Voltage monitoring module and battery cell

Abstract

The invention provides a voltage monitoring module and a battery unit. A voltage monitoring module monitors the voltage of a battery pack in which a plurality of partitions are arranged in a first direction, each of the plurality of partitions including a plurality of battery cells arranged in the first direction, the voltage monitoring module being provided with a plurality of flexible printed circuit boards each having a main body portion and a plurality of shunt portions, the main body part extends in the first direction, the plurality of branch parts are respectively branched from the main body part and are arranged at intervals in the first direction, and a connecting terminal is arranged on the top end side of each branch part. The plurality of flexible printed circuit boards are configured so as to be disposed in one-to-one correspondence with each of the plurality of partitions, and the connection terminal is connected to one corresponding terminal of the plurality of battery cells in the partition corresponding to the flexible printed circuit board.

Description

Cross - reference to related applications This application is based on Japanese Patent Application No. 2023 - 200074 filed with the Japan Patent Office on November 27, 2023, and the entire content of the Japanese patent application is incorporated herein by reference. Technical field

[0001] The present invention relates to a voltage monitoring module and a battery unit. Background art

[0002] In Japanese Unexamined Patent Application Publication No. 2020 - 013766, a bus bar module for a battery assembly including a plurality of single cells is disclosed. The bus bar module includes a flexible substrate having a plurality of wirings. The flexible substrate has a main line and a plurality of branch lines branched from the main line. One flexible substrate corresponds to the entire battery assembly, and a plurality of connection portions provided on the branch lines of the one flexible substrate are connected to all the positive electrodes and negative electrodes of the plurality of single cells constituting the battery assembly.

[0003] The battery assembly, single cell, positive electrode, negative electrode, and connection portion in Japanese Unexamined Patent Application Publication No. 2020 - 013766 correspond to the battery pack, battery cell, single - cell terminal, and connection terminal in the present application, respectively. In the technology of Japanese Unexamined Patent Application Publication No. 2020 - 013766, there is room for improvement in enabling the connection terminal of the voltage monitoring module to follow the movement of the single - cell terminal accompanying the shrinkage or expansion of the battery cell well. Summary of the invention

[0004] The voltage monitoring module according to an embodiment of the present invention monitors the voltage of a battery pack in which a plurality of partitions are arranged in a first direction, and each of the plurality of partitions includes a plurality of battery cells arranged in the first direction. The voltage monitoring module includes a plurality of flexible printed circuit boards, each of the plurality of flexible printed circuit boards having a main body portion and a plurality of branch portions. The main body portion extends in the first direction, and the plurality of branch portions are respectively branched from the main body portion and are arranged at intervals from each other in the first direction. Connection terminals are provided on the top - end sides of the plurality of branch portions. The plurality of flexible printed circuit boards are configured to be arranged in one - to - one correspondence with the plurality of partitions, and the connection terminals are connected to a corresponding one of the terminals of the plurality of battery cells in the partition corresponding to the flexible printed circuit board.

[0005] An object of the present invention is to provide a voltage monitoring module and a battery unit in which the connection terminal of the voltage monitoring module can follow the movement of the single - cell terminal accompanying the shrinkage or expansion of the battery cell well.

[0006] The voltage monitoring module of the present invention monitors the voltage of a battery pack having a plurality of partitions arranged in a first direction, where each of the plurality of partitions includes a plurality of battery cells arranged in the first direction. Among them, the voltage monitoring module includes a plurality of flexible printed circuit boards, each of the plurality of flexible printed circuit boards having a main body portion and a plurality of shunt portions. The main body portion extends in the first direction, and the plurality of shunt portions branch off from the main body portion and are arranged at intervals from each other in the first direction. Connection terminals are provided on the top side of each of the plurality of shunt portions. The plurality of flexible printed circuit boards are configured to be arranged in one-to-one correspondence with the plurality of partitions, and the connection terminals are connected to a corresponding one of the terminals of the plurality of battery cells in the partition corresponding to the flexible printed circuit board.

[0007] The battery unit of the present invention includes a battery pack and a voltage monitoring module for monitoring the voltage of the battery pack. The battery pack has a plurality of partitions arranged in a first direction, and each of the plurality of partitions has a plurality of battery cells arranged in the first direction. The voltage monitoring module has a plurality of flexible printed circuit boards, each of the plurality of flexible printed circuit boards having a main body portion and a plurality of shunt portions. The main body portion extends in the first direction, and the plurality of shunt portions branch off from the main body portion and are arranged at intervals from each other in the first direction. Connection terminals are provided on the top side of each of the plurality of shunt portions. The plurality of flexible printed circuit boards are configured to be arranged in one-to-one correspondence with the plurality of partitions, and the connection terminals are connected to a corresponding one of the terminals of the plurality of battery cells in the partition corresponding to the flexible printed circuit board.

[0008] According to the present invention, it is possible to make the connection terminals of the voltage monitoring module follow well the movement of the cell terminals accompanying the contraction or expansion of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a perspective view of the battery unit of the first embodiment. Figure 2 is a top view of the battery unit of the first embodiment. Figure 3 is a top view of the voltage monitoring module in the first embodiment. Figure 4 of (a) and Figure 4 of (b) are top views of the battery pack of the first embodiment, Figure 4 of (a) shows the state when the battery pack is discharging, Figure 4 of (b) shows the state when the battery pack is charging. Figure 5 is a perspective view showing the telescopic portion and its peripheral structure in the first embodiment. Figure 6 of (a) andFigure 6 Figure (b) is a partial enlarged view of the connection terminal and its peripheral structure in the first embodiment. Figure 6 Figure (a) is a perspective view. Figure 6 Figure (b) is a top view. Figure 7 Figure (a) and Figure 7 Figure (b) are side views showing the telescopic part and its peripheral structure in the first embodiment. Figure 7 Figure (a) shows the state when the battery pack is discharging. Figure 7 Figure (b) shows the state when the battery pack is charging. Figure 8 Figure (a) and Figure 8 Figure (b) are side views showing the telescopic part and its peripheral structure in Modification 1 of the first embodiment. Figure 8 Figure (a) shows the state when the battery pack is discharging. Figure 8 Figure (b) shows the state when the battery pack is charging. Figure 9 Figure (a) and Figure 9 Figure (b) are side views showing the telescopic part and its peripheral structure in Modification 2 of the first embodiment. Figure 9 Figure (a) shows the state when the battery pack is discharging. Figure 9 Figure (b) shows the state when the battery pack is charging. Figure 10 is a top view of the battery cell in Modification 3 of the first embodiment. Figure 11 is a top view of the battery cell in Modification 4 of the first embodiment. Figure 12 is a top view of the flexible printed circuit board in the second embodiment. Figure 13 Figure (a) is a partial enlarged top view of the shunt part and its peripheral structure in Modification 1 of the second embodiment. Figure 13 Figure (b) is a partial enlarged top view of the shunt part and its peripheral structure in Modification 2 of the second embodiment. Figure 14 is a top view of the voltage monitoring module in Modification 3 of the second embodiment. Figure 15 is a top view of the voltage monitoring module in the third embodiment. Figure 16 is a bottom view of the flexible printed circuit board in the third embodiment. Figure 17 is a bottom view of the flexible printed circuit board in Modification 1 of the third embodiment. Figure 18 is a top view of the flexible printed circuit board in Modification 2 of the third embodiment. Figure 19 is a perspective view of the flexible printed circuit board in the fourth embodiment. Figure 20 In (a) of Figure 20 and (b) of Figure 20 are side views showing the telescopic portion and its peripheral structure in the fourth embodiment. Figure 20 (a) of Figure 21 shows the state when the battery pack discharges, (b) of shows the state when the battery pack is charging.

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in all the drawings, the same reference numerals are assigned to the same structural elements, and the description may be appropriately omitted sometimes. In the following description, when explaining the positional relationship and the like between the respective structural elements of the voltage monitoring module 100 and the battery cell 300, Figure 1 the X direction shown in Figure 1 etc. is set as the first direction, and the Y direction is set as the second direction. The first direction as the X direction and the second direction as the Y direction are the long side direction and the short side direction of the voltage monitoring module 100 and the battery cell 300, respectively. In addition, the Z direction shown in etc. is set as the third direction. The third direction as the Z direction is the height direction of the voltage monitoring module 100 and the battery cell 300.

[0011] (First Embodiment) First, use Figures 1 to 7The (b) explains the first embodiment.

[0012] As Figure 1 and Figure 2 shown, the voltage monitoring module 100 of the present embodiment is a voltage monitoring module that monitors the voltage state of a battery pack 200 in which a plurality of partitions 250 are arranged in a first direction, and the plurality of partitions 250 each have a plurality of battery cells 210 stacked in the first direction. The voltage monitoring module 100 includes a plurality of flexible printed circuit boards 10 respectively corresponding to each of the plurality of partitions 250. The plurality of flexible printed circuit boards 10 each include a main body portion 11 extending in a first direction (in the case of the present embodiment, the X direction shown, etc.) and a plurality of shunt portions 20. The plurality of shunt portions 20 are respectively shunted from the main body portion 11 and are arranged at intervals separated from each other in the first direction. Figure 1 The shunt portion 20 has a connection terminal 55 (refer to (a) of Figure 6 ) connected to a cell terminal 220 that is a terminal of the battery cell 210 at the top end side. The connection terminals 55 of the shunt portions 20 of each flexible printed circuit board 10 are connected to the cell terminals 220 of the battery cells 210 of the partition 250 corresponding to the flexible printed circuit board 10. In addition, the first direction refers to the long side direction (left - right direction) of the flexible printed circuit board 10 and the main body portion 11. In addition, the partition 250 refers to a partition composed of a plurality of battery cells 210 arranged continuously in the first direction. In the case of the present embodiment, the battery pack 200 has a plurality of partitions 250, and the plurality of battery cells 210 are arranged in a straight line in a row in the first direction. The plurality of flexible printed circuit boards 10 are respectively provided in one - to - one correspondence with the plurality of partitions 250 of the battery pack 200. That is, the plurality of flexible printed circuit boards 10 are arranged in such a way that each partition 250 and each flexible printed circuit board 10 correspond to each other one - to - one. The connection terminal 55 is connected to the cell terminal 220 of a battery cell 210 of one partition 250 corresponding to one of the plurality of flexible printed circuit boards 10. On the other hand, the connection terminal 55 is not connected to the cell terminal 220 of a battery cell 210 of another partition 250 corresponding to a flexible printed circuit board other than the one flexible printed circuit board 10 and not corresponding to the one flexible printed circuit board 10. In other words, each connection terminal 55 of each flexible printed circuit board 10 is connected to the cell terminal 220 of the battery cell 210 of the corresponding partition 250, and is not connected to the cell terminal 220 of the battery cell 210 of the partition 250 corresponding to another flexible printed circuit board 10. In addition, each connection terminal 55 is connected to a corresponding single cell terminal 220 of the corresponding partition 250.

[0013] The voltage monitoring module 100 is mounted on the battery pack 200 such that the long side direction (first direction) of the main body portion 11 is along the stacking direction (arrangement direction, first direction) of the battery cells 210, and each connection terminal 55 of the voltage monitoring module 100 is connected to the single cell terminal 220 of the corresponding battery cell 210. Figure 4 (a) of shows the state when the battery pack 200 discharges. Figure 4 (b) of shows the state when the battery pack 200 charges. As Figure 4 As shown in (b), when the battery pack 200 charges, the plurality of battery cells 210 are respectively based on the first reference position 510 (in the case of this embodiment, the right end of the battery pack 200) in the stacking direction (first direction), and move away from the first reference position 510 ( Figure 4 the direction of arrow A shown in (a)). In addition, as Figure 4 shown in (a), when the battery pack 200 discharges, the plurality of battery cells 210 are respectively based on the first reference position 510, and move in the direction approaching the first reference position 510 (the direction opposite to Figure 4 the direction of arrow A shown in (a)). In addition, at least a part in the long side direction (first direction) of the flexible printed circuit board 10 is directly or indirectly fixed to the battery pack 200. The fixed position of this part with respect to the battery pack 200 in the first direction is set as the reference position for the movement of the connection terminal 55 (hereinafter referred to as the second reference position 520) (refer to Figure 2 etc.). When the battery pack 200 charges, with the expansion of the plurality of battery cells 210, each single cell terminal 220 moves in the first direction away from the first reference position 510. In addition, the connection terminal 55 connected to the single cell terminal 220 follows the single cell terminal 220 and moves in the direction away from the second reference position 520 (in the case of this embodiment, it is Figure 2 the directions of arrows B and C shown in ). The movable range of the connection terminal 55 at this time is defined according to the length dimension of the shunt portion 20 having the connection terminal 55. More specifically, the larger the length dimension of the shunt portion 20, the wider the movable range of the connection terminal 55. Further, when the battery pack 200 discharges, with the shrinkage of the plurality of battery cells 210, each cell terminal 220 moves in the first direction toward a direction closer to the first reference position 510. Further, the connection terminal 55 connected to the cell terminal 220 moves in a direction closer to the second reference position 520 following the cell terminal 220. The movable range of the connection terminal 55 at this time is defined according to the length dimension of the shunt portion 20 having the connection terminal 55. More specifically, the larger the length dimension of the shunt portion 20 is, the wider the movable range of the connection terminal 55 is.

[0014] Here, among the plurality of connection terminals 55, the connection terminal 55 connected to the cell terminal 220 that is farther from the second reference position 520 in the first direction requires a larger amount of movement (the amount of movement required to absorb the positional change of the cell terminal 220) to follow the cell terminal 220. In contrast, the voltage monitoring module 100 of the present embodiment includes a plurality of flexible printed circuit boards 10 respectively corresponding to each of the plurality of partitions 250 of the battery pack 200. Moreover, the connection terminals 55 of the shunt portions 20 of the plurality of flexible printed circuit boards 10 are connected to the cell terminals 220 of the battery cells 210 of the partition 250 corresponding to the flexible printed circuit board 10. Thereby, when the battery cell 210 expands or contracts, each connection terminal 55 of each flexible printed circuit board 10 can selectively follow the cell terminal 220 of the battery cell 210 in the corresponding partition 250 among the battery cells 210 of the entire battery pack 200. That is, compared with the case where the connection terminal 55 of one flexible printed circuit board 10 corresponds to the entire battery pack 200, the amount of movement required for each connection terminal 55 to follow the corresponding cell terminal 220 (the amount of movement required to absorb the positional change of the cell terminal 220) can be further reduced. Therefore, according to the present embodiment, the connection terminal 55 can follow the movement of the corresponding cell terminal 220 well. Furthermore, since the amount of movement required for each connection terminal 55 to follow the corresponding cell terminal 220 can be further reduced, the length dimension of the shunt portion 20 that defines the movable range of each connection terminal 55 can be set smaller. Therefore, according to the present embodiment, it is possible to configure the connection terminal 55 to follow the movement of the corresponding cell terminal 220 well, and the length dimension of the shunt portion 20 and thus the entire voltage monitoring module 100 can be designed to be more compact.

[0015] In addition, the battery unit 300 of the present embodiment includes the voltage monitoring module 100 and the battery pack 200 of the present embodiment. Each connection terminal 55 of the flexible printed circuit board 10 is connected to the cell terminal 220 corresponding to each connection terminal 55 in the battery pack 200.

[0016] According to this embodiment, as described above, the voltage monitoring module 100 includes a plurality of flexible printed circuit boards 10 respectively corresponding to each of the plurality of partitions 250 of the battery pack 200. Moreover, the connection terminals 55 of the shunt portions 20 of the plurality of flexible printed circuit boards 10 are connected to the cell terminals 220 of the battery cells 210 in the partition 250 corresponding to the flexible printed circuit board 10. Thereby, it can be configured such that the connection terminals 55 can follow the movement of the corresponding cell terminals 220 well, and the length dimension of the shunt portion 20 and thus the overall voltage monitoring module 100 can be designed to be more compact.

[0018] For example, a connector 90 (refer to Figure 5 ) is mounted on the flexible printed circuit board 10. The flexible printed circuit board 10 is configured to be connected to a measurement device that performs various controls via the connector 90, and can monitor the voltage. In addition, in Figure 1 and Figure 2 , the illustration of the connector 90 is omitted. The flexible printed circuit board 10 is used, for example, to monitor the voltage by connecting the wiring 51 to a bus bar 70 (described in detail later) that connects a plurality of battery cells 210. The connector 90 is mounted, for example, on the upper surface of an end portion (in the case of this embodiment, the left end portion) of the main body portion 11 of the flexible printed circuit board 10 on the side opposite to the side where the shunt portion 20 is formed.

[0019] As Figures 1 to 3 shown, the shape of the main body portion 11 of each of the plurality of flexible printed circuit boards 10 is formed, for example, as a substantially rectangular shape that is long in the first direction when viewed from above. The plurality of flexible printed circuit boards 10 are arranged and disposed in parallel with each other in the second direction, for example.

[0020] In the case of this embodiment, the main body portion 11 of one or more flexible printed circuit boards 10 has a corresponding partition extension portion 12 and other partition extension portions 13. The corresponding partition extension portion 12 extends in the first direction along the partition 250 corresponding to the flexible printed circuit board 10. The other partition extension portions 13 extend in the first direction along the partitions 250 corresponding to the other flexible printed circuit boards 10. The corresponding partition extension portion 12 and the other partition extension portions 13 are continuously provided in the first direction. In addition, as Figure 2 and Figure 3 shown, in the flexible printed circuit board 10, a plurality of shunt portions 20 are formed in the corresponding partition extension portion 12 among the corresponding partition extension portion 12 and the other partition extension portions 13. According to this structure, for example, by adjusting the length dimension of the other partition extension 13, the positions of the ends (left ends) of each flexible printed circuit board 10 on the side opposite to the side where the shunt portion 20 is formed in the first direction can be aligned with each other in the second direction. Thereby, the mounting positions of each flexible printed circuit board 10 with respect to the battery pack 200 and the positions of the connectors 90 mounted on each flexible printed circuit board 10 can be aligned with each other in the second direction. In the case of the present embodiment, the corresponding partition extension 12 extends from the battery cell 210 on one end side of the corresponding partition 250 to the battery cell 210 on the other end side in the first direction. More specifically, in the first direction, the length dimension of the corresponding partition extension 12 is set to be equal to or greater than the length dimension of the corresponding partition 250. However, in the present invention, the length dimension of the corresponding partition extension 12 may also be smaller than the length dimension of the corresponding partition 250. In addition, the other partition extension 13 extends from the battery cell 210 on one end side of the partition 250 corresponding to the other flexible printed circuit board 10 to the battery cell 210 on the other end side in the first direction. More specifically, in the first direction, the length dimension of the other partition extension 13 is set to be equal to the total value of the length dimensions of the respective partitions 250 corresponding to the other flexible printed circuit boards 10, or greater than the total value of the length dimensions of the respective partitions 250 corresponding to the other flexible printed circuit boards 10. However, in the present invention, the length dimension of the other partition extension 13 may also be smaller than the total value of the length dimensions of the respective partitions 250 corresponding to the other flexible printed circuit boards 10. The corresponding partition extension 12 and the other partition extension 13 may also be referred to as the first extension and the second extension, respectively. In such a case, the first extension extends in the first direction along one of the plurality of partitions 250 corresponding to one of the plurality of flexible printed circuit boards 10. The second extension extends in the first direction along the other of the plurality of partitions 250 corresponding to the other flexible printed circuit boards 10 among the plurality of flexible printed circuit boards 10. In other words, the second extension extends in the first direction along the other flexible printed circuit boards 10 other than the one flexible printed circuit board corresponding to the first extension. The first extension and the second extension are continuously formed in the main body portion 11. In addition, the corresponding partition extension 12 (first extension) is provided on the top side of the flexible printed circuit board 10 in the first direction, and the other partition extension 13 (second extension) is provided on the side opposite to the top side. In the present embodiment, the second extension is provided on the side of the flexible printed circuit board 10 where the connector 90 is mounted.

[0021] In addition, as an example, the main body portions 11 of the plurality of flexible printed circuit boards 10 are separated from each other. With this structure, the arrangement positions of the main body portions 11 of the plurality of flexible printed circuit boards 10 with respect to the battery pack 200 can be designed with greater degrees of freedom. In addition, the so-called "separated from each other" here means that the main body portions 11 of the plurality of flexible printed circuit boards 10 are each constituted by a separate member, and their main body portions 11 are not directly connected to each other. Therefore, for example, the main body portions 11 may also be indirectly connected by means of other members (such as the partition plate 260 described later).

[0022] More specifically, in the case of the present embodiment, the battery pack 200 has three partitions 250 (the first partition 250a, the second partition 250b, and the third partition 250c in order from the left). Moreover, the voltage monitoring module 100 includes three flexible printed circuit boards 10 (the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, and the third flexible printed circuit board 10c) respectively corresponding to each of the above three partitions 250. The main body portions 11 of the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, and the third flexible printed circuit board 10c are separated from each other. The first flexible printed circuit board 10a has: a corresponding partition extending portion 12, corresponding to the second partition 250b, and extending in the first direction along the second partition 250b; and other partition extending portions 13, extending in the first direction along the first partition 250a. The left end portion of the first flexible printed circuit board 10a is constituted by the left end portion of the other partition extending portion 13 of the first flexible printed circuit board 10a, and the right end portion of the first flexible printed circuit board 10a is constituted by the right end portion of the corresponding partition extending portion 12 of the first flexible printed circuit board 10a. The second flexible printed circuit board 10b has a corresponding partition extending portion 12 corresponding to the first partition 250a and extending in the first direction along the first partition 250a, and does not have other partition extending portions 13. The left end portion of the second flexible printed circuit board 10b is constituted by the left end portion of the corresponding partition extending portion 12 of the second flexible printed circuit board 10b, and the right end portion of the second flexible printed circuit board 10b is constituted by the right end portion of the corresponding partition extending portion 12 of the second flexible printed circuit board 10b. The third flexible printed circuit board 10c has: a corresponding partition extending portion 12, corresponding to the third partition 250c, and extending in the first direction along the third partition 250c; and other partition extending portions 13, extending in the first direction along the first partition 250a and the second partition 250b. The left end portion of the third flexible printed circuit board 10c is constituted by the left end portion of the other partition extending portion 13 of the third flexible printed circuit board 10c, and the right end portion of the third flexible printed circuit board 10c is constituted by the right end portion of the corresponding partition extending portion 12 of the third flexible printed circuit board 10c.

[0023] In the case of the present embodiment, with respect to the plurality of flexible printed circuit boards 10, the third flexible printed circuit board 10c, the first flexible printed circuit board 10a, and the second flexible printed circuit board 10b are arranged in sequence from the rear side toward the front side in the second direction. More specifically, with the battery pack 200 as a reference, the second flexible printed circuit board 10b is disposed on one side in the second direction (in the case of the present embodiment, the front side), and the third flexible printed circuit board 10c and the first flexible printed circuit board 10a are disposed on the other side in the second direction (in the case of the present embodiment, the rear side). In addition, the first flexible printed circuit board 10a is disposed between the third flexible printed circuit board 10c and the battery pack 200 in the second direction. The plurality of shunt portions 20 of the third flexible printed circuit board 10c are formed at the front edge of the corresponding partition extending portion 12 of the third flexible printed circuit board 10c. The connection terminals 55 of the plurality of shunt portions 20 of the third flexible printed circuit board 10c are connected to the cell terminals 220 of the battery cells 210 of the third partition 250c. Similarly, the plurality of shunt portions 20 of the first flexible printed circuit board 10a are formed at the front edge of the corresponding partition extending portion 12 of the first flexible printed circuit board 10a. The connection terminals 55 of the plurality of shunt portions 20 of the first flexible printed circuit board 10a are connected to the cell terminals 220 of the battery cells 210 of the second partition 250b. The plurality of shunt portions 20 of the second flexible printed circuit board 10b are formed at the rear edge of the corresponding partition extending portion 12 of the second flexible printed circuit board 10b. The connection terminals 55 of the plurality of shunt portions 20 of the second flexible printed circuit board 10b are connected to the cell terminals 220 of the battery cells 210 of the first partition 250a.

[0024] Here, in the case of the present embodiment, for example, the width of the corresponding partition extending portion 12 of one or more flexible printed circuit boards 10 is formed to be greater than the width of the other partition extending portions 13 of the flexible printed circuit board 10. That is, the length dimension of the corresponding partition extending portion 12 in the second direction is greater than the length dimension of the other partition extending portions 13 in the second direction. With this structure, even when one or more flexible printed circuit boards 10 are arranged farther from the battery pack 200 than the other flexible printed circuit boards 10 in the second direction, the shunt portions 20 of the corresponding partition extending portion 12 can be easily arranged near the battery pack 200. Therefore, the connection terminals 55 of the flexible printed circuit board 10 can be well connected to the corresponding cell terminals 220. More specifically, for example, in Figure 2In the example shown, a flexible printed circuit board 10 (third flexible printed circuit board 10c) and other flexible printed circuit boards 10 (first flexible printed circuit board 10a) are arranged to be isolated from each other in the second direction. In this case, it is preferable that the width dimension of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c is set to be larger than the dimension of the isolation distance between the third flexible printed circuit board 10c and the first flexible printed circuit board 10a. More preferably, the width dimension of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c is approximately equal to the sum of the width dimension of the other partition extension portion 13 of the third flexible printed circuit board 10c, the isolation distance between the third flexible printed circuit board 10c and the first flexible printed circuit board 10a, and the width dimension of the corresponding partition extension portion 12 of the first flexible printed circuit board 10a. With this structure, the positions of the corresponding partition extension portions 12 of the third flexible printed circuit board 10c and the first flexible printed circuit board 10a can be aligned with each other in the second direction. In the case of the present embodiment, as an example, the width of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c, which is arranged to be the farthest from the battery pack 200 in the second direction among the plurality of flexible printed circuit boards 10, is larger than the width of the first flexible printed circuit board 10a. More specifically, the width dimension (length dimension in the second direction) of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c is, for example, about twice the width dimension of the first flexible printed circuit board 10a.

[0025] In the present embodiment, as shown in Figure 1 and Figure 2 the length dimensions (dimensions in the first direction) of the plurality of flexible printed circuit boards 10 increase in the order of the second flexible printed circuit board 10b, the first flexible printed circuit board 10a, and the third flexible printed circuit board 10c. In addition, the left ends of the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, and the third flexible printed circuit board 10c are arranged at the same position in the first direction. On the other hand, the right end of the second flexible printed circuit board 10b terminates near the right end of the first partition 250a, the right end of the first flexible printed circuit board 10a terminates near the right end of the second partition 250b, and the right end of the third flexible printed circuit board 10c terminates near the right end of the third partition 250c.

[0026] As described above, in the case of the present embodiment, the width of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c is formed to be larger than the width of the other partition extension portion 13 of the third flexible printed circuit board 10c. That is, the length dimension in the second direction of the corresponding partition extension portion 12 of the third flexible printed circuit board 10c is larger than the length dimension of the other partition extension portion 13 of the third flexible printed circuit board 10c. On the other hand, the width of the conforming partition extension portion 12 of the first flexible printed circuit board 10a is set to the same width dimension as that of the other partition extension portions 13 of the first flexible printed circuit board 10a. That is, the width dimension of the main body portion 11 of the first flexible printed circuit board 10a is fixed regardless of the position in the long side direction (the first direction). Similarly, the width dimension of the main body portion 11 of the second flexible printed circuit board 10b including the conforming partition extension portion 12 is fixed regardless of the position in the long side direction (the first direction). The width dimensions of the other partition extension portions 13 of the third flexible printed circuit board 10c, the main body portion 11 of the first flexible printed circuit board 10a, and the main body portion 11 of the second flexible printed circuit board 10b are set to be, for example, the same width dimensions as each other.

[0027] In addition, as Figure 2 shown, it is set that the second reference position 520 of the flexible printed circuit board 10 corresponding to the partition 250 that is farther from the first reference position 510 in the first direction is farther from the first reference position 510. With this structure, in each flexible printed circuit board 10, the amount of movement required for the connection terminal 55 to follow the corresponding single terminal 220 can be reduced. More specifically, in the case of the present embodiment, both end portions of the main body portion 11 of the first flexible printed circuit board 10a are fixed to the battery pack 200 (for example, by means of a partition plate 260 described later). Among them, the end portion of the main body portion 11 of the first flexible printed circuit board 10a on the side of the first reference position 510 (in the case of the present embodiment, the right end portion) is the second reference position 520 of the first flexible printed circuit board 10a (hereinafter referred to as the second reference position 520a) in the first direction with respect to the fixed position of the battery pack 200. The second reference position 520a of the first flexible printed circuit board 10a is located near the battery cell 210 closest to the first reference position 510 side in the second partition 250b. Similarly, both end portions of the main body portion 11 of the third flexible printed circuit board 10c are fixed to the battery pack 200. Among them, the end portion of the main body portion 11 of the third flexible printed circuit board 10c on the side of the first reference position 510 (in the case of the present embodiment, the right end portion) is the second reference position 520 of the third flexible printed circuit board 10c (hereinafter referred to as the second reference position 520c) in the first direction with respect to the fixed position of the battery pack 200. The second reference position 520c of the third flexible printed circuit board 10c is located near the battery cell 210 closest to the first reference position 510 side in the third partition 250c. On the other hand, the end portion of the main body portion 11 of the second flexible printed circuit board 10b on the side opposite to the first reference position 510 side (in the case of the present embodiment, the left end portion) is fixed to the battery pack 200, and the end portion on the first reference position 510 side (in the case of the present embodiment, the right end portion) is not fixed to the battery pack 200. Moreover, the end portion of the second flexible printed circuit board 10b on the side opposite to the first reference position 510 side is the second reference position 520 of the second flexible printed circuit board 10b with respect to the fixing position of the battery pack 200 in the first direction (hereinafter referred to as the second reference position 520b). The second reference position 520b of the second flexible printed circuit board 10b is located near the battery cell 210 that is farthest from the first reference position 510 side in the first partition 250a.

[0028] Furthermore, in the case of the present embodiment, in each flexible printed circuit board 10, the isolation distance in the first direction between the second reference position 520 and the cell terminal 220 that is farthest from the second reference position 520 in the corresponding partition 250 is set to be substantially equal to each other. With this structure, in each flexible printed circuit board 10, the maximum value of the movement amount required for the connection terminal 55 to follow the corresponding cell terminal 220 can be made substantially equal to each other. Therefore, the movement of the cell terminal 220 accompanying the expansion and contraction of the battery cell 210 can be dispersed and absorbed substantially equally in each flexible printed circuit board 10. Furthermore, compared with the case where one flexible printed circuit board 10 corresponds to the entire battery pack 200, the maximum value of the movement amount required for the connection terminal 55 to follow the corresponding cell terminal 220 can be further reduced. Therefore, it is possible to configure the connection terminal 55 to follow the movement of the corresponding cell terminal 220 well in each flexible printed circuit board 10, and to design the length dimension of the shunt portion 20 and thus the entire voltage monitoring module 100 to be more compact.

[0029] In addition, in the present invention, it is not necessary to respectively arrange the flexible printed circuit boards 10 on both sides (in the case of the present embodiment, the front side and the rear side) in the second direction of the battery pack 200. For example, a plurality of flexible printed circuit boards 10 may be selectively arranged only on one side or the other side (the front side or the rear side) in the second direction of the battery pack 200. In addition, in the present invention, the flexible printed circuit board 10 arranged on one side in the second direction of the battery pack 200 and the flexible printed circuit board 10 arranged on the other side in the second direction may be replaced with each other. In this case, the shape and orientation of the flexible printed circuit board 10 may be appropriately set such that the front edge or the rear edge of the side of the flexible printed circuit board 10 where the shunt portion 20 is formed is arranged on the battery pack 200 side.

[0030] Here, among a plurality of flexible printed circuit boards 10, other partition extension portions 13 of the main body portions 11 of one or more of the flexible printed circuit boards 10, for example, have a telescopic portion 80 that can expand and contract in a first direction (see Figure 5 ). In addition, in Figure 1 , for convenience, the illustration of the telescopic portion 80 is omitted, and the entire other partition extension portion 13 is illustrated as a flat shape. With this structure, the other partition extension portion 13 can follow the expansion and contraction of the battery cells 210 (absorb the expansion and contraction of the battery cells 210) in the partition 250 corresponding to the other flexible printed circuit boards 10 by the expansion and contraction of the telescopic portion 80.

[0031] As shown in Figure 5 , Figure 7 's (a) and Figure 7 's (b), in the case of the present embodiment, in the telescopic portion 80 of the other partition extension portion 13, the main body portion 11 is folded back and a part of the main body portion 11 overlaps with each other. With this structure, the maximum elongation range of the telescopic portion 80 and the minimum contraction range of the telescopic portion 80 can be ensured well respectively. Here, "a part of the main body portion 11 overlaps with each other" means that a part of the main body portion 11 overlaps with each other in a direction parallel to the normal direction (third direction) of the portion that extends flatly in the main body portion 11.

[0032] More specifically, for example, in the telescopic portion 80, a part of the main body portion 11 is folded back in the first direction more than one and a half times for a round trip. A part of the main body portion 11 meanders with respect to the normal direction (third direction) of the main body portion 11. In other words, when observed along the second direction, a part of the main body portion 11 is folded back more than twice in the first direction in a manner that is wrinkled toward the third direction. With this structure, the maximum elongation range of the telescopic portion 80 can be ensured well.

[0033] More specifically, in the case of the present embodiment, the other partition extension portions 13 of the first flexible printed circuit board 10a and the other partition extension portions 13 of the third flexible printed circuit board 10c respectively have telescopic portions 80. As shown in Figure 5 and Figure 7As shown in (a) of FIG. 0, in the case of this embodiment, in the telescopic portions 80 of the first flexible printed circuit board 10a and the third flexible printed circuit board 10c, the other partition extension portions 13 are folded back in the first direction for more than about one and a half round trips. A part of the other partition extension portion 13 is bent into a substantially S-shaped lying-down shape when viewed along the second direction. More specifically, a part of the other partition extension portion 13 is bent and folded back from the second reference position 520 side (hereinafter simply referred to as the right side) toward the side opposite to the second reference position 520 (hereinafter simply referred to as the left side) in the first direction, and then further bent and folded back from the left side toward the right side in the first direction. In the telescopic portion 80, the portion folded back from the left side toward the right side (hereinafter referred to as the first portion 81) is laminated on the portion folded back from the right side toward the left side (hereinafter referred to as the second portion 82). Moreover, the planes of a part of the first portion 81 and a part of the second portion 82 are in a state of being opposed to each other in the up-down direction (third direction). As Figure 2 shown, the telescopic portion 80 of the third flexible printed circuit board 10c extends substantially along the entire lengths of the first partition 250a and the second partition 250b in the first direction. In addition, the telescopic portion 80 of the first flexible printed circuit board 10a extends substantially along the entire length of the first partition 250a in the first direction. In addition, in Figure 5 , Figure 7 (a) and Figure 7 (b) of FIG., the telescopic portion 80 of the first flexible printed circuit board 10a is illustrated, and the illustration of the telescopic portion 80 of the third flexible printed circuit board 10c is omitted. In addition, in the present invention, the shape of the telescopic portion 80 is not limited to the above example. For example, a part of the main body portion 11 may be folded back in the first direction for more than about two and a half round trips, for example, three and a half round trips. In addition, in the case of this embodiment, the telescopic portion 80 (main body portion 11) is configured to be in an extended state before being mounted on the battery pack 200, and becomes a folded-back state (contracted state) by being mounted on the battery pack 200 and fixed. However, in the present invention, the telescopic portion 80 (main body portion 11) may also be in a folded-back state (contracted state) before being mounted on the battery pack 200 (for example, by being held by a housing 65 described later).

[0034] In the case of the present embodiment, when the battery pack 200 is charged, as the battery cell 210 in the partition 250 corresponding to the other flexible printed circuit board 10 expands, the telescopic portion 80 extends in a direction away from the second reference position 520. More specifically, as the battery cell 210 expands, the starting point 80a of the fold-back of the telescopic portion 80 also moves in the same direction. At this time, a part of the telescopic portion 80 deforms from the folded-back shape to a substantially flat and extended shape (see (b) of Figure 7 ). Then, as the connection terminal 55 moves, the length dimension of the substantially flat and extended portion of the telescopic portion 80 gradually increases, and the length dimension of the folded-back portion gradually decreases. In this way, the telescopic portion 80 can extend in a direction away from the second reference position 520. In addition, when the battery pack 200 discharges, as the battery cell 210 in the partition 250 corresponding to the other flexible printed circuit board 10 contracts, the telescopic portion 80 contracts in a direction approaching the second reference position 520. More specifically, as the battery cell 210 contracts, the starting point 80a of the fold-back of the telescopic portion 80 also moves in the same direction. At this time, a part of the telescopic portion 80 deforms from the substantially flat and extended shape to the folded-back shape (see (a) of Figure 7 ). Then, as the connection terminal 55 moves, the length dimension of the substantially flat and extended portion of the telescopic portion 80 gradually decreases, and the length dimension of the folded-back portion gradually increases. In this way, the telescopic portion 80 can contract in a direction approaching the second reference position 520. In addition, in the present invention, the "starting point 80a of the fold-back" refers to the position where the other partition extension portion 13 starts to stand up from the flat and extended state.

[0035] As shown in Figure 2 and Figure 3 , the shunt portion 20 includes, for example, a first-direction extension portion 22 extending in the first direction. Each of the plurality of shunt portions 20 has, for example, a protruding portion 26, a first-direction extension portion 22, a tip protruding portion 28, and a connection terminal 55. The protruding portion 26 protrudes from the main body portion 11 in a second direction (Y direction) orthogonal to both the normal direction of the main body portion 11 and the first direction (X direction). The first-direction extension portion 22 extends from the tip of the protruding portion 26 in the first direction. The tip protruding portion 28 protrudes from the tip of the first-direction extension portion 22 (the end portion on the side opposite to the protruding portion 26 side) in the second direction. Moreover, as shown in (a) of Figure 6 , the tip protruding portion 28 has a connection terminal 55. In addition, in the figures other than (a) of Figure 6 , the illustration of the connection terminal 55 is appropriately omitted. The first-direction extension portion 22, the protruding portion 26, and the tip protruding portion 28 each extend linearly in a plan view.

[0036] In the case of this embodiment, when the battery pack 200 is charged, if each connection terminal 55 follows the corresponding single cell terminal 220 and moves in the first direction away from the first reference position 510, the top protruding portion 28 of the shunt portion 20 is also pulled by the single cell terminal 220 and moves in the direction away from the second reference position 520. In addition, when the movement amount of the single cell terminal 220 (the moving distance of the single cell terminal 220 in the first direction) is smaller than the length dimension of the first direction extension portion 22, a part of the first direction extension portion 22 is bent upward into a convex arc shape. Thereby, the connection terminal 55 can follow the corresponding single cell terminal 220. On the other hand, when the movement amount of the single cell terminal 220 is larger than the length dimension of the first direction extension portion 22, a part of the first direction extension portion 22 is deformed into a shape that bends and turns back from the second reference position 520 side in the first direction toward the opposite side of the second reference position 520. More specifically, the planes of a part of the first direction extension portion 22 are in a state of facing each other in the up-down direction. Moreover, as the top protruding portion 28 moves in the direction away from the second reference position 520, the turning-back starting point of the first direction extension portion 22 also moves in the same direction. At this time, in the first direction extension portion 22, the length dimension of the lower portion gradually decreases, and the length dimension of the upper portion gradually increases. Thereby, the connection terminal 55 can follow the corresponding single cell terminal 220.

[0037] In addition, when the battery pack 200 is discharged, if each connection terminal 55 follows the corresponding single cell terminal 220 and moves in the first direction toward the first reference position 510, the top protruding portion 28 of the shunt portion 20 is also pulled by the single cell terminal 220 and moves in the direction approaching the second reference position 520. At this time, when a part of the first direction extension portion 22 is bent upward into a convex arc shape during charging of the battery pack 200, the bent part is deformed (restored) into a shape that extends substantially flat. Thereby, the connection terminal 55 can follow the corresponding single cell terminal 220. On the other hand, when a part of the first direction extension portion 22 is deformed into a shape that bends and turns back from the second reference position 520 side in the first direction toward the opposite side of the second reference position 520 during charging of the battery pack 200, as the top protruding portion 28 moves in the direction approaching the second reference position 520, the turning-back starting point of the first direction extension portion 22 also moves in the same direction. At this time, in the first direction extension portion 22, the length dimension of the lower portion gradually increases, and the length dimension of the upper portion gradually decreases. Therefore, a part of the first direction extension portion 22 is deformed (restored) from the turning-back shape into a shape that extends substantially flat. Thereby, the connection terminal 55 can follow the corresponding single cell terminal 220.

[0038] In addition, the shunt portion 20 is, for example, in a form having a first portion 35 and a second portion 37. The first portion 35 is bent around an axis AX (see (a) of Figure 6 (a)) that intersects both the normal direction of the main body portion 11 and the first direction, and extends in the first direction. The second portion 37 has a connection terminal 55 and stands up from the first portion 35. Further, in Figure 6 (a) of, the axis AX is illustrated by a two-dot chain line. In addition, in the case of the present embodiment, the axial direction of the axis AX is a second direction orthogonal to both the normal direction (vertical direction) of the main body portion 11 and the first direction. However, in the present invention, the axis AX only needs to intersect both the normal direction of the main body portion 11 and the first direction, and does not necessarily need to be orthogonal to both the normal direction of the main body portion 11 and the first direction. A part (second portion 37) of the shunt portion 20 is erected in advance, and the erected part is configured to have a connection terminal 55. Therefore, when the battery pack 200 is charged, the first direction extending portion 22 can be smoothly deformed into a shape that folds back from the second reference position 520 side toward the opposite side of the second reference position 520 in the first direction. That is, the connection terminal 55 can smoothly move away from the second reference position 520 following the movement of the single cell terminal 220. More specifically, in the case of the present embodiment, the top end portion and the top end protruding portion 28 of the first direction extending portion 22 constitute the second portion 37, and the portion of the top end portion of the first direction extending portion 22 other than the second portion 37 constitutes the first portion 35.

[0039] In the case of the present embodiment, the first direction extending portions 22 of the plurality of flexible printed circuit boards 10 are each set to have an equal length dimension. That is, the movable ranges of the connection terminals 55 of the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, and the third flexible printed circuit board 10c are each set to be equal to each other. Even in this case, according to the voltage monitoring module 100 of the present embodiment described above, it is possible to further reduce the amount of movement required for each connection terminal 55 to follow the corresponding single cell terminal 220. Therefore, it is possible to configure the connection terminal 55 to follow the movement of the corresponding single cell terminal 220 well, and the length dimension of the shunt portion 20 and thus the entire voltage monitoring module 100 can be designed to be more compact. More specifically, the shunt portions 20 of the first flexible printed circuit board 10a and the third flexible printed circuit board 10c are each set to have the same shape and the same size. In addition, the shunt portion 20 of the second flexible printed circuit board 10b is formed to be symmetric about the left and right and symmetrically arranged with respect to the shunt portions 20 of the third flexible printed circuit board 10c and the first flexible printed circuit board 10a. However, in the present invention, the shunt portions 20 of each of the plurality of flexible printed circuit boards 10 may also be set to have different shapes and sizes from each other.

[0040] A plurality of wirings 51 of the flexible printed circuit board 10 respectively extend from inside the main body portion 11 to the top protruding portions 28 of the respective shunt portions 20. For example, one wiring 51 is disposed in each shunt portion 20. A connection terminal 55 is formed at each top protruding portion 28, and the top ends of the respective wirings 51 are connected to the corresponding connection terminals 55. The connection terminals 55 are exposed to the surface of the top protruding portions 28, for example.

[0041] As Figure 1 shown, the voltage monitoring module 100 includes, for example, a flexible printed circuit board 10 and a plurality of bus bars 70, and these bus bars 70 are used to connect a plurality of battery cells 210 in series. However, in the present invention, the bus bars 70 may also connect a part of the plurality of battery cells 210 in parallel, for example. The bus bars 70 are overlapped and disposed with the cell terminals 220 and are connected to the cell terminals 220 (for example, by laser welding). In addition, Figure 2 the illustration of the bus bars 70 is omitted. The bus bars 70 are formed by bending a flat metal member a plurality of times. The shape of the bus bars 70 is not particularly limited. As an example, when viewed along the second direction, it is formed in a substantially inverted U shape. More specifically, the bus bars 70 include a pair of left and right outer leg portions 72 and a main portion 74 disposed so as to straddle the pair of left and right outer leg portions 72. The pair of left and right outer leg portions 72 stand upright in the vertical direction, and the plate surfaces thereof become surfaces perpendicular to the first direction. As Figure 1 and Figure 6 (b) of FIG. show, each outer leg portion 72 is overlapped and disposed with the cell terminal 220 and is connected to the cell terminal 220 (for example, by laser welding). More specifically, the left outer leg portion 72 is connected to the cell terminal 220 of the left battery cell 210 among two battery cells 210 disposed adjacent to each other in the first direction, and the right outer leg portion 72 is connected to the cell terminal 220 of the right battery cell 210 among two battery cells 210 disposed adjacent to each other in the first direction. In addition, Figure 6 (b) of FIG., one of the pair of left and right outer leg portions 72 of the outer leg portion 72 is illustrated by a two-dot chain line. The main portion 74 is formed in a substantially rectangular flat plate shape that is long in the first direction in a plan view, for example, and the plate surface thereof is horizontally disposed. In addition, in the present invention, the shape of the bus bars 70 is not limited to Figure 1 the example shown, and may be formed in a substantially M shape when viewed along the second direction, for example.

[0042] As Figure 2As shown, in the case of the present embodiment, the battery unit 300 includes, for example, a box body 310 that houses the battery pack 200, and a buffer member 320 that applies a force to a plurality of battery cells 210 toward the first reference position 510 side. In addition, in Figure 2 , the box body 310 and the buffer member 320 are illustrated by a double-dashed line. As Figure 2 shown, the entire battery pack 200 is housed in the box body 310. In addition, in the present invention, the battery unit 300 may also include a thermistor (not shown) for detecting the temperature of the battery pack 200, and a wiring (not shown) that connects the thermistor to a measurement device that performs various controls. The buffer member 320 applies a force to a plurality of battery cells 210 toward the first reference position 510 side. Moreover, as the battery cells 210 expand and contract, the buffer member 320 can expand and contract in the first direction. More specifically, when the battery pack 200 is charged, the buffer member 320 is pressed by the battery cells 210 and is compressed in the first direction against the elastic restoring force. When the battery pack 200 is discharged, the buffer member 320 elastically restores and elongates in the first direction. Therefore, even if the battery cells 210 repeatedly expand and contract, the buffer member 320 can be used to suppress the relative displacement of the right end (first reference position 510) of the battery pack 200 with respect to the box body 310. The buffer member 320 is not particularly limited. In the case of the present embodiment, as an example, a gasket member can be used. However, in the present invention, the buffer member 320 can also be a spring member or the like that applies a force to the battery cells 210 toward the first reference position 510 side.

[0043] The plurality of battery cells 210 are each a secondary battery. As Figure 1 and Figure 2 shown, when viewed along the second direction, the plurality of battery cells 210 are each formed in a rectangular flat plate shape. The plurality of battery cells 210 are each set to have the same shape and the same size. The plurality of battery cells 210 each have, for example, a pair of front and rear cell terminals 220. The pair of front and rear cell terminals 220 each stand upward from the upper end surface of the corresponding battery cell 210, for example. The shape of the cell terminal 220 is not particularly limited. As an example, when viewed along the second direction, it is formed in a substantially rectangular flat plate shape, and the plate surface of the cell terminal 220 is a surface perpendicular to the first direction. One cell terminal 220 is connected to each connection terminal 55.

[0044] As Figure 6As shown in (a) of this embodiment, in this case, the connection terminal 55 is connected to the monomer terminal 220 in a posture orthogonal to the main body portion 11. In addition, in Figure 6 (a) and Figure 6 (b), the monomer terminal 220 is illustrated by a double-dot chain line. Thus, in the first direction, the connection terminal 55 can smoothly move away from the first reference position 510 following the movement of the monomer terminal 220.

[0045] In this embodiment, as shown in Figure 6 (b), the connection terminal 55 is connected to the monomer terminal 220 by means of, for example, a welding plate 40. The shape of the welding plate 40 is not particularly limited. As an example, it is formed in a substantially rectangular flat plate shape, and the plate surface of the welding plate 40 becomes a surface perpendicular to the first direction. The welding plate 40 is overlapped and arranged with one surface of the monomer terminal 220, and is joined to one surface of the monomer terminal 220 by welding. The side end portion of the welding plate 40 on the shunt portion 20 side protrudes from the monomer terminal 220 toward the shunt portion 20 side. The top protruding portion 28 of the shunt portion 20 and the connection terminal 55 are further connected to the portion of the welding plate 40 that protrudes from the monomer terminal 220. More specifically, the top end portion of the top protruding portion 28 is, for example, overlapped and arranged with the surface of the welding plate 40 on the monomer terminal 220 side, and is joined to the surface of the welding plate 40 on the monomer terminal 220 side by brazing. In this way, the connection terminal 55 is electrically connected to the monomer terminal 220 in a posture orthogonal to the main body portion 11. However, in the present invention, the method of connecting the connection terminal 55 to the monomer terminal 220 is not limited to this example. The connection terminal 55 can also be directly connected to the monomer terminal 220 without using the welding plate 40, for example. In addition, the outer leg portion 72 of the above-mentioned bus bar 70 is overlapped and arranged with the surface of the monomer terminal 220 on the side opposite to the welding plate 40 side, and is joined to the surface of the monomer terminal 220 on the side opposite to the welding plate 40 side. In addition, in the present invention, the bus bar 70 does not necessarily need to be connected to all the monomer terminals 220 respectively. In this embodiment, the bus bar 70 is not connected to the leftmost monomer terminal 220 and the rightmost monomer terminal 220 among the plurality of monomer terminals 220 respectively.

[0046] The battery cell 300 includes, for example, a plurality of separators 260. The battery pack 200 divides into a plurality of partitions 250 by using the plurality of separators 260. The plurality of separators 260 are arranged and configured in a first direction (the stacking direction of the battery cells 210) so as to sandwich the plurality of battery cells 210 therebetween. In the case of the present embodiment, the battery pack 200 includes four separators 260 (the first separator 260a, the second separator 260b, the third separator 260c, and the fourth separator 260d in order from the left), and the plurality of battery cells 210 are divided into three partitions 250 (the first partition 250a, the second partition 250b, and the third partition 250c) by the above four separators 260. Each partition 250 includes, for example, the same number (e.g., eight) of battery cells 210 as each other. However, in the present invention, the number of battery cells 210 included in each partition 250 may also be different from each other. The plate surface of each separator 260 is arranged along the plate surface of the adjacent battery cell 210. In each partition 250, the plate surfaces of the adjacent battery cells 210 are in surface contact with each other. In the case of the present embodiment, among the four separators 260, the fourth separator 260d arranged closest to the first reference position 510 side does not relatively displace with respect to the battery pack 200 when the battery cell 210 expands and contracts. On the other hand, the other separators 260 (the first separator 260a to the third separator 260c) move in a direction away from the first reference position 510 as the battery cell 210 expands, and move in a direction approaching the first reference position 510 as the battery cell 210 contracts. As Figure 2 shown, the width dimension (the dimension in the second direction) of the plurality of separators 260 is larger than the width dimension of each battery cell 210, and the plurality of separators 260 protrude more toward both sides in the second direction than each battery cell 210.

[0047] In the case of the present embodiment, as an example, the voltage monitoring module 100 is installed between the plurality of separators 260 and is arranged above the battery pack 200. More specifically, the left end portions of the main bodies 11 of the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, and the third flexible printed circuit board 10c are fixed to the rear end portion of the upper end surface of the first separator 260a. In addition, the right end portion of the main body 11 of the first flexible printed circuit board 10a is fixed to the rear end portion of the upper end surface of the third separator 260c. That is, the first flexible printed circuit board 10a extends in the first direction from the first separator 260a toward the third separator 260c across the second separator 260b and along the first partition 250a and the second partition 250b. The right end of the main body portion 11 of the second flexible printed circuit board 10b terminates in front of (left side of) the second partition plate 260b and is not fixed to the second partition plate 260b. The right end of the main body portion 11 of the third flexible printed circuit board 10c is fixed to the rear end portion of the upper end surface of the fourth partition plate 260d. That is, the third flexible printed circuit board 10c extends in the first direction from the first partition plate 260a toward the fourth partition plate 260d across the second partition plate 260b and the third partition plate 260c and along the first partition 250a to the third partition 250c. In this way, the voltage monitoring module 100 is installed between the plurality of partition plates 260 and is disposed above the battery pack 200. In the above state, as described above, the voltage monitoring module 100 is installed such that the long side direction (first direction) of the main body portion 11 is along the stacking direction of the battery cells 210.

[0048] In addition, in the present invention, the main body portion 11 of the flexible printed circuit board 10 may be directly fixed to the partition plate 260, or may be indirectly fixed to the partition plate 260 by means of a plate-like member 60 described later. Furthermore, in the present invention, as shown in a fifth embodiment described later, the battery pack 200 may not include a plurality of partition plates 260.

[0049] Hereinafter, an example of the operation when the battery unit 300 discharges and charges will be described in more detail. As described above, when the battery pack 200 is charged, the plurality of battery cells 210 expand in a direction away from the first reference position 510 with the first reference position 510 as a reference. Along with the expansion of the plurality of battery cells 210, each cell terminal 220 moves in the first direction away from the first reference position 510. In addition, the connection terminal 55 connected to the cell terminal 220 moves in a direction away from the corresponding second reference position 520 following the cell terminal 220. More specifically, the connection terminals 55 of the first flexible printed circuit board 10a and the third flexible printed circuit board 10c move in a direction away from the second reference positions 520a, 520c ( Figure 2 the direction of arrow B shown). The connection terminal 55 of the second flexible printed circuit board 10b moves in a direction away from the second reference position 520b ( Figure 2 the direction of arrow C shown). In addition, when the battery pack 200 discharges, the plurality of battery cells 210 contract to the right with the first reference position 510 as a reference respectively. Along with the contraction of the plurality of battery cells 210, each cell terminal 220 moves in the first direction toward a direction closer to the first reference position 510. In addition, the connection terminal 55 connected to the cell terminal 220 moves in a direction closer to the corresponding second reference position 520 following the cell terminal 220. More specifically, the connection terminals 55 of the first flexible printed circuit board 10a and the third flexible printed circuit board 10c move in directions closer to the second reference positions 520a and 520c respectively. The connection terminal 55 of the second flexible printed circuit board 10b moves in a direction closer to the second reference position 520b.

[0050] Here, as described above, among the plurality of connection terminals 55, the connection terminal 55 connected to the cell terminal 220 that is farther from the second reference position 520 in the first direction requires a larger amount of movement to follow the cell terminal 220. Moreover, in the case of the present embodiment, the voltage monitoring module 100 includes a plurality of flexible printed circuit boards 10 respectively corresponding to each of the plurality of partitions 250 of the battery pack 200. Moreover, the connection terminals 55 of the shunt portions 20 of the plurality of flexible printed circuit boards 10 are connected to the cell terminals 220 of the battery cells 210 of the partition 250 corresponding to the flexible printed circuit board 10. Therefore, compared with the case where one flexible printed circuit board 10 corresponds to the entire battery pack 200, the amount of movement required for each connection terminal 55 to follow the corresponding cell terminal 220 can be further reduced. Therefore, it can be configured such that the connection terminal 55 can follow the movement of the corresponding cell terminal 220 well, and the length dimension of the shunt portion 20 and thus the entire voltage monitoring module 100 can be designed to be more compact. In addition, as described above, in the case of the present embodiment, the other partition extension portions 13 of one or more flexible printed circuit boards 10 (the first flexible printed circuit board 10a and the third flexible printed circuit board 10c) have telescopic portions 80. Therefore, by the telescopic portion 80 telescoping, the other partition extension portions 13 can follow the expansion and contraction of the battery cells 210 of the partition 250 corresponding to the other flexible printed circuit boards 10 well. Therefore, the amount of movement required for each connection terminal 55 to follow the corresponding cell terminal 220 can be further reduced.

[0051] (Modification 1 of the First Embodiment) Next, Figure 8 of (a) and Figure 8 of (b) are used to illustrate Modification 1 of the First Embodiment. Additionally, Figure 8 of (a) and Figure 8The telescopic portion 80 of the first flexible printed circuit board 10a is illustrated in (b) thereof, and the illustration of the telescopic portion 80 of the third flexible printed circuit board 10c is omitted. The voltage monitoring module 100 of this modified example is different from the voltage monitoring module 100 of the above-described first embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described first embodiment in other aspects.

[0052] As Figure 8 shown in (a) and Figure 8 in (b), in the case of this modified example, in the telescopic portion 80, the main body portion 11 is folded back in the first direction once for a round trip. Even with this structure, by the expansion and contraction of the telescopic portion 80, one or more flexible printed circuit boards 10 can satisfactorily absorb the expansion and contraction of the battery cells 210 in the corresponding partition 250 with respect to the other flexible printed circuit boards 10. Therefore, the amount of movement required for each connection terminal 55 to follow the corresponding monomer terminal 220 can be further reduced. More specifically, a part of the other partition extension portion 13 has a shape that bends and folds back from the second reference position 520 side toward the side opposite to the second reference position 520 side in the first direction. The planes of a part of the other partition extension portion 13 face each other in the vertical direction. When the battery pack 200 is charged, with the expansion of the battery cells 210, the starting point 80a of the folding back of the telescopic portion 80 moves in a direction away from the second reference position 520 ( Figure 8 the direction of arrow B in (a)). At this time, in the other partition extension portion 13, the length dimension of the lower portion gradually decreases, and the length dimension of the upper portion gradually increases. Thus, the telescopic portion 80 can extend in a direction away from the second reference position 520. In addition, when the battery pack 200 is discharged, with the contraction of the battery cells 210, as Figure 8 shown in (b), the starting point 80a of the folding back of the telescopic portion 80 moves in a direction approaching the second reference position 520. At this time, in the other partition extension portion 13, the length dimension of the lower portion gradually increases, and the dimension of the upper portion gradually decreases. Thus, the telescopic portion 80 can contract in a direction approaching the second reference position 520.

[0053] (Second Modified Example of the First Embodiment) Next, (a) and Figure 9 (b) will be used to describe the second modified example of the first embodiment. In addition, in Figure 9 (a) and Figure 9 (b) and Figure 9The expansion / contraction part 80 of the first flexible printed circuit board 10a is illustrated in FIG. (b), and the illustration of the expansion / contraction part 80 of the third flexible printed circuit board 10c is omitted. The voltage monitoring module 100 of this modification is different from the voltage monitoring module 100 of the first embodiment described above in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the first embodiment in other aspects.

[0054] As Figure 9 shown in FIGS. (a) and Figure 9 (b) of this modification, in the expansion / contraction part 80, the main body part 11 is bent in the normal direction of the part other than the expansion / contraction part 80. In addition, the "normal direction of the part other than the expansion / contraction part 80" herein refers to the normal direction of the part of the main body part 11 that extends substantially flat without being folded back. In Figure 9 the examples shown in FIGS. (a) and Figure 9 (b), in the expansion / contraction part 80, the main body part 11 is bent downward. Even with this structure, by expanding and contracting the expansion / contraction part 80, one or more flexible printed circuit boards 10 can satisfactorily absorb the expansion and contraction of the battery cells 210 in the partition 250 corresponding to the other flexible printed circuit boards 10. Therefore, the amount of movement required for each connection terminal 55 to follow the corresponding cell terminal 220 can be further reduced. More specifically, a part of the other partition extension part 13 is bent downward into a convex substantially U shape, and the bent part constitutes the expansion / contraction part 80. The expansion / contraction part 80 is formed in a shape that descends and then ascends and returns to the original position. When the battery pack 200 is charged, with the expansion of the battery cells 210, the expansion / contraction part 80 deforms from the substantially U-shaped bent shape to a flatter shape. Thereby, the expansion / contraction part 80 can elongate in the direction away from the second reference position 520 ( Figure 9 the direction of arrow B shown in FIG. (a)). In addition, when the battery pack 200 is discharged, with the contraction of the battery cells 210, as Figure 9 shown in FIG. (a), the expansion / contraction part 80 deforms (returns) from the substantially flat extended shape to the substantially U-shaped bent shape. Thereby, the expansion / contraction part 80 can contract in the direction approaching the second reference position 520.

[0055] (Modifications 3 and 4 of the first embodiment) Next, FIGS. Figure 10 and Figure 11 are used to illustrate Modifications 3 and 4 of the first embodiment. In addition, the illustration of the expansion / contraction part 80 is omitted in Figure 10 and Figure 11 . The voltage monitoring module 100 of this modification is different from the voltage monitoring module 100 of the above-described first embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described first embodiment in other aspects.

[0056] In the present invention, the number of partitions 250 included in the battery pack 200 and the number of flexible printed circuit boards 10 included in the voltage monitoring module 100 are not particularly limited, and can be appropriately set according to the use and size of the voltage monitoring module 100 and the battery cells 300. More specifically, in Figure 10 and Figure 11 In the example shown, the battery pack 200 has four partitions 250 (the first partition 250a, the second partition 250b, the third partition 250c, and the fourth partition 250d in order from the left), and the voltage monitoring module 100 includes four flexible printed circuit boards 10 (the first flexible printed circuit board 10a, the second flexible printed circuit board 10b, the third flexible printed circuit board 10c, and the fourth flexible printed circuit board 10d) respectively corresponding to each of the above four partitions 250. The first flexible printed circuit board 10a corresponds to the second partition 250b, the second flexible printed circuit board 10b corresponds to the first partition 250a, the third flexible printed circuit board 10c corresponds to the third partition 250c, and the fourth flexible printed circuit board 10d corresponds to the fourth partition 250d. Further, in the first direction, the second reference positions 520b of the second flexible printed circuit board 10b, the second reference positions 520a of the first flexible printed circuit board 10a, the second reference positions 520c of the third flexible printed circuit board 10c, and the second reference positions 520d of the fourth flexible printed circuit board 10d are arranged in order from the left. With this structure, for example, even for a battery pack 200 having a larger length dimension than the battery pack 200 in the first embodiment, it is possible to configure the connection terminals 55 to well follow the movement of the corresponding single cell terminals 220, and it is possible to design the length dimension of the shunt portion 20 and thus the entire voltage monitoring module 100 to be more compact.

[0057] In addition, in the present invention, as described above, the flexible printed circuit boards 10 arranged on one side in the second direction of the battery pack 200 and the flexible printed circuit boards 10 arranged on the other side in the second direction may be replaced with each other. More specifically, as Figure 10 shown, for example, with the battery pack 200 as a reference, the first flexible printed circuit board 10a and the third flexible printed circuit board 10c may be arranged on one side (front side) in the second direction, and the second flexible printed circuit board 10b and the fourth flexible printed circuit board 10d may be arranged on the other side (rear side) in the second direction. In addition, as Figure 11As shown, for example, with the battery pack 200 as a reference, the second flexible printed circuit board 10b and the first flexible printed circuit board 10a are arranged on one side (front side) in the second direction, and the fourth flexible printed circuit board 10d and the third flexible printed circuit board 10c are arranged on the other side (rear side) in the second direction.

[0058] (Second Embodiment) Next, use Figure 12 to describe the second embodiment. The voltage monitoring module 100 of this embodiment is different from the voltage monitoring module 100 of the above-described first embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described first embodiment in other aspects.

[0059] Preferably, among the plurality of shunt portions 20 provided in one or more flexible printed circuit boards 10, the longer the length dimension of the first-direction extension portion 22 of the shunt portion 20 that is farther from the reference position (second reference position 520) in the first direction. In other words, preferably, the length dimension of the first-direction extension portion 22 of the shunt portion 20 increases as it approaches the center of the main body portion 11 from both ends (right end portion and left end portion) of the main body portion 11 in the first direction. Thereby, regarding the connection terminal 55 connected to the individual terminal 220 that is farther from the first reference position 510 in the first direction among the plurality of individual terminals 220, a sufficient movable range in the direction approaching the second reference position 520 and a movable range in the direction away from the second reference position 520 can be ensured. Therefore, even when the amount of movement of the individual terminal 220 associated with the contraction or expansion of the battery cell 210 in the corresponding partition 250 is large, the connection terminal 55 can follow the movement of the individual terminal 220 well.

[0060] In addition, in the present invention, regarding at least two of the plurality of shunt portions 20 provided in one or more flexible printed circuit boards 10, it is only necessary that the length dimension of the shunt portion 20 from the base end of the shunt portion 20 to the connection terminal 55 is larger for the shunt portion 20 that is farther from the second reference position 520 in the first direction. Preferably, among the plurality of shunt portions 20, the length dimension of the shunt portion 20 from the base end of the shunt portion 20 to the connection terminal 55 is larger for the shunt portion 20 that is farther from the second reference position 520 in the first direction.

[0061] In addition, among the plurality of shunt portions 20 included in one or more flexible printed circuit boards 10, there is a biased shunt portion 24 that is offset in a second direction (Y direction) orthogonal to both the normal direction of the main body portion 11 and the first direction with respect to the other shunt portions 20. The biased shunt portion 24 is provided at a position different from that of the other shunt portions 20 in the second direction. Moreover, when viewed along the second direction, the biased shunt portion 24 and a part of the other shunt portions 20 overlap each other. In Figure 12 the example shown, the first direction extension portion 22 of the biased shunt portion 24 of the first flexible printed circuit board 10a is provided on the rear side in the second direction compared to the first direction extension portion 22 of the other shunt portions 20 of the first flexible printed circuit board 10a. In addition, the first direction extension portion 22 of the biased shunt portion 24 of the second flexible printed circuit board 10b is provided on the front side in the second direction compared to the first direction extension portion 22 of the other shunt portions 20 of the second flexible printed circuit board 10b. With this structure, even when the movable ranges of the connection terminals 55 of the biased shunt portion 24 and the movable ranges of the connection terminals 55 of the other shunt portions 20 overlap in the first direction, interference between the connection terminals 55 of the biased shunt portion 24 and the connection terminals 55 of the other shunt portions 20 can be suppressed when following the movement of the single terminals 220.

[0062] In addition, a part of a part of the plurality of shunt portions 20 included in one or more flexible printed circuit boards 10 (in the case of the present embodiment, the biased shunt portion 24) is configured to be included in a rectangle 410 circumscribing the main body portion 11 in a plan view. Also, in Figure 12 it, the rectangle 410 is indicated by a double-dashed line. In Figure 12 the example shown, a part of the first direction extension portion 22 and the tip protruding portion 28 of the biased shunt portion 24 are configured to be included in the rectangle 410 in a plan view. Thereby, interference between the connection terminals 55 of the biased shunt portion 24 and the connection terminals 55 of the other shunt portions 20 can be more reliably suppressed. In the case of the present embodiment, a notch 11a is formed in the main body portion 11. In Figure 12In the example shown, a cutout 11a that is recessed rearward is formed at the front edge portion of the main body portion 11 of the first flexible printed circuit board 10a, and a cutout 11a that is recessed forward is formed at the rear edge portion of the main body portion 11 of the second flexible printed circuit board 10b. The first direction extension portions 22 of a part of the shunt portions 20 (offset shunt portions 24) are respectively disposed inside the cutouts 11a in a plan view. On the other hand, the tip portions of the tip protrusion portions 28 of a part of the shunt portions 20 (offset shunt portions 24) protrude outside the cutouts 11a in a plan view. In addition, in Figure 12 , in order to facilitate understanding of the shape of the rectangle 410, each side of the rectangle 410 is illustrated with a slight offset outward from the corresponding side of the main body portion 11.

[0063] In Figure 12 the example shown, regarding two of the four shunt portions 20 of each of the first flexible printed circuit board 10a and the second flexible printed circuit board 10b, the further the shunt portion 20 is from the second reference position 520 in the first direction, the larger the length dimension of the shunt portion 20 from the base end of the shunt portion 20 to the connection terminal 55. Furthermore, in Figure 12 the example shown, the plurality of shunt portions 20 of each of the first flexible printed circuit board 10a and the second flexible printed circuit board 10b include offset shunt portions 24. Moreover, a part of the offset shunt portions 24 converges in a rectangle 410 that circumscribes the main body portion 11 in a plan view. In addition, in Figure 12 , the illustration of the third flexible printed circuit board 10c in each flexible printed circuit board 10 is omitted. However, it can also be configured such that among the plurality of shunt portions 20 of the third flexible printed circuit board 10c, the further the shunt portion 20 is from the reference position (second reference position 520) in the first direction, the larger the length dimension of the first direction extension portion 22. Similarly, the plurality of shunt portions 20 of the third flexible printed circuit board 10c can also include offset shunt portions 24, and a part of a part of the plurality of shunt portions 20 of the third flexible printed circuit board 10c (for example, the offset shunt portion 24) can also converge in a rectangle 410 that circumscribes the main body portion 11 in a plan view.

[0064] (Modification Examples 1 and 2 of the Second Embodiment) Next, (a) of Figure 13 and Figure 13 (b) of are used to describe Modification Examples 1 and 2 of the second embodiment. The voltage monitoring module 100 of this modification example is different from the voltage monitoring module 100 of the above-described second embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described second embodiment in other aspects.

[0065] In Figure 13 In the case of Modification 1 shown in (a) below, the shunt portion 20 located on one end side in the first direction (the left end side in this modification) has: a protruding portion 26a that protrudes from one end of the main body portion 11 in the first direction; a first extension portion 31 that extends from the tip of the protruding portion 26a in the second direction (the rear side in this modification); a first-direction extension portion 22a that extends from the tip of the first extension portion 31 in a direction opposite to the protruding direction of the protruding portion 26; and a tip protruding portion 28a that protrudes from the tip of the first-direction extension portion 22a in the second direction. Moreover, the tip protruding portion 28a has a connection terminal 55. Thus, in the present invention, the shunt portion 20 can also be arranged in the same direction as the moving direction of the cell terminal 220 when the battery cell 210 expands. With this structure, the connection terminal 55 can also follow well the movement of the cell terminal 220 accompanying the contraction or expansion of the battery cell 210.

[0066] In Figure 13 In the case of Modification 2 shown in (b) below, the shunt portion 20 located on one end side in the first direction (the left end side in this modification) has: a protruding portion 26b that protrudes from the main body portion 11 in the second direction (the front side in this modification); a first extension portion 31a that extends from the tip of the protruding portion 26b in the first direction beyond one end of the main body portion 11 in the first direction (the left end in this modification); a second extension portion 33 that extends from the tip of the first extension portion 31a in a direction opposite to the protruding direction of the protruding portion 26b (the rear side in this modification) beyond the edge of the main body portion 11 in the second direction (the rear edge side in this modification); a first-direction extension portion 22b that extends from the tip of the second extension portion 33 in a direction opposite to the extending direction of the first extension portion 31a; and a tip protruding portion 28b that protrudes from the tip of the first-direction extension portion 22b in a direction opposite to the protruding direction of the protruding portion 26b. Moreover, the tip protruding portion 28b has a connection terminal 55. Thus, in the present invention, the shunt portion 20 can also be arranged in a detour at one end portion of the main body portion 11. With this structure, the connection terminal 55 can also follow well the movement of the cell terminal 220 accompanying the contraction or expansion of the battery cell 210. In addition, the shunt portion 20 located on one end side in the first direction (the left end side in this modification) here means the shunt portion 20 closest to one end side among the plurality of shunt portions 20.

[0067] (Modification 3 of the Second Embodiment) Next, useFigure 14 Describe Modification Example 3 of the Second Embodiment. The voltage monitoring module 100 of this modification example is different from the voltage monitoring module 100 of the above-described second embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described second embodiment in other aspects.

[0068] In the case of this modification example, the main body portions 11 of the plurality of flexible printed circuit boards 10 are connected to each other by a connecting portion 17 extending in the second direction. With this structure, the structural strength of the voltage monitoring module 100 can be sufficiently ensured. In addition, "the main body portions 11 of the plurality of flexible printed circuit boards 10 are connected to each other by the connecting portion 17" herein means that the main body portions 11 of the plurality of flexible printed circuit boards 10 are directly connected to the connecting portion 17, that is, these main body portions 11 are indirectly connected to each other by the connecting portion 17. More specifically, the main body portions 11 of the plurality of flexible printed circuit boards 10 are integrally punched and formed.

[0069] More specifically, as Figure 14 shown, in the case of this modification example, the left end portion of the first flexible printed circuit board 10a and the left end portion of the second flexible printed circuit board 10b among the plurality of flexible printed circuit boards 10 are connected to each other by the connecting portion 17. In addition, in Figure 14 the illustration of the third flexible printed circuit board 10c is omitted. However, in the present invention, the third flexible printed circuit board 10c can also be connected to other flexible printed circuit boards 10 by the connecting portion 17. More specifically, in the present invention, for example, all the flexible printed circuit boards 10 included in the voltage monitoring module 100 can be connected to each other by the connecting portion 17, or a part of the flexible printed circuit boards 10 can be connected to each other by the connecting portion 17.

[0070] (Third Embodiment) Next, use Figure 15 and Figure 16 to describe the third embodiment. The voltage monitoring module 100 of this embodiment is different from the voltage monitoring module 100 of the above-described first embodiment and second embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described first embodiment and second embodiment in other aspects.

[0071] In the case of this embodiment, as Figure 15 and Figure 16 shown, the voltage monitoring module 100 includes a rigid plate-like member 60 for mounting the main body portion 11. The plate-like member 60 is configured to be mounted on the main body portion 11 of at least one flexible printed circuit board 10. With this structure, the structural strength of the main body portion 11 can be sufficiently ensured.

[0072] More specifically, in the case of the present embodiment, one end of the main body portion 11 of the one or more flexible printed circuit boards 10 on the side having the corresponding partition extension portion 12, and the portion between the corresponding partition extension portion 12 and the expansion and contraction portion 80 in the main body portion 11 of the flexible printed circuit board 10 are indirectly fixed to the battery cell 210 by means of the rigid plate-like members 60, respectively. With this structure, the following structure can be more reliably achieved: in the one or more flexible printed circuit boards 10, the expansion and contraction of the battery cell 210 in the partition 250 corresponding to the other flexible printed circuit board 10 is absorbed by the expansion and contraction portion 80 of the other partition extension portion 13, and the position change of the single cell terminal 220 in the corresponding partition 250 is absorbed by the plurality of shunt portions 20 formed in the corresponding partition extension portion 12.

[0073] More specifically, in the case of the present embodiment, the voltage monitoring module 100 has a pair of first reinforcing plates 61 as the plate-like members 60. The material constituting the pair of first reinforcing plates 61 is not particularly limited, and as an example, a hard resin material can be cited. The pair of first reinforcing plates 61 are each formed in a rectangular shape that is long in the second direction in a plan view. The pair of first reinforcing plates 61 are respectively mounted along the lower surface (the surface on the battery pack 200 side) of the main body portion 11. The rear end portions of the pair of first reinforcing plates 61 each protrude rearward from the main body portion 11 in a plan view, for example. One of the pair of first reinforcing plates 61 is mounted on one end of the main body portion 11 of the flexible printed circuit board 10 on the side having the corresponding partition extension portion 12 (in the case of the present embodiment, the right end portion), and this end portion is fixed to the partition plate 260 (and further fixed to the battery cell 210) by means of one of the first reinforcing plates 61. The other of the pair of first reinforcing plates 61 is mounted on the portion between the corresponding partition extension portion 12 and the expansion and contraction portion 80 in the main body portion 11 of the flexible printed circuit board 10 (in the case of the present embodiment, the intermediate portion), and this intermediate portion is fixed to the partition plate 260 (and further fixed to the battery cell 210) by means of the other of the first reinforcing plates 61. In addition, in Figure 15 the partition plate 260 is illustrated by a double-dashed line. However, in the present invention, the pair of first reinforcing plates 61 may also be directly fixed to the corresponding battery cell 210. In addition, the method of fixing the pair of first reinforcing plates 61 to the main body portion 11 of the flexible printed circuit board 10 is not particularly limited. For example, it can be fixed by thermal riveting, or it can be fixed using an adhesive or the like. In addition, in Figure 15 and Figure 16An example in which the first flexible printed circuit board 10a is mounted on the plate-like member 60 (a pair of first reinforcing plates 61) is illustrated in the figure, but other flexible printed circuit boards 10 may also be mounted on the plate-like member 60 (a pair of first reinforcing plates 61). More specifically, in the present invention, for example, all the flexible printed circuit boards 10 included in the voltage monitoring module 100 may be respectively mounted on the plate-like member 60 (a pair of first reinforcing plates 61), or a part of the flexible printed circuit boards 10 may be mounted on the plate-like member 60 (a pair of first reinforcing plates 61).

[0074] (Modification 1 of the Third Embodiment) Next, Figure 17 Modification 1 of the third embodiment will be described. The voltage monitoring module 100 of this modification is different from the voltage monitoring module 100 of the above-described third embodiment in the aspects described below, and is configured in the same manner as the voltage monitoring module 100 of the above-described third embodiment in other aspects.

[0075] In the case of this modification, the voltage monitoring module 100 may further include a connection plate 62 that connects the pair of first reinforcing plates 61 to each other as the plate-like member 60 in addition to including the pair of first reinforcing plates 61 as the plate-like member 60. With this configuration, for example, without fixing the main body portion 11 to the battery pack 200 by means of the plate-like member 60 (more specifically, the pair of first reinforcing plates 61), the following configuration can be more reliably achieved: in one or more flexible printed circuit boards 10, the expansion and contraction of the battery cells 210 in the partition 250 corresponding to the other flexible printed circuit boards 10 are absorbed by the telescopic portions 80 of the other partition extension portions 13, and the position change of the cell terminals 220 in the corresponding partition 250 is absorbed by the plurality of shunt portions 20 formed in the corresponding partition extension portion 12. More specifically, the connection plate 62 extends linearly in the first direction, for example, and is spanned between one first reinforcing plate 61 and the other first reinforcing plate 61.

[0076] (Modification 2 of the Third Embodiment) Next, Figure 18 Modification 2 of the third embodiment will be described. The voltage monitoring module 100 of this embodiment is different from the voltage monitoring modules 100 of the above-described third embodiment and modification 1 in the aspects described below, and is configured in the same manner as the voltage monitoring modules 100 of the above-described third embodiment and modification 1 in other aspects.

[0077] In the case of this modification, as Figure 18 shown, the voltage monitoring module 100 includes a single second reinforcing plate 63 that extends linearly in the first direction as the plate-like member 60. With this structure, the structural strength of the main body portion 11 can be fully ensured. More specifically, the second reinforcing plate 63 extends over the entire region in the long side direction of the flexible printed circuit board 10, and the entire main body portion 11 of the flexible printed circuit board 10 is disposed on the upper surface of the second reinforcing plate 63. The material constituting the second reinforcing plate 63 is not particularly limited, and as an example, a hard resin material can be cited. In addition, in Figure 18 In the example shown, one end side (the right end side in this modification example) of the main body portion 11 of the flexible printed circuit board 10 having the corresponding partition extending portion 12 is fixed to the second reinforcing plate 63 by thermo - riveting. Similarly, the portion (the intermediate portion in this modification example) between the corresponding partition extending portion 12 and the telescopic portion 80 in the main body portion 11 of the flexible printed circuit board 10 is fixed to the second reinforcing plate 63 by thermo - riveting. More specifically, as an example, thermo - riveting portions 18 are respectively formed at the right end portion and the intermediate portion of the main body portion 11, and the main body portion 11 is fixed to the plate - like member 60 (the second reinforcing plate 63) by using the thermo - riveting portions 18. Protrusions (not shown) are formed on the upper surface of the second reinforcing plate 63, and through - holes (not shown) are formed at portions of the main body portion 11 corresponding to the protrusions. Then, in a state where the protrusions of the second reinforcing plate 63 are inserted into the through - holes of the main body portion 11, the tip portions of the protrusions are crushed by thermo - riveting so that the outer diameter thereof is larger than the inner diameter of the through - hole. Thereby, the thermo - riveting portions 18 are formed to prevent the protrusions of the plate - like member 60 from coming off the main body portion 11. In addition, in Figure 18 An example in which the first flexible printed circuit board 10a is mounted on the plate - like member 60 (the second reinforcing plate 63) is illustrated, but other flexible printed circuit boards 10 can also be mounted on the plate - like member 60 (the second reinforcing plate 63). More specifically, in the present invention, for example, all the flexible printed circuit boards 10 included in the voltage monitoring module 100 can be respectively mounted on the plate - like member 60 (the second reinforcing plate 63), or a part of the flexible printed circuit boards 10 can be mounted on the plate - like member 60 (the second reinforcing plate 63).

[0078] (Fourth Embodiment) Next, (a) of Figure 19 and Figure 20 and (b) of Figure 20 are used to explain the fourth embodiment. In addition, Figure 19 is a perspective view of the voltage monitoring module 100 as viewed from the bottom side. The voltage monitoring module 100 of the present embodiment is different from the voltage monitoring modules 100 of the above-described first to third embodiments in the aspects described below, and is configured in the same manner as the voltage monitoring modules 100 of the above-described first to third embodiments in other aspects.

[0079] In the case of the present embodiment, a housing 65 that houses the telescopic portion 80 of one or more flexible printed circuit boards 10 is provided, and the housing 65 restricts the expansion of the telescopic portion 80 in the normal direction of the portion other than the telescopic portion 80 in the main body portion 11. In addition, the "normal direction of the portion other than the telescopic portion 80" herein refers to the normal direction of the portion that extends substantially flat without being folded back in the main body portion 11. Furthermore, "restricting expansion" means restricting the telescopic portion 80 to a folded-back shape. With this structure, the telescopic portion 80 can maintain a folded-back shape in the first direction well and expand and contract along with the expansion and contraction of the battery cell 210.

[0080] Furthermore, in the case of the present embodiment, the starting point 80a of the fold-back in the telescopic portion 80 is fixed to the housing 65. With this structure, the telescopic portion 80 can expand and contract with good reproducibility based on the starting point 80a of the fold-back. In addition, as described above, in the present invention, the "starting point 80a of the fold-back" refers to the position where the other partition extension portion 13 starts to stand up from the flat extension state.

[0081] More specifically, the housing 65 includes, for example: a top surface portion 65a disposed along the upper plane in the telescopic portion 80; a bottom surface portion 65b disposed along the lower plane in the telescopic portion 80; and a pair of side surface portions (not shown) that cover the side of the telescopic portion 80 and connect the top surface portion 65a and the bottom surface portion 65b to each other. With this structure, it is possible to restrict the upward expansion of the telescopic portion 80 by the top surface portion 65a and restrict the downward expansion of the telescopic portion 80 by the bottom surface portion 65b. In addition, by using the pair of side surface portions, it is also possible to restrict the lateral protrusion of the telescopic portion 80. That is, the housing 65 is configured to restrict the upward, downward, and lateral expansion of the telescopic portion 80. The top surface portion 65a and the bottom surface portion 65b are each formed in a flat plate shape and extend linearly in the first direction. However, a part of the left end portion of the bottom surface portion 65b is configured as a stepped portion, for example. In addition, a part of the left end portion of the bottom surface portion 65b may not be configured as a stepped portion. As Figure 19 shown, the housing 65 is fixed to the telescopic portion 80 by a thermal riveting portion 18, for example. More specifically, in the other partition extension 13, a portion near the starting point 80a of the fold-back in the telescopic portion 80 and to the left of this starting point is fixed to the bottom surface portion 65b by the thermal riveting portion 18. Further, in the other partition extension 13, a portion near the ending point of the fold-back in the telescopic portion 80 and to the left of this ending point is fixed to the bottom surface portion 65b by the thermal riveting portion 18. In addition, Figure 20 in (a) of Figure 20 and in (b) of

[0082] the illustration of the thermal riveting portion 18 is omitted. Figure 19 The material constituting the housing 65 is not particularly limited, and as an example, a hard resin material can be cited. With this structure, the shape of the telescopic portion 80 can be well maintained by the housing 65, and the structural strength of each flexible printed circuit board 10 can be well ensured.

[0083] As Figure 20 shown in (a) of Figure 20 and in (b) of in the case of this embodiment, the starting point 80a of the fold-back in the telescopic portion 80 is fixed to the upper surface of the bottom surface portion 65b by the adhesive tape 68. In addition, in the present invention, the method of fixing the starting point 80a of the fold-back in the telescopic portion 80 to the housing 65 is not limited to this example, and other methods such as adhesive bonding or riveting fixation can be appropriately adopted. Figure 19 In addition, Figure 20 in (a) of Figure 20 and

[0084] (Fifth Embodiment) Next, Figure 21 the fifth embodiment will be described. The voltage monitoring module 100 of the present embodiment is different from the voltage monitoring modules 100 of the above-described first to fourth embodiments in the aspects described below, and is configured in the same manner as the voltage monitoring modules 100 of the above-described first to fourth embodiments in other aspects.

[0085] As Figure 21 shown, in the case of the present embodiment, the voltage monitoring module 100 does not include a plurality of partition plates 260, and in the entire battery pack 200, the plate surfaces of adjacent battery cells 210 are arranged in surface contact with each other. Moreover, the main body portions 11 of the respective flexible printed circuit boards 10 are directly or indirectly (for example, by means of the above-described plate-like member 60) fixed to the corresponding battery cells 210. More specifically, the end portion (the right end portion in the case of the present embodiment) of the main body portion 11 of the first flexible printed circuit board 10a located on the side of the first reference position 510 is directly or indirectly fixed to the battery cell 210 closest to the first reference position 510 among the battery cells 210 in the second partition 250b. Moreover, the second reference position 520a of the first flexible printed circuit board 10a is located at the same position as or near the battery cell 210 closest to the first reference position 510 among the battery cells 210 in the second partition 250b in the first direction. On the other hand, the end portion (the left end portion in the case of the present embodiment) of the main body portion 11 of the first flexible printed circuit board 10a on the side opposite to the first reference position 510 can move in a direction away from the first reference position 510 and a direction approaching the first reference position 510 following the expansion and contraction of the battery pack 200. More specifically, the left end portion of the main body portion 11 of the first flexible printed circuit board 10a is, for example, directly or indirectly (for example, by means of the above-described plate-like member 60 or buffer member 320) fixed to the battery cell 210 farthest from the first reference position 510 among the battery cells 210 of the entire battery pack 200. Similarly, the end portion (the right end portion in the case of the present embodiment) of the main body portion 11 of the third flexible printed circuit board 10c located on the side of the first reference position 510 is directly or indirectly fixed to the battery cell 210 closest to the first reference position 510 among the battery cells 210 in the third partition 250c. Moreover, the second reference position 520c of the third flexible printed circuit board 10c is located at the same position as or near the battery cell 210 closest to the first reference position 510 among the battery cells 210 in the third partition 250c in the first direction. On the other hand, the end portion (the left end portion in the case of the present embodiment) of the main body portion 11 of the third flexible printed circuit board 10c on the side opposite to the first reference position 510 can move in a direction away from the first reference position 510 and in a direction approaching the first reference position 510 following the expansion and contraction of the battery pack 200. More specifically, the left end portion of the main body portion 11 of the third flexible printed circuit board 10c is fixed, for example, directly or indirectly, to the battery cell 210 that is farthest from the first reference position 510 among the battery cells 210 of the entire battery pack 200. The end portion (the right end portion in the case of the present embodiment) of the main body portion 11 of the second flexible printed circuit board 10b on the side of the first reference position 510 is not fixed to the battery pack 200. On the other hand, the end portion (the left end portion in the case of the present embodiment) of the main body portion 11 of the second flexible printed circuit board 10b on the side opposite to the first reference position 510 can move in a direction away from the first reference position 510 and in a direction approaching the first reference position 510 following the expansion and contraction of the battery pack 200. More specifically, the left end portion of the main body portion 11 of the second flexible printed circuit board 10b is fixed, for example, directly or indirectly, to the battery cell 210 that is farthest from the first reference position 510 among the battery cells 210 of the entire battery pack 200. The second reference position 520b of the second flexible printed circuit board 10b is located at or near the same position as the battery cell 210 that is farthest from the first reference position 510 in the first direction.

[0086] The above-described embodiments have been described with reference to the accompanying drawings. However, these embodiments are illustrative of the present invention, and various structures other than the above-described embodiments can also be adopted.

[0087] For example, in the above-described embodiment, an example in which the single cell terminal 220 is formed in a flat plate shape has been described. However, in the present invention, the shape of the single cell terminal 220 is not limited to this example, and it can also be formed in a cylindrical shape, for example.

[0088] In addition, in the present invention, the first reference position 510 at which the battery cell 210 expands and contracts is not limited to the position at one end in the first direction, and it can also be, for example, the central position of the battery pack 200.

[0089] The present embodiment includes the following technical concepts. (1) A voltage monitoring module monitors the voltage of a battery pack having a plurality of partitions arranged in a first direction, where the plurality of partitions each contain a plurality of battery cells arranged in the first direction. Among them, the voltage monitoring module includes a plurality of flexible printed circuit boards, and the plurality of flexible printed circuit boards each have a main body portion and a plurality of shunt portions. The main body portion extends in the first direction, and the plurality of shunt portions branch off from the main body portion respectively and are arranged at intervals separated from each other in the first direction. Connection terminals are provided on the top side of each of the plurality of shunt portions. The plurality of flexible printed circuit boards are configured to be arranged in one-to-one correspondence with the plurality of partitions respectively, and the connection terminals are connected to a corresponding one of the terminals of the plurality of battery cells in the partition corresponding to the flexible printed circuit board. (2) According to the voltage monitoring module described in (1), the main body portion of one or more of the flexible printed circuit boards has a first extension portion and a second extension portion. The plurality of shunt portions branch off from the first extension portion of the main body portion. The first extension portion is configured to extend along the partition corresponding to one of the plurality of flexible printed circuit boards. The second extension portion is configured to extend along the partitions corresponding to the flexible printed circuit boards other than the one flexible printed circuit board. (3) According to the voltage monitoring module described in (2), the length dimension of the first extension portion in a second direction that is orthogonal to both the normal direction of the main body portion and the first direction is greater than the length dimension of the second extension portion in the second direction. (4) According to the voltage monitoring module described in any one of (1) to (3), the plurality of shunt portions each include a first direction extension portion extending in the first direction. The length dimensions of the first direction extension portions of the plurality of shunt portions of one or more of the flexible printed circuit boards increase in the first direction as they approach the center from both ends of the main body portion. (5) According to the voltage monitoring module described in any one of (1) to (4), the plurality of shunt portions include offset shunt portions. The offset shunt portions are configured to be provided at positions different from those of the other shunt portions in a second direction that is orthogonal to both the normal direction of the main body portion and the first direction. When observed along the second direction, a part of the offset shunt portion overlaps with a part of the other shunt portion. (6) According to the voltage monitoring module described in any one of (1) to (5), a part of a part of the shunt portions among the plurality of shunt portions is included in a rectangle circumscribing the main body portion in a top view. (7) According to the voltage monitoring module described in any one of (1) to (6), it further has a plate-like member, and the plate-like member is mounted on the main body portion of at least one of the flexible printed circuit boards. (8) The voltage monitoring module according to any one of (1) to (7), wherein the main body portions of the plurality of flexible printed circuit boards are separated from each other. (9) The voltage monitoring module according to any one of (1) to (8), further comprising a connecting portion that extends in a second direction orthogonal to both the normal direction of the main body portion and the first direction, and the main body portions of the plurality of flexible printed circuit boards are connected to each other by means of the connecting portion. (10) The voltage monitoring module according to any one of (2) to (9), wherein the second extending portion has a telescopic portion that can be telescoped in the first direction. (11) The voltage monitoring module according to (10), wherein in the telescopic portion, the main body portion is folded back, so that a part of the main body portion overlaps with each other. (12) The voltage monitoring module according to (11), wherein in the telescopic portion, a part of the main body portion is folded back more than one and a half times in the first direction, and a part of the main body portion meanders with respect to the normal direction of the main body portion. (13) The voltage monitoring module according to (10), wherein in the telescopic portion, the main body portion bends downward. (14) The voltage monitoring module according to (12), further comprising a housing that houses the telescopic portion, and the housing is configured to restrict the telescopic portion from expanding upward and downward. (15) The voltage monitoring module according to (14), wherein the starting point of the folding back in the telescopic portion is fixed to the housing. (16) A battery cell, comprising: a battery pack; and a voltage monitoring module that monitors the voltage of the battery pack, the battery pack having a plurality of partitions arranged in a first direction, each of the plurality of partitions having a plurality of battery cells arranged in the first direction, the voltage monitoring module having a plurality of flexible printed circuit boards, each of the plurality of flexible printed circuit boards having a main body portion and a plurality of shunt portions, the main body portion extending in the first direction, the plurality of shunt portions branching off from the main body portion respectively and being arranged at intervals from each other in the first direction, connection terminals being provided on the top side of each of the plurality of shunt portions, the plurality of flexible printed circuit boards being configured to be arranged in one-to-one correspondence with the plurality of partitions respectively, and the connection terminals being connected to a corresponding one of the terminals of the plurality of battery cells of the partition corresponding to the flexible printed circuit board. (17) The battery cell according to (16), the main body portions of one or more of the flexible printed circuit boards have a first extension portion and a second extension portion, the plurality of shunt portions shunt from the first extension portion of the main body portion, the first extension portion is configured to extend along the partition corresponding to one of the plurality of flexible printed circuit boards, and the second extension portion is configured to extend along the partition corresponding to the flexible printed circuit boards other than the one flexible printed circuit board. (18) The battery cell according to (17), the second extension portion has a telescopic portion that can be telescoped in the first direction. (19) The battery cell according to (18), the voltage monitoring module further has a plurality of plate-like members, the end portion of the main body portion of one or more of the flexible printed circuit boards on the side having the first extension portion, and the portion between the first extension portion and the telescopic portion in the main body portion of the flexible printed circuit board are configured to be fixed to the battery cell body by means of the plate-like members respectively. (20) The battery cell according to any one of (16) to (19) further has a plurality of separator plates, and the plurality of separator plates are configured to divide the battery pack into the plurality of partitions. The detailed description has been given for purposes of illustration and description. Many variations and changes are possible in light of the above teachings. The detailed description is not without omissions or intended to limit the subject matter described herein. Although the subject matter has been described in terms of particular structural features and / or methodological processes, it should be understood that the subject matter defined in the claims is not necessarily limited to the specific features or specific processes described. Rather, the specific features and specific processes are described as examples for implementing the claims.

Claims

1. A voltage monitoring module for monitoring the voltage of a battery pack having a plurality of partitions arranged in a first direction, wherein the plurality of partitions respectively include a plurality of battery cells arranged in the first direction, wherein the voltage monitoring module is characterized in that: Equipped with multiple flexible printed circuit boards, The plurality of flexible printed substrates respectively have a main body and a plurality of branching parts. The main body extends in the first direction, The plurality of branching parts are respectively branched from the main body part and are arranged at intervals from each other in the first direction. A connection terminal is provided at the top end side of each of the plurality of branching parts. The plurality of flexible printed circuit boards are arranged in one-to-one correspondence with the plurality of sections, respectively, and the connection terminal is connected to a corresponding one of the terminals of the plurality of battery cells in the section corresponding to the flexible printed circuit board.

2. The voltage monitoring module according to claim 1, characterized in that: The main body of at least one of the flexible printed circuit boards has a first extending portion and a second extending portion. The plurality of branch portions branch from the first extension portion of the main body portion, The first extension portion is configured to extend along the partition corresponding to one of the plurality of flexible printed substrates. The second extension portion is configured to extend along the section corresponding to the other flexible printed circuit board other than the one flexible printed circuit board.

3. The voltage monitoring module according to claim 2, characterized in that: A length dimension of the first extension portion in a second direction orthogonal to both the normal direction of the main body portion and the first direction is greater than a length dimension of the second extension portion in the second direction.

4. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: The plurality of branch portions respectively include a first direction extending portion extending in the first direction, The length dimension of the first-direction extending portion of the plurality of branch portions of one or more of the flexible printed circuit boards increases in the first direction as it approaches the center from both ends of the main body portion.

5. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: The plurality of shunt sections include a bias shunt section, The bias branch portion is configured to be arranged at a position different from other branch portions other than the bias branch portion in a second direction orthogonal to both the normal direction of the main body portion and the first direction, and when viewed along the second direction, a portion of the bias branch portion overlaps with a portion of the other branch portions.

6. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: A portion of a portion of the plurality of branch portions is contained in a rectangle circumscribing the main body portion in a plan view.

7. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: It also has a plate-like member, The plate-shaped member is attached to the main body portion of at least one of the flexible printed circuit boards.

8. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: The main bodies of the plurality of flexible printed circuit boards are separated from each other.

9. The voltage monitoring module according to any one of claims 1 to 3, characterized in that: It also has a connecting portion, The connecting portion extends in a second direction that is orthogonal to both the normal direction of the main body and the first direction. The main body portions of the plurality of flexible printed circuit boards are connected to one another via the connection portion.

10. The voltage monitoring module according to claim 2, characterized in that: The second extension portion has an expandable portion that is expandable and contractible in the first direction.

11. The voltage monitoring module according to claim 10, characterized in that: In the telescopic portion, the main body portion is folded back so that parts of the main body portions overlap each other.

12. The voltage monitoring module according to claim 11, characterized in that: In the telescopic portion, a portion of the main body is folded back and forth more than once and a half times in the first direction, and the portion of the main body meanders with respect to a normal direction of the main body.

13. The voltage monitoring module according to claim 10, characterized in that: In the telescopic portion, the main body is bent downward.

14. The voltage monitoring module according to claim 12, characterized in that: A housing for accommodating the telescopic portion is also provided. The housing is configured to restrict upward and downward expansion of the telescopic portion.

15. The voltage monitoring module according to claim 14, characterized in that: A starting point of the folding in the telescopic portion is fixed to the housing.

16. A battery cell, characterized in that: include: Battery pack; as well as A voltage monitoring module monitors the voltage of the battery pack, The battery pack has a plurality of partitions arranged in a first direction, each of the plurality of partitions having a plurality of battery cells arranged in the first direction, The voltage monitoring module has a plurality of flexible printed substrates. The plurality of flexible printed substrates respectively have a main body and a plurality of branching parts. The main body extends in the first direction, The plurality of branching parts are respectively branched from the main body part and are arranged at intervals from each other in the first direction. A connection terminal is provided at the top end side of each of the plurality of branching parts. The plurality of flexible printed circuit boards are arranged in one-to-one correspondence with the plurality of sections, respectively, and the connection terminal is connected to a corresponding one of the terminals of the plurality of battery cells in the section corresponding to the flexible printed circuit board.

17. The battery cell according to claim 16, characterized in that: The main body of at least one of the flexible printed circuit boards has a first extending portion and a second extending portion. The plurality of branch portions branch from the first extension portion of the main body portion, The first extension portion is configured to extend along the partition corresponding to one of the plurality of flexible printed substrates. The second extension portion is configured to extend along the section corresponding to the other flexible printed circuit board other than the one flexible printed circuit board.

18. The battery cell according to claim 17, characterized in that: The second extension portion has an expandable portion that is expandable and contractible in the first direction.

19. The battery cell according to claim 18, characterized in that The voltage monitoring module also has a plurality of plate-shaped components. An end portion of the main body of the one or more flexible printed circuit boards having the first extension portion and a portion of the main body of the flexible printed circuit board between the first extension portion and the elastic portion are fixed to the battery cell via the plate-shaped member.

20. The battery cell according to any one of claims 16 to 19, characterized in that: It also has multiple partitions. The plurality of partition plates are configured to divide the battery pack into the plurality of partitions.

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