Battery module and power storage system

Abstract

A battery module of an embodiment comprises a plurality of batteries, a housing that that houses the batteries, a terminal board, and an electrically insulating base member. A circuit in which current flows through the batteries is connected to the terminal board at a first connection position, and an external terminal is connected to the terminal board at a second connection position set apart from the first connection position outward in a first direction. The base member comprises a bottom wall part adjacent to the terminal board from one side in a second direction intersecting the first direction, and a pair of side wall parts adjacent to the terminal board from opposite sides with respect to each other in a third direction intersecting the first and second directions. The terminal board is fastened to the bottom wall part, and each of the side wall parts is fastened to the housing.

Description

[Technical field]

[0001] An embodiment of the present invention relates to a battery module and a power storage system. [Background technology]

[0002] In a battery module, multiple batteries (single cells) are housed inside a housing. The battery module is also provided with a pair of terminal plates, and a circuit (main circuit) in which current flows through the multiple batteries is formed between the pair of terminal plates. In the battery module, one of the pair of terminal plates forms a module terminal on the positive side (high potential side), and the other of the pair of terminal plates forms a module terminal on the negative side (low potential side). An external terminal provided at one end of a cable or the like is connected to each of the terminal plates, and the battery module is electrically connected to other battery modules or the like via the cable or the like.

[0003] In a battery module as described above, the above-mentioned circuit (electrical path) in which a current flows through the multiple batteries is formed by electrically connecting the multiple batteries with a bus bar or the like. In a circuit in which a current flows through the multiple batteries, the bus bar electrically connected to the terminal plate with the battery between them has a different potential from the terminal plate.

[0004] In addition, the battery module is provided with an electronic board on which electronic components including a detection circuit, a control circuit, and a communication circuit are mounted, and the conductive portion of the electronic board is formed by the electronic components and the wiring pattern. In the conductive portion of the electronic board, the detection circuit, etc. are electrically connected to the circuit through which current flows through the battery, and have the same potential as any position of the circuit between the pair of terminal plates. On the other hand, the control circuit, etc. of the electronic board have a predetermined potential with respect to the ground. When a plurality of battery modules including the above-mentioned electronic boards are provided and the plurality of battery modules are electrically connected for use, the potential of each of the terminal plates is much higher than that of the control circuit, etc. of the electronic board, especially in the battery module on the high potential side. Therefore, even on the electronic board, there are conductive parts with a different potential from the terminal board, and in particular, the potential difference of the terminal board with respect to the conductive parts forming the control circuit, etc. may be large. In the battery module, it is required that the electrical insulation of the terminal board, which is the connection part of the external terminal with the conductive parts with different potentials, is properly ensured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2015-125799 [Patent Document 2] International Publication No. 2017 / 158733 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem that the present invention aims to solve is to provide a battery module in which electrical insulation of a terminal plate, which is a connection part of an external terminal to a conductive part having a different potential, is properly ensured, and an energy storage system including such a battery module. [Means for solving the problem]

[0007] The battery module of the embodiment includes a plurality of batteries, a housing, a terminal plate, and a base member. The housing accommodates the plurality of batteries and has electrical insulation. The terminal plate is conductive and connected at a first connection position to a circuit in which a current flows through the plurality of batteries. The terminal plate extends from the first connection position toward the outside in a first direction, and an external terminal is connected to the terminal plate at a second connection position away from the first connection position toward the outside in the first direction. The base member has electrical insulation and is attached to the terminal plate at a portion away from the first connection position toward the outside in the first direction. The base member includes a bottom wall portion and a pair of side wall portions. The bottom wall portion is adjacent to the terminal plate from one side in a second direction intersecting the first direction, and the terminal plate is fastened to the bottom wall portion. The pair of side wall portions are adjacent to the terminal plate from opposite sides to each other in a third direction intersecting the first direction and the second direction, and each of the side wall portions is fastened to the housing. The terminal board includes an extension portion and a bent portion, and the extension portion extends through a fastening position with the bottom wall portion of the base member. The bent portion is connected to the extension portion from the outside in the first direction and bent relative to the extension portion to the side adjacent to the bottom wall portion of the base member in the second direction. The bent portion extends through the second connection position. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view that illustrates an example of a single battery unit according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing the battery module according to the first embodiment. [Diagram 3] FIG. 3 is a perspective view showing the battery module according to the first embodiment, disassembled into individual members. [Figure 4] FIG. 4 is a perspective view showing the battery module according to the first embodiment with the housing cover omitted. [Diagram 5] FIG. 5 is a perspective view showing one of a pair of connection units and its vicinity in the battery module according to the first embodiment, with the housing cover omitted. [Figure 6] FIG. 6 is a perspective view showing one of a pair of connection units and its vicinity in the battery module according to the first embodiment, with the upper case and cover of the housing omitted. [Figure 7]FIG. 7 is a perspective view showing one of a pair of connection units and its surrounding configuration in the battery module according to the first embodiment, with the housing cover omitted and the cable terminal (external terminal) connected to the terminal board. [Figure 8] FIG. 8 is a cross-sectional view showing the configuration of one of a pair of connection units and its vicinity in a cross section perpendicular or substantially perpendicular to the third direction in the battery module according to the first embodiment. [Figure 9] FIG. 9 is a perspective view showing the configuration of one of a pair of connection units in the battery module according to the first embodiment. [Figure 10] FIG. 10 is a perspective view showing the configuration of one of a pair of connection units in the battery module according to the first embodiment, viewed from a different direction than that of FIG. [Figure 11] FIG. 11 is a perspective view showing one of a pair of connection units in the battery module according to the first embodiment with a cover member attached to a base member. [Figure 12] FIG. 12 is a perspective view showing the configuration of a cover member that is removably attached to a base member of the connection unit in the battery module according to the first embodiment. [Figure 13] FIG. 13 is a perspective view showing one of a pair of connection units and its vicinity in a battery module according to a first modified example, with the housing cover omitted. [Figure 14] FIG. 14 is a perspective view showing the configuration of one of a pair of connection units in a battery module according to a first modified example. [Figure 15] FIG. 15 is a perspective view showing the connector unit and the configuration in the vicinity thereof in a battery module according to a second modified example with the housing cover omitted. [Figure 16] FIG. 16 is a perspective view showing the configuration of a connector unit in a battery module according to a second modified example. [Figure 17] FIG. 17 is a schematic diagram illustrating an example of a power storage system according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] A battery module according to an embodiment includes a plurality of batteries (single cells) and a housing that houses the plurality of batteries inside. Each of the plurality of batteries is, for example, a secondary battery such as a lithium ion secondary battery.

[0011] [battery] First, the battery (single cell) will be described. FIG. 1 shows an example of a single battery 1. The battery 1 includes an electrode group 2 and an outer container 3 in which the electrode group 2 is housed. In the example shown in FIG. 1, etc., the outer container 3 is made of a metal such as aluminum, an aluminum alloy, iron, or stainless steel. The outer container 3 includes a container body 5 and a lid 6. Here, the battery 1 and the outer container 3 are regulated in a depth direction (direction indicated by arrows X1 and X2), a lateral direction (direction indicated by arrows Y1 and Y2) intersecting (perpendicular or substantially perpendicular) with respect to the depth direction, and a height direction (direction indicated by arrows Z1 and Z2) intersecting (perpendicular or substantially perpendicular) with respect to both the depth direction and the lateral direction. In the example shown in FIG. 1, etc., the dimension in the depth direction is much smaller than the dimension in the lateral direction and the dimension in the height direction in each of the battery 1 and the outer container 3.

[0012] The container body 5 includes a bottom wall 7 and a peripheral wall 8. An internal cavity 10 in which the electrode group 2 is housed is defined by the bottom wall 7 and the peripheral wall 8. In the battery 1, the internal cavity 10 opens toward the side opposite to the side on which the bottom wall 7 is located in the height direction. The peripheral wall 8 surrounds the internal cavity 10 over the entire circumference in the circumferential direction. The lid 6 is attached to the container body 5 at the opening of the internal cavity 10. Therefore, the lid 6 is attached to the peripheral wall 8 at the end opposite to the bottom wall 7. The lid 6 and the bottom wall 7 face each other in the height direction with the internal cavity 10 in between.

[0013] The electrode group 2 includes a positive electrode and a negative electrode (neither of which is shown in the figure). In addition, a separator (not shown in the figure) is interposed between the positive electrode and the negative electrode in the electrode group 2. The separator has electrical insulation properties and electrically insulates the positive electrode from the negative electrode.

[0014] The positive electrode comprises a positive electrode current collector such as a positive electrode current collector foil, and a positive electrode active material-containing layer supported on the surface of the positive electrode current collector. The positive electrode current collector is, but is not limited to, for example, an aluminum foil or an aluminum alloy foil, and has a thickness of about 5 μm to 20 μm. The positive electrode active material-containing layer comprises a positive electrode active material, and may optionally contain a binder and a conductive agent. Examples of the positive electrode active material include, but are not limited to, oxides, sulfides, and polymers that can absorb and release lithium ions. The positive electrode current collector comprises a positive electrode current collector tab as a portion not supported by the positive electrode active material-containing layer.

[0015] The negative electrode comprises a negative electrode current collector such as a negative electrode current collector foil, and a negative electrode active material-containing layer (not shown) supported on the surface of the negative electrode current collector. The negative electrode current collector is, but is not limited to, for example, an aluminum foil, an aluminum alloy foil, or a copper foil, and has a thickness of about 5 μm to 20 μm. The negative electrode active material-containing layer comprises a negative electrode active material, and may optionally contain a binder and a conductive agent. The negative electrode active material is, but is not limited to, a metal oxide, a metal sulfide, a metal nitride, a carbon material, and the like, which can occlude and release lithium ions. The negative electrode current collector comprises a negative electrode current collector tab as a portion not supported by the negative electrode active material-containing layer.

[0016] In the electrode group 2, a pair of current collecting tabs is formed by the positive electrode current collecting tab and the negative electrode current collecting tab. In the electrode group 2, a pair of current collecting tabs protrude. In one example, in the electrode group 2, the positive electrode current collecting tab protrudes to one side in the lateral direction of the battery 1, and the negative electrode current collecting tab protrudes to the side opposite to the side from which the positive electrode current collecting tab protrudes in the lateral direction of the battery 1. In another example, in the electrode group 2, each of the pair of current collecting tabs protrudes toward the side where the lid 6 is located in the height direction of the battery 1. In this case, the pair of current collecting tabs are located apart from each other in the lateral direction of the battery 1.

[0017] In addition, in the internal cavity 10, the electrode group 2 is retained (impregnated) with an electrolytic solution (not shown). The electrolytic solution may be a non-aqueous electrolytic solution in which an electrolyte is dissolved in an organic solvent, or may be an aqueous electrolytic solution such as an aqueous solution. Instead of the electrolytic solution, a gel electrolyte or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, the solid electrolyte may be interposed between the positive electrode and the negative electrode in the electrode group instead of a separator. In this case, the positive electrode is electrically insulated from the negative electrode by the solid electrolyte.

[0018] In the battery 1, a pair of electrode terminals 11 are attached to the outer surface (upper surface) of the lid 6 of the outer container 3. The electrode terminals 11 are made of a conductive material such as metal. One of the electrode terminals 11 is a positive electrode terminal of the battery 1, and the other electrode terminal 11 is a negative electrode terminal of the battery 1. An insulating member 12 is provided between each of the electrode terminals 11 and the lid 6. Each of the electrode terminals 11 is electrically insulated from the outer container 3 including the lid 6 by the insulating member 12.

[0019] The positive electrode current collecting tab of the electrode group 2 is electrically connected to a positive electrode terminal, which is one of the corresponding electrode terminals 11, via one or more leads (positive electrode side leads). In addition, the negative electrode current collecting tab of the electrode group 2 is electrically connected to a negative electrode terminal, which is one of the corresponding electrode terminals 11, via one or more leads (negative electrode side leads). Each of the leads is formed of a conductive material such as metal. In the internal cavity 10 of the outer container 3, each of the pair of current collecting tabs and leads is electrically insulated from the outer container 3 (container body 5 and lid 6) by one or more insulating members (not shown).

[0020] 1, a gas release valve 13 and a liquid inlet are formed in the lid 6. Then, a sealing plate 15 for closing the liquid inlet is welded to the outer surface of the lid 6. Note that the gas release valve 13, the liquid inlet, etc. do not necessarily have to be provided in the battery.

[0021] Furthermore, the configuration of the battery (single cell) is not limited to the example shown in Fig. 1. In one example, the exterior of the battery may be formed from a laminate film. In this case, in the exterior of the battery, a metal layer is sandwiched between two insulating layers having electrical insulation properties, and the outer surface of the exterior is formed by one of the two insulating layers. Then, an electrode group is housed inside the exterior formed from the laminate film.

[0022] [Battery module] The battery module will be described below. The battery module includes a plurality of batteries (single cells). In one example, each of the plurality of batteries has the same configuration as the battery 1 described above.

[0023] (First embodiment) A first embodiment will be described below. Figures 2 and 3 show a battery module 20 according to this embodiment. In Figure 3, the battery module 20 is shown disassembled into its components. As shown in Figures 2 and 3, the battery module 20 includes a plurality of batteries 1 and a housing 21 in which the plurality of batteries 1 are housed. The housing 21 has electrical insulation properties. Examples of materials for forming the housing 21 include resins such as polyphenylene ether (PPE), polycarbonate (PC), and polybutylene terephthalate (PBT).

[0024] In a battery module 20 including a plurality of batteries 1 and a housing 21, a first direction (direction indicated by arrows Y3 and Y4), a second direction (direction indicated by arrows Z3 and Z4) intersecting (perpendicular or substantially perpendicular) with the first direction, and a third direction (direction indicated by arrows X3 and X4) intersecting (perpendicular or substantially perpendicular) with both the first direction and the second direction are defined. In the battery module 20 of Figs. 2 and 3, etc., the first direction corresponds to the horizontal direction, the second direction corresponds to the height direction, and the third direction corresponds to the depth direction. In addition, in one example of Figs. 2 and 3, etc., the housing 21 is formed of three members, a lower case 22, an upper case 23, and a cover 25. The lower case 22 is attached to the upper case 23 from one side in the second direction (lower side in the height direction). The cover 25 is attached to the upper case 23 from the opposite side to the lower case 22 in the second direction.

[0025] The housing 21 includes a top wall 31, a bottom wall 32, a pair of side walls 33A and 33B, and a pair of side walls 35A and 35B. In the housing 21, an internal cavity is defined by the top wall 31, the bottom wall 32, and the side walls 33A, 33B, 35A, and 35B. The top wall 31 and the bottom wall 32 are spaced apart from each other in the second direction (height direction) with the internal cavity therebetween. In the housing 21, the side walls 33A, 33B, 35A, and 35B form a peripheral wall that surrounds the internal cavity all around the circumferential direction of the battery module 20. Each of the side walls 33A, 33B, 35A, and 35B, i.e., the peripheral wall, extends from the top wall 31 to the bottom wall 32 along the second direction.

[0026] The pair of side walls 33A, 33B are arranged apart from each other in the first direction (horizontal direction) with an internal cavity therebetween. The pair of side walls 35A, 35B are arranged apart from each other in the third direction (depth direction) with an internal cavity therebetween. Each of the side walls 33A, 33B extends from the side wall 35A to the side wall 35B along the third direction. Each of the side walls 35A, 35B extends from the side wall 33A to the side wall 33B along the first direction. In one example such as FIG. 2 and FIG. 3, the top wall 31 is formed from the cover 25, and the bottom wall 32 is formed from the lower case 22. Each of the side walls 33A, 33B, 35A, 35B, i.e., the peripheral walls, are formed from the lower case 22 and the upper case 23.

[0027] As shown in FIG. 3, the upper case 23 of the housing 21 includes an intermediate wall 36. The intermediate wall 36 is disposed in the internal cavity of the housing 21, and is disposed between the top wall 31 and the bottom wall 32 in the second direction (height direction). The intermediate wall 36 extends from the side wall 33A to the side wall 33B along the first direction (lateral direction), and extends from the side wall 35A to the side wall 35B along the third direction (depth direction). The internal cavity of the housing 21 is divided by the intermediate wall 36 into a space 26 between the top wall 31 and the intermediate wall 36, and a space 27 between the bottom wall 32 and the intermediate wall 36. That is, the intermediate wall 36 serves as a partition wall (partition wall) that separates the two spaces 26, 27. Inside the housing 21, a plurality of batteries 1 are disposed in the space 27 between the bottom wall 32 and the intermediate wall 36.

[0028] In addition, in the space 27 between the bottom wall 32 and the intermediate wall 36, a partition wall 37 is formed by the lower case 22 and the upper case 23 of the housing 21, and in one example such as FIG. 3, two partition walls 37 are formed. The two partition walls 37 are arranged apart from each other in the first direction (lateral direction) and are arranged between the side walls 33A and 33B in the first direction. In addition, each of the partition walls 37 extends from the bottom wall 32 to the intermediate wall 36 along the second direction (height direction), and extends from the side wall 35A to the side wall 35B along the third direction (depth direction). The space 27 is divided into three regions by the partition walls 37, and the three regions are separated from each other by the partition walls 37.

[0029] 3 etc., three battery columns 28 are formed by a plurality of batteries 1 arranged in the space 27. Each of the battery columns 28 is arranged in a corresponding one of three regions separated by partition walls 37. Adjacent battery columns 28 in the first direction are separated by partition walls 37. A plurality of batteries 1 are arranged in each of the battery columns 28, and in the example of FIG. 3 etc., eight batteries 1 are arranged in each of the battery columns 28. In each of the battery columns 28, the batteries 1 are arranged such that the arrangement direction of the batteries 1 coincides or approximately coincides with the third direction (depth direction).

[0030] In each of the battery strings 28, the depth direction of each of the batteries 1 coincides or approximately coincides with the third direction of the battery module 20, and the width direction of each of the batteries 1 coincides or approximately coincides with the first direction of the battery module 20. In each of the battery strings 28, the height direction of each of the batteries 1 coincides or approximately coincides with the second direction of the battery module 20. Each of the batteries 1 is arranged in the space 27 with the outer surface of the bottom wall 7 facing the side where the bottom wall 32 of the housing 21 is located, and the outer surface of the lid 6 facing the side where the intermediate wall 36 of the housing 21 is located. In each of the battery strings 28, partition plates (separators) 38 are provided between the batteries 1 adjacent to each other in the arrangement direction (third direction). At least the outer surface of each of the partition plates 38 is electrically insulating.

[0031] Further, the intermediate wall 36 is formed with a plurality of holes 41 penetrating the intermediate wall 36 in the second direction (height direction). Here, each of the plurality of batteries 1 arranged in the space 27 has a pair of electrode terminals 11. The number of holes 41 formed is the same as the total number of electrode terminals 11 provided in the battery module 20, and is twice the number of batteries 1. In each battery 1, each of the pair of electrode terminals 11 is inserted into a corresponding one of the holes 41. Then, each of the electrode terminals 11 protrudes into the space 26 between the top wall 31 and the intermediate wall 36 through a corresponding one of the holes 41.

[0032] FIG. 4 shows the battery module 20 with the cover 25 omitted. As shown in FIG. 3 and FIG. 4, a plurality of bus bars 42 are arranged in the space 26 between the top wall 31 and the intermediate wall 36. Each of the bus bars 42 has electrical conductivity and is made of a metal such as aluminum or an aluminum alloy. In each of the plurality of batteries 1, a corresponding one of the bus bars 42 is connected to each of a pair of electrode terminals. In addition, the battery module 20 is provided with a pair of terminal plates 43. Each of the terminal plates 43 has electrical conductivity and is made of a metal such as copper, a copper alloy, aluminum or an aluminum alloy. In the battery module 20, the plurality of batteries 1 are electrically connected to each other via the bus bars 42 and the like other than the bus bars 42A and 42B. Note that, in the electrical connection structure between the plurality of batteries 1, at least one of a series connection structure in which two or more batteries 1 are electrically connected in series and a parallel connection structure in which two or more batteries 1 are electrically connected in parallel is formed.

[0033] Each of the bus bars 42A, 42B connects one or more corresponding ones of the multiple batteries 1 to a corresponding one of the pair of terminal plates 43 in the space 26. In one example such as Figs. 3 and 4, two batteries 1A are connected to one of the pair of terminal plates 43, terminal plate 43A, by the bus bar 42A. Then, two batteries 1B other than the batteries 1A are connected to the other terminal plate 43B of the pair of terminal plates 43, other than terminal plate 43A, by the bus bar 42B. Thus, the multiple batteries 1 are electrically connected to each of the pair of terminal plates 43 by the bus bars 42A, 42B.

[0034] Since the busbar 42 and the terminal plate 43 are provided as described above, in the battery module 20, a circuit (main circuit) in which a current flows through the plurality of batteries 1 and the busbar 42 is formed between the pair of terminal plates 43. In the battery module 20, a positive side (high potential side) module terminal is formed by one of the pair of terminal plates 43 (43A, 43B), and a negative side (low potential side) module terminal is formed by the other of the pair of terminal plates 43. In one example shown in Figs. 2 to 4, each of the terminal plates 43 is attached to the upper case 23 and disposed between the upper case 23 and the cover 25 in the second direction (height direction). In the upper case 23, a corresponding one of the base members 48 described later is attached to a boss (not shown) provided on the intermediate wall 36, and each of the terminal plates 43 is attached to a corresponding one of the base members 48. Each of the pair of terminal boards 43 protrudes from the space 26 between the top wall 31 and the intermediate wall 36 to the outside of the housing 21, and protrudes outward in the first direction (lateral direction) relative to the outer surface of the side wall 33A. The pair of terminal boards 43 are also spaced apart from each other in the third direction (depth direction).

[0035] An electronic board 45 is disposed in the space 26 between the top wall 31 and the intermediate wall 36. Electronic components including a detection circuit, a control circuit, a communication circuit, and the like are mounted on the electronic board 45. The electronic board 45 is, for example, a printed circuit board (PCB), and a wiring pattern, etc. that electrically connects the mounted electronic components is formed. The electronic board 45 has a conductive portion formed by the electronic components and the wiring pattern, etc. One or more of the bus bars 42 described above are connected to the detection circuit that is a part of the conductive portion of the electronic board 45. Therefore, the circuit (electrical path) formed by the battery 1 and the bus bar 42 between the pair of terminal plates 43 is electrically connected to the detection circuit that is a part of the conductive portion of the electronic board 45. In the electronic board 45, any of the voltage of the entire plurality of batteries 1 (voltage between the terminal plates 43), the voltage of one or more of the plurality of batteries 1, the temperature of one or more of the plurality of batteries 1, and the current flowing in the circuit (electrical path) between the terminal plates 43 is detected by the detection circuit, etc.

[0036] 2 to 4, two connectors 46 are mounted on the electronic board 45. Each of the connectors 46 is disposed between the upper case 23 and the cover 25 in the second direction (height direction). Each of the connectors 46 has an opening, which opens to the outside of the housing 21 on the outer surface of the side wall 33A and opens toward the outside in the first direction (lateral direction). The two connectors 46 are disposed apart from each other in the third direction (depth direction) and are disposed between the pair of terminal boards 43 in the third direction.

[0037] A connector (external connector) provided at one end of a cable such as a LAN cable can be connected to each of the connectors 46. When the connector of the cable is connected to the connector 46, the electronic board 45 can communicate with an external terminal or control device via the cable. For example, detection results of the detection circuits for the above-mentioned current, voltage, temperature, etc. are transmitted from the electronic board 45 to the external control device. In addition, for example, control signals related to charging or discharging the multiple batteries 1 are transmitted from the external control device to the electronic board 45.

[0038] 3 and 4 , etc., a control circuit, a communication circuit, etc. are provided in the connector 46 and in a region 45A nearby the connector 46. The control circuit, the communication circuit, etc. communicate with an external terminal or a control device, etc., via a cable, etc., connected to the connector 46. In addition, the above-mentioned detection circuit is provided in a region of the electronic board 45 other than the region 45A. And, the conductive parts of the detection circuit, etc. formed in the region of the electronic board 45 other than the region 45A are electrically connected to the above-mentioned circuit (electrical path) formed by the bus bar 42 and the battery 1.

[0039] 3 and 4, an insulating part having electrical insulation properties is formed between the control circuit and communication circuit, etc. arranged in the region 45A and the detection circuit, etc. arranged in the region other than the region 45A. Therefore, in the electronic board 45, the control circuit and communication circuit, etc. are electrically insulated from the detection circuit. Also, in the electronic board 45, the control circuit and communication circuit, etc. communicate with the detection circuit via an isolation IC, a photocoupler, etc.

[0040] In one example of FIG. 3 and FIG. 4, in the space 26, the electronic board 45 is disposed between each of the bus bars 42 and the top wall 31 in the second direction. An insulating case 47 having electrical insulation properties is disposed between the region 45A of the electronic board 45 and each of the bus bars 42. The insulating case 47 prevents each of the bus bars 42 from contacting the region 45A of the electronic board 45. The insulating case 47 effectively prevents a short circuit from occurring between the aforementioned circuit (electrical path) formed by the bus bar 42 and the battery 1 and the conductive part of the electronic board 45. The insulating case 47 also ensures an appropriate insulation distance between the conductive part (control circuit, etc.) of the region 45A of the electronic board 45 and the circuit (electrical path) formed by the bus bar 42 and the battery 1.

[0041] The battery module 20 is provided with a pair of base members 48. Each of the base members 48 has electrical insulation properties. Each of the base members 48 is formed from resin, for example, from the same material as the housing 21. Each of the base members 48 is separate from the members forming the housing 21, such as the lower case 22, the upper case 23, and the cover 25. Each of the pair of terminal boards 43 is attached to the upper case 23 of the housing 21 with a corresponding one of the pair of base members 48 interposed therebetween. Each of the pair of terminal boards 43 constitutes a connection unit 40 together with a corresponding one of the pair of base members 48. For this reason, the battery module 20 includes a pair of connection units 40, and each of the connection units 40 includes a terminal board 43 and a base member 48. In one of the pair of connection units 40, a module terminal on the positive side (high potential side) is formed by the terminal board 43, and in the other of the pair of connection units 40, a module terminal on the negative side (low potential side) is formed by the terminal board 43.

[0042] 5 to 8 show the configuration of one of the pair of connection units 40 and its vicinity, and FIG. 9 and FIG. 10 show the configuration of one of the pair of connection units 40. The configuration of the other of the pair of connection units 40 and its vicinity is the same as the configuration shown in FIG. 5 to FIG. 8, and the configuration of the other of the pair of connection units 40 is the same as the configuration shown in FIG. 9 and FIG. 10. FIG. 5 shows a perspective view in which the cover 25 is omitted, and FIG. 6 shows a perspective view in which the upper case 23 and the cover 25 are omitted. FIG. 7 shows a perspective view in which the cover 25 is omitted and a terminal (external terminal) 102 provided at one end of the cable 101 is connected to the terminal board 43. FIG. 8 shows a cross section perpendicular or substantially perpendicular to the third direction (depth direction) in which the terminal (external terminal) 102 of the cable 101 is connected to the terminal board 43. FIG. 9 and FIG. 10 are perspective views viewed from different directions.

[0043] As shown in Figs. 3 to 10, etc., in each of the connection units 40, the terminal plate 43 is formed in a plate shape. In each of the terminal plates 43, a plate length direction, a plate width direction intersecting (perpendicular or approximately perpendicular) with the plate length direction, and a plate thickness direction intersecting (perpendicular or approximately perpendicular) with both the plate length direction and the plate width direction are defined. Each of the terminal plates 43 has extension ends E1, E2, and extends along the plate length direction from the extension end E1 to the extension end E2. Each of the terminal plates 43 is attached to the upper case 23 of the housing 21 with the plate width direction coinciding or approximately coinciding with the third direction (depth direction) of the battery module 20. In each of the terminal plates 43, the extension end E2 is located outside the extension end E1 in the first direction.

[0044] Each of the terminal plates 43 includes extensions 51 and 52, a relay portion 53, and a bent portion 55. In each of the extensions 51 of the terminal plates 43, the plate length direction coincides or approximately coincides with the first direction (lateral direction) of the battery module 20, and the plate thickness direction coincides or approximately coincides with the second direction (height direction) of the battery module 20. In each of the terminal plates 43, the extension end E1 is formed by the extension 51, and the extension (first extension) 51 extends from the extension end E1 toward the outside in the first direction. As shown in FIG. 9 and FIG. 10, each of the terminal plates 43 has a through hole H1 penetrating the extension 51 in the plate thickness direction (second direction). In each of the terminal plates 43, the extension 51 extends beyond the through hole H1 toward the outside in the first direction.

[0045] Each of the terminal plates 43 is connected to one of the corresponding bus bars 42A, 42B at the through hole H1. Therefore, in each of the terminal plates 43, the through hole H1 and its vicinity are connection positions (first connection positions) where the circuit through which current flows through the plurality of batteries 1 is connected to the circuit (electrical path) formed by the plurality of batteries 1 and the bus bar 42 between the pair of terminal plates 43. In one example such as Figs. 3 to 10, each of the terminal plates 43 is fastened to the corresponding one of the bus bars 42A, 42B at the through hole H1 and its vicinity by a fastening screw 58 and a nut 59 (see Figs. 3 and 6) to be connected to the circuit (electrical path). In each of the terminal plates 43, the extension portion 51 extends from the extension end E1 toward the outside in the first direction, passing through the connection position (first connection position) to the circuit formed by the plurality of batteries 1 and the bus bar 42.

[0046] Each of the terminal plates 43 extends outward in the first direction from the connection position (through hole H1) to the circuit. In each of the terminal plates 43, the extension portion (second extension portion) 52 is located outward in the first direction with respect to the extension portion (first extension portion) 51, and is located away from the through hole H1 and the first connection position in the vicinity thereof outward in the first direction (horizontal direction). In each of the extension portions 52 of the terminal plates 43, the plate length direction coincides or approximately coincides with the first direction (horizontal direction) of the battery module 20, and the plate thickness direction coincides or approximately coincides with the second direction (height direction) of the battery module 20.

[0047] In each of the terminal plates 43, the extension portions 51 and 52 are connected by the relay portion 53. In each of the terminal plates 43, one end of the relay portion 53 is connected to the end of the extension portion 51 opposite to the extension end E1, and the extension portion 51 is connected to the relay portion 53 from the inside in the first direction. In each of the terminal plates 43, the end of the relay portion 53 opposite to the extension portion 51 is connected to the extension portion 52, and the extension portion 52 is connected to the relay portion 53 from the outside in the first direction. In each of the terminal plates 43, the extension portion 52 is extended from the connection position to the relay portion 53 toward the outside in the first direction. In each of the terminal plates 43, the relay portion 53 is bent in the second direction (height direction) relative to the extension portions 51 and 52. Therefore, in each relay portion 53 of the terminal board 43, for example, the plate length direction coincides or approximately coincides with the second direction of the battery module 20, and the plate thickness direction coincides or approximately coincides with the first direction of the battery module 20.

[0048] In each of the terminal plates 43, a bent structure is formed between the extension portions 51, 52 by providing the relay portion 53. In each of the terminal plates 43, a step is formed between the extension portions 51, 52 by the relay portion 53. In each of the terminal plates 43, the step formed by the relay portion 53 causes the extension portions 51, 52 to be misaligned with respect to each other in the second direction. In one example shown in Figs. 3 to 10 etc., in each of the terminal plates 43, the extension portion (second extension portion) 52 is disposed closer to the top wall 31 than the extension portion (first extension portion) 51.

[0049] In each of the terminal plates 43, the bent portion 55 is connected to the end of the extension portion 52 opposite to the connection position to the relay portion 53. Therefore, in each of the terminal plates 43, the bent portion 55 is connected to the extension portion 52 from the outside in the first direction. In each of the terminal plates 43, the bent portion 55 is bent relative to the extension portion 52 in the second direction (height direction) toward the side where the intermediate wall 36 and the batteries 1 are located. Therefore, in each of the bent portions 55 of the terminal plates 43, for example, the plate length direction coincides or approximately coincides with the second direction of the battery module 20, and the plate thickness direction coincides or approximately coincides with the first direction of the battery module 20. In each of the terminal plates 43, the bent portion 55 extends from the connection position to the extension portion 52 along the second direction toward the side where the batteries 1 are located. Furthermore, in each of the terminal plates 43, the extended end E2 is formed by a bent portion 55, and the bent portion 55 extends to the extended end E2 in the second direction toward the side where the battery 1 (middle wall 36) is located.

[0050] In each of the terminal plates 43, the bent portion 55 is located on the outside in the first direction with respect to the extension portion 51 and the through hole H1. In each of the terminal plates 43, the end of the extension portion 52 on the side where the bent portion 55 is located, and the bent portion 55 protrude outward in the first direction (lateral direction) with respect to the outer surface of the side wall 33A. In each of the terminal plates 43, a through hole H2 is formed that penetrates the bent portion 55 in the plate thickness direction (first direction). In each of the terminal plates 43, the bent portion 55 extends beyond the through hole H2 toward the side where the battery 1 is located in the second direction. In each of the terminal plates 43, the through hole H2 is located away from the through hole H1, which is the connection position of the circuit described above, on the outside in the first direction.

[0051] As shown in Figs. 7 and 8, each of the terminal plates 43 is connected to a terminal (external terminal) 102 provided at one end of the cable 101 through a through hole H2. Therefore, in each of the terminal plates 43, the through hole H2 and its vicinity become a connection position (second connection position) where the terminal 102 is connected. In each of the terminal plates 43, the bent portion 55 passes through the connection position (second connection position) of the cable 101 to the terminal 102 and extends from the connection position to the extension portion 52 to the extension end E2 in the second direction. In the cable 101, the terminal 102 is connected to a conductive wire (not shown) inside the cable 101. In the cable 101, the conductive wire is covered with a cable coating 103 having electrical insulation properties.

[0052] In each of the terminal plates 43, a bolt 56 is removably attached to a through hole H2 formed in the bent portion 55. The bolt 56 attached to each of the terminal plates 43 has a head 56A. In each of the terminal plates 43, a terminal 102 of a cable 101 is connected to the through hole H2 and a second connection position nearby the through hole H2 using the bolt 56 and a nut 57 screwed with the bolt 56. In each of the terminal plates 43, the bolt 56 is inserted into the through hole H2 from the outside in the first direction. Then, in each of the connection units 40, the bolt 56 is screwed (engaged) with the nut 57 while being inserted into the through hole H2 of the terminal plate 43.

[0053] In each of the connection units 40, in a state in which the bolt 56 is attached to the terminal board 43 via the through hole H2, the head 56A of the bolt 56 approaches the bent portion 55 of the terminal board 43 from the outside in the first direction, and the nut 57 approaches the bent portion 55 of the terminal board 43 from the inside in the first direction. In each of the connection units 40, the bent portion 55 of the terminal board 43 is sandwiched between the head 56A of the bolt 56 and the nut 57. In each of the connection units 40, in an operation of connecting the terminal 102 of the cable 101 to the terminal board 43, the terminal 102 is connected to the terminal board 43 by being sandwiched between the head of the bolt 56 and the bent portion 55 of the terminal board 43. By connecting the terminal 102 to each of the terminal boards 43, the battery module 20 is electrically connected to other battery modules, etc. via the cable 101, etc. In the example shown in FIG. 7 etc., the terminal (external terminal) 102 of the cable 101 is a round terminal, but the terminal 102 may be either a C-type terminal or a Y-type terminal, etc.

[0054] In each of the pair of connection units 40, the base member 48 is attached to the extension portion (second extension portion) 52 of the terminal board 43. For this reason, the base member 48 is attached to each of the terminal boards 43 at a portion spaced outward in the first direction from the through hole H1, i.e., at a portion spaced outward in the first direction from the connection position (first connection position) to the circuit formed by the battery 1 and the bus bar 42. Also, in each of the connection units 40, the base member 48 is disposed outward in the first direction with respect to the extension portion (first extension portion) 51 and relay portion 53 of the terminal board 43.

[0055] Each of the pair of base members 48 includes a bottom wall portion 61 and a pair of side wall portions 62. In each of the connection units 40, the bottom wall portion 61 is adjacent to the extension portion 52 of the terminal board 43 from one side in the second direction (height direction), and is adjacent to the extension portion 52 from the side where the battery 1 (bus bar 42) and the intermediate wall 36 are located in the second direction. In each of the connection units 40, the side wall portion 62A, which is one of the pair of side wall portions 62, is adjacent to the extension portion (second extension portion) 52 and the bent portion 55 of the terminal board 43 from one side in the third direction (depth direction). In each of the connection units 40, the side wall portion 62B, which is the other side of the pair of side wall portions 62 other than the side wall portion 62A, is adjacent to the extension portion 52 and the bent portion 55 of the terminal board 43 from the side opposite to the side wall portion 62A in the third direction. Therefore, in each connection unit 40, a pair of side walls 62 are adjacent to terminal board 43 from opposite sides in the third direction, and terminal board 43 extends between the pair of side walls 62.

[0056] In each of the base members 48, a recess 63 is formed by the bottom wall portion 61 and a pair of side wall portions 62. In each of the connection units 40, the recess 63 is recessed in the second direction toward the side where the battery 1 and the intermediate wall 36 are located, and opens in the second direction toward the side where the top wall 31 is located. In each of the base members 48, the bottom surface of the recess 63 is formed by the bottom wall portion 61, and the side surface of the recess 63 is formed by the pair of side wall portions 62. In each of the bottom wall portions 61 of the base members 48, the bottom surface of the recess 63 is formed from the inner end to the outer end in the first direction. In each of the connection units 40, the extension portion 52 of the terminal board 43 extends along the first direction through the recess 63. In each of the connection units 40, the end portion of the extension portion 52 on the side where the bent portion 55 is located, and the bent portion 55 protrude toward the outside in the first direction (lateral direction) relative to the recess 63.

[0057] In each of the connection units 40, the extension portion (second extension portion) 52 of the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48 in the recess 63 of the base member 48. Therefore, in each of the connection units 40, the extension portion 52 of the terminal board 43 extends along the first direction through the fastening position of the terminal board 43 to the base member 48. In one example of Figs. 3 to 10 etc., in each of the connection units 40, the extension portion 52 is fastened to the bottom wall portion 61 via three fastening screws 65 (65A to 65C). Therefore, in each of the connection units 40, the extension portion of the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48 at a plurality of fastening positions, and in one example of Figs. 3 to 10 etc., it is fastened to the bottom wall portion 61 at three fastening positions.

[0058] In one example shown in FIG. 3 to FIG. 10, three through holes 91 (see FIG. 8, etc.) are formed in each extension portion 52 of the terminal board 43, and three holes 92 (see FIG. 8 and FIG. 10, etc.) are formed in each bottom wall portion 61 of the base member 48. In each bottom wall portion 61 of the base member 48, one nut 93 (see FIG. 8, etc.) is installed in each of the three holes 92. In each connection unit 40, each fastening screw 65 is inserted into a corresponding one of the through holes 91, and is connected to a corresponding one of the nuts 93 in a corresponding one of the holes 92 by screwing or the like. In addition, in FIG. 10, etc., in each connection unit 40, each of the holes 92 in the bottom wall portion 61 opens to the side opposite to the side where the terminal board 43 (extension portion 52) is located in the second direction. However, in each of connection units 40, each of holes 92 in bottom wall portion 61 does not have to be open to the side opposite to the side on which terminal board 43 is located in the second direction.

[0059] 3 to 10, etc., in each of the connection units 40, the fastening position by the fastening screw 65C is located away inward in the first direction from the fastening positions by the fastening screws 65A and 65B. Therefore, in each of the connection units 40, at least one of the multiple fastening positions of the terminal board 43 to the bottom wall portion 61 is located away in the first direction from the other fastening positions. Note that, in the example of FIGS. 3 to 10, etc., in each of the connection units 40, the fastening positions by the fastening screws 65A and 65B are not misaligned or are barely misaligned from each other in the first direction.

[0060] In each of connection units 40, the fastening positions by fastening screws 65A and 65B are spaced apart from each other in the third direction and are arranged side by side along the third direction. In each of connection units 40, the fastening position by fastening screw 65C is shifted in the third direction from the fastening positions by fastening screws 65A and 65B. In each of connection units 40, at least one of the multiple fastening positions of terminal board 43 to bottom wall portion 61 is spaced apart in the third direction from the other fastening positions.

[0061] In each of the connection units 40, the pair of side walls 62 of the base member 48 each include a protruding piece 66. In each of the connection units 40, the protruding piece 66 of each of the side walls 62 protrudes in the third direction opposite to the side where the terminal board 43 is located, and protrudes outward in the plate width direction of the terminal board 43. In each of the pair of base members 48, the pair of side walls 62 each are fastened to the upper case 23 of the housing 21. In one example of Figs. 3 to 10, etc., in each of the connection units 40, each of the pair of protruding pieces 66 is fastened to the housing 21 via a fastening screw 67. In each of the pair of base members 48, each of the pair of protruding pieces 66 is formed with one through hole 95 (see Fig. 10, etc.). In each of the connection units 40, each of the fastening screws 67 is inserted into one of the corresponding through holes 95 of the protruding pieces 66 and connected to a boss or the like installed on the intermediate wall 36.

[0062] In each of the connection units 40, as described above, the protrusions 66 of the base member 48 are fastened to the housing 21. For this reason, in each of the connection units 40, the base member 48 is fastened to the housing 21 at positions on both sides away from the terminal board 43 in the third direction, and is fastened to the housing 21 at positions on one side and the other side in the plate width direction of the terminal board 43 away from the extension portion 52. In each of the connection units 40, the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48 as described above, and each of the pair of side wall portions 62 of the base member 48 is fastened to the housing 21 as described above, whereby the terminal board 43 is attached to the housing 21 with the base member 48 therebetween.

[0063] As shown in FIG. 8, in each of the base members 48, the bottom wall portion 61 has an outer end surface 64, and the outer end surface 64 is an outer end surface of the bottom wall portion 61 in the first direction. In each of the base members 48, the outer end surface 64 of the bottom wall portion 61 faces outward in the first direction. In each of the connection units 40, the end portion on the side where the bent portion 55 is located in the extension portion 52 and the bent portion 55 protrude outward in the first direction (lateral direction) from the outer end surface 64 of the bottom wall portion 61. In each of the terminal boards 43 of the connection unit 40, the bent portion 55 is bent with respect to the extension portion 52 toward the side where the bottom wall portion 61 of the base member 48 is adjacent in the second direction. In each of the connection units 40, the bent portion 55 of the terminal board 43 is extended from the connection position with the extension portion 52 toward the side where the bottom wall portion 61 is adjacent in the second direction.

[0064] As shown in FIG. 7, in each of the base members 48, the pair of side wall portions 62 each includes a protruding portion 68 protruding outward in the first direction from the outer end surface 64 of the bottom wall portion 61 and the recessed portion 63. In each of the base members 48, the protruding portions 68 of the pair of side wall portions 62 protrude outward in the first direction (lateral direction) relative to the outer surface of the side wall 33A of the housing 21, and are separated from each other in the third direction. In each of the connection units 40, the bent portion 55 of the terminal board 43 extends between the protruding portions 68 of the pair of side wall portions 62, and the through hole H2, which is the connection position (second connection position) of the terminal (external terminal) 102, is located between the pair of protruding portions 68 in the third direction. In each of the connection units 40, the bent portion 55 of the terminal board 43 faces the outer end surface 64 of the bottom wall portion 61 of the base member 48 from the outside in the first direction. In each of the connection units 40, the bent portion 55 of the terminal board 43 has a gap between it and the outer end surface 64 of the bottom wall portion 61, and the through hole H2 is located away from the outer end surface 64 outward in the first direction.

[0065] In each of the connection units 40, in a state where the bolt 56 and the nut 57 are attached to the bent portion 55 of the terminal board 43 at the through hole H2 and the second connection position in the vicinity thereof, the nut 57 is located in a gap between the bent portion 55 and the outer end surface 64 of the bottom wall portion 61. In each of the connection units 40, in a state where the terminal (external terminal) 102 is connected to the terminal board 43 at the through hole H2 as described above, the terminal 102 is sandwiched between the protruding portions 68 of the pair of side wall portions 62 of the base member 48. At this time, in each of the connection units 40, the terminal 102 is sandwiched between the pair of side wall portions 62 (the pair of protruding portions 68) in the third direction. In each of the connection units 40, in a state where the terminal (external terminal) 102 is connected to the terminal board 43 at the through hole H2 as described above, the respective protruding portions 68 of the pair of side wall portions 62 of the base member 48 may or may not abut against the terminal 102.

[0066] As shown in Fig. 8 etc., in each of the connection units 40, a cover member 70 is removably attached to the base member 48. The cover member 70 has electrical insulation properties and is formed, for example, from the same material as the base member 48. Fig. 11 shows a state in which the cover member 70 is attached to the base member 48 in one of the connection units 40, and Fig. 12 shows the configuration of the cover member 70. Note that in the other connection unit 40, the cover member 70 is attached to the base member 48 in the same manner as in Fig. 11.

[0067] As shown in FIG. 8, FIG. 11, FIG. 12, etc., the cover member 70 includes a top plate portion 71, a front plate portion 72, and a pair of side plate portions 73. In the cover member 70, an internal space is defined by the top plate portion 71, the front plate portion 72, and the pair of side plate portions 73. In the cover member 70, the internal space opens to the side opposite to the side where the top plate portion 71 is located and the side opposite to the side where the front plate portion 72 is located. In each of the connection units 40, the cover member 70 is attached to the base member 48, so that the protruding portion of the terminal board 43 protruding outward in the first direction from the outer surface of the side wall 33A of the housing 21, i.e., the protruding portion of the terminal board 43 protruding from the outer end surface 64 of the bottom wall portion 61 of the base member 48, is covered by the cover member 70. Therefore, in each of the connection units 40, the cover member 70 is attached to the base member 48, so that the connection position (second connection position) of the terminal 102 in the terminal board 43 is covered. That is, in each of the connection units 40, the cover member 70 is attached to the base member 48, so that the bent portion 55, or the bent portion 55, the terminal 102, and the bolt 56 are covered by the cover member 70.

[0068] In each of the connection units 40, when the cover member 70 is attached to the base member 48, the top plate portion 71 covers the protruding portion of the terminal board 43 from the outer surface of the side wall 33A from one side in the second direction, i.e., the side where the top wall 31 is located in the second direction. In each of the connection units 40, when the cover member 70 is attached to the base member 48, the front plate portion 72 covers the protruding portion of the terminal board 43 from the outside in the first direction. Then, the side plate portion 73A, which is one of the pair of side plate portions 73, covers the protruding portion of the terminal board 43 from one side in the third direction, and the side plate portion 73B, which is the other side of the pair of side plate portions 73 other than the side plate portion 73A, covers the protruding portion of the terminal board 43 from the opposite side to the side plate portion 73A in the third direction. In each of the connection units 40, when the cover member 70 is attached to the base member 48, each of the top plate portion 71 and the side plate portion 73 of the cover member 70 extends inward in the first direction to the outer surface of or near the outer surface of the side wall 33A of the housing 21. Note that, in one example, when each of the cover members 70 is attached to a corresponding one of the base members 48, each of the top plate portions 71 of the cover members 70 may be inserted into the space 26 between the top wall 31 (cover 25) and the intermediate wall 36.

[0069] Furthermore, in each of the connection units 40, when the cover member 70 is attached to the base member 48, the internal space of the cover member 70 opens in the second direction on the side opposite to the side on which the top plate portion 71 is located. In each of the connection units 40, when the cover member 70 is attached to the base member 48 and the terminal (external terminal) 102 is connected to the terminal board 43, the cable 101 extends from the connection position of the terminal 102 with the terminal board 43 to the outside of the cover member 70 through the opening in the cover member 70. The cable 101 then extends from the connection position of the terminal 102 with the terminal board 43 toward the side on which the battery 1 is located in the second direction.

[0070] The cover member 70 is also provided with a pair of protruding plate portions 75, each of which protrudes from a corresponding one of the pair of side plate portions 73 toward the side opposite to the side on which the internal space is located. Furthermore, in the cover member 70, one or more engagement pieces 76 are formed on each of the pair of protruding plate portions 75. In each of the protruding plate portions 75, the engagement pieces 76 protrude toward the side opposite to the side on which the front plate portion 72 is located.

[0071] In each of the base members 48, an engagement groove 77 is formed in each of the protruding portions 68 of the pair of side wall portions 62. In one example such as FIG. 11, in each of the base members 48, the number of engagement grooves 77 formed in the protruding portion 68 of the side wall portion 62A is the same as the number of engagement pieces 76 formed in the protruding plate portion 75A protruding from the side plate portion 73A, and the number of engagement grooves 77 formed in the protruding portion 68 of the side wall portion 62B is the same as the number of engagement pieces 76 formed in the protruding plate portion 75B protruding from the side plate portion 73B. In each of the base members 48, the cover member 70 is attached by engaging each of the engagement pieces 76 with a corresponding one of the engagement grooves 77. That is, the cover member 70 is attached to each of the base members 48 by snap-fitting.

[0072] In the battery module 20, in the circuit (electrical path) formed by the batteries 1 and the busbars 42, there are formed areas (conductive portions) having a different potential from the terminal boards 43A of the busbars 42, etc. other than the busbars 42A. In the circuit formed by the batteries 1 and the busbars 42, there are formed areas (conductive portions) having a different potential from the terminal boards 43B of the busbars 42, etc. other than the busbars 42B.

[0073] In addition, in the electronic board 45, the detection circuit, etc., which is a part of the conductive part, is electrically connected to the aforementioned circuit formed by the battery 1 and the bus bar 42. Therefore, the detection circuit, etc., formed in the area other than the area 45A of the electronic board 45, has the same potential as any position of the circuit (main circuit) between the pair of terminal boards 43. On the other hand, the control circuit, etc., formed in the area 45A of the electronic board 45 has a predetermined potential with respect to the ground, and in one example, the potential difference with the ground is about 20V. Here, in the case where a plurality of battery modules 20 are provided and the plurality of battery modules 20 are electrically connected in series for use, the potential of each of the terminal boards 43, particularly in the battery module 20 on the high potential side, is much higher than the conductive part formed in the area 45A of the electronic board 45. Therefore, even in the electronic board 45, there are conductive parts with potentials different from each of the terminal boards 43, and in particular, the potential difference of each of the terminal boards 43 with respect to the conductive parts (control circuits, etc.) formed in the area 45A may be large.

[0074] In this embodiment, in each of the connection units 40, a base member 48 is attached to the terminal board 43, and the base member 48 is attached to the housing 21. In each of the connection units 40, the base member 48 is attached to the terminal board 43 at a location away from the through hole H1, which is the connection position (first connection position) of the circuit described above, to the outside in the first direction. In each of the connection units 40, the bottom wall portion 61 of the base member 48 is adjacent to the terminal board 43 from one side in the second direction (the side where the battery 1 is located), and a pair of side wall portions 62 of the base member 48 are adjacent to the terminal board 43 from opposite sides to each other in the third direction. By providing the bottom wall portion 61 and the side wall portion 62 to each of the base members 48 as described above, in the battery module 20, each of the terminal boards 43, which are connection parts of external terminals such as the terminal 102, is appropriately insulated from conductive parts having different potentials. That is, electrical insulation of each of the terminal plates 43 from conductive portions having different potentials is properly ensured.

[0075] 3 to 10, each of the base members 48 has the above-described configuration, and therefore, in each of the connection units 40, the insulation distance of the terminal board 43 from the conductive portion including the control circuit and the like provided in the region 45A of the electronic board 45 is increased by the base member 48. This improves the electrical insulation of each of the terminal boards 43 from the conductive portion of the electronic board 45. In particular, each of the terminal boards 43 is appropriately insulated from the conductive portion of the region 45A where the potential difference with each of the terminal boards 43 may be large.

[0076] Furthermore, in this embodiment, a configuration can be applied in which the holes 92 in the bottom wall portion 61 of each connection unit 40 do not open on the side opposite to the side on which the terminal board 43A (extension portion 52) is located. With this configuration, in each connection unit 40, the bottom wall portion 61 ensures an insulation distance from the terminal board 43 even for conductive parts arranged adjacent to the side on which the battery 1 is located in the second direction. Therefore, in each connection unit 40, even if a bus bar 42 or the like having a different potential from the terminal board 43 is arranged adjacent to the side on which the battery 1 is located in the second direction, the terminal board is appropriately insulated from the bus bar 42 or the like having a different potential.

[0077] In addition, in cases where the base members 48 are not provided on each of the connection units 40, each of the terminal plates 43 must be directly fastened to the upper case 23 of the housing 21. Here, a conductive part (such as the bus bar 42 and the electrode terminal 11 of the battery 1, which have different potentials) with respect to the terminal plates 43 may be disposed in the area adjacent to the side of each of the terminal plates 43 on which the battery 1 is located in the second direction. For this reason, strict restrictions are imposed on the fastening positions of each of the terminal plates 43 to the upper case 23, and the positions at which each of the terminal plates 43 can be fastened to the upper case 23 are limited. By forming a protruding portion on the upper case 23 that protrudes outward in the first direction and allowing the terminal plate 43 to be fastened to the protruding portion, it is possible to widely secure the positions at which each of the terminal plates 43 can be fastened to the upper case 23. However, in this case, the volume of the upper case 23 increases due to the protruding portion protruding outward in the first direction, and the volume of the housing 21 increases. Furthermore, each of the terminal plates 43 can be fastened to an insulating member such as the upper case 23 of the housing 21 near the connection position (first connection position) of the circuit described above. However, in this case, the extension length of each of the terminal plates 43 becomes long, and therefore the insulation property of each of the terminal plates 43 with respect to conductive parts having different potentials, such as the bus bars 42 having different potentials, decreases.

[0078] In this embodiment, since the base member 48 is provided for each of the connection units 40, there is no need to form a first outward protruding portion or the like on the upper case 23. Therefore, the volume of the upper case 23 does not increase, and the volume of the housing 21 does not increase. Also, in this embodiment, since there is no need to fasten each of the terminal boards 43 to the upper case 23 of the housing 21 near the connection position (first connection position) of the circuit, it is possible to reduce the extension length of each of the terminal boards 43. By shortening the extension length, the insulation distance from conductive parts with different potentials, such as bus bars 42 with different potentials, is more appropriately ensured for each of the terminal boards 43.

[0079] Also, in this embodiment, in each of the connection units 40, the base member 48 is disposed away from the connection position (first connection position) to the terminal board 43 of the circuit through which current flows through the multiple batteries 1, on the outside in the first direction. Therefore, even if each of the connection units 40 is provided with the above-mentioned base member 48, when the terminal board 43 is connected to the above-mentioned circuit after the terminal board 43 is fastened to the base member 48 by the fastening screw 65 in each of the connection units 40, the work efficiency of connecting each of the terminal boards 43 to the above-mentioned circuit, that is, the work of connecting the corresponding one of the bus bars 42A, 42B to each of the terminal boards 43 is improved. Furthermore, in each of the connection units 40, when the terminal board 43 is connected to the above-mentioned circuit after the terminal board 43 is fastened to the base member 48 by the fastening screw 65, the work of connecting each of the terminal boards 43 to the circuit is performed in a state in which the insulation of each of the terminal boards 43 against conductive parts with different potentials is ensured by the corresponding base member 48. Therefore, the safety of the work of connecting each of the terminal boards 43 to the above-mentioned circuit is improved.

[0080] In each of the connection units 40, the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48, and each of the side wall portions 62 of the base member 48 is fastened to the housing 21. Therefore, even if each of the connection units 40 is composed of the terminal board 43 and the base member 48, in each of the connection units 40, the terminal board 43 can be easily attached to the housing 21 via the base member 48.

[0081] Furthermore, in each of the connection units 40, since the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48, the terminal board 43 can be fastened to the bottom wall portion 61 of the base member 48 at a position inside (inner peripheral side) with respect to the side walls 33A, 33B, 35A, and 35B (circumferential walls of the housing 21) of the housing 21. Therefore, in the present embodiment, in each of the connection units 40, the terminal board 43 can be fastened to the bottom wall portion 61 at a position inside with respect to the peripheral walls of the housing 21, such as the fastening position by the fastening screw 65C. As a result, in each of the connection units 40, the terminal board 43 is fastened to the bottom wall portion 61 not only at the fastening positions by the fastening screws 65A and 65B, but also at the fastening position by the fastening screw 65C away in the first direction from the fastening positions by the fastening screws 65A and 65B.

[0082] Here, in each of the connection units 40, in a state in which the terminal (external terminal) 102 is connected to the terminal board 43 via the through hole H2 as described above, a force may act on the cable 101 toward the outside in the first direction. In the present embodiment, in each of the connection units 40, the terminal board 43 is fastened to the bottom wall portion 61 as described above, and therefore at least one of the multiple fastening positions of the terminal board 43 to the bottom wall portion 61 is located away in the first direction from the other fastening positions. Therefore, in each of the connection units 40, the strength of the terminal board 43 is improved against a load caused by a force acting on the cable 101 toward the outside in the first direction.

[0083] In each of the connection units 40, in a state in which the terminal (external terminal) 102 is connected to the terminal plate 43 via the through hole H2 as described above, a force may act to rotate the cable 101 around the central axis of the bolt 56. In the present embodiment, in each of the connection units 40, at least one of the multiple fastening positions of the terminal plate 43 to the bottom wall portion 61 is located away from the other fastening positions in the third direction. For example, in each of the connection units 40, the fastening positions by the fastening screws 65A to 65C are located away from each other in the third direction. Therefore, in each of the connection units 40, the strength of the terminal plate 43 against a load caused by a force to rotate the cable 101 around the central axis of the bolt 56 is improved.

[0084] In each of the connection units 40, when the terminal (external terminal) 102 is connected to the terminal board 43 at the through hole H2, the terminal 102 is sandwiched between the pair of side wall portions 62 (the pair of protruding portions 68) in the third direction. In each of the connection units 40, the terminal 102 is sandwiched between the side wall portions 62, thereby effectively preventing the terminal 102 from rotating around the central axis of the bolt 56.

[0085] In each of the terminal plates 43 of this embodiment, the extension portion 51 extends through the through hole H1 that is the connection position to the circuit formed by the battery 1 and the bus bar 42, and the extension portion 52 is formed through the fastening position to the bottom wall portion 61 of the base member 48. In each of the terminal plates 43, the extension portions 51 and 52 are shifted from each other in the second direction due to the step formed by the relay portion 53. In each of the terminal plates 43, the step is formed between the extension portions 51 and 52, so that thermal stress and the like at the connection position to the circuit formed by the battery 1 and the bus bar 42 is alleviated. That is, in each of the connection units 40, even if the terminal plate 43 thermally expands, the load acting on the connection position (first connection position) of the terminal plate 43 to the circuit (bus bar 42A or 42B) formed by the battery 1 and the bus bar 42 is appropriately reduced. In addition, in each connection unit 40, a step is formed between extension portions 51, 52 in terminal board 43, so that even if terminal board 43 vibrates, the load acting on the connection position (first connection position) of terminal board 43 to the circuit formed by battery 1 and bus bar 42 is appropriately reduced.

[0086] Further, an electrically insulating cover member 70 is attached to each of the base members 48. In each of the connection units 40, when the cover member 70 is attached to the base member 48, the cover member 70 covers the second connection position and the area nearby the second connection position in the terminal board 43. In each of the connection units 40, the cover member 70 covers the second connection position and the area nearby the second connection position in the terminal board 43 from the outside in the first direction, the side where the top wall 31 is located in the second direction, and both sides in the third direction. In each of the connection units 40, a part of the terminal board 43 is covered by the cover member 70 as described above, so that the electrical insulation of the terminal board 43 from the conductive parts having different potentials is more appropriately ensured.

[0087] Furthermore, in this embodiment, a configuration can be applied in which, with each of the cover members 70 attached to a corresponding one of the base members 48, the top plate portion 71 of each of the cover members 70 is inserted into the space 26 between the top wall 31 (cover 25) and the intermediate wall 36. By adopting such a configuration, electrical insulation of each of the terminal boards 43 from the conductive parts outside the battery module 20 (housing 21) is more appropriately ensured.

[0088] (Modification) 13 and 14, terminal board 43 does not have bent portion 55 in each of connection units 40. Here, FIG. 13 shows the configuration of one of the pair of connection units 40 and its vicinity, and FIG. 14 shows the configuration of one of the pair of connection units 40. In this modification, the configuration of the other of the pair of connection units 40 and its vicinity is similar to the configuration shown in FIG. 13 etc., and the configuration of the other of the pair of connection units 40 is also similar to the configuration shown in FIG. 14 etc. Also, FIG. 13 is a perspective view showing a state in which cover 25 is omitted.

[0089] As shown in Figs. 13 and 14, in each of the terminal plates 43 in this modification, the extension portion 51 extends through a connection position (first connection position) where a circuit through which a current flows through the multiple batteries 1 and the bus bar 42 is connected, and the extension portion 52 extends through a fastening position to the base member 48. However, in this modification, in each of the terminal plates 43, a through hole H2 is formed that penetrates the extension portion 52 in the plate thickness direction (second direction). In each of the terminal plates 43, the extension portion 52 extends beyond the through hole H2 to the outside in the first direction, and an extension end E2 is formed by the extension portion 52. In each of the connection units 40, the terminal plate 43 (extension portion 52) does not protrude outward in the first direction relative to the outer surface of the side wall 33A of the housing 21 and the base member 48. However, in this modification as well, in each of the terminal boards 43, the through hole H2 is located away from the through hole H1, which is the connection position of the above-mentioned circuit, to the outside in the first direction.

[0090] Each of the terminal plates 43 is connected to the terminal (external terminal) 102 of the cable 101 at the through hole H2. Therefore, in the present modification, the through hole H2 is the connection position (second connection position) of each of the terminal plates 43 where the terminal 102 is connected. However, in the present modification, the extension portion 52 is extended along the first direction to the extension end E2 through the connection position (second connection position) of the terminal 102 of the cable 101. Also, in each of the connection units 40, the bottom wall portion 61 of the base member 48 is adjacent to the connection position (second connection position) of the terminal 102 located at the extension portion 52 from one side in the second direction. That is, in each of the connection units 40, the bottom wall portion 61 of the base member 48 is adjacent to the through hole H2 formed in the extension portion 52 from the side where the battery 1 and the intermediate wall 36 are located in the second direction.

[0091] In this modification, terminal 102 of cable 101 is connected to each of terminal plates 43 at through hole H2 and the second connection position nearby using bolt 56 and nut 57. However, in this modification, in each of terminal plates 43, bolt 56 is inserted into through hole H2 from the side where top wall 31 is located in the second direction. Then, in each of connection units 40, when bolt 56 is attached to terminal plate 43 at through hole H2, head 56A of bolt 56 approaches extension portion 52 of terminal plate 43 from the side where top wall 31 is located in the second direction, and nut 57 approaches extension portion 52 of terminal plate 43 from the side where bottom wall portion 61 of base member 48 and the battery are located in the second direction.

[0092] In this modified example, in each of the connection units 40, the terminal board 43 is fastened to the bottom wall portion 61 of the base member 48. In one example such as Figs. 13 and 14, in each of the connection units 40, the extension portion 52 is fastened to the bottom wall portion 61 via two fastening screws 65 (65D, 65E). Here, in one example such as Figs. 13 and 14, in each of the connection units 40, the fastening position by the fastening screw 65E is located away inward in the first direction from the fastening position by the fastening screw 65D. Therefore, in each of the connection units 40, at least one of the multiple fastening positions of the terminal board 43 to the bottom wall portion 61 is located away in the first direction from the other fastening positions.

[0093] In this modification, each of the pair of side wall portions 62 of each of the base members 48 does not have a protrusion 68, and each of the side wall portions 62 does not protrude outward in the first direction relative to the outer surface of the side wall 33A of the housing 21, and does not protrude outward in the first direction relative to the bottom wall portion 61. However, even in this modification, each of the side wall portions 62 of each of the base members 48 includes a protrusion 66. And, in each of the base members 48, each protrusion 66 of the side wall portions 62 is fastened to the upper case 23 of the housing 21 by a fastening screw 67.

[0094] In addition, in this modification, relay portion 53 is not provided in each of terminal boards 43, and no step is formed between extension portions 51, 52 due to relay portion 53. Therefore, in each of terminal boards 43, extension portions 51, 52 are not misaligned or are barely misaligned with respect to each other in the second direction.

[0095] In this modification, each of the terminal plates 43 extends outward in the first direction from the connection position (first connection position) of the circuit formed by the battery 1 and the bus bar 42. In each of the terminal plates 43, the connection position (second connection position) of the terminal 102 is located away from the connection position of the circuit described above toward the outside in the first direction. In each of the connection units 40, the base member 48 is attached to the terminal plate 43 at a location away from the connection position (first connection position) of the circuit described above toward the outside in the first direction. In each of the connection units 40, the bottom wall portion 61 of the base member 48 is adjacent to the terminal plate 43 from one side in the second direction, and the terminal plate 43 is fastened to the bottom wall portion 61. In each of the connection units 40, a pair of side wall portions 62 of the base member 48 are adjacent to the terminal plate 43 from opposite sides to each other in the third direction, and each of the side wall portions 62 is fastened to the housing 21. Due to this configuration, in this modification, as in the above-described embodiment, the electrical insulation of each of the terminal plates 43 from the conductive parts having different potentials is appropriately ensured. Thus, in this modification, the same actions and effects as in the above-described embodiment are achieved.

[0096] In a certain modification, in each of the terminal boards 43, a through hole H2 serving as a connection position (second connection position) of the terminal (external terminal) 102 is formed in the bent portion 55, as in the first embodiment, and a step is not formed between the extension portions 51 and 52, as in the first modification. In another modification, in each of the terminal boards 43, a through hole H2 serving as a connection position (second connection position) of the terminal (external terminal) 102 is formed in the extension portion 52 passing through the fastening position to the bottom wall portion 61 of the base member 48, as in the first modification, and a step is formed between the extension portions 51 and 52 by the relay portion 53, as in the first embodiment. In each of these modifications, as in the above-mentioned embodiment, electrical insulation of each of the terminal boards 43 from conductive parts having different potentials is appropriately ensured.

[0097] In the battery module 20, the pair of connection units 40 may have different configurations from each other as long as each of the pair of connection units 40 has the same configuration as any of the above-described embodiments, etc. In one modification, one of the pair of connection units 40 has the same configuration as the first embodiment, and the other of the pair of connection units 40 has the same configuration as the first modification.

[0098] In a second modified example shown in Figs. 15 and 16, the battery module 20 includes only one connection unit 40 of any of the above-described embodiments and the like, and also includes one connector unit 80. In this modified example, one of a pair of module terminals of the battery module 20 is formed by the terminal plate 43 of the connection unit 40, as in the above-described embodiments and the like. However, in this modified example, the other of the pair of module terminals of the battery module 20, which is the module terminal formed by the terminal plate 43, is formed by the connector unit 80. In the battery module 20, the positive module terminal may be formed by the connector unit 80, and the negative module terminal may be formed by the connector unit 80. Fig. 15 shows the configuration of the connector unit 80 and its vicinity with the cover 25 omitted, and Fig. 16 shows the configuration of the connector unit 80.

[0099] As shown in Fig. 15 and Fig. 16, the connector unit 80 includes a conductive plate 81 and a connector housing 82. The conductive plate 81 is conductive. The conductive plate 81 has a plate length direction, a plate width direction intersecting (perpendicular or approximately perpendicular) with the plate length direction, and a plate thickness direction intersecting (perpendicular or approximately perpendicular) with both the plate length direction and the plate width direction. The conductive plate 81 has extension ends E3 and E4, and extends along the plate length direction from the extension end E3 to the extension end E4. In the conductive plate 81, the plate length direction coincides or approximately coincides with the first direction (lateral direction) of the battery module 20, and the plate thickness direction coincides or approximately coincides with the second direction (height direction) of the battery module 20. In addition, in the conductive plate 81, the plate width direction coincides or approximately coincides with the third direction (depth direction) of the battery module 20. In the conductive plate 81, the extension end E4 is located outside in the first direction relative to the extension end E3, and the conductive plate 81 extends from the extension end E3 to the extension end E4 toward the outside in the first direction.

[0100] The conductive plate 81, similar to the terminal plate 43 in the above-described embodiment, is connected to one of the corresponding bus bars 42A, 42B, and is connected to the above-described circuit in which current flows through the multiple batteries 1. For this reason, the conductive plate 81 is formed with connection positions that are connected to the circuit (electrical path) formed by the multiple batteries 1 and the bus bar 42. Similar to the terminal plate 43, the conductive plate 81 is fastened to one of the corresponding bus bars 42A, 42B with fastening screws 58 and nuts 59, thereby being connected to the above-described circuit (electrical path).

[0101] In the connector unit 80, the connector housing 82 is attached to the conductive plate 81. The connector housing 82 has electrical insulation properties and is formed, for example, from the same material as the housing 21. The connector housing 82 is attached to the conductive plate 81 at a location away from the connection position to the circuit formed by the battery 1 and the bus bar 42 toward the outside in the first direction. Therefore, in the conductive plate 81, the connection position to the circuit is located inside the connector housing 82 in the first direction. An internal space 85 is formed inside the connector housing 82, and the connector housing 82 covers the internal space 85 from the inside in the first direction, both sides in the second direction, and both sides in the third direction. In addition, the internal space 85 of the connector housing 82 opens toward the outside in the first direction and opens to the outside of the housing 21. Therefore, in the connector housing 82, the internal space 85 opens on the side opposite to the side where the conductive plate 81 is inserted.

[0102] In the connector unit 80, the extended end E4 and a portion in the vicinity thereof of the conductive plate 81 are inserted into the internal space 85 of the connector housing 82 and positioned in the internal space 85. However, the conductive plate 81 does not protrude outward in the first direction relative to the connector housing 82 and does not protrude from the opening of the internal space 85. Moreover, the connector housing 82 does not protrude outward in the first direction relative to the side wall 33A of the housing 21. In the connector unit 80, the portion of the conductive plate 81 positioned in the internal space 85 serves as a connector terminal. The connector terminal of the connector unit 80 serves as one of a pair of module terminals of the battery module 20. In one example, the connector terminal may be formed of a conductive member separate from the conductive plate 81, and the conductive plate 81 may be connected to the connector terminal in the internal space 85 of the connector housing 82.

[0103] Moreover, in the connector unit 80, the connector housing 82 includes a pair of side walls 86. One of the pair of side walls 86, a side wall 86A, covers the internal space 85 from one side in the third direction (depth direction), and the other of the pair of side walls 86, a side wall 86B, covers the internal space 85 from the opposite side to the side wall 86A in the third direction. Each of the pair of side walls 86 of the connector housing 82 includes a protruding piece 87. In the connector housing 82, each protruding piece 87 of the side wall 86 protrudes toward the opposite side to the side where the internal space 85 is located in the third direction, and protrudes outward in the plate width direction of the conductive plate 81.

[0104] In the connector unit 80, each of the protrusions 87 of the connector housing 82 is fastened to the upper case 23 of the housing 21 via a fastening screw 67. The connector housing 82 can be fastened to the housing 21 at the same fastening positions as the base member 48 of the connection unit 40 described above. Therefore, the connector unit 80 can be attached to the housing 21 instead of the connection unit 40.

[0105] A connector (external connector) formed at one end of a cable can be attached to connector housing 82 of connector unit 80. For example, the connector of the cable is inserted into internal space 85 of connector housing 82 from the outside in the first direction, that is, by inserting the connector of the cable into internal space 85 from an opening to the outside of housing 21, the connector of the cable (external connector) is attached to connector housing 82. By attaching the connector of the cable to connector housing 82, the connector terminal of connector unit 80 formed from conductive plate 81 is connected to the connector terminal of cable.

[0106] In this modification, as in the above-described embodiment, electrical insulation of terminal board 43 from conductive parts having different potentials is properly ensured in connection unit 40. Moreover, in connector unit 80, electrical insulation of conductive plate 81 from conductive parts having different potentials is properly ensured by connector housing 82, etc. Therefore, this modification also provides the same functions and effects as the above-described embodiment.

[0107] Furthermore, in the above-described embodiment and the like, in the connection unit 40, the bottom wall portion 61 of the base member 48 is adjacent to the extension portion 52 of the terminal board 43 from the side where the battery 1 (bus bar 42) and the intermediate wall 36 are located in the second direction (height direction). However, in one modified example, in the connection unit 40, the bottom wall portion 61 of the base member 48 may be adjacent to the extension portion 52 of the terminal board 43 from the side where the top wall 31 is located in the second direction (height direction).

[0108] In addition, in the connection unit 40, the extension portion 52 of the terminal plate 43 may be fastened to the bottom wall portion 61 of the base member 48 using a rivet instead of the fastening screw 65. In addition, in the connection unit 40, a protrusion protruding toward the extension portion 52 of the terminal plate 43 may be formed on the bottom wall portion 61 of the base member 48, and the extension portion 52 of the terminal plate 43 may be fastened to the bottom wall portion 61 of the base member 48 by heat fusing the protrusion of the bottom wall portion 61 to the extension portion 52. In the connection unit 40, the terminal plate 43 and the base member 48 may be integrally formed by insert molding or the like. In this case, in the connection unit 40, the extension portion 52 of the terminal plate 43 is fastened to the bottom wall portion 61 of the base member 48 at the entire contact portion with the bottom wall portion 61 of the base member 48. Even in these modified examples, the same actions and effects as those of the above-mentioned embodiment and the like are achieved.

[0109] [Energy storage system] Next, a power storage system using the battery modules described above will be described. FIG. 17 shows an example of a power storage system 100 according to an embodiment. As shown in FIG. 17, the power storage system 100 includes a power storage unit 110, and a large number of battery modules 20 are electrically connected in the power storage unit 110. In the example of FIG. 17, a large number of battery modules 20 are electrically connected in series in the power storage unit 110. The power storage system 100 is used, for example, in a railway vehicle or the like. Among the battery modules 20 forming the power storage unit 110, the battery module 20A is the battery module on the lowest potential side, and the battery module 20B is the battery module on the highest potential side. In addition, since a series connection structure is formed by a large number of battery modules 20 in the power storage unit 110, a high voltage is applied to the power storage unit 110 when the power storage unit 110 is electrically connected to a power source and / or a load.

[0110] Each of the battery modules 20 other than the battery modules 20A and 20B includes a pair of the connection units 40. In each of the battery modules 20 other than the battery modules 20A and 20B, each of a pair of module terminals is formed from a corresponding one of the terminal plates 43 of the connection unit 40, similar to the battery modules 20 of the first embodiment and the first modified example. In each of the battery modules 20A and 20B, each of the battery modules 20 includes one connection unit 40 and one connector unit 80, similar to the battery modules 20 of the second modified example. In the battery module 20A, the module terminal on the positive side (high potential side) is formed from the terminal plate 43 of the connection unit 40, and the module terminal on the negative side (low potential side) is formed from the connector terminal (conductive plate 81) of the connector unit 80. In the battery module 20B, the module terminal on the negative side is formed from the terminal plate 43 of the connection unit 40, and the module terminal on the positive side is formed from the connector terminal of the connector unit 80.

[0111] Terminals (external terminals) 102 such as round terminals formed on the cable 101 described above are connected to the module terminals of the battery modules 20 other than the battery modules 20A and 20B, the positive module terminal of the battery module 20A, and the negative module terminal of the battery module 20B. As described above, in each of these module terminals, the terminals 102 of the cable 101 are connected to the terminal board 43 at the through hole H2 and the second connection position in the vicinity thereof. By connecting the terminals 102 corresponding to the respective module terminals as described above, in the power storage unit 110, the battery modules 20 are electrically connected to each other via the cable 101 having terminals 102 such as round terminals formed on both ends.

[0112] In each of the battery modules 20A, 20B, a connector (external connector) 106 formed on a cable 105 is attached to a connector housing 82 of the connector unit 80. As a result, the connector terminals of the connector 106 of the cable 105 are connected to the negative module terminal of the battery module 20A and the positive module terminal of the battery module 20B, respectively. By connecting the connector terminals corresponding to the respective terminals as described above, each of the battery modules 20A, 20B is electrically connected to a power source and / or a load via the cable 105 in which the connector 106 is formed.

[0113] Here, the connection unit 40 including the terminal plate 43 requires less labor and cost in manufacturing than the connector unit 80. The cable 101 on which the terminal 102 such as a round terminal is formed also requires less labor and cost in manufacturing than the cable 105 on which the connector 106 is formed. In one example such as FIG. 17, in the power storage unit 110, each of the module terminals other than the positive module terminal of the battery module 20A and the negative module terminal of the battery module 20B is formed from the terminal plate 43 of the corresponding connection unit 40. The terminal 102 of the cable 101 is connected to each of the module terminals other than the positive module terminal of the battery module 20A and the negative module terminal of the battery module 20B. This reduces the labor and cost in manufacturing the power storage unit 110.

[0114] When performing electrical connection work in the power storage system 100, first, the multiple battery modules 20 are electrically connected to each other using the cables 101. Then, with the multiple battery modules 20 electrically connected, each of the battery modules 20A, 20B is electrically connected to a power source and / or a load, etc., using the cables 105. By performing the electrical connection work according to the above-mentioned procedure, the safety of the electrical connection work is improved.

[0115] According to at least one of these embodiments or examples, a circuit through which a current flows through the battery is connected to the terminal plate at a first connection position, and an external terminal is connected to the terminal plate at a second connection position away from the first connection position toward the outside in the first direction. The base member includes a bottom wall portion adjacent to the terminal plate from one side in a second direction intersecting the first direction, and a pair of side wall portions adjacent to the terminal plate from opposite sides relative to each other in a third direction intersecting the first direction and the second direction. The terminal plate is fastened to the bottom wall portion, and each of the side wall portions is fastened to the housing. This makes it possible to provide a battery module in which electrical insulation of the terminal plate, which is a connection portion of the external terminal to a conductive portion having a different potential, is properly ensured, and an energy storage system including the battery module.

[0116] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. The following are additional notes. [1] A number of batteries; a housing that houses the plurality of batteries and has electrical insulation properties; a terminal plate having electrical conductivity and connected at a first connection position to a circuit in which a current flows through the plurality of batteries, the terminal plate extending outward in a first direction from the first connection position and having an external terminal connected at a second connection position spaced away from the first connection position outward in the first direction; a base member having electrical insulation properties and attached to the terminal board at a portion away from the first connection position toward the outside in the first direction, a bottom wall portion adjacent to the terminal plate from one side in a second direction intersecting the first direction and to which the terminal plate is fastened; a pair of side walls adjacent to the terminal board from opposite sides with respect to each other in a third direction intersecting the first direction and the second direction, and each of the side walls being fastened to the housing; A base member comprising: A battery module comprising: [2] A bolt having a head and removably attached to the second connection position of the terminal board, When the bolt is attached to the second connection position of the terminal board, the bolt connects the external terminal to the terminal board by sandwiching the external terminal between the head and the terminal board. [1] Battery module. [3] The battery module of [2], wherein when the external terminal is connected to the second connection position of the terminal board, the external terminal is sandwiched between the pair of side wall portions of the base member in the third direction. [4] The terminal board is fastened to the bottom wall portion of the base member at each of a plurality of fastening positions, At least one of the plurality of fastening positions is located away from the other fastening positions in the first direction. [1] to [3] any one of the battery modules. [5] The terminal board is fastened to the bottom wall portion of the base member at each of a plurality of fastening positions, At least one of the plurality of fastening positions is located away from the other fastening positions in the third direction. Any one of the battery modules [1] to [4]. [6] The terminal board is a first extension portion extending through the first connection position; a second extension portion disposed outside the first extension portion in the first direction and extending through a fastening position with the bottom wall portion of the base member; a relay portion that relays between the first extension portion and the second extension portion and forms a step such that the first extension portion and the second extension portion are shifted from each other in the second direction; Equipped with the second connection position where the external terminal is connected to the terminal plate is located on a side where the second extension portion is located with respect to the relay portion in the first direction; [1] to [5] any one of the battery modules. [7] Any one of the battery modules [1] to [6], further comprising a cover member having electrical insulation properties and removably attached to the base member, the cover member covering the second connection position of the terminal board by being attached to the base member. [8] The terminal board is an extension portion extending through a fastening position between the base member and the bottom wall portion; a bending portion that is connected to the extension portion from the outside in the first direction and bends with respect to the extension portion toward a side where the bottom wall portion of the base member is adjacent in the second direction, the bending portion extending through the second connection position; A battery module comprising any one of [1] to [7]. [9] The terminal board includes an extension portion that extends through the second connection position and a fastening position between the terminal board and the bottom wall portion of the base member, The bottom wall portion of the base member is adjacent to the second connection position located on the extension portion from one side in the second direction. [1] to [7] any one of the battery modules.

[10] Any one of the battery modules according to [1] to [9]; a cable having the external terminal at one end, the external terminal being connected to the terminal plate of the battery module at the second connection position; A power storage system comprising:

Claims

1. A number of batteries; a housing that houses the plurality of batteries and has electrical insulation properties; a terminal plate having electrical conductivity and connected at a first connection position to a circuit in which a current flows through the plurality of batteries, the terminal plate extending outward in a first direction from the first connection position and having an external terminal connected at a second connection position spaced away from the first connection position outward in the first direction; a base member having electrical insulation properties and attached to the terminal board at a portion away from the first connection position toward the outside in the first direction, a bottom wall portion adjacent to the terminal board from one side in a second direction intersecting the first direction and to which the terminal board is fastened; a pair of side walls adjacent to the terminal board from opposite sides to each other in a third direction intersecting the first direction and the second direction, and fastened to the housing; A base member comprising: Equipped with The terminal board is an extension portion extending through a fastening position between the base member and the bottom wall portion; a bent portion that is connected to the extension portion from the outside in the first direction and bent with respect to the extension portion toward a side where the bottom wall portion of the base member is adjacent in the second direction, the bent portion extending through the second connection position; A battery module comprising:

2. a bolt having a head and removably attached to the second connection position of the terminal board; When the bolt is attached to the second connection position of the terminal board, the bolt connects the external terminal to the terminal board by sandwiching the external terminal between the head and the terminal board. The battery module of claim 1 .

3. 3 . The battery module according to claim 2 , wherein when the external terminal is connected to the second connection position of the terminal board, the external terminal is sandwiched between the pair of side walls of the base member in the third direction.

4. the terminal board is fastened to the bottom wall portion of the base member at each of a plurality of fastening positions; At least one of the plurality of fastening positions is located away from the other fastening positions in the first direction. The battery module according to claim 1 .

5. the terminal board is fastened to the bottom wall portion of the base member at each of a plurality of fastening positions; At least one of the plurality of fastening positions is located away from the other fastening positions in the third direction. The battery module according to claim 1 .

6. The terminal board is a first extension portion extending through the first connection position; a second extension portion disposed outside the first extension portion in the first direction and extending through a fastening position between the base member and the bottom wall portion; a relay portion that relays between the first extension portion and the second extension portion and forms a step such that the first extension portion and the second extension portion are shifted from each other in the second direction; Equipped with the second connection position where the external terminal is connected to the terminal plate is located on a side where the second extension portion is located with respect to the relay portion in the first direction; The battery module according to claim 1 .

7. 7. A battery module according to claim 1, further comprising a cover member having electrical insulation properties and removably attached to the base member, the cover member covering the second connection position of the terminal board when attached to the base member.

8. A battery module according to any one of claims 1 to 7; a cable having the external terminal at one end, the external terminal being connected to the terminal plate of the battery module at the second connection position; A power storage system comprising:

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