avoid the damage to the cover plate body 210 caused by too small distance D2 during the assembly and disassembly of the maintenance cover plate 220.

As shown in fig. 5, in an embodiment of the utility model, the electrical bin 110 and the battery bin are still arranged along the first direction X, and the maintenance window 211 is located at one end of the cover body 210 along the first direction X, and on this basis, along the second direction Y perpendicular to the first direction X, the distance D3 between the maintenance window 211 and the edge of the cover body 210 in the second direction Y may be greater than the width of the frame of the case 100. Through the above structural design, the present utility model can avoid the damage to the cover plate body 210 caused by too small distance D3 during the assembly and disassembly of the maintenance cover plate 220.

Referring to fig. 6, a schematic perspective view of a battery pack capable of embodying the principles of the present utility model in another exemplary embodiment is representatively illustrated in fig. 6.

As shown in fig. 6, in an embodiment of the present utility model, the cover body 210 may be provided with at least two maintenance windows 211, for example, but not limited to, two maintenance windows 211 shown in the drawings, and the two maintenance windows 211 are arranged at intervals. Through the above structural design, the utility model can divide the area of the electrical warehouse 110 by utilizing at least two maintenance windows 211 to respectively correspond to different areas, so that when the electrical components contained in the different areas of the electrical warehouse 110 are required to be overhauled or replaced, the maintenance cover plate 220 of the corresponding maintenance window 211 is only required to be disassembled, thereby facilitating the operation of maintenance personnel and being beneficial to improving the efficiency.

Referring to fig. 7 and 8, a schematic perspective view of a battery pack capable of embodying the principles of the present utility model in yet another exemplary embodiment is representatively illustrated in fig. 7; a plan view of the cap plate body 210 of the battery pack shown in fig. 7 is representatively illustrated in fig. 8.

As shown in fig. 7 and 8, in an embodiment of the present utility model, the electrical bin 110 and the battery bin are still arranged along the first direction X as an example, the heat exchange flow channel includes a heat exchange section 201 and a liquid inlet/outlet section 202, the position of the heat exchange section 201 corresponds to that of the battery bin, one end of the liquid inlet/outlet section 202 is connected to the heat exchange section 201, and the other end of the liquid inlet/outlet section 202 is connected to the liquid inlet/outlet joint 300. On this basis, the cover body 210 may be provided with two maintenance windows 211, the two maintenance windows 211 are located at one end of the cover body 210 along the first direction X, and the two maintenance windows 211 are spaced apart along the second direction Y perpendicular to the first direction X. The portion of the cover body 210 between the two maintenance windows 211 is a bridge 212, and the liquid inlet and outlet section 202 may be located on the bridge 212. In other words, the liquid inlet and outlet section 202 of the heat exchange flow channel of the cover plate body 210 is located at a side of the heat exchange section 201 facing the maintenance window 211. Through the above structural design, the heat exchange flow channel directly passes through the area where the cover plate body 210 is provided with the maintenance window 211, so that the length of the heat exchange flow channel arrangement can be reduced, and the heat exchange flow channel is not required to pass through the area where the maintenance window 211 is arranged from the edge of the cover plate body 210, so that more edge space is required to be occupied by the heat exchange flow channel, the maintenance window 211 is positioned at a more central position along the second direction Y, and therefore, the maintenance and the replacement of electric parts on two sides are not facilitated, and the operation space is smaller. In some embodiments, for example, in the embodiment shown in fig. 6, the liquid inlet and outlet section 202 of the heat exchange flow channel of the cover plate body 210 may also be located on a side of the heat exchange section 201 facing away from the maintenance window 211, which is not limited to this embodiment.

As shown in fig. 7 and 8, based on the structural design that the liquid inlet and outlet section 202 of the heat exchange flow channel of the cover plate body 210 is located at the bridge portion 212 of the cover plate body 210, in an embodiment of the present utility model, a ratio of the width W1 of the bridge portion 212 to the width W2 of the cover plate body 210 along the second direction Y may be less than or equal to 0.5, for example, 0.1, 0.2, 0.3, 0.5, and so on. Through the structural design, the utility model can avoid insufficient arrangement space of the heat exchange flow channels caused by too small width W1 of the bridge 212, and can avoid too small maintenance window 211 caused by too large width W1 of the bridge 212. In some embodiments, the width W1 of the bridge 212 may be greater than one half of the width W2 of the cover body 210, for example, the ratio of the width W1 of the bridge 212 to the width W2 of the cover body 210 may be greater than 0.5, such as 0.51, etc., but is not limited to this embodiment.

As shown in fig. 1, 6 or 7, in some embodiments of the present utility model, when the cover body 210 has the bridge portion 212, an end of the bridge portion 212 facing away from the heat exchange section 201 may protrude from the case 100 to form a first protruding portion 213, and the liquid inlet and outlet section 202 of the heat exchange channel of the cover body 210 may extend to the first protruding portion 213. Accordingly, the fluid access connector 300 may be located outside the housing 100 and connected to the fluid access section 202 of the first protrusion 213. Through the above structural design, the present utility model can utilize the first protruding portion 213 to connect the liquid inlet and outlet connector 300, so as to avoid space waste caused by the liquid inlet and outlet connector 300 being disposed in the box 100.

Referring to fig. 9, a schematic perspective view of a battery pack capable of embodying the principles of the present utility model in yet another exemplary embodiment is representatively illustrated in fig. 9.

As shown in fig. 9, still taking the structure design of the cover plate body 210 with the first protruding portion 213 as an example, in an embodiment of the utility model, the battery pack according to the utility model may further include a lower heat exchange plate 400, where the lower heat exchange plate 400 is disposed at the bottom of the case 100, and the lower heat exchange plate 400 has a second protruding portion 410 protruding out of the case 100, and the heat exchange flow channel of the lower heat exchange plate 400 extends to the second protruding portion 410. On this basis, the positions of the first protruding portion 213 and the second protruding portion 410 correspond to each other, and the heat exchange flow channel of the first protruding portion 213 and the heat exchange flow channel of the second protruding portion 410 are respectively connected to the liquid inlet and outlet connector 300. Through the structural design, the utility model can utilize the lower heat exchange plate 400 to exchange heat with the bottom of the battery, further improve the thermal performance of the battery pack, and on the basis, the utility model can lead out the same sides of the heat exchange flow channels of the upper heat exchange plate (namely the case cover 200) and the lower heat exchange plate 400 and be connected on one liquid inlet and outlet connector 300 together, thereby being beneficial to reducing the number of parts and improving the structural rationality of the battery pack.

As shown in fig. 6 to 9, based on the structural design that the cover body 210 is provided with at least two maintenance windows 211, in some embodiments of the present utility model, the areas of the at least two maintenance windows 211 may not be equal. Through the structural design, the area of the plurality of maintenance windows 211 can be flexibly selected, so that the areas of the electrical bin 110 corresponding to the maintenance windows 211 respectively correspond to different areas, and the disassembly requirements of electrical components in the different areas are met.

Based on the structural design that the cover body 210 is provided with at least two maintenance windows 211, in some embodiments of the present utility model, the case cover 200 may include at least two maintenance covers 220, and the at least two maintenance covers 220 are in one-to-one correspondence with the at least two maintenance windows 211. In other words, each of the maintenance windows 211 is correspondingly provided with one maintenance cover 220, and each of the maintenance covers 220 correspondingly closes one maintenance window 211. Through the above structural design, the present utility model can facilitate the selective disassembly of the required maintenance cover 220, and avoid the influence on other parts of the case cover 200. In some embodiments, when the cover body 210 is provided with at least two maintenance windows 211, the cover 200 may also include at least one maintenance cover 220, and the at least one maintenance cover 220 covers the at least two maintenance windows 211 at the same time. Through the structural design, the utility model can reduce the number of parts and reduce the cost.

It should be noted herein that the battery packs shown in the drawings and described in this specification are only a few examples of the wide variety of battery packs that can employ the principles of the present utility model. It should be clearly understood that the principles of the present utility model are in no way limited to any of the details of the battery pack or any of the components of the battery pack shown in the drawings or described in the present specification.

In summary, the battery pack according to the present utility model includes a case 100 and a case cover 200, where the case cover 200 has a heat exchange channel and can be used as an upper heat exchange plate, the case cover 200 includes a cover body 210 and a maintenance cover 220, the cover body 210 is provided with a maintenance window 211, the maintenance window 211 corresponds to the electrical cabinet 110 of the case 100, and the maintenance cover 220 is detachably connected to the cover body 210 and seals the maintenance window 211. Through the above structural design, the cover 200 can be conveniently and partially disassembled, namely, the electric components in the electric bin 110 are exposed out of the maintenance window 211 by disassembling the maintenance cover 220, so that the electric components are convenient to overhaul or maintain, the cover 200 or other related structures are not easy to damage due to the disassembling operation, and particularly, the heat exchange flow channel of the cover 200 is not easy to damage.

Exemplary embodiments of the battery pack according to the present utility model are described and/or illustrated in detail above. Embodiments of the utility model are not limited to the specific embodiments described herein, but rather, components and/or steps of each embodiment may be utilized independently and separately from other components and/or steps described herein. Each component and/or each step of one embodiment may also be used in combination with other components and/or steps of other embodiments. When introducing elements/components/etc. that are described and/or illustrated herein, the terms "a," "an," and "the" are intended to mean that there are one or more of the elements/components/etc. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements/components/etc., in addition to the listed elements/components/etc. Furthermore, the terms "first" and "second" and the like in the claims and in the description are used for descriptive purposes only and not for numerical limitation of their subject matter.

While the utility model has been described in terms of various specific embodiments, those skilled in the art will recognize that the utility model can be practiced with modification within the spirit and scope of the claims.

Claims (13)

1. The utility model provides a battery package, its characterized in that includes box and case lid, the case lid connect in the top opening of box, the case lid includes apron body and maintenance apron, the inside heat transfer runner that has of apron body can be as last heat exchanger plate, the maintenance window who link up along the thickness direction has been seted up to the apron body, the position of maintenance window with the position of the electrical storehouse of box corresponds, maintenance apron detachably connect in the apron body and seal the maintenance window.

2. The battery pack of claim 1, wherein a gasket is disposed between the service cover and the cover body.

3. The battery pack according to claim 1, wherein an inner wall of the service window is provided with a mounting step, and the service cover plate is accommodated in the service window and detachably connected to the mounting step.

4. A battery pack according to claim 3, wherein:

the maintenance cover plate is detachably connected with the cover plate body through a connecting piece, and the connecting piece penetrates through the maintenance cover plate and the mounting step; and/or

And a sealing gasket is arranged between the maintenance cover plate and the cover plate body and is positioned between the bottom surface of the maintenance cover plate and the top surface of the installation step.

5. The battery pack according to claim 1, wherein the electrical compartment is aligned with the battery compartment of the case in a first direction, and the maintenance window is located at an end of the cover body in the first direction; the heat exchange flow channel comprises a heat exchange section and a liquid inlet and outlet section, the position of the heat exchange section corresponds to that of the battery compartment, one end of the liquid inlet and outlet section is connected with the heat exchange section, and the other end of the liquid inlet and outlet section is connected with a liquid inlet and outlet joint; wherein:

the distance between the maintenance window and the heat exchange section is greater than or equal to 6mm along the first direction; and/or

Along the first direction, the distance between one side of the maintenance window, which is away from the heat exchange section, and the edge of the adjacent cover plate body in the first direction is larger than the width of the frame of the box body.

6. The battery pack according to claim 1, wherein the electrical compartment is aligned with the battery compartment of the case in a first direction, and the maintenance window is located at an end of the cover body in the first direction; and the distance between the maintenance window and the edge of the cover plate body in the second direction is larger than the width of the frame of the box body along the second direction perpendicular to the first direction.

7. The battery pack according to any one of claims 1 to 6, wherein the cover plate body is provided with at least two of the maintenance windows, and the at least two maintenance windows are arranged at intervals.

8. The battery pack according to claim 7, wherein the electric bin and the battery bin of the box body are arranged along a first direction, the heat exchange flow channel comprises a heat exchange section and a liquid inlet and outlet section, the position of the heat exchange section corresponds to that of the battery bin, one end of the liquid inlet and outlet section is connected with the heat exchange section, and the other end of the liquid inlet and outlet section is connected with the liquid inlet and outlet joint; the cover plate body is provided with two maintenance windows, the two maintenance windows are located at one end of the cover plate body along the first direction and are arranged at intervals along a second direction perpendicular to the first direction, the part of the cover plate body located between the two maintenance windows is a bridge, and the liquid inlet and outlet section is located at the bridge.

9. The battery pack of claim 8, wherein a ratio of a width of the bridge portion in a width of the cap body in the second direction is less than or equal to 0.5.

10. The battery pack according to claim 8, wherein an end of the bridge portion facing away from the heat exchange section protrudes from the case body to form a first protruding portion, the liquid inlet/outlet section extends to the first protruding portion, and the liquid inlet/outlet connector is located outside the case body and connected to the liquid inlet/outlet section of the first protruding portion.

11. The battery pack according to claim 10, further comprising a lower heat exchange plate provided at the bottom of the case, the lower heat exchange plate having a second protrusion protruding outside the case, the heat exchange flow passage of the lower heat exchange plate extending to the second protrusion; the positions of the first bulge and the second bulge are corresponding, and the heat exchange flow channel of the first bulge and the heat exchange flow channel of the second bulge are respectively connected to the liquid inlet and outlet connector.

12. The battery pack of claim 7, wherein at least two of the repair windows are unequal in area.

13. The battery pack according to claim 7, wherein:

the box cover comprises at least two maintenance cover plates, and the at least two maintenance cover plates correspond to the at least two maintenance windows one by one; or alternatively

The cover comprises at least one maintenance cover plate, and at least one maintenance cover plate simultaneously covers at least two maintenance windows.