Power storage device

Abstract

To provide a power storage device which can detect water immersion before water reaches a battery module.SOLUTION: A power storage device comprises: a battery module 10 which includes a battery cell 11; an electrical instrument which is arranged on the upper side of the battery module 10; a first wire harness which is connected to the ground; a second wire harness which is connected to the electrical instrument; and a water detection unit 40 in which the first wire harness and the second wire harness are arranged with a gap. The water detection unit 40 is located on the lower side with respect to a lower surface 11B of the battery cell 11.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Japanese Patent Publication No. 2021-125400 (Patent Document 1) discloses a stationary battery that includes one or more battery modules and electrical equipment such as a circuit board arranged above the battery modules, and is covered with a box-shaped case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-125400 Summary of the Invention [Problem to be solved by the invention]

[0004] From a safety standpoint, there is a demand to place electrical equipment such as circuit boards at the top of the power storage device, while there is also a demand to detect water before it reaches the battery modules if the power storage device is flooded.

[0005] The present disclosure proposes an electricity storage device that can detect water intrusion before water reaches the battery module. [Means for solving the problem]

[0006] The power storage device according to the present disclosure includes a battery module including battery cells, an electric device arranged above the battery module, a first wire harness connected to earth, a second wire harness connected to the electric device, and a water detector arranged with a gap between the first wire harness and the second wire harness. The water detector is located below the bottom surface of the battery cells.

[0007] By locating the water detection unit below the battery cells, the water detection unit is submerged in water before the battery cells are submerged, and water intrusion into the power storage device can be detected at the time the water detection unit is submerged in water. Therefore, water intrusion into the power storage device can be detected before water reaches the battery modules.

[0008] The above-mentioned power storage device may further include a current detection unit that detects current flow between the first wire harness and the second wire harness. The current flow between the first wire harness and the second wire harness can be detected via water present in the space between the first wire harness and the second wire harness, thereby enabling accurate detection of water intrusion into the power storage device.

[0009] The power storage device may further include a notification unit that notifies a mobile terminal of a user of the power storage device when the current detection unit detects current flow, thereby allowing the user of the power storage device to quickly recognize that the power storage device has been flooded. [Effects of the Invention]

[0010] According to the power storage device of the present disclosure, it is possible to detect water intrusion before water reaches the battery module. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a perspective view showing the outline of the appearance of the electricity storage device. [Figure 2] FIG. 2 is a perspective view showing an outline of the electricity storage device with the sealing cover removed. [Figure 3] FIG. [Figure 4] FIG. 3 is a circuit diagram of a water detection unit. [Figure 5] 10A and 10B are diagrams illustrating the vertical positional relationship between the water detector and the battery cell. [Figure 6] 10 is a block diagram showing a system configuration that notifies a user when flooding in a power storage device is detected. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed description thereof will not be repeated.

[0013] FIG. 1 is a perspective view showing a schematic appearance of an energy storage device 1. The energy storage device 1 is used, for example, as a home storage battery. The energy storage device 1 includes a base plate 3 and a sealing cover 6. The sealing cover 6 includes a top cover 7 and a side cover 8. The top cover 7 forms the upper surface of the energy storage device 1 and covers the battery modules 10 (described later) from above. The side cover 8 forms the side surface of the energy storage device 1 and covers the battery modules 10 from the sides. The sealing cover 6 has a lid-like shape that opens downward.

[0014] Home storage batteries are generally installed outdoors. An electricity storage device 1 installed outdoors is exposed to rainwater and the like. To maintain the functionality of the electricity storage device 1, the electricity storage device 1 has a sealed structure. The lower edge of the sealing cover 6 is attached liquid-tight to the upper surface of the base plate 3. Foreign matter such as rainwater or dust is prevented from entering the interior of the electricity storage device 1 through the gap between the base plate 3 and the sealing cover 6. A sealing material may be provided between the sealing cover 6 and the base plate 3. The sealing material may be made of an elastic resin material or rubber material.

[0015] The base plate 3 has mounting portions 4 and 5 on its lower surface. The mounting portions 4 and 5 are provided to fix the electricity storage device 1 to an installation location such as a foundation.

[0016] FIG. 2 is a perspective view showing an outline of the energy storage device 1 with the sealing cover 6 that seals the energy storage device 1 removed. The interior of the energy storage device 1 has a multi-story structure. The energy storage device 1 is equipped with battery modules 10. In this embodiment, the battery modules 10 are stacked in two tiers. The first tier of battery modules 10 are mounted on a first floor section 21 provided on the upper surface of the base plate 3. The second tier of battery modules 10 are mounted on a second floor section 22 above the first floor section 21.

[0017] A plurality of frame portions 25 are fixed to the upper surface of the base plate 3. The frame portions 25 extend perpendicular to the upper surface of the base plate 3. The frame portions 25 extend parallel to one another. The frame portions 25 support the second floor portion 22. The second-tier battery modules 10 are supported by the frame portions 25 via the second floor portion 22. A side plate 26 that covers the battery modules 10 from the sides is attached to the frame portion 25 on the far side in FIG. 2. A similar side plate is also attached to the frame portion 25 on the near side in FIG. 2, but this side plate is not shown in the figure to make the illustration easier.

[0018] The frame portion 25 further supports the third floor portion 23. The third floor portion 23 is disposed above the second floor portion 22. Electrical devices 31, 32, and 33 are mounted on the third floor portion 23. The electrical device 31 may be, for example, a battery ECU (Electronic Control Unit). The electrical device 32 may be, for example, a voltage sensor. The electrical device 33 may be, for example, a junction box. The electrical devices 31, 32, and 33 are disposed above the battery module 10. The third floor portion 23 is also provided with an earth point 34. The earth point 34 is electrically grounded.

[0019] The battery modules 10 do not necessarily have to be mounted in two layers. One layer of battery modules 10 may be mounted on the base plate 3, and the electrical equipment 31, 32, 33 may be mounted on the second layer or any layer higher than that. The battery modules 10 may also be stacked in three or more layers.

[0020] A bracket 28 is also fixed to the upper surface of the base plate 3. The bracket 28 is arranged facing the end surface of the battery module 10 in the longitudinal direction of the battery module 10 (the stacking direction of the battery cells). The bracket 28 supports a water detection unit 40. The water detection unit 40 is arranged below the electrical devices 31, 32, and 33. The electrical devices 31, 32, and 33 are arranged at the top of the energy storage device 1. The water detection unit 40 is arranged at the bottom of the energy storage device 1.

[0021] Fig. 3 is an enlarged view of the water detection unit 40. Fig. 4 is a circuit diagram of the water detection unit 40. The power storage device 1 includes a first wire harness 41 and a second wire harness 42. One end of the first wire harness 41 is connected to an earth point 34 inside the power storage device 1. The first wire harness 41 is connected to earth. The first wire harness 41 is an earth wire drawn from the earth point 34. One end of the second wire harness 42 is connected to an electric device 33. The second wire harness 42 is a power line drawn from the electric device 33.

[0022] The other end of the first wire harness 41 is connected to the conductive end 45. The first wire harness 41 between one end and the other end is covered by a covering portion 43. The other end of the second wire harness 42 is connected to the conductive end 46. The second wire harness 42 between one end and the other end is covered by a covering portion 44. The conductive end 45 and the conductive end 46 are arranged at a distance from each other and are not connected to each other. The water detection unit 40 is formed by arranging the other end of the first wire harness 41 and the other end of the second wire harness 42 at a distance from each other.

[0023] FIG. 5 is a diagram showing the vertical positional relationship between the water detection unit 40 and the battery cells 11. The battery module 10 includes the battery cells 11. The battery module 10 has a stack in which a plurality of battery cells 11 are stacked in a stacking direction. The plurality of battery cells 11 are arranged side by side in a direction along the upper surface of the base plate 3. Each of the plurality of battery cells 11 is a secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. Two adjacent battery cells 11 in the stacking direction are electrically connected to each other by a connecting part (not shown) to form the battery module 10. The battery module 10 has end plates 12 arranged at the ends of the battery cells 11 in the stacking direction.

[0024] The battery cell 11 has a lower surface 11B. The lower surface 11B of the battery cell 11 faces the upper surface of the base plate 3. As shown in FIG. 5 , the water detection unit 40 is located below the lower surface 11B of the battery cell 11. In the vertical direction, the water detection unit 40 is disposed between the lower surface 11B of the battery cell 11 and the upper surface of the base plate 3. The water detection unit 40 is disposed closer to the base plate 3 than the lower surface 11B of the battery cell 11. Preferably, the water detection unit 40 is located below the lower surface of the battery module 10.

[0025] Both the conductive end 45 and the conductive end 46 are located below the lower surface 11B of the battery cell 11. At least a portion of the conductive end 45, 46 is located below the lower surface 11B of the battery cell 11. The lower surfaces of the conductive end 45, 46 are disposed below the lower surface 11B of the battery cell 11. Preferably, the entire conductive end 45, 46 is located below the lower surface 11B of the battery cell 11. Preferably, the upper surfaces of the conductive end 45, 46 are disposed below the lower surface 11B of the battery cell 11. The first wire harness 41 and the second wire harness 42 extend from the top to the bottom of the energy storage device 1.

[0026] 6 is a block diagram showing a system configuration that notifies a user when flooding in the power storage device 1 is detected. The power storage device 1 includes an energization detection unit 51 and a notification unit 52. The energization detection unit 51 and the notification unit 52 may form part of the configuration of the electric device 31, which is a battery ECU. The energization detection unit 51 and the notification unit 52 may be included in the electric device 33, which is a junction box. The energization detection unit 51 and the notification unit 52 may form part of the configuration of an ECU housed in the junction box.

[0027] The current detection unit 51 detects current flow between the first wire harness 41 and the second wire harness 42. The base plate 3 or the sealing cover 6 may be damaged due to an object blown by strong wind colliding with the electricity storage device 1, vibrations during an earthquake, or the like, which may impair the sealing of the electricity storage device 1. In this case, if the electricity storage device 1 is flooded, water will also enter the interior of the electricity storage device 1. If water accumulates in the space where the water detection unit 40 is located, the first wire harness 41 and the second wire harness 42 will become conductive to each other through the water. By detecting current flow between the first wire harness 41 and the second wire harness 42, it becomes possible to determine that the electricity storage device 1 has been flooded.

[0028] When current flow detection unit 51 detects current flow between first wire harness 41 and second wire harness 42 and determines that power storage device 1 is submerged, notification unit 52 notifies mobile terminal 53 of the user of power storage device 1 that power storage device 1 has been submerged. Notification unit 52 may be configured to perform short-range wireless communication with mobile terminal 53, or may be configured to be able to communicate with mobile terminal 53 via a communication network such as the Internet. Mobile terminal 53 may be a smartphone, a tablet terminal, or a wearable device.

[0029] In the energy storage device 1 of the embodiment described above, as shown in Fig. 2, the electrical devices 31, 32, and 33 are arranged above the battery module 10. This makes it possible to ensure safety.

[0030] 3 and 4, the electricity storage device 1 includes a water detection unit 40 in which a first wire harness 41 connected to earth and a second wire harness 42 connected to an electrical device 33 are arranged with a gap between them. As shown in FIG. 5, the water detection unit 40 is arranged below the lower surface 11B of the battery cell 11.

[0031] By locating the water detection unit 40 below the power storage device 1, where it is easier to detect water, rather than at the top of the power storage device 1 where the electrical equipment 33 and the like are located, it is possible to detect water at a relatively early stage when the power storage device 1 is flooded. In particular, by locating the water detection unit 40 below the battery cells 11, which are high-voltage components, the water detection unit 40 becomes flooded before the battery cells 11 become flooded, and water intrusion into the power storage device 1 can be detected at the time the water detection unit 40 becomes flooded. Therefore, water intrusion into the power storage device 1 can be detected before water reaches the battery modules 10. Because water can be detected by the water detection unit 40, which is configured using existing circuits, without the need for a new sensor to detect water, an increase in the cost of the power storage device 1 is suppressed.

[0032] 6, the power storage device 1 may further include a current flow detection unit 51 that detects current flow between the first wire harness 41 and the second wire harness 42. When the water detection unit 40 detects current flow between the first wire harness 41 and the second wire harness 42, which are arranged apart from each other, it can be determined that water is present in the space between the first wire harness 41 and the second wire harness 42, and that current is flowing between the first wire harness 41 and the second wire harness 42 through the water. In this way, flooding of the power storage device 1 can be accurately detected.

[0033] 6, the power storage device 1 may further include a notification unit 52 that, when the current flow detection unit 51 detects current flow, notifies a mobile terminal 53 of the user of the power storage device 1. In this way, the user of the power storage device 1 can quickly recognize that the power storage device 1 has been flooded, and can take necessary measures early on.

[0034] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include any modifications within the scope of the claims and meanings equivalent to the claims. [Explanation of symbols]

[0035] 1 Energy storage device, 3 Base plate, 4, 5 Mounting portion, 6 Sealing cover, 7 Top cover, 8 Side cover, 10 Battery module, 11 Battery cell, 11B Underside, 12 End plate, 21 First floor portion, 22 Second floor portion, 23 Third floor portion, 25 Frame portion, 26 Side plate, 28 Bracket, 31, 32, 33 Electrical equipment, 34 Earth point, 40 Water detection portion, 41 First wire harness, 42 Second wire harness, 43, 44 Covering portion, 45, 46 Conductive end portion, 51 Current detection portion, 52 Notification portion, 53 Mobile terminal.

Claims

1. A power storage device, a battery module including battery cells; an electrical device disposed above the battery module; a ground point provided above the battery module and electrically grounded; a first wire harness having one end connected to the ground point and extending from a top to a bottom of the power storage device; a second wire harness having one end connected to the electrical device and extending from the top to the bottom of the power storage device; a water detection unit located below the bottom surface of the battery cell, in which a first conductive part connected to the other end of the first wire harness and a second conductive part connected to the other end of the second wire harness are arranged with a gap between them.

2. The power storage device according to claim 1 , further comprising: a current detection unit that detects current flow between the first wire harness and the second wire harness.

3. The power storage device according to claim 2 , further comprising a notification unit that notifies a mobile terminal of a user of the power storage device when the current flow detection unit detects current flow.

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