Battery pack and electric device

Abstract

The embodiment of the invention provides a battery pack and an electric device. The battery pack comprises a first circuit board, a second circuit board, a connector, a flexible circuit board and a battery cell assembly. The second circuit board and the first circuit board are arranged at an interval in the first direction, and the projection of the second circuit board and the projection of the first circuit board partially coincide in the first direction; the connector is connected to the second circuit board and located on the side, facing the first circuit board, of the second circuit board; the flexible circuit board comprises a first welding part welded to the first circuit board and a second welding part welded to the second circuit board, the flexible circuit board is provided with a first bending part, and the first bending part abuts against the connector; the battery cell assembly comprises a plurality of battery cells, and the battery cells are connected to the first circuit board.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery pack and an electrical device. Background Art

[0002] The circuit module of the battery pack usually includes a plurality of circuit boards, and connection structures need to be provided between the circuit boards to realize circuit connection relationship and electrical signal connection relationship.

[0003] The layout of various circuit boards and connection structures requires a lot of space, which is not conducive to improving the integration of the battery pack. Summary of the invention

[0004] The embodiments of the present invention provide a battery pack and an electric device, which can improve the integration of the battery pack.

[0005] In a first aspect, an embodiment of the present invention provides a battery pack, including a first circuit board, a second circuit board, a connector, a flexible circuit board, and a battery cell assembly. The second circuit board is spaced apart from the first circuit board along a first direction, and along the first direction, the projection of the second circuit board partially overlaps with the projection of the first circuit board; the connector is connected to the second circuit board, and the connector is located on the side of the second circuit board facing the first circuit board; the flexible circuit board includes a first welding portion welded to the first circuit board and a second welding portion welded to the second circuit board, and the flexible circuit board has a first bending portion, and the first bending portion abuts against the connector; the battery cell assembly includes a plurality of battery cells, and the battery cells are connected to the first circuit board.

[0006] In the above embodiment, along the first direction, the projection of the connector and the projection of the first circuit board are separated.

[0007] In one or more of the above optional embodiments, the connector includes an inclined surface, and along the first direction, the first circuit board exceeds the inclined surface, and a portion of the first bent portion is located above the inclined surface.

[0008] In one or more optional embodiments above, the connector includes a limiting portion and a connecting portion, the connecting portion and the limiting portion form a receiving groove, a portion of the first bent portion is located in the receiving groove, and the first bent portion abuts against the limiting portion.

[0009] In one or more of the above optional embodiments, the connecting portion is closer to the first circuit board than the limiting portion, and the inclined surface is provided on the connecting portion.

[0010] In one or more optional embodiments above, the battery pack includes a shell, the shell is provided with an opening, the connecting portion is fixed to the shell, and a portion of the connector is exposed outside the shell.

[0011] In one or more of the above optional embodiments, the second circuit board includes a first side surface and a second side surface spaced apart along a second direction, and along the first direction, the projection of the first welding portion is located between the projection of the first side surface and the projection of the second side surface; the flexible circuit board includes a second bending portion, and a portion of the second bending portion is located between the first circuit board and the second circuit board; the second bending portion bypasses the second side surface.

[0012] In one or more of the above optional embodiments, the second bending portion abuts against the first circuit board.

[0013] In one or more of the above optional embodiments, the first circuit board has a first welding area, the second circuit board has a second welding area, the first welding portion is welded to the first welding area, and the second welding portion is welded to the second welding area; along the first direction, the projection of the first welding area is located within the projection of the second circuit board, and the projection of the second welding area is located within the projection of the first circuit board.

[0014] In one or more optional embodiments above, the first welding area is provided on the surface of the first circuit board facing the second circuit board. The first welding area is copper foil. The first welding portion welds the first welding area by SMT.

[0015] In one or more optional embodiments above, the second welding area is arranged on a surface of the second circuit board away from the first circuit board. The second welding area is copper foil. The second welding part welds the second welding area by SMT.

[0016] In one or more optional embodiments above, along the first direction, the projection of the first welding area overlaps with the projection of the second welding area, which is conducive to better utilization of the space between the first circuit board and the second circuit board.

[0017] In one or more of the above optional embodiments, along the first direction, at least a portion of the projection of the first bending portion is separated from the projection of the first circuit board.

[0018] In one or more optional embodiments above, the first circuit board includes a third welding area, and the second circuit board includes a fourth welding area; along the first direction, the projection of the third welding area and the projection of the second circuit board are separated; the battery pack includes a first wiring harness, the first wiring harness is welded to the third welding area and the fourth welding area, and the first wiring harness is configured to transmit power.

[0019] In one or more of the above optional embodiments, the first wiring harness is welded to a side of the second circuit board away from the first circuit board, which is beneficial to the arrangement of the first wiring harness.

[0020] In one or more optional embodiments above, the first circuit board includes a fifth welding area, and the second circuit board includes a sixth welding area; along the first direction, the projection of the fifth welding area and the projection of the second circuit board are separated, the battery pack includes a second wiring harness, the second wiring harness is welded to the fifth welding area and the sixth welding area, and the second wiring harness is configured to transmit power.

[0021] In one or more of the above optional embodiments, the second wiring harness is welded to a side of the second circuit board away from the first circuit board, which is beneficial to the arrangement of the second wiring harness.

[0022] In one or more of the above optional embodiments, when viewed from a direction opposite to the first direction, the first wiring harness and the second wiring harness are located on two sides of the flexible circuit board.

[0023] In one or more of the above optional embodiments, the flexible printed circuit board is configured to transmit parameters of the battery cell.

[0024] In one or more of the above optional embodiments, the battery pack includes a plurality of conductive sheets welded to the first circuit board, and the plurality of conductive sheets are electrically connected to the flexible circuit board; the battery cell includes electrode terminals, the electrode terminals are connected to the conductive sheets, and the conductive sheets are configured to collect parameters of the battery cell.

[0025] In a second aspect, an embodiment of the present invention provides an electrical device, the device comprising a battery pack as described in the first aspect, the battery pack being used to provide electrical energy.

[0026] The battery pack and electrical device provided by the embodiments of the present invention, by stacking the first circuit board and the second circuit board along the first direction, are beneficial to reducing the space occupied by the first electrical connection portion and the second circuit board along the second direction and the third direction. At the same time, by arranging a flexible circuit board that is bent and placed between the first circuit board and the second circuit board, it is possible to achieve electrical connection between the first circuit board and the second circuit board, and fully utilize the gap between the first circuit board and the second circuit board, thereby reducing the space occupied by the flexible circuit board along the second direction and / or the third direction of the battery pack, which is beneficial to reducing the size of the battery pack along the second direction and the third direction and improving the integration of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following briefly introduces the drawings required to be used in the embodiment of the present invention.

[0028] Figure 1 A schematic diagram of a partial structure of a battery pack provided in some embodiments of the present application;

[0029] Figure 2 An exploded view of a local structure of a battery pack provided in some embodiments of the present application;

[0030] Figure 3 A schematic diagram of a planar structure of a battery pack provided in some embodiments of the present application;

[0031] Figure 4 for Figure 3 A schematic diagram of the structure enlargement in the middle;

[0032] Figure 5 An exploded view of a battery pack provided for some embodiments of the present application;

[0033] Figure 6 for Figure 5 A magnified schematic diagram of the structure at B in the middle;

[0034] Figure 7 A schematic diagram of the structure of a second circuit board and a connector of a battery pack provided in some embodiments of the present application;

[0035] Figure 8 A partial cross-sectional view of a battery pack provided for some embodiments of the present application;

[0036] Fig. 9 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application;

[0037] Fig.10 Another structural schematic diagram of a battery pack provided in some embodiments of the present application;

[0038] Fig.11 Schematic diagram of the partial structure of a battery pack provided for some other embodiments of the present application.

[0039] Description of Figure Numbers:

[0040] 1. first circuit board; 13. first welding area; 14. third welding area; 15. fifth welding area;

[0041] 2. second circuit board; 21. first side surface; 22. second side surface; 23. second welding area; 24. fourth welding area; 25. sixth welding area;

[0042] 3. Connector; 31. Limiting portion; 32. Connecting portion; 321. Inclined surface; 33. Receiving groove;

[0043] 4. Flexible circuit board; 41. First bending portion; 42. Second bending portion; 43. First welding portion; 44. Second welding portion;

[0044] 5. battery cell assembly; 51. battery cell; 52. electrode terminal;

[0045] 6. outer shell; 61. first shell; 611. opening; 62. second shell;

[0046] 71. first wiring harness; 72. second wiring harness;

[0047] 8. Conductive sheet;

[0048] M. Radiator;

[0049] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0050] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, rather than to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0052] The battery pack and the electrical device of the present application are described below with reference to the accompanying drawings.

[0053] like Figures 1 to 6 As shown, an embodiment of the present application provides a battery pack, wherein the battery pack includes a battery cell assembly 5 , the battery cell assembly 5 includes a plurality of battery cells 51 , the battery cells 51 are used to provide electrical energy, and each battery cell 51 includes an electrode terminal 52 .

[0054] In some embodiments, the battery pack includes a first circuit board 1, a second circuit board 2, and a flexible circuit board 4. The flexible circuit board 4 includes a first welding portion 43 and a second welding portion 44, the first welding portion 43 is welded to the first circuit board 1, and the second welding portion 44 is welded to the second circuit board 2. The flexible circuit board 4 is configured to transmit battery cell parameters and / or power.

[0055] In some embodiments, the second circuit board 2 is spaced from the first circuit board 1 along the first direction X. Along the first direction X, the projection of the second circuit board 2 partially overlaps with the projection of the first circuit board 1. By utilizing the space of the battery pack along the first direction X, the space between the first circuit board 1 and the second circuit board 2 along the second direction Y and / or the third direction Z of the battery pack is reduced, which is conducive to reducing the size of the battery pack along the second direction Y and the third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0056] In some embodiments, the first circuit board 1 and the second circuit board 2 are substantially perpendicular to the first direction X, and the first circuit board 1 and the second circuit board 2 are substantially parallel.

[0057] In some embodiments, the battery pack includes a connector 3, the connector 3 is connected to the second circuit board 2, and the connector 3 is located on the side of the second circuit board 2 facing the first circuit board 1; it can be understood that the connector 3 is located in the space between the first circuit board 1 and the second circuit board 2. Optionally, the connector 3 is welded to the second circuit board 2.

[0058] In some embodiments, the connector 3 is an aviation plug connector, and the connector 3 is configured for power connection and signal transmission between the battery pack and the electrical device.

[0059] In some embodiments, the flexible circuit board 4 has a first bending portion 41, which is formed by bending the flexible circuit board 4. The first bending portion 41 abuts against the connector 3, and the connector 3 provides a limit for the first bending portion 41 to maintain the position of the flexible circuit board 4 between the first circuit board 1 and the second circuit board 2.

[0060] By bending the flexible circuit board 4 and setting it between the first circuit board 1 and the second circuit board 2, the first circuit board 1 and the second circuit board 2 can be electrically connected while utilizing the space between the first circuit board 1 and the second circuit board 2 to reduce the space of the flexible circuit board 4 along the second direction Y and / or the third direction Z of the battery pack, which is beneficial to reducing the size of the battery pack along the second direction Y and the third direction Z and improving the integration of the battery pack.

[0061] In some embodiments, the first circuit board 1 is provided with electronic devices, including but not limited to resistors, chips, etc.

[0062] In some embodiments, a BMS component (Battery Management System) is provided on the second circuit board 2. The BMS component can control the charging and discharging of the battery cell assembly 5, prevent overcharging and overdischarging, extend the life of the battery cell assembly 5, and ensure the safety and stability of the battery pack.

[0063] like Figure 3 and Figure 4As shown, in some embodiments, along the first direction X, the projection of the connector 3 is separated from the projection of the first circuit board 1. There is a distance between the connector 3 and the first circuit board 1 along the second direction Y, which can provide a setting space for the flexible circuit board 4, so that the flexible circuit board 4 extends along the second direction Y and is connected to the first circuit board 1 after bending.

[0064] like Figure 8 As shown, in some embodiments, the connector 3 includes an inclined surface 321, and along the first direction X, the first circuit board 1 exceeds the inclined surface 321, and along the first direction X, part of the first bending portion 41 is located above the inclined surface 321. The inclined surface 321 can guide and avoid the first bending portion 41 of the flexible circuit board 4, and provide a setting space for the first bending portion 41.

[0065] like Figure 7 and Figure 8 As shown, in some embodiments, the connector 3 includes a limiting portion 31 and a connecting portion 32, the connecting portion 32 and the limiting portion 31 form a receiving groove 33, a portion of the first bent portion 41 is located in the receiving groove 33, and the first bent portion 41 abuts against the limiting portion 31. The limiting portion 31 provides support for the first bent portion 41, maintains the position of the first bent portion 41, reduces the elastic restoring force generated by the bending of the first bent portion 41, and reduces the stress concentration and damage at the connection between the first bent portion 41 and the first circuit board 1 and the connection between the second bent portion 42 and the second circuit board 2.

[0066] In some embodiments, the connection portion 32 is connected to the side of the limiting portion 31 away from the second circuit board 2 along the first direction X. The limiting portion 31 and the connection portion 32 are integrally formed and connected, and have good structural strength. The limiting portion 31 and the connection portion 32 generally form an L-shaped structure.

[0067] like Figure 7 and Figure 8 As shown, in some embodiments, the connection portion 32 is closer to the first circuit board 1 than the limiting portion 31, and the inclined surface 321 is provided on the connection portion 32, and along the first direction X, the inclined surface 321 gradually inclines toward the direction close to the first circuit board 1. The flexible circuit board 4 is guided to bend and extend toward the direction close to the first circuit board 1 by the cooperation between the inclined surface 321 and the limiting portion 31.

[0068] In some embodiments, the first bending portion 41 abuts against the inclined surface 321 .

[0069] like Figures 8 to 11As shown, in some embodiments, the battery pack includes a shell 6, and a portion of the connector 3, the first circuit board 1, the second circuit board 2, the flexible circuit board 4 and the battery cell assembly 5 are all arranged inside the shell 6, and the shell 6 provides protection for the portion of the connector 3 located inside the shell 6, the first circuit board 1, the second circuit board 2, the flexible circuit board 4 and the battery cell assembly 5.

[0070] In some embodiments, Fig.10 As shown, the housing 6 is provided with an opening 611 , the connecting portion 32 is fixed to the housing 6 , and part of the connector 3 is exposed outside the housing 6 for electrical connection with other components of the electrical device.

[0071] In some embodiments, the housing 6 includes a first shell 61 and a second shell 62 , and the first shell 61 and the second shell 62 are detachably sealed and enclosed to form a complete housing 6 .

[0072] In some embodiments, a heat sink M is provided on the first shell 61 and / or the second shell 62 to dissipate heat from the battery cell assembly 5 .

[0073] like Figures 3 to 7 As shown, in some embodiments, the second circuit board 2 includes a first side surface 21 and a second side surface 22 spaced apart along the second direction Y, and along the first direction X, the projection of the first welding portion 43 is located between the projection of the first side surface 21 and the projection of the second side surface 22.

[0074] The flexible circuit board 4 includes a second bending portion 42 . A portion of the second bending portion 42 is located between the first circuit board 1 and the second circuit board 2 . The second bending portion 42 goes around the second side surface 22 .

[0075] like Figures 3 to 7 As shown, in some embodiments, the second bending portion 42 goes around the second side surface 22 from the side of the second circuit board 2 toward the first circuit board 1 , extends to the side of the second circuit board 2 away from the first circuit board 1 , and is soldered to the second circuit board 2 .

[0076] While the flexible circuit board 4 is electrically connected to the second circuit board 2, the size of the flexible circuit board 4 in the first direction X is increased, the bending pressure on the flexible circuit board 4 is reduced, and the service life of the flexible circuit board 4 is improved; and a part of the flexible circuit board 4 is bent to form a second bending portion 42, and then extends in a state roughly perpendicular to the first direction X, and is connected to the second circuit board 2 in a state roughly parallel to the second circuit board 2, thereby improving the connection reliability between the flexible circuit board 4 and the second circuit board 2 and reducing the damage between the flexible circuit board 4 and the second circuit board 2 due to stress concentration.

[0077] In some embodiments, see Fig.11The second bent portion 42 abuts against the first circuit board 1, and the first circuit board 1 provides support and retention for the second bent portion 42, thereby reducing the elastic restoring force generated by the bending of the flexible circuit board 4, and reducing the stress concentration and damage at the connection between the first bent portion 41 and the first circuit board 1 and the connection between the second bent portion 42 and the second circuit board 2.

[0078] In some embodiments, the first circuit board 1 has a first welding area 13, the second circuit board 2 has a second welding area 23, the first welding portion 43 is welded to the first welding area 13, and the second welding portion 44 is welded to the second welding area 23. For example, welding is performed by SMT.

[0079] In some embodiments, the first welding area 13 is disposed on the surface of the first circuit board 1 facing the second circuit board 2. The first welding area 13 is a copper foil. The first welding portion welds the first welding area 13 by SMT.

[0080] In some embodiments, the second welding area 23 is disposed on a surface of the second circuit board 2 away from the first circuit board 2. The second welding area 23 is a copper foil. The second welding portion welds the second welding area 23 by SMT.

[0081] In some embodiments, along the first direction X, the projection of the first welding area 13 and the projection of the second welding area 23 overlap, which is beneficial to better utilize the space between the first circuit board 1 and the second circuit board 2 .

[0082] In some embodiments, along the first direction X, the projection of the first welding area 13 is located within the projection of the second circuit board 2, and the projection of the second welding area 23 is located within the projection of the first circuit board 1, so that the first circuit board 1 and the second circuit board 2 are partially staggered along the second direction Y, which can reduce the size of the first welding area 13 and the second welding area 23 along the second direction Y, reduce the bending curvature of the first bending portion 41 and the second bending portion 42, and reduce the overall size of the flexible circuit board 4 along the first direction X and the second direction Y.

[0083] like Figure 4 As shown, in some embodiments, along the first direction X, at least a portion of the projection of the first bend portion 41 is separated from the projection of the first circuit board 1, so that a portion of the flexible circuit board 4 is bent to form the first bend portion 41 and then extends in a state approximately perpendicular to the first direction X, and is connected to the first circuit board 1 in a state approximately parallel to the first circuit board 1, thereby improving the connection reliability between the flexible circuit board 4 and the first circuit board 1 and reducing the damage between the flexible circuit board 4 and the first circuit board 1 due to stress concentration.

[0084] like Figure 6As shown, in some embodiments, the first circuit board 1 includes a third welding area 14, and the second circuit board 2 includes a fourth welding area 24. The battery pack includes a first wiring harness 71, and the first wiring harness 71 is welded to the third welding area 14 and the fourth welding area 24. The first wiring harness 71 is configured to transmit power, for example, the first wiring harness 71 can be a positive electrode, and in other embodiments, the first wiring harness 71 can be a negative electrode.

[0085] like Figure 6 As shown, in some embodiments, the third welding area 14 is arranged on the side of the first circuit board 1 facing the second circuit board 2, the fourth welding area 24 is arranged on the side of the second circuit board 2 away from the first circuit board 1, and the first wiring harness 71 is welded to the side of the second circuit board 2 away from the first circuit board 1, which is facilitating the welding of the first wiring harness 71.

[0086] In some embodiments, along the first direction X, the projection of the third welding area 14 is separated from the projection of the second circuit board 2, and the first wiring harness 71 extends approximately along the second direction Y when connecting the third welding area 14 and the fourth welding area 24, thereby reducing the bending of the first wiring harness 71, reducing the difficulty of connecting and laying out the first wiring harness 71, and improving the connection reliability between the first wiring harness 71 and the third welding area 14, and between the first wiring harness 71 and the fourth welding area 24.

[0087] like Figure 6 As shown, in some embodiments, the first circuit board 1 includes a fifth welding area 15, and the second circuit board 2 includes a sixth welding area 25. The battery pack includes a second wiring harness 72, and the second wiring harness 72 is welded to the fifth welding area 15 and the sixth welding area 25. The second wiring harness 72 is configured to transmit power, for example, the second wiring harness 72 can be a positive electrode, and in other embodiments, the second wiring harness 72 can be a negative electrode. One of the first wiring harness 71 and the second wiring harness 72 is positive and negative, and the other is a negative electrode.

[0088] like Figure 6 As shown, in some embodiments, the fifth welding area 15 is arranged on the side of the first circuit board 1 facing the second circuit board 2, the sixth welding area 25 is arranged on the side of the second circuit board 2 away from the first circuit board 1, and the second wiring harness 72 is welded to the side of the second circuit board 2 away from the first circuit board 1, which is facilitating welding of the second wiring harness 72.

[0089] In some embodiments, along the first direction X, the projection of the fifth welding area 15 is separated from the projection of the second circuit board 2, and the second wiring harness 72 extends along the second direction Y, thereby reducing the bending of the second wiring harness 72, reducing the difficulty of connecting and laying out the second wiring harness 72, and improving the connection reliability between the second wiring harness 72 and the fifth welding area 15, and between the second wiring harness 72 and the sixth welding area 25.

[0090] In some embodiments, the flexible circuit board 4 is configured to transmit parameters of the battery cell 51 , including but not limited to voltage, current, temperature, and resistance.

[0091] like Figure 6 As shown, in some embodiments, the battery pack includes a conductive sheet 8 welded to the first circuit board 1; the conductive sheet 8 is electrically connected to the flexible circuit board 4 through the conductive wires of the first circuit board 1.

[0092] In some embodiments, the electrode terminal 52 is connected to the conductive sheet 8 , and the conductive sheet 8 is configured to collect parameters of the battery cell 51 . For example, the conductive sheet 8 collects the voltage signal of the electrode terminal 52 to monitor the charging and discharging safety of the battery cell assembly 5 .

[0093] An embodiment of the present application further provides an electrical device, wherein the electrical device includes the battery pack as described above, and the battery pack is used to provide electrical energy.

[0094] In the battery pack of the electrical device provided in the embodiment of the present application, a flexible circuit board 4 is provided to be connected to the first circuit board 1 and the second circuit board 2 respectively. The flexible circuit board 4 has a first bending portion 41, and the first bending portion 41 is formed by bending the flexible circuit board 4. The first bending portion 41 abuts against the connector 3. The connector 3 provides support for the first bending portion 41 and the entire flexible circuit board 4, so that the position of the flexible circuit board 4 between the first circuit board 1 and the second circuit board 2 is maintained.

[0095] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: The battery pack comprises: a first circuit board; a second circuit board, spaced apart from the first circuit board along a first direction, wherein a projection of the second circuit board partially overlaps with a projection of the first circuit board along the first direction; A connector connected to the second circuit board, wherein the connector is located on a side of the second circuit board facing the first circuit board; A flexible circuit board, comprising a first welding portion welded to the first circuit board and a second welding portion welded to the second circuit board, the flexible circuit board having a first bending portion, the first bending portion abutting against the connector; The battery cell assembly includes a plurality of battery cells, and the battery cells are connected to the first circuit board.

2. The battery pack according to claim 1, characterized in that: Along the first direction, a projection of the connector and a projection of the first circuit board are separated.

3. The battery pack according to claim 1 or 2, characterized in that: The connector includes an inclined surface. Along the first direction, the first circuit board exceeds the inclined surface, and a portion of the first bending portion is located above the inclined surface.

4. The battery pack according to claim 3, characterized in that: The connector includes a limiting portion and a connecting portion, wherein the connecting portion and the limiting portion form a receiving groove, a portion of the first bending portion is located in the receiving groove, and the first bending portion abuts against the limiting portion.

5. The battery pack according to claim 4, characterized in that: The connecting portion is closer to the first circuit board than the limiting portion, and the inclined surface is arranged on the connecting portion.

6. The battery pack according to claim 4 or 5, characterized in that: The battery pack includes a shell having an opening, the connecting portion is fixed to the shell, and a portion of the connector is exposed outside the shell.

7. The battery pack according to any one of claims 1 to 6, characterized in that: The second circuit board comprises a first side surface and a second side surface spaced apart along a second direction, wherein a projection of the first welding portion is located between a projection of the first side surface and a projection of the second side surface along the first direction; The flexible circuit board includes a second bending portion, a portion of the second bending portion is located between the first circuit board and the second circuit board; and the second bending portion goes around the second side surface.

8. The battery pack according to claim 7, characterized in that: The second bending portion abuts against the first circuit board.

9. The battery pack according to any one of claims 1 to 8, characterized in that: The first circuit board has a first welding area, the second circuit board has a second welding area, the first welding portion is welded to the first welding area, and the second welding portion is welded to the second welding area; Along the first direction, the projection of the first welding area is located within the projection of the second circuit board, and the projection of the second welding area is located within the projection of the first circuit board.

10. The battery pack according to claim 9, characterized in that: Along the first direction, at least a portion of a projection of the first bending portion is separated from a projection of the first circuit board.

11. The battery pack according to any one of claims 1 to 10, characterized in that: The first circuit board includes a third welding area, and the second circuit board includes a fourth welding area; Along the first direction, the projection of the third welding area and the projection of the second circuit board are separated; The battery pack includes a first wire harness welded to the third welding region and the fourth welding region, the first wire harness being configured to transmit power.

12. The battery pack according to any one of claims 1 to 11, characterized in that: The flexible circuit board is configured to transmit parameters of the battery cell.

13. The battery pack according to claim 12, characterized in that: The battery pack includes a plurality of conductive sheets welded to the first circuit board, and the plurality of conductive sheets are electrically connected to the flexible circuit board; The battery cell includes an electrode terminal connected to the conductive sheet, and the conductive sheet is configured to collect parameters of the battery cell.

14. An electrical device, characterized in that: The electrical device comprises a battery pack as claimed in any one of claims 1 to 13, wherein the battery pack is used to provide electrical energy.

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