Battery pack

Abstract

To reduce design man-hours of a battery pack.SOLUTION: A battery pack 1 includes a plurality of battery cells, a pack case having a pair of side walls facing each other and housing the plurality of battery cells arranged in a plurality of rows between the pair of side walls, and a bus bar module 30 connecting the plurality of battery cells in series for each row. Each of the plurality of battery cells includes a rectangular cell case in which a positive electrode terminal 13 and a negative electrode terminal 15 are disposed at a side end portion of an upper surface at a predetermined interval. The plurality of battery cells arranged in a row for each predetermined number are sequentially arranged such that the positions of the positive electrode terminal 13 and the negative electrode terminal 15 are alternately changed in the direction in which the plurality of battery cells are arranged in a row. In the plurality of rows of battery cells, the positions of the positive electrode terminal 13 and the negative electrode terminal 15 are switched by 180 degrees for each adjacent row, and the bus bar module 30 for each of the plurality of rows is shared.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a battery pack. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2023-114147 discloses a battery pack including a first assembled battery including a plurality of first battery cells arranged in a first direction, and a second assembled battery including a plurality of second battery cells arranged in the first direction and aligned with the first assembled battery along a second direction perpendicular to the first direction. The plurality of first battery cells and the plurality of second battery cells each include an electrode terminal. The battery pack further includes bus bars joined to the electrode terminals of the first battery cells and the second battery cells located midway along the first direction of the first assembled battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-114147 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present invention would like to reduce the number of steps required to design a battery pack. [Means for solving the problem]

[0005] The battery pack disclosed herein includes a plurality of battery cells, a pack case having a pair of opposing side walls in which the plurality of battery cells are arranged in multiple rows, and a busbar module that connects the plurality of battery cells housed in the pack case in series for each row. Each of the plurality of battery cells includes a rectangular cell case having a positive terminal and a negative terminal arranged at a predetermined interval on a side edge of the upper surface. The plurality of battery cells are arranged in a row between the pair of side walls of the pack case in predetermined numbers. The battery cells arranged in a row between the pair of side walls of the pack case are arranged in order so that the positions of the positive terminals and negative terminals alternate in the direction in which the plurality of battery cells are arranged in a row. The busbar modules include a plurality of inter-cell busbars that connect adjacent positive and negative terminals of adjacent battery cells so as to connect adjacent battery cells in series among the battery cells arranged between a pair of side walls of the pack case, and end busbars that are attached to the positive terminals of battery cells arranged at one end and the negative terminals of battery cells arranged at the other end of the battery cells arranged between the pair of side walls of the pack case. The positions of the positive and negative terminals of the battery cells in each of the multiple battery cell rows are swapped by 180 degrees between adjacent rows, and the busbar modules are shared among the multiple battery cell rows.

[0006] In the battery pack disclosed herein, the busbar module provided for each column of battery cells is common, eliminating the need to design separate busbar modules for each column of battery cells. This eliminates the need to design multiple types of busbar modules, reducing the number of steps required to design the battery pack. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view schematically showing a battery pack. [Figure 2] FIG. 2 is a perspective view schematically showing a battery cell. [Figure 3]FIG. 3 is a plan view schematically showing the arrangement of a plurality of battery cells in a battery pack according to a reference example. [Figure 4] FIG. 4 is a plan view schematically showing a bus bar module according to a reference example. [Figure 5] FIG. 5 is a plan view schematically showing the arrangement of a plurality of battery cells in a battery pack according to one embodiment. [Figure 6] FIG. 6 is a plan view schematically illustrating a bus bar module according to an embodiment. [Figure 7] FIG. 7 is a plan view that schematically shows a battery pack in which battery cells from different battery strings are connected to each other. [Figure 8] FIG. 8 is a side cross-sectional view that schematically shows a plurality of battery cells and a bus bar module. [Figure 9] FIG. 9 is a plan view schematically showing a bus bar module according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the technology disclosed herein will be described below with reference to the drawings. The embodiment described herein is, of course, not intended to limit the present invention. The drawings are schematic and do not necessarily reflect the actual product. Furthermore, identical reference numerals are used to designate components and parts that perform the same function, and redundant descriptions will be omitted where appropriate. The reference numerals F, Rr, L, R, U, and D in the drawings represent front, rear, left, right, top, and bottom, respectively. The reference numerals X, Y, and Z in the drawings represent the front-to-back direction, left-to-right direction, and up-and-down direction, respectively. The Y direction is perpendicular to the X direction. The Z direction is perpendicular to the X and Y directions. However, these directions are merely used for convenience of explanation and do not limit the installation form of the battery pack 1 in any way.

[0009] FIG. 1 is a perspective view schematically showing a battery pack 1. The battery pack 1 includes a pack case 5, a plurality of battery cells 10, and a bus bar module 30. Note that FIG. 1 illustrates the battery pack 1 with the bus bar module 30 removed. The battery pack 1 of this embodiment is a battery pack with a cell-to-pack structure in which the plurality of battery cells 10 are directly housed inside the pack case 5.

[0010] The pack case 5 is formed in a substantially rectangular parallelepiped shape. The pack case 5 has a bottom wall, a pair of side walls 6, and a pair of end walls 7. Note that the bottom wall is not shown in FIG. 1. The bottom wall is a member that forms the bottom surface of the pack case 5. The bottom wall is a plate-shaped member that extends in the X and Y directions. The pair of side walls 6 face each other in the X direction. The pair of side walls 6 extend upward from both X-direction ends of the bottom wall. The pair of end walls 7 face each other in the Y direction. The pair of end walls 7 extend upward from both Y-direction ends of the bottom wall. The pair of end walls 7 connect both Y-direction ends of the pair of side walls 6. The pair of side walls 6 and the pair of end walls 7 form the side surfaces of the pack case 5.

[0011] FIG. 2 is a perspective view schematically illustrating a battery cell 10. The battery cell 10 includes a cell case 11, a positive electrode terminal 13, and a negative electrode terminal 15. The cell case 11 is formed in a substantially rectangular parallelepiped shape, a so-called rectangular cell case. An electrode assembly (not shown) is housed inside the cell case 11. The electrode assembly has a positive electrode and a negative electrode. The positive electrode terminal 13 and the negative electrode terminal 15 are respectively provided at the Y-direction end portions of the top surface of the cell case 11. The positive electrode terminal 13 and the negative electrode terminal 15 are arranged at a predetermined interval in the Y direction. The positive electrode terminal 13 is electrically connected to the positive electrode of the electrode assembly inside the cell case 11. The negative electrode terminal 15 is electrically connected to the negative electrode of the electrode assembly inside the cell case 11.

[0012] In this specification, "battery cell" refers to the smallest unit of an electricity storage device. "Electricity storage device" refers to a device that can be charged and discharged. In this specification, electricity storage devices include batteries generally referred to as lithium ion batteries and lithium secondary batteries, as well as batteries such as lithium polymer batteries. A secondary battery generally refers to a battery that can be repeatedly charged and discharged through the movement of charge carriers between the positive and negative electrodes. An electricity storage device may use a liquid electrolyte or a solid electrolyte. For example, the secondary battery may be a secondary battery that uses a so-called liquid electrolyte, or a so-called all-solid-state battery that uses a solid electrolyte.

[0013] As shown in FIG. 1 , a plurality of battery cells 10 are arranged in a row between a pair of side walls 6 of a pack case 5 in predetermined numbers to form a battery string 20. In the embodiment shown in FIG. 1 , one battery string 20 is formed by arranging a plurality of battery cells 10 in the X direction. The number of battery cells 10 included in one battery string 20 is not particularly limited. In this embodiment, the number of battery cells 10 included in one battery string 20 is an odd number. More specifically, in this embodiment, one battery string 20 has nine battery cells 10.

[0014] The pack case 5 houses a plurality of battery cells 10 arranged in a row between a pair of side walls 6. That is, the battery pack 1 has a plurality of battery strings 20, which are housed inside the pack case 5. The plurality of battery strings 20 are arranged in the Y direction. The number of battery strings 20 in the battery pack 1 is not particularly limited. In this embodiment, the battery pack 1 has three battery strings 20.

[0015] In the following description, when it is necessary to distinguish between the three battery strings 20, they will be designated by the reference symbols 20A, 20B, and 20C. Battery string 20A is the battery string located on the leftmost side. Battery string 20C is the battery string located on the rightmost side. Battery string 20B is located between battery string 20A and battery string 20C.

[0016] 3 is a plan view schematically showing the arrangement of multiple battery cells 10 in a battery pack 1 according to a reference example. In the drawing, the symbol "+" represents a positive terminal 13, and the symbol "-" represents a negative terminal 15. The battery cells 10 arranged in a row between the pair of side walls 6 of the pack case 5 are arranged in order so that the positions of the positive terminals 13 and the negative terminals 15 alternate in the direction in which the battery cells 10 are arranged in a row. That is, in one battery string 20, the battery cells 10 are arranged in a row in the X direction so that the positive terminals 13 and the negative terminals 15 are arranged alternately in the X direction.

[0017] In addition, in the configuration shown in Fig. 3, the multiple battery strings 20 are all arranged in the same orientation. In the configuration shown in Fig. 3, the battery cells 10 in each battery string 20, of the battery cells 10 arranged most forward, are arranged so that the positive terminal 13 is on the left side and the negative terminal 15 is on the right side. In the configuration shown in Fig. 3, the battery cells 10 adjacent to each other in the Y direction are arranged so that the positive terminal 13 and the negative terminal 15 face each other.

[0018] FIG. 4 is a plan view schematically showing a busbar module 30 in a battery pack 1 according to a reference example. The busbar modules 30 are arranged on each of the plurality of battery strings 20. The busbar modules 30 connect the plurality of battery cells 10 housed in the pack case 5 in series for each battery string 20 using inter-cell busbars 33 (described later). The battery pack 1 includes the same number of busbar modules 30 as the number of battery strings 20. In the embodiment shown in FIG. 4, the battery pack 1 includes three battery strings 20, and therefore includes three busbar modules 30. The busbar module 30 includes a frame body 25, inter-cell busbars 33, end busbars 35, voltage measurement wires (not shown), and a lid body (not shown). The busbar module 30 may include other components, but their description will be omitted here.

[0019] In the following description, when it is necessary to distinguish between the three busbar modules 30, they will be designated by the reference symbols 30A, 30B, and 30C. The busbar module 30A is a busbar module arranged above the battery string 20A. The busbar module 30B is a busbar module arranged above the battery string 20B. The busbar module 30C is a busbar module arranged above the battery string 20C.

[0020] The frame bodies 25 are provided on each of the plurality of battery strings 20. The frame bodies 25 are formed in a substantially rectangular parallelepiped shape. The frame bodies 25 are made of, for example, an electrically insulating resin material. The frame bodies 25 have openings 26. The openings 26 are located above the positive electrode terminals 13 or negative electrode terminals 15 of the battery cells 10. The openings 26 are formed in positions that overlap the positive electrode terminals 13 or negative electrode terminals 15 when viewed from above. Inter-cell bus bars 33 and end bus bars 35 are fixed to the frame bodies 25.

[0021] The inter-cell busbar 33 connects the adjacent positive electrode terminals 13 and negative electrode terminals 15 of the battery cells 10 adjacent in the X direction so as to connect the battery cells 10 adjacent in the X direction in series. The inter-cell busbar 33 is made of a material with high electrical conductivity, such as aluminum or copper. The inter-cell busbar 33 is joined to the positive electrode terminal 13 of one of the battery cells 10 adjacent in the X direction and is also joined to the negative electrode terminal 15 of the other battery cell 10. The method for joining the inter-cell busbar 33 and the positive electrode terminal 13 is not particularly limited. For example, the inter-cell busbar 33 may be joined to the positive electrode terminal 13 by welding. The method for joining the inter-cell busbar 33 and the negative electrode terminal 15 is also not particularly limited, and welding or the like may be used. The number of inter-cell busbars 33 included in one busbar module 30 is one less than the number of battery cells 10 included in one battery string 20. 4, one battery string 20 has nine battery cells 10, and therefore one bus bar module 30 has eight inter-cell bus bars 33. The inter-cell bus bars 33 are formed so as to have a substantially U-shape that opens in the X direction when viewed from above.

[0022] The end bus bars 35 are attached to the battery cells 10 arranged at both ends in the X direction of one battery string 20. Specifically, the end bus bars 35 are attached to the positive terminal 13 of the battery cell 10 arranged at one end in the X direction and the negative terminal 15 of the battery cell 10 arranged at the other end in the X direction. One bus bar module 30 includes two end bus bars 35. Therefore, the battery pack 1 includes six end bus bars 35. The end bus bars 35 are made of a material with high electrical conductivity, such as aluminum or copper. The end bus bars 35 are joined to the positive terminal 13 or the negative terminal 15. There are no particular limitations on the method for joining the end bus bars 35 to the positive terminal 13 or the negative terminal 15, and welding or other methods may be used. The end bus bars 35 are formed to have a substantially L-shape when viewed from above.

[0023] In the following description, when it is necessary to distinguish between the six end bus bars 35 of the battery pack 1, they will be designated by the reference numerals 35Aa, 35Ab, 35Ba, 35Bb, 35Ca, and 35Cb. The end bus bar 35Aa is attached to the positive terminal 13 of the battery cell 10 located at the rear end of the battery string 20A. The end bus bar 35Ab is attached to the negative terminal 15 of the battery cell 10 located at the front end of the battery string 20A. The end bus bar 35Ba is attached to the positive terminal 13 of the battery cell 10 located at the front end of the battery string 20B. The end bus bar 35Bb is attached to the negative terminal 15 of the battery cell 10 located at the rear end of the battery string 20B. The end bus bar 35Ca is attached to the positive terminal 13 of the battery cell 10 located at the rear end of the battery string 20C. The end bus bar 35Cb is attached to the negative terminal 15 of the battery cell 10 located at the front end of the battery string 20C.

[0024] The voltage measurement wires are electrically connected to the inter-cell bus bars 33. The voltage measurement wires are provided to measure the voltage of the battery cells 10. The voltage measurement wires may be formed on a flexible printed circuit board arranged on the frame 25, for example. The lid is a member that covers the frame 25, the inter-cell bus bars 33, the end bus bars 35, the voltage measurement wires, etc. The lid is preferably made of an electrically insulating material.

[0025] The arrangement of the battery cells 10 and the busbar modules 30 in the battery pack 1 according to the reference example have been described above with reference to FIGS. 3 and 4 . The inventors of the present application wish to reduce the number of steps required for designing the battery pack 1. Therefore, the inventors focused on the fact that the configuration of the busbar modules 30 differs for each battery string 20. For example, in the configuration shown in FIG. 4 , the busbar modules 30A and 30C have the same configuration, but the busbar module 30B has a different configuration from the busbar module 30A. Therefore, when designing the battery pack 1 of the configuration shown in FIG. 4 , two types of busbar modules 30 must be designed. Therefore, in order to reduce the number of steps required for designing the busbar modules 30, the inventors considered standardizing the configuration of the busbar modules 30 provided in each battery string 20 to one type. Here, "busbar modules 30 having the same configuration" refers to the busbar modules 30 having the same arrangement and shape, etc., of the inter-cell busbars 33 and end busbars 35 included in each busbar module 30.

[0026] FIG. 5 is a plan view schematically illustrating the arrangement of multiple battery cells 10 in a battery pack 1 according to this embodiment. In the drawing, the symbol "+" represents a positive terminal 13, and the symbol "-" represents a negative terminal 15. The battery cells 10 arranged in a row between the pair of side walls 6 of the pack case 5 are arranged in order so that the positions of the positive terminals 13 and the negative terminals 15 alternate in the direction in which the battery cells 10 are arranged in a row. That is, in one battery string 20, the battery cells 10 are arranged in a row in the X direction so that the positive terminals 13 and the negative terminals 15 alternate in the X direction. The multiple battery cells 10 are arranged such that the positions of the positive terminals 13 and the negative terminals 15 are swapped by 180 degrees for each battery string 20 adjacent to each other in the Y direction. That is, the battery cells 10 adjacent to each other in the Y direction are arranged inside the pack case 5 so that the positive terminals 13 or the negative terminals 15 face each other.

[0027] Fig. 6 is a plan view schematically showing a bus bar module 30 according to this embodiment. By arranging the battery cells 10 as shown in Fig. 5, the bus bar modules 30A, 30B, and 30C can all have the same configuration and can be standardized, as shown in Fig. 6.

[0028] Fig. 7 is a plan view schematically showing the battery pack 1 when battery cells 10 of different battery columns 20 are connected to each other. Fig. 8 is a side view schematically showing a plurality of battery cells 10 and a bus bar module 30. The battery pack 1 includes an inter-column bus bar 37 and a common terminal bus bar 39.

[0029] The inter-row busbars 37 connect the busbar modules 30 arranged on different battery strings 20 to each other, thereby connecting the battery cells 10 of adjacent battery strings 20 in series. The inter-row busbars 37 are made of a highly electrically conductive material such as aluminum or copper. The inter-row busbars 37 connect the end busbars 35 attached to the battery cells 10 of adjacent battery strings 20 to each other, thereby connecting the battery cells 10 of adjacent battery strings 20 in series. The inter-row busbar 37 is joined to the end busbar 35 attached to the positive terminal 13 of one of the adjacent battery strings 20, and is also joined to the end busbar 35 attached to the negative terminal 15 of the other battery string 20. There are no particular limitations on the method of joining the inter-row busbar 37 to the end busbar 35, and welding, for example, may be used. The number of inter-row busbars 37 is one less than the number of battery strings 20. In this embodiment, the battery pack 1 includes two inter-row bus bars 37. As shown in Fig. 8, the inter-row bus bars 37 extend in the Y direction while bending up and down.

[0030] In the following description, when a distinction is required between the inter-row bus bars 37, they will be designated by the reference numerals 37a and 37b. As shown in FIG. 7, the inter-row bus bar 37a is joined to the end bus bars 35Bb and 35Ca, connecting the battery row 20B and the battery row 20C in series. The inter-row bus bar 37b is joined to the end bus bars 35Ab and 35Ba, connecting the battery row 20A and the battery row 20B in series. In the configuration shown in FIG. 7, the inter-row bus bars 37a and 37b have the same shape.

[0031] The common terminal bus bar 39 is a member that serves as an output terminal for connecting the battery cells 10, which are arranged and connected in series inside the pack case 5, to an external device. The type of external device is not particularly limited. The battery pack 1 includes two common terminal bus bars 39. The common terminal bus bars 39 are made of a material with high electrical conductivity, such as aluminum or copper. The common terminal bus bar 39 is connected to the end bus bars 35 that are not connected to the inter-row bus bars 37, among the end bus bars 35 provided on the battery rows 20 arranged at both ends in the Y direction. The common terminal bus bar 39 is joined to the end bus bars 35 using welding or the like.

[0032] In the following description, when it is necessary to distinguish between the main terminal bus bars 39, they will be designated by the reference symbols 39a and 39b. The main terminal bus bar 39a is joined to the end bus bar 35Aa. The main terminal bus bar 39a is connected to the positive terminal 13 of the battery cell 10 via the end bus bar 35Aa. The main terminal bus bar 39a serves as the positive output terminal of the battery pack 1. The main terminal bus bar 39b is joined to the end bus bar 35Cb. The main terminal bus bar 39b is connected to the negative terminal 15 of the battery cell 10 via the end bus bar 35Cb. The main terminal bus bar 39b serves as the negative output terminal of the battery pack 1.

[0033] As shown in FIG. 8 , the general terminal bus bar 39b extends in the Y direction while bending up and down. Although not shown, the general terminal bus bar 39a also extends in the Y direction while bending up and down. The general terminal bus bar 39b is arranged so as to overlap with the inter-row bus bar 37b when viewed from above. The general terminal bus bar 39b extends in the Y direction above the inter-row bus bar 37b. The general terminal bus bar 39b and the inter-row bus bar 37b are arranged at a distance greater than a predetermined distance so as to be electrically insulated from each other. The inter-row bus bar 37b and the general terminal bus bar 39 may be covered with an insulating coating.

[0034] As shown in FIG. 6 , the battery pack 1 of this embodiment includes three battery strings 20 and three busbar modules 30. The positions of the positive electrode terminals 13 and negative electrode terminals 15 of each battery cell 10 are swapped 180 degrees between adjacent battery strings 20 in the Y direction. By arranging the multiple battery cells 10 in this manner, all three busbar modules 30 can have the same configuration and can be standardized. Because a common busbar module 30 can be used for multiple battery strings 20, there is no need to design a busbar module 30 for each battery string 20. This reduces the number of steps required to design the battery pack 1.

[0035] 4, in the case of a battery pack 1 that uses multiple types of busbar modules 30, there is a risk that the battery string 20 and the busbar module 30 will be incorrectly combined when the busbar module 30 is assembled to the battery string 20. However, with the battery pack 1 of this embodiment as shown in FIG. 6, a common busbar module 30 is assembled to multiple battery strings 20, so that the battery string 20 and the busbar module 30 will not be incorrectly combined.

[0036] In this embodiment, the number of battery cells 10 arranged in a row between the pair of side walls 6 of the pack case 5 is nine. Therefore, one battery string 20 has an odd number of battery cells 10. In this case, as shown in FIG. 6 , one bus bar module 30 can be equipped with only one type of end bus bar 35. This allows the number of types of parts used in the battery pack 1 to be reduced.

[0037] According to this embodiment, the battery pack 1 includes an inter-row bus bar 37 that connects adjacent battery rows 20 in the Y direction in series. This electrically connects the adjacent battery rows 20 in the Y direction, and all the battery cells 10 in the battery pack 1 are connected in series.

[0038] Fig. 9 is a plan view schematically showing a busbar module 30 according to another embodiment. In the embodiment shown in Fig. 9, one battery string 20 has eight battery cells 10. That is, one battery string 20 has an even number of battery cells 10. As shown in Fig. 9, even when one battery string 20 has an even number of battery cells 10, the busbar module 30 can be shared.

[0039] The technology disclosed herein has been described in various ways. Unless otherwise specified, the embodiments and the like described herein do not limit the present invention. Furthermore, the technology disclosed herein can be modified in various ways, and as long as no particular problems arise, each component and each process described herein can be omitted or combined as appropriate. Furthermore, this specification includes the disclosures described in the following sections.

[0040] Section 1: A plurality of battery cells; a pack case having a pair of opposing side walls, the pack case containing the plurality of battery cells arranged in multiple rows between the pair of side walls; a bus bar module that connects the plurality of battery cells housed in the pack case in series by column, The plurality of battery cells include Each battery has a rectangular cell case with a positive electrode terminal and a negative electrode terminal arranged at a predetermined interval on the side edge of the upper surface, a predetermined number of the nozzles are arranged in a row between the pair of side walls of the pack case, The battery cells arranged in a row between the pair of side walls of the pack case include the plurality of battery cells are arranged in order such that the positions of the positive electrode terminals and the negative electrode terminals alternate in the direction in which the plurality of battery cells are arranged in a row; The plurality of bus bar modules include: a plurality of inter-cell bus bars that connect the positive electrode terminals and negative electrode terminals of adjacent battery cells so as to connect adjacent battery cells in series among the battery cells arranged in a row between the pair of side walls of the pack case; an end bus bar attached to the positive terminal of a battery cell arranged at one end of a row of battery cells arranged between the pair of side walls of the pack case and the negative terminal of a battery cell arranged at the other end of the row of battery cells, the positions of the positive electrode terminals and the negative electrode terminals of the battery cells in the plurality of rows are swapped by 180 degrees between adjacent rows, and a bus bar module is shared among the plurality of rows.

[0041] Section 2: Item 2. The battery pack according to item 1, wherein the number of battery cells arranged in a row between the pair of side walls of the pack case is odd.

[0042] Section 3: Item 3. The battery pack according to item 1 or 2, further comprising an inter-row bus bar that connects the battery cells in the adjacent rows in series. [Explanation of symbols]

[0043] 1 battery pack 5 pack case 6 side wall 10 battery cells 11 Cell Case 13 Positive terminal 15 Negative terminal 20 battery strings 30 Busbar Module 33 Inter-cell busbar 35 End busbar 37 Inter-row busbar

Claims

1. A plurality of battery cells; a pack case having a pair of opposing side walls, the pack case containing the plurality of battery cells arranged in multiple rows between the pair of side walls; a bus bar module that connects the plurality of battery cells housed in the pack case in series for each row, The plurality of battery cells Each battery has a rectangular cell case with a positive electrode terminal and a negative electrode terminal arranged at a predetermined interval on the side edge of the upper surface, a predetermined number of the nozzles are arranged in a row between the pair of side walls of the pack case, The battery cells arranged in one row between the pair of side walls of the pack case include the plurality of battery cells are arranged in order such that the positions of the positive electrode terminals and the negative electrode terminals alternate in the direction in which the plurality of battery cells are arranged in a row; The plurality of bus bar modules include: a plurality of inter-cell bus bars that connect the positive electrode terminals and negative electrode terminals of adjacent battery cells so as to connect adjacent battery cells in series among the battery cells arranged in a row between the pair of side walls of the pack case; an end bus bar attached to the positive terminal of a battery cell arranged at one end of a row of battery cells arranged between the pair of side walls of the pack case and the negative terminal of a battery cell arranged at the other end of the row of battery cells, the positions of the positive electrode terminals and the negative electrode terminals of the battery cells in the plurality of rows are swapped by 180 degrees between adjacent rows, and a bus bar module is shared among the plurality of rows.

2. The battery pack according to claim 1 , wherein the number of the battery cells arranged in a row between the pair of side walls of the pack case is odd.

3. The battery pack according to claim 1 , further comprising an inter-row bus bar that connects the battery cells in the adjacent rows in series.

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