Battery pack

Abstract

The utility model belongs to battery technical field discloses a kind of battery pack, including box, battery module, maintenance cover and fire extinguisher, accommodating cavity for accommodating battery module is provided in box, box is provided with maintenance port, maintenance cover is used to block maintenance port, maintenance cover includes bottom plate, support part and connecting part, the side of bottom plate towards battery module is provided with a circle of support part around the outer edge of bottom plate, support part is enclosed and is formed with the installation cavity for accommodating fire extinguisher, connecting part is provided on the outer circumferential wall of support part, and connecting part is detachably connected with box.The utility model's battery pack is by being provided with annular support part on the bottom plate of maintenance cover, to be enclosed and form installation cavity for accommodating fire extinguisher, battery module can be ensured to separate from fire extinguisher, avoid fire extinguisher to occupy the accommodating space of battery module in box, ensure the capacity of battery pack, and reasonable layout fire extinguisher, can enhance the fire protection function of battery pack, improve the overall safety of battery pack.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack. Background Technology

[0002] With the increasing development of new energy sources, battery energy storage technology has become a key technology. The basic structure of battery energy storage is a battery pack, which consists of a battery box and multiple battery modules built into the battery box. During the charging and discharging process of the battery modules, a large amount of heat is generated, so air cooling or liquid cooling is required to dissipate heat and reduce the possibility of thermal runaway.

[0003] Currently, with the increasing energy density of battery packs, the fire safety issue of thermal runaway protection is becoming more and more important. For traditional battery packs, if fire-fighting devices need to be installed inside the battery box, it will squeeze the space of the battery modules and affect the capacity of the battery pack. Utility Model Content

[0004] The purpose of this utility model is to provide a battery pack with a simple structure, and its maintenance cover is provided with a fire extinguisher installation cavity to ensure the storage space for the battery module inside the box.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A battery pack is provided, including a housing, a battery module, a maintenance cover, and a fire extinguisher. The housing has a cavity for accommodating the battery module. The housing has mounting surfaces arranged along a first direction. The mounting surfaces have a maintenance opening communicating with the cavity. The maintenance cover is used to seal the maintenance opening. The maintenance cover includes a base plate, a support portion, and a connecting portion. The support portion is arranged around the outer edge of the base plate on the side facing the battery module. The support portion encloses and forms a mounting cavity for accommodating the fire extinguisher. The connecting portion is arranged around the outer edge of the support portion on its outer peripheral wall, and the connecting portion is adjacent to the side of the support portion away from the base plate. The connecting portion is detachably connected to the housing.

[0007] As a preferred embodiment of the battery pack, the mounting surface is provided with a plurality of first connection holes, all of which are arranged around the maintenance port. The connecting part is provided with a plurality of first through holes, and bolts are passed through the first through holes and screwed into the first connection holes to achieve the connection between the connecting part and the housing.

[0008] As a preferred embodiment of the battery pack, the battery pack further includes a first sealing ring and a second sealing ring, both of which are disposed between the connecting portion and the mounting surface, and both of which surround the maintenance port, with the first through hole located between the first sealing ring and the second sealing ring.

[0009] As a preferred embodiment of the battery pack, the connecting portion is provided with a first limiting groove and a second limiting groove at intervals, and both the first limiting groove and the second limiting groove are arranged around the base plate. The first through hole is located between the first limiting groove and the second limiting groove. The first sealing ring is partially inserted into the first limiting groove, and the second sealing ring is partially inserted into the second limiting groove.

[0010] As a preferred embodiment of the battery pack, the first sealing ring is disposed adjacent to the service port, the compression ratio of the first sealing ring is C1, and the compression ratio of the second sealing ring is C2, where C1 > C2; and / or,

[0011] The cross-sectional diameter of the first sealing ring is D1, and the cross-sectional diameter of the second sealing ring is D2, where D1 > D2; and / or,

[0012] The cross-sectional diameter D of the first sealing ring and / or the second sealing ring satisfies: 0.2mm≤D≤0.5mm.

[0013] As a preferred embodiment of the battery pack, the base plate has multiple mounting posts protruding from the side facing the battery module, and the fire extinguisher is detachably connected to the mounting posts.

[0014] As a preferred embodiment of the battery pack, the battery pack further includes an explosion-proof valve, and the maintenance cover is provided with a pressure relief hole communicating with the receiving cavity, with the explosion-proof valve located at the pressure relief hole.

[0015] As a preferred embodiment of the battery pack, the explosion-proof valve is detachably connected to the maintenance cover. The battery pack also includes a third sealing ring, which is disposed between the explosion-proof valve and the maintenance cover. A third limiting groove is provided on one side of the two adjacent sides of the explosion-proof valve and the maintenance cover, and a limiting protrusion is provided on the other side. The third sealing ring is engaged between the limiting protrusion and the bottom of the third limiting groove.

[0016] As a preferred embodiment of the battery pack, the pressure relief hole includes a first explosion-proof hole and a plurality of second explosion-proof holes communicating with the first explosion-proof hole, and all the second explosion-proof holes are evenly distributed along the outer edge of the first explosion-proof hole.

[0017] As a preferred embodiment of the battery pack, the base plate is provided with a plurality of first reinforcing ribs at intervals on the side away from the battery module, the length of the first reinforcing ribs extending along a second direction, and the first direction and the second direction being set at an angle.

[0018] As a preferred embodiment of the battery pack, the base plate is provided with a plurality of second reinforcing ribs at intervals on the side adjacent to the battery module. The length of the second reinforcing ribs extends along a third direction, and the first direction and the second direction are respectively set at an angle to the third direction.

[0019] The beneficial effects of this utility model are as follows: By setting a maintenance port on the mounting surface of the enclosure, it is easy to open the detachable maintenance cover and pass through the maintenance port to inspect and maintain the battery module and other components inside the enclosure. The maintenance cover is easy to install and remove, which can effectively improve the convenience and efficiency of battery pack maintenance. By setting an annular support part on the bottom plate of the maintenance cover to form an installation cavity for accommodating fire extinguishers, it is possible to ensure that the fire extinguishers are separated from the battery module, avoid the fire extinguishers occupying the storage space of the battery module inside the enclosure, ensure the capacity of the battery pack, and the reasonable layout of the fire extinguishers can enhance the fire protection function of the battery pack and improve the overall safety of the battery pack. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the battery pack structure according to an embodiment of the present invention;

[0022] Figure 2 This is an exploded view of the battery pack according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of the maintenance cover according to an embodiment of the present utility model;

[0024] Figure 4 This is a cross-sectional view of the maintenance cover according to an embodiment of the present utility model;

[0025] Figure 5 This is a schematic diagram illustrating the cooperation between the maintenance cover and the fire extinguisher according to an embodiment of this utility model;

[0026] Figure 6 This is an explosion diagram of the maintenance cover and fire extinguisher according to an embodiment of this utility model.

[0027] In the picture:

[0028] 1. Housing; 11. Receiving cavity; 12. Mounting surface; 13. Maintenance port; 2. Battery module; 3. Maintenance cover; 31. Base plate; 32. Support part; 33. Connecting part; 331. First through hole; 332. First limiting groove; 333. Second limiting groove; 34. Mounting cavity; 35. Mounting column; 36. Pressure relief hole; 361. First explosion-proof hole; 362. Second explosion-proof hole; 37. First reinforcing rib; 38. Weight reduction groove; 4. Fire extinguisher; 5. First sealing ring; 6. Second sealing ring; 7. Explosion-proof valve. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0033] like Figures 1 to 6As shown, the battery pack of this utility model embodiment includes a housing 1, a battery module 2, a maintenance cover 3, and a fire extinguisher 4. The housing 1 has a receiving cavity 11 for accommodating the battery module 2. The housing 1 has mounting surfaces 12 arranged along a first direction (the first direction is the X direction shown in the figure). The mounting surfaces 12 have a maintenance opening 13 communicating with the receiving cavity 11. The maintenance cover 3 is used to seal the maintenance opening 13. The maintenance cover 3 includes a base plate 31, a support portion 32, and a connecting portion 33. A ring of support portions 32 is arranged around the outer edge of the base plate 31 facing the battery module 2, forming a ring of... The mounting cavity 34 is used to accommodate the fire extinguisher 4. A connecting part 33 is provided around the outer edge of the support part 32 on the outer peripheral wall of the support part 32. That is, a supporting part 32 is formed around the outer edge of the bottom plate 31 facing the battery module 2. The length of the supporting part 32 extends along the first direction. A connecting part 33 is formed around the outer edge of the support part 32 on the outer peripheral wall of the support part 32. The length of the connecting part 33 extends along the thickness direction of the support part 32. The connecting part 33 is adjacent to the side of the support part 32 away from the bottom plate 31. The connecting part 33 is detachably connected to the housing 1.

[0034] It is understandable that by providing a maintenance port 13 on the mounting surface 12 of the housing 1, it is convenient to open the detachable maintenance cover 3 and pass through the maintenance port 13 to inspect and maintain the battery module 2 and other components inside the housing 1. Moreover, the maintenance cover 3 is easy to install and remove, which can effectively improve the maintenance convenience and efficiency of the battery pack. By providing an annular support part 32 on the bottom plate 31 of the maintenance cover 3 to form an installation cavity 34 for accommodating the fire extinguisher 4, it is possible to ensure that the fire extinguisher 4 is separated from the battery module 2, avoid the fire extinguisher 4 occupying the storage space of the battery module 2 inside the housing 1, ensure the capacity of the battery pack, and the reasonable layout of the fire extinguisher 4 can enhance the fire protection function of the battery pack and improve the overall safety of the battery pack.

[0035] It should be noted that in this embodiment, the maintenance cover 3 is integrally injection molded from insulating material, that is, the base plate 31, the support part 32, and the connecting part 33 are integrally injection molded. This results in high structural strength. Compared with the traditional sheet metal parts that require multiple processes such as bending, welding, and painting, the integral injection molding method has high production efficiency, lower material cost of insulating material, and is less prone to rust and corrosion. In addition, the company name, structural logo, and other identification information can be directly injection molded on the outside of the base plate 31. The identification has high connection strength and is not easy to fall off, reducing the investment in traditional labels.

[0036] Optionally, such as Figure 2 and Figure 3As shown, the mounting surface 12 has multiple first connecting holes, all of which surround the maintenance port 13. The connecting part 33 has multiple first through holes 331. Bolts pass through the first through holes 331 and are screwed into the first connecting holes to connect the connecting part 33 to the housing 1. In this embodiment, the first connecting holes are threaded holes. The bolts pass through the first through holes 331 and are screwed into the threaded holes to achieve the connection. That is, the bolt screwing clamps the connecting part 33 between the bolt head and the housing 1. The bolt thread connection can provide strong clamping force and can withstand high loads, ensuring the connection stability between the maintenance cover 3 and the housing 1 and reducing the risk of loosening or failure. The bolt connection is convenient to install and remove and has low replacement cost.

[0037] Furthermore, such as Figure 4 and Figure 5 As shown, the battery pack also includes a first sealing ring 5 and a second sealing ring 6. Both the first sealing ring 5 and the second sealing ring 6 are disposed between the connecting part 33 and the mounting surface 12, and both surround the maintenance opening 13. The first through hole 331 is located between the first sealing ring 5 and the second sealing ring 6. The two sealing rings effectively enhance the sealing between the maintenance cover 3 and the housing 1, thereby effectively preventing external moisture, dust, or other impurities from entering the battery pack and improving its sealing performance. Furthermore, the arrangement of the first sealing ring 5 and the second sealing ring 6 around the maintenance opening 13 is simple in structure and easier to install compared to a structure where a sealing ring is placed around each bolt. The first through hole 331 is located between the two sealing rings, meaning the bolt is located between the two sealing rings, effectively ensuring the sealing of the bolt's periphery and reducing the possibility of gaps in a single sealing ring or premature wear leading to a poor seal.

[0038] Preferably, combined with Figure 6 As shown, the connecting part 33 is provided with a first limiting groove 332 and a second limiting groove 333 at intervals, and both the first limiting groove 332 and the second limiting groove 333 are arranged around the base plate 31. The first through hole 331 is located between the first limiting groove 332 and the second limiting groove 333. The first sealing ring 5 is partially inserted into the first limiting groove 332, and the second sealing ring 6 is partially inserted into the second limiting groove 333. By setting the limiting grooves, the installation position accuracy of the sealing ring is effectively improved. Moreover, compared with a single surface contacting the sealing ring, the groove wall and bottom of the limiting groove have a larger sealing contact surface with the sealing ring, resulting in a better sealing effect.

[0039] Furthermore, the first sealing ring 5 is positioned adjacent to the service port 13, and its compression ratio is C1, while the compression ratio of the second sealing ring 6 is C2, where C1 > C2. Since the battery module 2 generates heat during operation, causing an increase in air pressure within the receiving cavity 11, the first sealing ring 5, which is adjacent to the service port 13 and in contact with the receiving cavity 11, must adapt to the pressure changes within the receiving cavity 11 to ensure its sealing effect. Of course, the second sealing ring 6 is in contact with the atmosphere, and its material selection should prioritize dustproofing and resistance to air humidity.

[0040] Optionally, such as Figure 4 As shown, the cross-sectional diameter of the first sealing ring 5 is D1, and the cross-sectional diameter of the second sealing ring 6 is D2, where D1 > D2. The cross-sectional diameter is the outer diameter minus the inner diameter of the sealing ring. By increasing the cross-sectional diameter of the first sealing ring 5, the compressible deformation size of the first sealing ring 5 and the sealing contact surface are ensured, thus guaranteeing the sealing effect between the maintenance cover 3 and the housing 1. The second sealing ring 6 is in long-term contact with the external environment and is more prone to corrosion and aging. Therefore, the smaller size of the second sealing ring 6 can achieve double sealing protection, and the replacement cost of the second sealing ring 6 is lower, resulting in lower maintenance costs compared to the traditional single-ring sealing method.

[0041] Furthermore, the cross-sectional diameter D of the first sealing ring 5 and the second sealing ring 6 satisfies: 0.2mm ≤ D ≤ 0.5mm. For example, the cross-sectional diameter D of the first sealing ring 5 and the second sealing ring 6 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc. If the cross-sectional diameter of the sealing ring is too large, it occupies too much space, the connection part 33 will be wider, and the production cost will be high. If the cross-sectional diameter of the sealing ring is too small, it is easy to cause poor sealing, poor durability, and easy damage. The sealing rings in this design have moderate dimensions, good sealing effect, and long service life.

[0042] In some embodiments, such as Figure 5 and Figure 6As shown, the base plate 31 protrudes from the side facing the battery module 2 and has multiple mounting posts 35. The fire extinguisher 4 is detachably connected to the mounting posts 35. That is, multiple mounting posts 35 are integrally injection molded on the side of the base plate 31 facing the battery module 2, resulting in a stable, one-piece structure that is easier to manufacture than traditional sheet metal welded nut posts. In this embodiment, the fire extinguisher 4 includes a fire extinguishing body, a detector, and a fire extinguishing agent. The fire extinguishing body has multiple second through holes, and the mounting posts 35 have second connection holes, i.e., second threaded holes. Bolts pass through the second through holes and are screwed into the second threaded holes to achieve a detachable connection between the fire extinguisher 4 and the mounting posts 35. The fire extinguishing body is equipped with a mechanism to detect thermal runaway within the containment cavity 11, so that the triggering mechanism can promptly spray the fire extinguishing agent within the fire extinguishing body to extinguish the fire and achieve the fire extinguishing purpose. Of course, the fire extinguisher 4 can also be connected to liquid cooling media, external water sources, or pneumatic fire extinguishing structures via other pipes; no specific limitations are imposed here.

[0043] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the battery pack also includes an explosion-proof valve 7. The maintenance cover 3 has a pressure relief hole 36 communicating with the receiving cavity 11, and the explosion-proof valve 7 is located at the pressure relief hole 36. The explosion-proof valve 7 is designed so that in the event of thermal runaway within the battery pack, the high-pressure gas inside can break through the explosion-proof valve 7 and be released through the pressure relief hole 36. This prevents gas accumulation or excessive internal pressure due to overcharging, overheating, or short circuits from causing an explosion, thus improving the safety of the battery pack.

[0044] Furthermore, the explosion-proof valve 7 and the maintenance cover 3 are detachably connected. The battery pack also includes a third sealing ring, which is positioned between the explosion-proof valve 7 and the maintenance cover 3. A third limiting groove is provided on one side of the two adjacent sides of the explosion-proof valve 7 and the maintenance cover 3, and a limiting protrusion is provided on the other side. The third sealing ring is engaged between the limiting protrusion and the bottom of the third limiting groove. The explosion-proof valve 7 has multiple third through holes, and the maintenance cover 3 has multiple third threaded holes spaced around the pressure relief hole 36. Bolts are passed through the third through holes and screwed into the third threaded holes to achieve a detachable connection between the explosion-proof valve 7 and the maintenance cover 3. The threaded connection is secure, and the detachable connection between the explosion-proof valve 7 and the maintenance cover 3 also allows for maintenance in the event of thermal runaway of the battery pack, where only the explosion-proof valve 7 needs to be removed and replaced, reducing the maintenance cost of battery pack thermal runaway.

[0045] Of course, the third sealing ring effectively ensures the sealing of the connection between the explosion-proof valve 7 and the maintenance cover 3. In this embodiment, the explosion-proof valve 7 is connected to the base plate 31. A third limiting groove is arranged around the side of the explosion-proof valve 7 facing the base plate 31. A limiting protrusion is arranged around the pressure relief hole 36 on the base plate 31. The third sealing ring is placed in the third limiting groove and clamped between the limiting protrusion and the bottom of the third limiting groove. On the one hand, this can enhance the installation and positioning accuracy of the third sealing ring. On the other hand, it can increase the sealing contact area of ​​the third sealing ring and ensure the squeezing effect of the third sealing ring when the explosion-proof valve 7 is connected to the base plate 31, thereby ensuring the sealing effect of the third sealing ring.

[0046] Preferably, the pressure relief hole 36 includes a first explosion-proof hole 361 and a plurality of second explosion-proof holes 362 communicating with the first explosion-proof hole 361. All the second explosion-proof holes 362 are evenly distributed along the outer edge of the first explosion-proof hole 361. This structural layout of the pressure relief hole 36 can effectively ensure the pressure relief area. In this embodiment, the third threaded hole is disposed between two adjacent second explosion-proof holes 362, which not only ensures the pressure relief area but also effectively ensures the tightness of the fit between the third threaded hole and the pressure relief hole 36, reducing structural damage to the maintenance cover 3 and ensuring the structural strength of the maintenance cover 3.

[0047] In other embodiments, such as Figure 4 , Figure 5 and Figure 6 As shown, multiple first reinforcing ribs 37 are spaced apart on the side of the base plate 31 away from the battery module 2. The length of the first reinforcing ribs 37 extends along a second direction (the second direction is the Y direction shown in the figure), and the first direction and the second direction are set at an angle. That is, multiple first reinforcing ribs 37 are integrally injection molded on the side of the base plate 31 away from the battery module 2. Since the maintenance cover 3 has a large area, the setting of the first reinforcing ribs 37 can strengthen the structural strength of the base plate 31, enhance the compressive strength, bending strength and deformation resistance of the base plate 31, and reduce the possibility of damage to the battery module 2 or other components in the receiving cavity 11 due to deformation caused by external impact. Of course, multiple weight-reducing grooves 38 are set on the side of the base plate 31 adjacent to the battery module 2, corresponding to the multiple first reinforcing ribs 37. The length of the weight-reducing grooves 38 extends along the second direction, and part of the weight-reducing grooves 38 extends into the first reinforcing ribs 37, so as to strengthen the structural strength of the maintenance cover 3 while reducing the weight of the overall structure.

[0048] In addition to the weight-reducing groove, the side of the base plate 31 adjacent to the battery module 2 can also have multiple second reinforcing ribs spaced apart. The length of the second reinforcing ribs extends along a third direction (the third direction is the Z direction shown in the figure), and the first and second directions are respectively set at angles to the third direction. By setting the second reinforcing ribs on the side of the base plate 31 adjacent to the battery module 2, and the second reinforcing ribs are set at an angle to the first reinforcing ribs 37, the structural strength of the base plate 31 can be further strengthened, preventing the maintenance cover 3 from deforming or being damaged when the battery pack is subjected to external impact or pressure, thereby improving the overall pressure resistance and protection performance of the battery pack. Furthermore, the protrusion of the second reinforcing ribs can increase the heat exchange contact area between the base plate 31 and the high-temperature gas in the accommodating cavity 11, and the protrusion of the first reinforcing ribs 37 can increase the heat exchange area between the base plate 31 and the external environment, thereby improving the overall heat exchange effect between the maintenance cover 3 and the external environment.

[0049] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery pack, characterized in that, The device includes a housing (1), a battery module (2), a maintenance cover (3), and a fire extinguisher (4). The housing (1) has a cavity (11) for accommodating the battery module (2). The housing (1) has mounting surfaces (12) arranged along a first direction. The mounting surfaces (12) have a maintenance opening (13) communicating with the cavity (11). The maintenance cover (3) is used to seal the maintenance opening (13). The maintenance cover (3) includes a base plate (31), a support (32), and a connecting part (33). 31) A support portion (32) is provided around the outer edge of the base plate (31) on the side facing the battery module (2). The support portion (32) forms an installation cavity (34) for accommodating the fire extinguisher (4). A connecting portion (33) is provided around the outer edge of the support portion (32) on the outer peripheral wall of the support portion (32). The connecting portion (33) is adjacent to the side of the support portion (32) away from the base plate (31). The connecting portion (33) is detachably connected to the housing (1).

2. The battery pack according to claim 1, characterized in that, The mounting surface (12) is provided with a plurality of first connection holes, all of which are arranged around the maintenance port (13). The connecting part (33) is provided with a plurality of first through holes (331). Bolts are passed through the first through holes (331) and screwed into the first connection holes to realize the connection between the connecting part (33) and the housing (1).

3. The battery pack according to claim 2, characterized in that, The battery pack also includes a first sealing ring (5) and a second sealing ring (6). The first sealing ring (5) and the second sealing ring (6) are both disposed between the connecting part (33) and the mounting surface (12), and the first sealing ring (5) and the second sealing ring (6) are both disposed around the maintenance port (13). The first through hole (331) is located between the first sealing ring (5) and the second sealing ring (6).

4. The battery pack according to claim 3, characterized in that, The connecting part (33) is provided with a first limiting groove (332) and a second limiting groove (333) at intervals, and the first limiting groove (332) and the second limiting groove (333) are both arranged around the bottom plate (31). The first through hole (331) is located between the first limiting groove (332) and the second limiting groove (333). The first sealing ring (5) is partially inserted into the first limiting groove (332), and the second sealing ring (6) is partially inserted into the second limiting groove (333).

5. The battery pack according to claim 3, characterized in that, The first sealing ring (5) is disposed adjacent to the service port (13), the compression ratio of the first sealing ring (5) is C1, the compression ratio of the second sealing ring (6) is C2, C1 > C2; and / or, The cross-sectional diameter of the first sealing ring (5) is D1, and the cross-sectional diameter of the second sealing ring (6) is D2, where D1 > D2; and / or, The cross-sectional diameter D of the first sealing ring (5) and / or the second sealing ring (6) satisfies: 0.2mm≤D≤0.5mm.

6. The battery pack according to any one of claims 1-5, characterized in that, The base plate (31) has multiple mounting posts (35) protruding from the side facing the battery module (2), and the fire extinguisher (4) is detachably connected to the mounting posts (35).

7. The battery pack according to any one of claims 1-5, characterized in that, The battery pack also includes an explosion-proof valve (7), and the maintenance cover (3) is provided with a pressure relief hole (36) communicating with the receiving cavity (11), and the explosion-proof valve (7) is located at the pressure relief hole (36).

8. The battery pack according to claim 7, characterized in that, The explosion-proof valve (7) is detachably connected to the maintenance cover (3). The battery pack also includes a third sealing ring. The third sealing ring is disposed between the explosion-proof valve (7) and the maintenance cover (3). A third limiting groove is provided on one side of the two adjacent sides of the explosion-proof valve (7) and the maintenance cover (3), and a limiting protrusion is provided on the other side. The third sealing ring is engaged between the limiting protrusion and the bottom of the third limiting groove.

9. The battery pack according to claim 7, characterized in that, The pressure relief hole (36) includes a first explosion-proof hole (361) and a plurality of second explosion-proof holes (362) communicating with the first explosion-proof hole (361). All the second explosion-proof holes (362) are evenly distributed along the outer edge of the first explosion-proof hole (361).

10. The battery pack according to any one of claims 1-5, characterized in that, The base plate (31) is provided with a plurality of first reinforcing ribs (37) at intervals on the side away from the battery module (2). The length of the first reinforcing ribs (37) extends along the second direction, and the first direction is set at an angle to the second direction.

11. The battery pack according to claim 10, characterized in that, The base plate (31) is provided with a plurality of second reinforcing ribs at intervals on the side adjacent to the battery module (2). The length of the second reinforcing ribs extends along a third direction, and the first direction and the second direction are respectively set at an angle to the third direction.

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