Battery pack

Abstract

Provided is a battery pack that can reliably detect submergence. A battery pack 100 is provided with: one or more battery blocks 3, each including a plurality of secondary battery cells 1; an exterior case 10 that houses the battery blocks 3; and a submergence sensor 40 for detecting water that has infiltrated into the inside of the exterior case 10. The exterior case 10 is provided with a base surface 20 that comprises a mounting surface where the battery blocks 3 are mounted, the submergence sensor 40 is disposed on a part of the base surface 20 that is lower than the mounting surface, and the base surface 20 is inclined so as to form a downward slope toward the submergence sensor 40. Accordingly, because the base surface 20 of the exterior case 10 is inclined and the submergence sensor 40 is disposed at the end of the incline, water that has infiltrated into the exterior case 10 is guided to the submergence sensor 40, making it possible to sense submergence reliably and increasing the accuracy of submergence detection.

Description

Battery pack

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

[0002] Battery packs, which consist of multiple rechargeable secondary battery cells such as lithium-ion secondary batteries connected in series or parallel and housed in an exterior case, are used in various fields as power supplies for driving devices. Some such battery packs are equipped with a water ingress sensor that detects unintentional water ingress into the exterior case (see, for example, Patent Document 1).

[0003] However, even if a water intrusion sensor is installed inside the exterior case, it cannot detect water intrusion unless the water reaches the water intrusion sensor. In particular, battery packs contain many components in addition to secondary battery cells, and depending on the location of the water intrusion and the path of the water intrusion to the water intrusion sensor, the water may not reach the water intrusion sensor, resulting in an inability to properly detect water intrusion.

[0004] Patent No. 7351356

[0005] One object of the present disclosure is to provide a battery pack that can reliably detect water intrusion. Another object is to provide a battery pack that makes it easy for water that has infiltrated into the exterior case to reach a water intrusion sensor. Note that the description of these objects and objects of the present disclosure does not preclude the existence of other objects and objects. Furthermore, it is not necessary for one embodiment of the present disclosure to solve all of these objects. Furthermore, other objects can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0006] A battery pack according to one embodiment of the present disclosure comprises one or more battery blocks each including a plurality of secondary battery cells, an outer case for housing the battery block, and a water ingress sensor for detecting water that has entered the outer case, wherein the outer case has a floor having a mounting surface on which the battery block is placed, the water ingress sensor is provided on a part of the floor that is lower than the mounting surface, and the floor is inclined downwardly toward the water ingress sensor.

[0007] According to a battery pack according to one embodiment of the present disclosure, the floor of the outer case is inclined and a water intrusion sensor is placed at the end of the inclination, so that water that has entered the outer case is guided to the water intrusion sensor, enabling reliable detection of water intrusion and improving the accuracy of water intrusion detection.

[0008] 12 is a perspective view showing a battery pack according to an embodiment; FIG. 13 is a cross-sectional view of the battery pack of FIG. 1 taken along line II-II; FIG. 14 is an exploded perspective view of the battery pack of FIG. 1; FIG. 15 is an exploded perspective view of the battery pack of FIG. 3 taken from diagonally below; FIG. 16 is a plan view of the lower case of FIG. 3; FIG. 17 is an enlarged plan view showing the flow of water entering the lower case of FIG. 5; FIG. 18 is a cross-sectional view taken along line VII-VII of FIG. 6; FIG. 19 is a cross-sectional view taken along line VIII-VIII of FIG. 6; FIG. 19 is a cross-sectional view taken along line IX-IX of FIG. 6; FIG. 19 is a cross-sectional view of line XX of FIG. 6; FIG. 19 is a plan view showing the lower case of a battery pack according to a comparative example; FIG. 3 is an enlarged perspective view of the lower case of FIG. 3; FIG. 19 is an enlarged perspective view of the lower case of FIG. 12; FIG. 19 is a cross-sectional view of a battery pack according to an embodiment;

[0009] The embodiments of the present disclosure may be specified by the following configurations and features.

[0010] In a battery pack according to another aspect of the present disclosure, the floor surface is inclined so that a portion of the floor surface is at its lowest position. With this configuration, a water intrusion sensor can be installed in a location where water that has entered the exterior case collects, thereby improving operational reliability.

[0011] In addition, a battery pack according to another aspect of the present disclosure is any of the above-described aspects, and includes a plurality of the battery blocks, the exterior case is partitioned into a plurality of areas in which the plurality of battery blocks are respectively arranged, the floor surface is inclined across the plurality of areas, and the water ingress sensor is provided in one of the plurality of areas. With the above configuration, it is possible to detect water ingress using a common water ingress sensor without providing a water ingress sensor for each battery block.

[0012] In a battery pack according to another aspect of the present disclosure, in any of the above aspects, the exterior case is divided by partitions into a plurality of areas in which the plurality of battery blocks are respectively arranged, and each partition forms a flow passage that connects adjacent areas divided by the partitions, and water that has entered the exterior case is guided via the flow passage to the area in which the water ingress sensor is provided. With this configuration, even while the battery pack is divided into a plurality of areas, water ingress across the areas can be collected and detected by a common water ingress sensor.

[0013] In a battery pack according to still another aspect of the present disclosure, in any of the above aspects, each battery block includes a block-side terminal for electrical connection, and the plurality of areas each have a surrounding partition wall formed on the bottom surface thereof, and each battery block housed in each of the plurality of areas is configured so that the block-side terminal is located within the partition wall. With this configuration, by locating the block-side terminal of each battery block in an area surrounded by the partition wall, it is possible to avoid situations in which the block-side terminal is submerged in water and a short circuit occurs, even if water enters the exterior case.

[0014] In yet another aspect of the battery pack of the present disclosure, in any of the above aspects, the plurality of areas are arranged in one direction, and the water intrusion sensor is provided in an area located midway among the plurality of areas. With this configuration, water that has entered the exterior case is guided to the area midway in the longitudinal direction, thereby reducing the difference in the path length leading to the water intrusion sensor and enabling similar detection regardless of whether water intrusion occurs from either end in the longitudinal direction, thereby improving reliability and stability.

[0015] In a battery pack according to still another aspect of the present disclosure, in any of the above aspects, the plurality of areas are arranged in a plurality of rows, each row has one water intrusion sensor disposed on a surface facing an adjacent row, and by distributing the water intrusion sensors unevenly between the rows, it is possible to easily collect and manage the detection results of the water intrusion sensors.

[0016] In yet another aspect of the battery pack of the present disclosure, in any of the above aspects, the plurality of areas includes a first row and a second row in which the areas are aligned in one direction, the first row and the second row each include one water immersion sensor, a circuit board is disposed between the first row and the second row, and the water immersion sensors are disposed on the sides of the first row and the second row facing the circuit board, and each water immersion sensor is connected to the circuit board. With the above configuration, by disposing the circuit board between the first row and the second row and disposing the water immersion sensors on the sides facing the circuit board, it is easy to connect the detection results of the water immersion sensors to the circuit board and the configuration for routing wiring can be simplified.

[0017] In yet another aspect of the battery pack according to the present disclosure, in any of the above aspects, the exterior case includes a first extension portion that houses the plurality of battery blocks arranged in the first row area, a second extension portion that houses the plurality of battery blocks arranged in the second row area, and a board housing portion that houses the circuit board and is arranged between the first extension portion and the second extension portion, the first extension portion and the second extension portion each having a side wall on the side facing the circuit board, and each side wall has a side wall opening that communicates with the board housing portion at a position where the water intrusion sensor is arranged. With this configuration, the water intrusion sensors arranged in the first row and the second row can be connected to the circuit board through the side wall opening, simplifying the configuration for routing wiring.

[0018] In a battery pack according to another aspect of the present disclosure, in any of the above aspects, the battery block holds a plurality of rechargeable battery cells in a horizontal position, and each rechargeable battery cell has an electrode on its end surface. With this configuration, by not aligning the end surfaces with the bottom surface, it is possible to prevent the bottom surfaces of the rechargeable battery cells from becoming waterlogged and causing a short circuit.

[0019] Embodiments of the present disclosure will be described below with reference to the drawings. However, the embodiments described below are merely examples for embodying the technical concepts of the present disclosure, and the present disclosure is not limited to the following. Furthermore, this specification does not in any way specify the components set forth in the claims to be those of the embodiments. The dimensions, materials, shapes, relative positions, etc. of components described in the embodiments are not intended to limit the scope of the present disclosure, and are merely illustrative examples, unless otherwise specified. The size and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are identical or of the same quality, and detailed descriptions will be omitted as appropriate. Furthermore, the elements constituting the present disclosure may be configured with the same components, such that multiple elements are served by a single component, or conversely, the functions of a single component may be shared by multiple components.

[0020] The battery pack of the present disclosure can be used as a driving power source for marine sports such as jet skis and motorboats, or as a power source for assisting land-based two-wheeled and four-wheeled vehicles, such as power-assisted bicycles, electric scooters and electric carts, hybrid vehicles, and electric vehicles, as well as a power source for portable electrical equipment such as power tools, or as a stationary power source, such as a backup power source for data centers, a home, office, or factory power storage device that stores power generated by solar power generation or the like, or a power source for daytime peak cutting. Hereinafter, a battery pack used as a driving power source for a jet ski will be described as one embodiment of the present disclosure. [Embodiment 1]

[0021] A battery pack 100 according to a first embodiment of the present disclosure is shown in FIGS. 1 to 10 . In these figures, FIG. 1 is a perspective view of the battery pack 100 according to the embodiment, FIG. 2 is a cross-sectional view of the battery pack 100 taken along line II-II in FIG. 1 , FIG. 3 is an exploded perspective view of the battery pack 100 in FIG. 1 , FIG. 4 is an exploded perspective view of the battery pack 100 in FIG. 3 viewed obliquely from below, FIG. 5 is a plan view of the lower case 12 in FIG. 3 , FIG. 6 is an enlarged plan view showing the flow of water entering the lower case 12 in FIG. 5 , FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6 , FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6 , FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 6 , and FIG. 10 is a cross-sectional view taken along line X-X in FIG. 6 . The battery pack 100 shown in these figures includes an outer case 10, one or more battery modules 2, a circuit board 30, and a water intrusion sensor 40. (Outer Case 10)

[0022] The exterior case 10 is a component for housing one or more battery modules 2, a circuit board 30, and a water intrusion sensor 40, and constitutes the exterior shape of the battery pack 100. The exterior case 10 shown in FIGS. 1 to 4 defines a storage space therein for housing the battery modules 2 and the circuit board 30. Specifically, the exterior case 10 is divided into an upper case 11 and a lower case 12, forming a storage space between them. The lower case 12 is formed in a box shape with an open top. The upper case 11 is formed large enough to close the open end of the top of the lower case 12. While the exterior case 10 is U-shaped in plan view in the example shown in FIG. 1 and elsewhere, it is not limited to this shape and can be formed in any shape appropriate for the specifications required of the battery pack. This exterior case 10 can be formed, for example, from a resin molded product such as polycarbonate or ABS, or an aluminum extrusion molded product. (Battery Module 2)

[0023] One or more battery modules 2 are housed in the exterior case 10. To house the battery modules 2, the exterior case 10 is formed in a shape that is elongated in the positional direction. In the example of the exploded perspective views of Figures 3 and 4, two battery modules 2 are arranged in a parallel position at a distance from each other. Each battery module 2 is housed in an extension section 14. Here, the first battery module 2A is housed in the first extension section 14A, and the second battery module 2B is housed in the second extension section 14B. The number of battery modules 2 included in the battery pack is not limited to this, and may be one or three or more.

[0024] A circuit board 30 is disposed between the battery modules 2. For this reason, the exterior case 10 is provided with a board storage section 15 for storing the circuit board 30. The board storage section 15 is disposed between the first extension section 14A and the second extension section 14B. The first extension section 14A and the second extension section 14B each have a sidewall 18 on the side facing the circuit board 30. (Battery Block 3)

[0025] Each battery module 2 is composed of one or more battery blocks 3. In the example shown in FIGS. 2 to 4, three battery blocks 3 are connected together to form one battery module 2. The number of battery blocks constituting a battery module is not limited to this, and may be two or less, or four or more. As shown in FIG. 4, each battery block 3 is equipped with block-side terminals 4 for electrical connection. Each battery block 3 also includes multiple rechargeable battery cells 1. Each rechargeable battery cell 1 has electrodes on its end surfaces. Each battery block 3 connects the multiple rechargeable battery cells 1 constituting the battery block 3 in series or parallel, and supplies their output to the battery pack 100 via the block-side terminals 4. The output of the battery pack 100 is output to the outside via an external output terminal 5, as shown in FIG. 4.

[0026] The battery block 3 is constructed by arranging, for example, a large number of cylindrical secondary battery cells 1 horizontally and parallel to one another and storing them in a battery holder 6. This prevents the end faces from being aligned with the bottom surface, thereby preventing the bottom surfaces of the secondary battery cells 1 from becoming submerged in water and causing a short circuit. If multiple secondary battery cells were held vertically, multiple end faces would be aligned with the bottom surface, which could lead to electrical conduction between them in the event of flooding. In contrast, if the cells are held horizontally, the end faces are aligned vertically, which prevents simultaneous electrical conduction between the end faces unless the cells are partially submerged, i.e., not completely submerged, thereby improving safety.

[0027] The battery holder 6 is preferably made of a material with excellent insulating and heat-resistant properties, such as a resin such as polycarbonate or ABS. The multiple secondary battery cells 1 are connected in parallel and in series. The number of series connections or parallel connections of the multiple secondary battery cells 1 constituting the battery block 3 can be adjusted as needed depending on the required specifications.

[0028] Lithium-ion secondary batteries are suitable for use as the secondary battery cells 1. A battery module 2 using lithium-ion secondary batteries as the secondary battery cells 1 can achieve a high output relative to its volume and weight. However, instead of lithium-ion secondary batteries, lithium polymer batteries or nickel-metal hydride batteries can also be used as the secondary battery cells. (Partition wall 16)

[0029] The exterior case 10 is divided into multiple areas in which multiple battery blocks 3 are respectively arranged. In the examples of Figures 3 to 5 and 12, the first extension section 14A and the second extension section 14B, which respectively house the battery modules 2, are provided with partition walls 16 to separate the areas into which the battery blocks 3 are housed. The partition walls 16 extend vertically from the floor surface 20 of the exterior case 10. The partition walls 16 do not need to completely separate the internal storage space of the first extension section 14A or the second extension section 14B physically; they are sufficient as long as they can position the battery blocks 3. In the examples of Figures 3 and 12, the height of the partition walls 16 is lower than the height of the battery blocks 3. (Water intrusion sensor 40)

[0030] The exterior case 10 is also equipped with a water intrusion sensor 40 for detecting water that has entered the exterior case 10. Any known sensor capable of detecting water can be used as the water intrusion sensor 40. For example, a sensor that detects electrical continuity between two spaced apart terminals due to submersion in water can be used. The water intrusion sensor 40 can be shaped like a box, strip, wire, or other suitable form.

[0031] The water intrusion sensor 40 is provided on a part of the floor surface 20 of the exterior case 10. As shown in Figures 6 to 10, the floor surface 20 is inclined downward toward the sensor placement area 25 where the water intrusion sensor 40 is located. The floor surface 20 also has the water intrusion sensor 40 located at a position lower than the mounting surface on which each battery block 3 is placed. By sloping the floor surface 20 of the exterior case 10 in this way and placing the water intrusion sensor 40 at the end of the incline, water that has entered the exterior case 10 is guided to the water intrusion sensor 40, enabling reliable water intrusion detection. As a result, the reliability and accuracy of water intrusion detection are improved.

[0032] Some conventional battery packs are equipped with water intrusion sensors, but even if water penetrates the interior of the exterior case, the water does not reach the water intrusion sensor, and the water intrusion sensor is not always able to detect it. Battery packs contain many components, such as battery blocks and circuit boards, and there are many gaps between them, so even if water penetrates, it may be blocked by these components and not reach the water intrusion sensor. In particular, in recent years, there has been a strong demand for easier portability and smaller size, and there is also a demand for smaller and thinner battery packs themselves, which means that the gaps tend to become smaller.

[0033] Therefore, in the battery pack 100 according to this embodiment, the water intrusion sensor 40 is installed on the floor surface 20 inside the outer case 10, and the floor surface 20 is inclined so that the water intrusion sensor 40 is located at the end of the inclination, i.e., in the sensor placement area 25 where the height of the floor surface 20 is lowest. This makes it easier to guide water that has entered the outer case 10 to the water intrusion sensor 40, and ensures that water intrusion can be detected reliably.

[0034] Furthermore, it is preferable to divide the first extension section 14A and the second extension section 14B, which house multiple battery blocks 3, into multiple areas and arrange the battery blocks 3 in each area, but to provide a water ingress sensor 40 in one area rather than providing a water ingress sensor 40 in each area. This makes it possible to detect water ingress using a common water ingress sensor 40, without providing a separate water ingress sensor 40 for each battery block 3, thereby reducing the number of parts.

[0035] Specifically, it is preferable to arrange multiple areas in a line and provide the water intrusion sensor 40 in the area located in the middle. In the example of Figure 5, the first extension 14A and the second extension 14B each have a water intrusion sensor 40 located in the center area. In other words, no water intrusion sensors 40 are provided in the left and right areas. As shown in the cross-sectional view of Figure 7, a symmetrical V-shaped slope is formed so that the center in the longitudinal direction is the bottom, and water that has entered the exterior case 10 is guided to the central area. This reduces the difference in the path length leading to the water intrusion sensor 40 regardless of whether water intrusion occurs from either of the longitudinal ends, allowing for similar detection, thereby improving the stability and reliability of the water intrusion detection operation. (Flow path 17)

[0036] Each partition 16 forms a flow passage 17 that communicates between adjacent areas partitioned by the partition 16. This allows water that has entered the exterior case 10 to pass through the partition 16 via the flow passage 17, while the first extension portion 14A and the second extension portion 14B are partitioned into multiple areas by the partition 16.

[0037] Furthermore, it is preferable that the floor surface 20 be sloped across multiple areas. With this configuration, water that has entered the exterior case 10 moves along the slope of the floor surface 20, passes through the partition wall 16 via the flow path 17, and is ultimately guided to the area where the water intrusion sensor 40 is installed. If the slope of the floor surface 920 were to remain within the area where the water intrusion sensor 940 is installed, as in the battery pack 900 according to the comparative example shown in FIG. 11 , water that has entered this area could be guided to the water intrusion sensor 940, but it would be uncertain whether water that has entered other areas could be guided to the area where the water intrusion sensor 940 is installed. Therefore, by providing the floor surface 20 with slopes in other areas and making the downward slope continuous across the areas, water can be collected at the water intrusion sensor 40 across the areas even while the area is divided into multiple areas, and water intrusion can be detected using a common water intrusion sensor 40.

[0038] As described above, the extension sections 14 are divided into multiple areas and arranged in multiple rows, with one water intrusion sensor 40 located in each row. Here, the first extension section 14A is referred to as the first row, and the second extension section 14B is referred to as the second row. Here, the water intrusion sensors 40 are located on the opposing surfaces of adjacent rows. By unevenly distributing the water intrusion sensors 40 between the rows in this manner, it is possible to easily collect and manage the detection results of the water intrusion sensors 40.

[0039] As shown in Fig. 5 , the slope of the floor surface 20 of the exterior case 10 is formed radially from a sensor placement area 25 where the water intrusion sensor 40 is provided. That is, in the extension direction (left-right direction in Fig. 5 ) of the first extension portion 14A and the second extension portion 14B, a first inclined surface 21 and a second inclined surface 22 are formed symmetrically, each V-shaped recessed with a valley in the center, as shown in Figs. 7 and 8 . On the other hand, in the width direction (up-down direction in Fig. 5 ) intersecting the extension direction, a third inclined surface 23 is formed, sloping downward toward the side wall 18, as shown in Figs. 9 and 10 . Boundaries 24 between the first inclined surface 21 and the third inclined surface 23, and between the third inclined surface 23 and the second inclined surface 22, extend radially from the sensor placement area 25, as shown in the plan view of Fig. 5 . With this configuration, as shown in Figure 6, no matter where water is present in the first extension 14A, it is guided along the slope of the floor 20 to the sensor placement area 25 where the water intrusion sensor 40 is located, and water intrusion can be reliably detected by the water intrusion sensor 40. (Circuit board 30)

[0040] A circuit board 30 is disposed between the first and second rows. As shown in FIG. 3, the exterior case 10 has a board storage section 15 between the first extension section 14A and the second extension section 14B, and boards are stored in the board storage section 15. A water ingress sensor 40 is disposed on the side of each of the first and second rows facing the circuit board 30. Each water ingress sensor 40 is connected to the circuit board 30. In this way, by disposing the circuit board 30 between the first and second rows and disposing the water ingress sensors 40 on the side facing the circuit board 30, it becomes easier to connect the detection results of the water ingress sensors 40 to the circuit board 30, and the configuration for routing wiring can be simplified. (Side wall opening 19)

[0041] Each side wall 18 of the exterior case 10 has a side wall opening 19 that communicates with the board housing section 15 at the position where the water intrusion sensor 40 is located. In the example of Figures 12 and 13, a side wall opening 19 is provided in the left side wall 18 of the first extension section 14A (the front side in the figures) and in the right side wall 18 of the second extension section 14B (the back side in the figures), respectively, so as to rise from the floor surface 20. This allows the water intrusion sensors 40 located in the first extension section 14A and the second extension section 14B to be connected to the circuit board 30 via the side wall opening 19, simplifying the wiring configuration.

[0042] The location where the water intrusion sensor 40 is located is preferably a flat surface. That is, by making the lowest point, which is the end point of the downward slope of the inclined surface, a flat surface, water can be easily accumulated, making it easier for the water intrusion sensor 40 located there to detect water intrusion (separation wall 26).

[0043] As shown in FIG. 5 , each of the multiple areas in which the battery blocks 3 are arranged has a surrounding partition wall 26 formed on the floor surface 20. Each battery block 3 housed in each of the multiple areas is placed on the upper end of the partition wall 26, with the block-side terminals 4 for electrical connection located within the partition wall 26. The upper end of the partition wall 26 forms the mounting surface of the floor surface 20 on which each battery block 3 is placed. With this configuration, the block-side terminals 4 of each battery block 3 are located in an area surrounded by the partition wall 26, preventing the block-side terminals 4 from becoming submerged and causing a short circuit or the like even if water enters the exterior case 10. Existing connecting members such as bus bars, circuit boards, and connectors can be used for the block-side terminals 4.

[0044] As shown in Figures 6, 9, etc., it is preferable that the inside of the partition wall 16 be a flat surface regardless of the inclination of the floor surface 20. This is because the inside of the partition wall 16 is waterproof, eliminating the need for water guides, and also because the battery block 3 can be stably held. [Embodiment 2]

[0045] The inclined surface formed on the floor surface 20 is not necessarily limited to a configuration in which the middle is recessed, and recesses may be formed at other positions. For example, in the battery pack 200 according to embodiment 2 shown in Fig. 14, the inclined surface of the floor surface 20B is formed so that the area on the right side in the figure is at the lowest height, and water is guided to the water intrusion sensor 40. For example, this configuration can be used appropriately in cases where water intrusion from the right side is more likely to occur than from the left side, or when it is difficult to recess the middle due to the arrangement of battery modules and other components housed in the exterior case 10B.

[0046] The battery pack according to the present disclosure can be suitably used as a driving power source for marine sports such as jet skis and motorboats, or as an assist power source for land-based two-wheeled and four-wheeled vehicles, such as power-assisted bicycles, electric scooters and electric carts, hybrid vehicles and electric vehicles, and as a power source for portable electrical equipment such as power tools, or as a stationary power source, such as a backup power source for data centers, a power storage device for storing electricity generated by solar power generation or the like for home, business or factory use, or as a power source for daytime peak shaving.

[0047] DESCRIPTION OF SYMBOLS 100, 200... Battery pack 1... Secondary battery cell 2... Battery module; 2A... First battery module; 2B... Second battery module 3... Battery block 4... Block side terminal 5... External output terminal 6... Battery holder 10, 10B... Outer case 11... Upper case 12... Lower case 14... Extension portion; 14A... First extension portion; 14B... Second extension portion 15... Board storage portion 16... Partition wall 17... Flow path 18... Side wall 19... Side wall opening 20, 20B... Floor surface 21... First inclined surface 22... Second inclined surface 23... Third inclined surface 24... Boundary line 25... Sensor placement area 26... Partition wall 30... Circuit board 40... Water intrusion sensor 900... Battery pack 920... Floor surface 940... Water intrusion sensor

Claims

1. A battery pack comprising: one or more battery blocks each including a plurality of secondary battery cells; an outer case for housing the battery block; and a water intrusion sensor for detecting water that has entered the outer case, wherein the outer case has a floor with a mounting surface on which the battery block is placed, the water intrusion sensor is provided on a part of the floor that is lower than the mounting surface, and the floor is inclined downwardly toward the water intrusion sensor.

2. A battery pack according to claim 1, wherein the floor surface is inclined so that a portion of the floor surface is at the lowest position.

3. A battery pack as claimed in claim 1, comprising a plurality of the battery blocks, the exterior case being divided into a plurality of areas in which the plurality of battery blocks are respectively arranged, the floor surface being inclined across the plurality of areas, and the water intrusion sensor being provided in one of the plurality of areas.

4. A battery pack as claimed in claim 3, wherein the exterior case is divided by partitions into a plurality of areas in which the plurality of battery blocks are respectively arranged, each partition forming a flow passage that connects adjacent areas divided by the partition, and wherein water that has entered the exterior case is guided via the flow passage to the area in which the water intrusion sensor is provided.

5. A battery pack as claimed in claim 3, wherein each battery block is provided with a block-side terminal for electrical connection, and the plurality of areas form a surrounding isolation wall on the bottom surface thereof, and each battery block housed in the plurality of areas is configured so that the block-side terminal is located within the isolation wall.

6. A battery pack according to claim 3, wherein the plurality of areas are arranged in one direction, and the water intrusion sensor is provided in an area located between the plurality of areas.

7. A battery pack according to claim 3, wherein the plurality of areas are arranged in a plurality of rows, each row has one water ingress sensor, and the water ingress sensors are arranged on the opposite side of adjacent rows.

8. A battery pack as claimed in claim 3, wherein the plurality of areas include a first row and a second row in which the areas are aligned in one direction, one water intrusion sensor is disposed in each of the first and second rows, a circuit board is disposed between the first and second rows, and a water intrusion sensor is disposed on the side of each of the first and second rows facing the circuit board, and each water intrusion sensor is connected to the circuit board.

9. A battery pack as described in claim 8, wherein the outer case comprises: a first extension section that houses a plurality of battery blocks arranged in the first row area; a second extension section that houses a plurality of battery blocks arranged in the second row area; and a board storage section that houses the circuit board and is arranged between the first extension section and the second extension section; wherein the first extension section and the second extension section each have a side wall on the side facing the circuit board, and each side wall forms a side wall opening that communicates with the board storage section at the position where the water intrusion sensor is arranged.

10. A battery pack according to any one of claims 1 to 9, wherein the battery block holds a plurality of secondary battery cells in a horizontal position, and each secondary battery cell has an electrode on its end face.

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