Battery pack

Abstract

A battery pack comprising: a case; a partition plate that divides the interior of the case into a plurality of areas; an in-area battery housed in each area; and a connection part that connects the in-area batteries in series. A communication opening for allowing communication between adjacent areas is formed in the partition plate, and a lower end of a positive electrode terminal portion constituting a positive electrode and a lower end of a negative electrode terminal portion constituting a negative electrode of the in-area battery are positioned lower than the communication opening.

Description

battery pack

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

[0002] JP2018-037244A discloses a power supply device with a built-in power supply unit.

[0003] The bottom plate of the exterior case of the power supply device is formed with an upper plate portion and a lower plate portion, each having a step. A battery unit is disposed on each of the upper and lower plate portions. When the device is submerged in water, the battery unit on the lower plate will be submerged before the battery unit on the upper plate, and each battery unit will discharge in order.

[0004] In this power supply device, it is necessary to provide a number of steps according to the number of battery units to be installed, which means that the height dimension increases as the number of battery units installed increases, making layout adjustment difficult.

[0005] The present invention has been made in consideration of these problems, and aims to provide a battery pack that can discharge batteries in each area in the event of flooding without creating an elevation difference between the areas in which the batteries are placed.

[0006] According to one aspect of the present invention, a battery pack includes a case, a partition plate that divides the interior of the case into multiple areas, intra-area batteries housed in each area, and a connector that connects the intra-area batteries in series. The partition plate has a communication opening that connects adjacent areas, and the lower ends of the positive electrode terminals that constitute the positive electrodes of the intra-area batteries and the negative electrode terminals that constitute the negative electrodes of the intra-area batteries are located lower than the communication opening.

[0007] According to one aspect of the present invention, if, for example, part of the case is damaged and a certain area within the case becomes flooded, only the batteries within that area will be submerged until the water level reaches the communication port in the partition plate.

[0008] At this time, the lower ends of the positive and negative terminals of the batteries in the area are positioned lower than the communication port, so the battery pack can discharge only the batteries in the area until the water level reaches the communication port and the adjacent area begins to flood.

[0009] Therefore, the battery pack can discharge the batteries in each area without providing a difference in elevation between the areas in which the batteries are arranged.

[0010] FIG. 1 is a schematic diagram showing a battery pack according to an embodiment. FIG. 2 is a perspective view showing an intra-area battery. FIG. 3 is a schematic cross-sectional view showing a battery pack according to an embodiment. FIG. 4 is an explanatory diagram showing a state in which water has leaked from one adjacent area to the other. FIG. 5 is an explanatory diagram for explaining the effect of a battery pack having a communication port located in the center of the divider plate in the plate width direction. FIG. 6 is a schematic cross-sectional view showing a battery pack according to a first modified example. FIG. 7 is a diagram showing a communication port of a battery pack according to a second modified example. FIG. 8 is a diagram showing a communication port of a battery pack according to a third modified example. FIG. 9 is a diagram showing a communication port of a battery pack according to a fourth modified example. FIG. 10 is a diagram showing a communication port of a battery pack according to a fifth modified example. FIG. 11 is a diagram showing a communication port of a battery pack according to a sixth modified example. FIG. 12 is a diagram showing a communication port of a battery pack according to a seventh modified example. FIG. 13 is a schematic diagram showing a battery pack according to an eighth modified example. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13 and is an explanatory diagram showing the state of water leaking. Fig. 15 is a schematic diagram showing a battery pack according to a ninth modified example. Fig. 16 is a diagram showing a communication hole formed in a partition plate of the battery pack according to the ninth modified example.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] FIG. 1 is a schematic diagram showing a battery pack 10 according to an embodiment. FIG. 2 is a perspective view showing an intra-area battery. FIG. 3 is a schematic cross-sectional view showing a battery pack 10 according to an embodiment. FIG. 4 is an explanatory diagram showing a state in which water has entered one adjacent area into the other. FIG. 5 is an explanatory diagram for explaining the effect of a battery pack 10 in which a communication port 40 is located in the center of the partition plate 30 in the plate width direction PW. The battery pack 10 is mounted, for example, on an electric vehicle and used as a driving power source for a motor that drives the drive wheels.

[0013] As shown in FIGS. 1 , 3 , and 4 , the battery pack 10 includes a rectangular container-shaped case 12. The upper opening of the case 12 is covered with, for example, a lid (not shown), and the inside of the case 12 is sealed. The case 12 is made of, for example, an insulator. Examples of insulators include synthetic resin. Note that, in this embodiment, the case 12 is formed of synthetic resin, but the case 12 is not limited to being made of synthetic resin. For example, in the case of a sealed case 12, the case 12 can be made of aluminum or iron.

[0014] The interior of the case 12 is formed by partitions into a first area 20, a second area 22, a third area 24, and a fourth area 26. The partitions that separate the interior of the case 12 include a first partition plate 30 that separates the first area 20 from the second area 22, and a second partition plate 32 that separates the second area 22 from the third area 24. The partitions that separate the interior of the case 12 also include a third partition plate 34 that separates the third area 24 from the fourth area 26, and a fourth partition plate 36 that separates the fourth area 26 from the first area 20.

[0015] Each partition plate 30, 32, 34, 36 has a communication opening 40 that connects adjacent areas (20, 22, 24, 26) (see FIGS. 3 and 4). The communication opening 40 is a horizontally elongated rectangular opening. The communication opening 40 is located in the center of each partition plate 30, 32, 34, 36 in the plate width direction PW (see FIGS. 3 and 5). The communication opening 40 is located closer to the upper edge of each partition plate 30, 32, 34, 36 than the center in the height direction.

[0016] In the battery pack 10, when a portion of the case 12 is damaged and a liquid W such as impurity-containing water or salt water enters an area (20), only the intra-area batteries (50) in that area (20), which will be described later, are submerged until the water level reaches the communication openings 40 of the partition plates (30) (see FIG. 3). Then, when the water level reaches the communication openings 40 of the partition plates 30, 32, 34, and 36, the water begins to enter the adjacent areas (22) (see FIG. 4).

[0017] The first area 20 to the fourth area 26 house, in that order, a first area battery 50, a second area battery 52, a third area battery 54, and a fourth area battery 56. The area batteries 50, 52, 54, and 56 are connected in series by a connector 60 such as a bus bar. The negative terminal of the first area battery 50 constitutes the negative electrode of the battery pack 10, and the positive terminal of the fourth area battery 56 constitutes the positive electrode of the battery pack 10.

[0018] 2, the first area battery 50 is composed of multiple batteries connected in series. In this embodiment, the configuration of the area batteries (50, 52, 54, 56) will be described using the first area battery 50 as an example, but each of the area batteries 50, 52, 54, 56 has a similar configuration.

[0019] In the battery pack 10 of this embodiment, the series-connected batteries that make up each of the intra-area batteries 50 , 52 , 54 , 56 are made up of a first battery module 70 and a second battery module 72 .

[0020] The first battery module 70 is composed of six cells (single cells). The cells are composed of a first cell 80-1 to a sixth cell 80-6. The positive terminal of one adjacent cell (80-1 to 80-6) is connected to the negative terminal of the other adjacent cell (80-1 to 80-6), and the first cell 80-1 to the sixth cell 80-6 are connected in series. The negative terminal 70A of the first cell 80-1 constitutes the negative electrode of the first battery module 70, and the positive terminal 70B of the sixth cell 80-6 constitutes the positive electrode of the first battery module 70.

[0021] Like the first battery module 70, the second battery module 72 is also composed of a plurality of cells (single cells). The cells are composed of a first cell 80-1 to a sixth cell 80-6. The positive terminal of one adjacent cell is connected to the negative terminal of the other adjacent cell, and the first cell 80-1 to the sixth cell 80-6 are connected in series. The negative terminal 72A of the first cell 80-1 constitutes the negative electrode of the second battery module 72, and the positive terminal 72B of the sixth cell 80-6 constitutes the positive electrode of the second battery module 72.

[0022] The first battery module 70, which is one of the batteries connected in series, and the second battery module 72, which is the other battery, have adjacent terminals of different polarities connected to each other by a conductive member 90 such as a bus bar. One adjacent terminal is formed by the + terminal 70B of the sixth cell 80-6 of the first battery module 70, and the other terminal is formed by the − terminal 72A of the first cell 80-1 of the second battery module 72.

[0023] The positive terminal 70B of the sixth cell 80-6 of the first battery module 70 and the negative terminal 72A of the first cell 80-1 of the second battery module 72 are positioned higher than the communication openings 40 formed in the partition plates 30, 32, 34, and 36 (see FIG. 3). Furthermore, the conductive member 90 connects, for example, the upper surface of the positive terminal 70B of the sixth cell 80-6 of the first battery module 70 to the upper surface of the negative terminal 72A of the first cell 80-1 of the second battery module 72.

[0024] As a result, the conductive member 90 and the terminals 70B, 72A to which the conductive member 90 is connected are positioned higher than the communication openings 40 formed in the partition plates 30, 32, 34, 36.

[0025] The negative electrode of the first in-area battery 50 is formed by the negative terminal 70A of the first cell 80-1 in the first battery module 70. A negative electrode terminal portion 100 formed by a bus bar or the like is connected to the negative terminal 70A.

[0026] The negative electrode terminal portion 100 is made of a metal plate and has, for example, a negative terminal connection portion 100A connected to the negative terminal 70A of the first cell 80-1, and a negative electrode extension portion 100B connected to an end of the negative terminal connection portion 100A and extending downward along the side surface of the first cell 80-1.

[0027] The upper end of the negative electrode extension portion 100B extends above the negative terminal 70A of the first cell 80-1. The lower end of the negative electrode extension portion 100B reaches the lower end of the side surface of the first cell 80-1. The lower end of the negative electrode extension portion 100B in the negative electrode terminal portion 100 is located lower than the lower edges 40A, which serve as the lowermost portions of the communication ports 40 formed in the partition plates 30, 32, 34, and 36 (see FIG. 3 ).

[0028] The positive electrode of the first area battery 50 is formed by the + terminal 72B of the sixth cell 80-6 in the second battery module 72. A positive electrode terminal portion 102 formed by a bus bar or the like is connected to the + terminal 72B.

[0029] The positive electrode terminal portion 102 is made of a metal plate and has, for example, a positive terminal connection portion 102A connected to the positive terminal 72B of the sixth cell 80-6, and a positive electrode extension portion 102B connected to an end of the positive terminal connection portion 102A and extending downward along the side surface of the sixth cell 80-6.

[0030] The upper end of the positive electrode extension portion 102B extends above the positive terminal 72B of the sixth cell 80-6. The lower end of the positive electrode extension portion 102B reaches the lower end of the side surface of the sixth cell 80-6. The lower end of the positive electrode extension portion 102B in the positive electrode terminal portion 102 is located lower than the lower edges 40A, which serve as the lowermost portions of the communication holes 40 formed in the partition plates 30, 32, 34, and 36 (see FIG. 3 ).

[0031] As a result, the lower end of the positive electrode terminal 102 constituting the positive electrode of each of the in-area batteries 50 , 52 , 54 , 56 and the lower end of the negative electrode terminal 100 constituting the negative electrode are located lower than the communication opening 40 .

[0032] The negative electrode terminal 100 of the first area battery 50 arranged in the first area 20 constitutes the negative electrode of the battery pack 10. The negative electrode terminal 100 of each of the area batteries 52, 54, 56 arranged in the second area 22, third area 24, and fourth area 26 is connected via connection parts 60 to the positive electrode terminal 102 of each of the area batteries 50, 52, 54 arranged in the adjacent areas 20, 22, 24.

[0033] The positive electrode terminal 102 of the fourth area battery 56 arranged in the fourth area 26 constitutes the positive electrode of the battery pack 10. The positive electrode terminal 102 of each of the area batteries 50, 52, 54 arranged in the first area 20, second area 22, and third area 24 is connected via connection parts 60 to the negative electrode terminal 100 of each of the area batteries 50, 52, 54 arranged in the adjacent areas 20, 22, 24.

[0034] (Operations and Effects) As described above, the battery pack 10 of this embodiment includes a case 12 and dividers (30, 32, 34, 36) that divide the interior of the case 12 into a plurality of areas (20, 22, 24, 26). The battery pack 10 also includes intra-area batteries 50, 52, 54, 56 housed in each of the areas 20, 22, 24, 26, and a connector 60 that connects the intra-area batteries 50, 52, 54, 56 in series. Each of the dividers 30, 32, 34, 36 has a communication opening 40 that connects adjacent areas (20, 22, 24, 26). The lower ends of the positive electrode terminals 102 that constitute the positive electrodes of each intra-area battery 50, 52, 54, 56 and the lower ends of the negative electrode terminals 100 that constitute the negative electrodes are located lower than the communication openings 40.

[0035] In the battery pack 10 configured in this manner, if a part of the case 12 is damaged and water enters the first area 20, which is an area within the case 12 (see Figure 3), only the batteries 50 within the first area of ​​the first area 20 will be submerged until the water level reaches the communication openings 40 of the first partition plate 30 and the fourth partition plate 36.

[0036] At this time, the lower ends of the positive electrode terminal portion 102 and the negative electrode terminal portion 100 of the first area battery 50 are located lower than the communication port 40. Therefore, the battery pack 10 can discharge only the first area battery 50 in that first area 20 until the water level reaches the communication port 40 and water begins to enter the adjacent second area 22.

[0037] Therefore, in the event of flooding, the battery pack 10 can discharge the batteries 50, 52, 54, 56 in each of the areas 20, 22, 24, 26 independently, without providing differences in elevation between the areas in which the batteries are arranged.

[0038] Furthermore, because this battery pack 10 does not require differences in height between areas, it is possible to suppress an increase in the height of the battery pack 10 even if an increase in the number of batteries 50, 52, 54, 56 is installed in each area. This makes it easy to adjust the layout of the battery pack 10 when it is installed in, for example, a vehicle 310 (see FIG. 13 ).

[0039] Furthermore, compared to when the battery pack 10 is submerged and discharged between the positive and negative electrodes using a liquid W such as impurity-containing water or salt water, the battery pack 10 can prevent high-voltage short circuits. This makes it possible to prevent problems caused by heat generation.

[0040] In this embodiment, each of the intra-area batteries 50, 52, 54, 56 is composed of a plurality of batteries (70, 72) connected in series. The first battery module 70, which is one of the series-connected batteries, and the second battery module 72, which is the other battery, have their adjacent terminals (70B, 72A) connected to each other by a conductive member 90. The conductive member 90 and the terminals (70B, 72A) to which the conductive member 90 is connected are positioned higher than the communication opening 40, and the lower ends of the positive electrode terminal portion 102 and the negative electrode terminal portion 100 of each of the intra-area batteries 50, 52, 54, 56 are positioned lower than the communication opening 40.

[0041] In this configuration, each of the in-area batteries 50, 52, 54, 56 is made up of a plurality of batteries (70, 72) connected in series. The terminals (70B, 72A) of the series-connected batteries (70, 72) and the conductive member 90 connected to both terminals (70B, 72A) are positioned higher than the communication opening 40. Therefore, as the water level in the case 12 rises, the in-area batteries 50, 52, 54, 56 in each of the areas 20, 22, 24, 26 are discharged in order, and then the conductive member 90 of each of the in-area batteries 50, 52, 54, 56 in each of the areas 20, 22, 24, 26 becomes submerged.

[0042] As a result, after the in-area batteries 50, 52, 54, 56 in all of the areas 20, 22, 24, 26 have been discharged, the conductive members 90 of the in-area batteries 50, 52, 54, 56 in each of the areas 20, 22, 24, 26 are short-circuited by the submerged liquid W. This makes it possible to suppress high-voltage short circuits compared to when the conductive members 90 of the in-area batteries 50, 52, 54, 56 in different areas 20, 22, 24, 26 are short-circuited before the in-area batteries 50, 52, 54, 56 are sequentially discharged.

[0043] In each of the in-area batteries 50, 52, 54, and 56, one battery (70) and the other battery (72) that are connected in series have their adjacent terminals (70B, 72A) connected by a conductive member 90. The positive and negative electrodes of each of the in-area batteries 50, 52, 54, and 56 are formed by the terminal (70B) of one battery (70) and the terminal (72A) of the other battery (72), which are arranged apart from each other.

[0044] 3, the separation distance R1 from the positive electrode terminal 102 to the negative electrode terminal 100 is longer than the separation distance R2 from the positive electrode terminal 102 to the terminal (72A) to which the conductive member 90 is connected. Also, the separation distance R1 from the positive electrode terminal 102 to the negative electrode terminal 100 is longer than the separation distance R3 from the negative electrode terminal 100 to the terminal (70B) to which the conductive member 90 is connected.

[0045] The conductive member 90 and the terminals (70B, 72A) to which the conductive member 90 is connected are positioned higher than the communication opening 40, while the lower ends of the positive electrode terminal 102 and the negative electrode terminal 100 are positioned lower than the communication opening 40. As a result, the current path when the first area battery 50 is discharged by the liquid W in the first area 20 is the separation distance R1 from the positive electrode terminal 102 to the negative electrode terminal 100, which is longer than the separation distances R2 and R3.

[0046] Therefore, the battery pack 10 can lengthen the current path when discharging the first area batteries 50 compared to when, for example, the conductive member 90 and the terminals (70B, 72A) to which the conductive member 90 is connected are positioned lower than the communication opening 40. As a result, the battery pack 10 can increase the current resistance, which increases in proportion to the length of the current path, and suppress the current flow, thereby suppressing heat generation.

[0047] In this embodiment, the communication opening 40 is disposed at the center of the partition plates (30, 32, 34, 36) in the plate width direction PW.

[0048] In such a configuration, for example, if the battery pack 10 is tilted with the communication port 40X positioned on one side of the first partition plate 30 in the plate width direction PW as shown in Figure 5, there is a risk that liquid W will enter the adjacent second area 22 even if the amount of water in the first area 20 is small.

[0049] However, in the battery pack 10 of this embodiment, the communication opening 40 is located at the center of the partition plates (30, 32, 34, 36) in the plate width direction PW, which makes it possible to prevent water from entering the adjacent areas (20, 22, 24, 26) when the battery pack 10 is tilted. Therefore, even if the battery pack 10 is tilted while mounted on the vehicle 310, it is possible to sequentially discharge the intra-area batteries 50, 52, 54, 56 housed in each area 20, 22, 24, 26.

[0050] In this embodiment, the intra-area batteries (50, 52, 54, 56) housed in each of the areas 20, 22, 24, 26 are configured as a first battery module 70 and a second battery module 72 connected in series. However, the battery pack 10 is not limited to this configuration. The battery pack 10 may also be configured as in the first modified example shown below.

[0051] (First Modification) FIG. 6 is a schematic cross-sectional view showing a battery pack 200 according to a first modification.

[0052] In the battery pack 200 according to the first modification, the intra-area batteries 50, 52, 54, 56 housed in the areas 20, 22, 24, 26 are each configured as a single battery module (50, 52, 54, 56).

[0053] Even with such a configuration, the same or equivalent parts as those in the above-described embodiment have the same effects as those in the above-described embodiment.

[0054] In the first modified example, the case where each of the in-area batteries 50, 52, 54, 56 is configured as a single battery module has been described as an example, but each of the in-area batteries 50, 52, 54, 56 may also be a single cell.

[0055] In the above-described embodiment, the communication openings 40 are formed by openings formed in the partition plates 30, 32, 34, and 36, but the communication openings 40 are not limited to this configuration. The communication openings 40 formed in the partition plates 30, 32, 34, and 36 may also be configured as in the second modified example shown below.

[0056] (Second Modification) FIG. 7 is a diagram showing a communication port 212 of a battery pack 210 according to a second modification.

[0057] As shown in a second modified example in Fig. 7, the communication openings 212 that connect the adjacent areas (20, 22, 24, 26) may be configured, for example, by rectangular notches formed in the upper edges of the partition plates (30, 32, 34, 36). Note that Fig. 7 illustrates the first partition plate 30 as an example.

[0058] Even with such a configuration, the same or equivalent parts as those in the above-described embodiment have the same effects as those in the above-described embodiment.

[0059] In the above-described embodiment, the communication openings 40 are formed as rectangular openings in the partition plates 30, 32, 34, and 36, but the communication openings 40 are not limited to this configuration. The communication openings 40 formed in the partition plates 30, 32, 34, and 36 may also be configured as in the third to seventh modified examples shown below.

[0060] 8 is a diagram showing a communication port 222 of a battery pack 220 according to a third modification. The communication port 222 of the battery pack 220 according to the third modification is configured as a triangular opening with its apex facing downward. The opening width OW of this communication port 222 is wider at the high position than at the low position.

[0061] (Fourth Modification) Figure 9 is a diagram showing a communication port 232 of a battery pack 230 according to a fourth modification. The communication port 232 of the battery pack 230 according to the fourth modification is configured as a triangular notch formed in the upper edge of each partition plate 30, 32, 34, 36 with its apex facing downward. The opening width OW of this communication port 232 is wider at the high position than at the low position. Note that Figure 9 shows the first partition plate 30 as an example.

[0062] 10 is a diagram showing a communication port 242 of a battery pack 240 according to a fifth modification. The communication port 242 of the battery pack 240 according to the fifth modification is configured as a trapezoidal opening whose bottom is shorter than its top. The opening width OW of this communication port 242 is wider at the upper position than at the lower position.

[0063] 11 is a diagram showing a communication port 262 of a battery pack 260 according to a sixth modification. The communication port 262 of the battery pack 260 according to the sixth modification is configured as a semicircular opening with an arc on the lower side. The opening width OW of this communication port 262 is wider at the high position than at the low position.

[0064] 12 is a diagram showing a communication port 282 of a battery pack 280 according to a seventh modification. The communication port 282 of the battery pack 280 according to the seventh modification is configured with a first rectangular hole 284 and a second rectangular hole 286 of different heights that are arranged so that their upper edges are at the same height.

[0065] The opening width OW of this communication opening 282 at the low position is equal to the opening width OW1 of the first rectangular hole 284. Furthermore, the opening width OW of the communication opening 282 at the high position is equal to the opening width OW1 of the first rectangular hole 284 plus the opening width OW2 of the second rectangular hole 286. As a result, the opening width OW of this communication opening 282 is wider at the high position than at the low position.

[0066] (Operations and Effects) In the assembled batteries 220, 230, 240, 260, and 280 according to the third to seventh modifications, the opening width OW of each communication opening 222, 232, 242, 262, and 282 is wider at the high position than at the low position.

[0067] In the assembled batteries 220, 230, 240, 260, 280 configured as described above, when the water level in a predetermined area (20, 22, 24, 26) is low, the amount of water entering the adjacent areas (20, 22, 24, 26) is suppressed. On the other hand, in the assembled batteries 220, 230, 240, 260, 280, when the water level in a predetermined area (20, 22, 24, 26) is high, the amount of water entering the adjacent areas (20, 22, 24, 26) increases.

[0068] Therefore, the assembled batteries 220, 230, 240, 260, 280 can take time to discharge the in-area batteries 50, 52, 54, 56 in each of the areas 20, 22, 24, 26 until the water level rises. Then, when the water level in each area 20, 22, 24, 26 rises, the assembled batteries 220, 230, 240, 260, 280 can increase the amount of water entering the adjacent areas 20, 22, 24, 26. This allows the assembled batteries 220, 230, 240, 260, 280 to quickly discharge the in-area batteries 50, 52, 54, 56 in the adjacent areas 20, 22, 24, 26 when the water level in each area 20, 22, 24, 26 rises.

[0069] (Eighth Modification) Next, an eighth modification will be described with reference to FIGS. 13 and 14. FIG.

[0070] Fig. 13 is a schematic diagram showing a battery pack 300 according to an eighth modification. Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 13, illustrating the state of flooding. Note that in-area batteries in each area (320, 322, 324, 326, 328) are omitted from Figs. 13 and 14.

[0071] The battery pack 300 according to the eighth modification differs from the above-described embodiment in the number of areas (320, 322, 324, 326, 328) formed in the case 12.

[0072] 13 , a plurality of areas (320, 322, 324, 326, 328) are formed in the interior of the case 12 of the battery pack 300 according to the eighth modification in the vehicle width direction VW when the battery pack 300 is mounted on a vehicle 310. Specifically, four rows of areas are formed in the vehicle front-rear direction FR and five columns of areas are formed in the vehicle width direction VW inside the case 12. As a result, twenty areas are formed inside the case 12.

[0073] 13 and 14 , a plurality of partition plates (330, 332, 334, 336) are arranged side by side in the vehicle width direction VW in the case 12. In each of the partition plates (330, 332, 334, 336), a lower edge 40A, which is the lowermost part of the communication opening 40 of the partition plate arranged on the vehicle width center C side, is positioned higher than a lower edge 40A, which is the lowermost part of the communication opening 40 of the partition plate arranged on the vehicle width outer side O of the partition plate.

[0074] This configuration will be specifically described using the areas 320, 322, 324, 326, and 328 in the second row formed on the case 12 as an example.

[0075] The sixth partition plate 332 that separates the eighth area 324 and the seventh area 322 is disposed closer to the center C in the vehicle width direction than the fifth partition plate 330 that separates the seventh area 322 and the sixth area 320. The lower edge 40A of the communication opening 40 of the sixth partition plate 332 is disposed at a higher position than the lower edge 40A of the communication opening 40 of the fifth partition plate 330.

[0076] The seventh partition plate 334 that separates the eighth area 324 and the ninth area 326 is disposed closer to the center C in the vehicle width direction than the eighth partition plate 336 that separates the ninth area 326 and the tenth area 328. The lower edge 40A of the communication opening 40 of the seventh partition plate 334 is disposed at a higher position than the lower edge 40A of the communication opening 40 of the eighth partition plate 336.

[0077] (Operation and Effect) In the battery pack 300 according to the eighth modification, a plurality of areas (320, 322, 324, 326, 328) are formed in the vehicle width direction VW when the battery pack 300 is mounted on the vehicle 310. Of the plurality of partition plates (330, 332, 334, 336) arranged side by side in the vehicle width direction VW, the lowermost part of the communication opening 40 of the partition plate (332, 334) arranged on the vehicle width center C side is positioned higher than the lowermost part of the communication opening 40 of the partition plate (330, 336) arranged on the vehicle width outer side O.

[0078] In this configuration, if the area (320, 328) on the outer side O in the vehicle width direction is flooded, when the water level reaches the lowest part of the communication opening 40 of the partition plate (330, 336) on the outer side O in the vehicle width direction, the water will flood into the adjacent area (322, 326) on the vehicle width center C side. Then, when the water level in the area (320, 326) adjacent to the vehicle width center C side reaches the lowest part of the communication opening 40 of the partition plate (332, 334) arranged on the vehicle width center C side, the water will further flood into the area (324) adjacent to the vehicle width center C side.

[0079] In this way, it is possible to flood the area from the outer area O in the vehicle width direction to the area on the center C in the vehicle width direction, thereby controlling the order in which the batteries (50, 52, 54, 56) in each area are discharged.

[0080] Here, the area on the outer side O in the vehicle width direction is located further outward in the vehicle width direction O than the area on the vehicle width center C side, and has a higher risk of flooding than the area on the vehicle width center C side. This makes it possible to control flooding in the order from areas with a high risk of flooding to areas on the vehicle width center C side with a low risk of flooding.

[0081] (Ninth Modification) Next, a ninth modification will be described with reference to FIGS. 15 and 16. FIG.

[0082] Fig. 15 is a schematic diagram showing a battery pack 400 according to a ninth modification. Fig. 16 is a diagram showing communication openings 40 formed in the partition plates (30, 32, 34, 36) of the battery pack 400 according to the ninth modification. In the battery pack 400 according to the ninth modification, the heights of the communication openings 40 formed in the partition plates (30, 32, 34, 36) vary depending on the location, as compared to the above-described embodiment.

[0083] In the battery pack 400 according to the ninth modification, in a predetermined area adjacent to a plurality of areas (20, 22, 24, 26), the height positions of the lower edges 40A, which are the lowest parts of the communication openings 40 in each of the partition plates (30, 32, 34, 36) that separate the predetermined area, are different.

[0084] 15 , a first area 20 as a predetermined area formed in the case 12 of the battery pack 400 is adjacent to a second area 22 and a fourth area 26. The second area 22 as a predetermined area is adjacent to the first area 20 and a third area 24. The third area 24 as a predetermined area is adjacent to the second area 22 and the fourth area 26. The fourth area 26 as a predetermined area is adjacent to the first area 20 and the third area 24. Each of the areas 20, 22, 24, 26 constitutes a predetermined area adjacent to multiple areas (20, 22, 24, 26).

[0085] 16 , the height position of the lower edge 40A of the communication opening 40 of the third partition plate 34 that separates the fourth area 26 and the third area 24 is higher than the height position of the lower edge 40A of the communication opening 40 of the fourth partition plate 36 that separates the fourth area 26 and the first area 20. As a result, the communication openings 40 of the third partition plate 34 and the fourth partition plate 36 that separate the fourth area 26 as a predetermined area have lower edges 40A that are different in height.

[0086] Similarly, in the first area 20, the height position of the lower edge 40A of the communication opening 40 formed in the fourth partition plate 36 that separates the first area 20 from the fourth area 26 is lower than the lower edge 40A of the communication opening 40 formed in the first partition plate 30 that separates the first area 20 from the second area 22. As a result, the communication openings 40 of the first partition plate 30 and the fourth partition plate 36 that separate the first area 20 as a predetermined area have lower edges 40A that are different in height.

[0087] In the second area 22, the height position of the lower edge 40A of the communication opening 40 formed in the second partition plate 32 that separates the second area 22 from the third area 24 is lower than the height position of the lower edge 40A of the communication opening 40 formed in the first partition plate 30 that separates the second area 22 from the first area 20. As a result, the communication openings 40 of the first partition plate 30 and the second partition plate 32 that separate the second area 22 as a predetermined area have lower edges 40A that are different in height.

[0088] In the third area 24, the height position of the lower edge 40A of the communication opening 40 formed in the second partition plate 32 that separates the third area 24 from the second area 22 is lower than the height position of the lower edge 40A of the communication opening 40 formed in the third partition plate 34 that separates the third area 24 from the fourth area 26. As a result, the communication openings 40 of the second partition plate 32 and the third partition plate 34 that separate the third area 24 as a predetermined area have lower edges 40A that are different in height.

[0089] In addition, each communication port 40 in this modified example may also be configured as a notch formed in the upper edge of each partition plate 30, 32, 34, 36.

[0090] (Operations and Effects) In the battery pack 400 according to the ninth modification, in a predetermined area adjacent to a plurality of areas (20, 22, 24, 26), the communication openings 40 of the partition plates (30, 32, 34, 36) that separate the predetermined area are located at different height positions at the bottom.

[0091] In this configuration, when a predetermined area (20, 22, 24, 26) is flooded, the battery pack 400 can manipulate the flooding order of the adjacent areas (20, 22, 24, 26). This makes it possible to prevent the batteries (50, 52, 54, 56) in the adjacent areas (20, 22, 24, 26) from discharging simultaneously, thereby reducing the amount of heat that can be generated during discharge.

[0092] The above describes the embodiments and modifications of the present invention, but the above embodiments and modifications merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments and modifications.

[0093] Although the battery packs 10, 200, 210, 220, 230, 240, 260, 280, 300, and 400 of the above-described embodiment and each modified example have been described as being used in an electric vehicle whose drive wheels are driven by a motor, the present invention is not limited to this configuration. The battery packs 10, 200, 210, 220, 230, 240, 260, 280, 300, and 400 may also be used in, for example, a hybrid vehicle whose drive wheels are driven by both an engine and a motor.

[0094] In addition, in the present embodiment and each modified example, the case where the communication opening 40 is formed in the center of each partition plate (30, 32, 34, 36, 330, 332, 334, 336) in the plate width direction PW has been described as an example. However, the battery packs 10, 200, 210, 220, 230, 240, 260, 280, 300, 400 are not limited to this configuration. The battery packs 10, 200, 210, 220, 230, 240, 260, 280, 300, 400 may have the communication opening 40 formed in a location other than the center of each partition plate (30, 32, 34, 36, 330, 332, 334, 336) in the plate width direction PW.

Claims

1. An assembled battery comprising: a case; partition plates that divide the interior of the case into a plurality of areas; intra-area batteries housed in each area; and connection parts that connect the intra-area batteries in series; wherein the partition plates are formed with communication openings that connect adjacent areas; and the lower ends of the positive electrode terminal parts that constitute the positive electrodes of the intra-area batteries and the negative electrode terminal parts that constitute the negative electrodes are positioned lower than the communication openings.

2. A battery pack as claimed in claim 1, wherein the intra-area battery is made up of a plurality of batteries connected in series, and adjacent terminals of one battery and the other battery connected in series are connected by a conductive member, and the conductive member and the terminal to which the conductive member is connected are positioned higher than the communication opening, and the lower ends of the positive electrode terminal portion and the negative electrode terminal portion of the intra-area battery are positioned lower than the communication opening.

3. The battery pack according to claim 1 or 2, wherein the communication opening is disposed at the center of the partition plate in the plate width direction.

4. The battery pack according to claim 1, wherein the opening width of the communication port is wider at the high position than at the low position.

5. A battery pack as claimed in claim 1, wherein, when mounted on a vehicle, the areas are formed in a plurality of sections in the vehicle width direction, and the partition plates are arranged side by side in the vehicle width direction, with the lowest part of the communication opening of the partition plate arranged towards the centre in the vehicle width direction being positioned higher than the lowest part of the communication opening of the partition plate arranged on the outer sides in the vehicle width direction.

6. The battery pack according to claim 1, wherein in a predetermined area adjacent to a plurality of the areas, the communication openings of the partition plates that separate the predetermined area have their lowest points positioned at different heights.

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