Battery pack collision detection device, battery pack and electric equipment

Abstract

The utility model belongs to the technical field of battery safety, and particularly relates to a battery pack collision detection device, a battery pack and electric equipment. The battery pack collision detection device comprises a detection module, a power supply circuit and a plurality of strain type resistance wires, the strain type resistance wires are suitable for being arranged between a battery cell group of a battery pack and a box body in an insulating mode, and each strain type resistance wire is electrically connected with the power supply circuit; the power supply circuit is used for providing voltage for the strain type resistance wire; and the detection module is used for detecting the resistance change of the deformed strain type resistance wire so as to position the impacted position of the battery pack. When the battery pack is collided and deformed, the strain type resistance wire corresponding to the collision position deforms along with the battery pack, the resistance of the deformed strain type resistance wire changes, and the detection module detects that the resistance value of a certain strain type resistance wire changes. Therefore, it is confirmed that the position of the battery pack corresponding to the position of the strain type resistance wire with the changed resistance value is impacted, and the impacted position of the battery pack is positioned.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery safety, and in particular relates to a battery pack collision detection device, a battery pack and electrical equipment. Background Art

[0002] The power battery pack is usually arranged under electric vehicles and other electrical equipment, which makes the power battery pack extremely vulnerable to collision during the driving of the electric vehicle. In severe cases, the power battery pack may cause it to rupture. If the owner cannot discover it in time, there may be a major safety hazard.

[0003] To solve the above problems, the battery pack of the related art arranges a detection device between the battery cell and the box body, the detection device includes a metal sheet, the metal sheet is insulated from the battery cell, the box body is a grounded metal structure, there is a safe distance between the metal sheet and the box body, and a detection circuit is electrically connected between the metal sheet and the box body. When the battery pack is hit and the metal sheet is deformed and contacts the box body, the detection circuit detects that the metal sheet and the box body are conductive, and it is determined that the battery pack has been hit.

[0004] However, the above-mentioned battery pack detection device can only detect that the battery pack is impacted, but cannot detect the impact position of the battery pack. Utility Model Content

[0005] The technical problem to be solved by the utility model is: in view of the problem that the existing detection device cannot detect the impacted position of the battery pack, a battery pack and an electrical device are provided.

[0006] In order to solve the above technical problems, on the one hand, the embodiment of the utility model provides a battery pack collision detection device, including a detection module, a power supply circuit and a plurality of strain gauge resistor wires, wherein the plurality of strain gauge resistor wires are suitable for being insulated and arranged between a battery cell group and a box of a battery pack, and each of the strain gauge resistor wires is electrically connected to the power supply circuit;

[0007] The power supply circuit is used to provide voltage to the strain gauge resistor wire;

[0008] The detection module is used to detect the resistance change of the deformed strain gauge resistor wire to locate the impacted position of the battery pack.

[0009] Optionally, the multiple strain-type resistance wires include a plurality of first resistance wires arranged at intervals along a first direction and a plurality of second resistance wires arranged at intervals along a second direction, the angle between the first direction and the second direction is not zero, and at least one of the first resistance wires intersects with a plurality of the second resistance wires to form a resistance wire network.

[0010] Optionally, the first direction is perpendicular to the second direction.

[0011] Optionally, the power supply circuit comprises a power supply and a plurality of reference resistors, the power supply provides a constant voltage for the power supply circuit, and the plurality of reference resistors correspond one-to-one to the plurality of strain gauge resistance wires;

[0012] The reference resistor has a set resistance value, and is electrically connected between the power supply and one end corresponding to the strain gauge resistance wire, and the other end of the strain gauge resistance wire is grounded.

[0013] Optionally, the power source is a power chip, and the power chip is integrated into a battery management system.

[0014] Optionally, the strain gauge resistor wire includes an inner core and an insulating layer wrapped around the outer periphery of the inner core.

[0015] Optionally, the strain gauge resistor wire comprises a first part and a second part which are intertwined with each other, a first end of the first part in the length direction is integrally connected with a first end of the second part in the length direction, and an end surface of the second end of the first part in the length direction is arranged side by side with an end surface of the second end of the second part in the length direction;

[0016] The detection module is used to detect the resistance change of the strain gauge resistor wire when the insulation layer is melted and the inner core of the first part and the inner core of the second part are short-circuited, so as to locate the thermal runaway position.

[0017] In the battery pack collision detection device of the utility model, a plurality of strain-type resistor wires are insulated and arranged between the cell group and the box body of the battery pack. When the battery pack is deformed by impact, the strain-type resistor wire corresponding to the impact position is deformed along with the battery pack, and the resistance of the deformed strain-type resistor wire changes. The detection module detects that the resistance value of the deformed strain-type resistor wire changes, thereby confirming that the battery pack position corresponding to the position of the strain-type resistor wire with the changed resistance value is impacted, so as to locate the impacted position of the battery pack.

[0018] On the other hand, an embodiment of the utility model provides a battery pack, including a box, a battery cell group and the above-mentioned battery pack collision detection device, wherein the battery cell group and the battery pack collision detection device are installed in the box.

[0019] Optionally, a plurality of battery cell groups are provided, a plurality of the battery pack collision detection devices are provided, and a plurality of the strain gauge resistor wires of each battery pack collision detection device are insulated and arranged between the corresponding battery cell group and the box.

[0020] On the other hand, an embodiment of the utility model provides an electrical device, including the above-mentioned battery pack collision detection device or the above-mentioned battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a schematic diagram of the structure of a battery pack provided by an embodiment of the utility model;

[0022] Figure 2 yes Figure 1 A schematic diagram of the structure of the battery pack collision detection device;

[0023] Figure 3 yes Figure 2 A schematic diagram of a battery pack when it is impacted;

[0024] Figure 4 yes Figure 2 The structural diagram of the strain gauge twisted pair cable;

[0025] Figure 5 yes Figure 4 Schematic diagram of the end portion;

[0026] Figure 6 yes Figure 1 Schematic diagram of the electrical connection of the strain gauge twisted pair cable.

[0027] The reference numerals in the specification are as follows:

[0028] 1. Upper cover; 2. Liquid cooling plate; 3. Battery cell group; 4. Battery pack collision detection device; 41. Strain gauge resistor wire; 411. Inner core; 412. Insulation layer; 42. First part; 43. Second part; 5. Tray; 6. Buffer layer; 7. Reference resistor. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0030] like Figure 1 and Figure 2 As shown, an embodiment of the utility model provides a battery pack including a box, a battery cell group 3 and a battery pack collision detection device 4, wherein the battery cell group 3 and the battery pack collision detection device 4 are installed in the box. The battery pack collision detection device 4 includes a detection module, a power supply circuit and a plurality of strain gauge resistor wires 41, wherein the plurality of strain gauge resistor wires 41 are insulated and arranged between the battery cell group 3 and the box, and each strain gauge resistor wire 41 is electrically connected to the power supply circuit.

[0031] A power supply circuit, used for providing voltage to the strain gauge resistance wire 41;

[0032] The detection module is used to detect the resistance change of the deformed strain-type resistor wire 41 to locate the impacted position of the battery pack.

[0033] It should be noted that the arrangement position and arrangement shape of the strain gauge resistor wire 41 can be adjusted according to the required detection position of the battery pack. For example, when there is a collision detection requirement at the bottom of the battery pack, the multiple strain gauge resistor wires 41 of the battery pack collision detection device 4 can be arranged at the bottom of the battery cell group 3, so that the strain gauge resistor wire 41 can truly reflect the deformation amount and collision position of the battery pack.

[0034] like Figure 3 As shown, when the battery pack is impacted, the impact force causes the strain-type resistor wire 41 corresponding to the impact position to deform, and the length of the strain-type resistor wire 41 changes. According to the characteristics of the strain-type resistor wire 41, the resistance value of the strain-type resistor wire 41 changes with the change of the length. The detection module detects the resistance value of each strain-type resistor value to confirm the strain-type resistor wire 41 with a changed resistance value, thereby confirming that the battery pack position corresponding to the strain-type resistor wire 41 with a changed resistance value is impacted, so as to locate the impacted position of the battery pack. Moreover, due to the physical relationship between the resistance and length of the strain-type resistor wire 41, the length change of the strain-type resistor wire 41 can be obtained under the condition of obtaining the resistance change of the strain-type resistor wire 41, thereby determining the deformation of the battery pack.

[0035] Specifically, the detection module includes an acquisition module, a first confirmation module, a second confirmation module and a third confirmation module. The acquisition module obtains the resistance information of the strain gauge resistance wire 41 in real time according to a preset acquisition frequency during the operation of the battery. The resistance information includes resistance, resistance differential, length, and length change. The resistance differential refers to the difference between the resistance value at the current acquisition moment and the resistance value at the previous acquisition moment.

[0036] The first confirmation module has a first threshold value, and is used to determine whether the battery has collided and the collision position information according to the first threshold value and information of all strain gauge resistor wires 41 in the battery pack collision detection device 4 .

[0037] Specifically, the first confirmation module compares the resistance differential values ​​of all strain gauge resistor wires 41 according to a preset first threshold value, and for the strain gauge resistor wire 41 whose resistance differential exceeds the first threshold value, converts the resistance differential value into a length change of the strain gauge resistor wire 41 to determine the position and deformation amount of the battery collision.

[0038] When the resistance differential value of the strain gauge resistor wire 41 exceeds the first threshold, the serial number of the strain gauge resistor wire 41 whose resistance differential exceeds the first threshold is captured to determine the position where the battery is impacted, and the length change of the strain gauge resistor wire 41 is calculated based on the resistance differential value to determine the degree of battery damage.

[0039] The second determination module has a second threshold, wherein the first threshold is greater than the second threshold. The second confirmation module is used to determine whether the battery has collided and the collision position information according to the second threshold and the information of all strain gauge resistor wires 41 in the battery pack collision detection device 4.

[0040] Specifically, the second confirmation module is used to compare the resistance differential values ​​of all strain-type resistor wires 41 according to a preset second threshold value. When the resistance differential value of the strain-type resistor wire 41 exceeds the second threshold value and is less than the first threshold value, the battery is in a safe state. At this time, the deformation of the strain-type resistor wire 41 may be caused by the battery pack being deformed by bumps or other external forces, which in turn causes the strain-type resistor wire 41 to produce a small resistance change, but the resistance change is within an acceptable range.

[0041] The third determination module has a third threshold value, which is used to evaluate the risk level of the battery in the event of a collision based on the third threshold value and information of all strain gauge resistor wires 41 in the battery pack collision detection device 4, and trigger a system alarm or warning accordingly.

[0042] Specifically, the third confirmation module compares the length change of the strain-type resistor wire 41 whose resistance differential exceeds the first threshold according to the third threshold. When the length change of the strain-type resistor wire 41 does not exceed the third threshold, the deformation of the battery pack is small and the danger is relatively low. The system sends a collision position and triggers a low-risk warning; when the length change of the strain-type resistor wire 41 exceeds the third threshold, the deformation of the battery pack is large and the danger is relatively high. The system sends a collision position and triggers a high-risk warning.

[0043] The working process of the battery pack collision detection device 4 is as follows:

[0044] In step S101 , the acquisition module obtains the current resistance of all strain gauge resistor wires 41 in real time at a preset acquisition frequency during the operation of the battery, and obtains the resistance-time curves of all strain gauge resistor wires 41 in real time.

[0045] In step S102 , a resistance difference-time curve is calculated based on the resistance-time curves of all the strain gauge resistor wires 41 in the battery pack collision detection device 4 obtained in real time.

[0046] In step S103 , the first confirmation module determines whether the resistance difference values ​​of all strain gauge resistor wires 41 exceed a preset first threshold.

[0047] When it is determined that the resistance differential values ​​of all the strain gauge resistor wires 41 do not exceed the preset first threshold, step S104 is executed.

[0048] In step S104 , the second confirmation module determines whether the resistance difference of all strain gauge resistor wires 41 exceeds a second threshold.

[0049] When it is determined that the resistance differences of all strain gauge resistor wires 41 exceed the second threshold, step S101 is executed and the process is repeated.

[0050] When it is determined that the resistance difference values ​​of all the strain gauge resistor wires 41 exceed the preset first threshold, step S105 is executed.

[0051] In step S105 , the serial number of the strain gauge resistor wire 41 whose resistance difference exceeds the first threshold is captured, and the battery collision position is determined according to the serial number of the strain gauge resistor wire 41 , and step S106 is executed.

[0052] In step S106, the length variation of the strain gauge resistor wire 41 whose resistance difference exceeds the first threshold is calculated according to the physical relationship between resistance and length to determine the deformation amount of the battery, and step S107 is executed.

[0053] In step S107 , the third confirmation module determines whether the length variation of the strain gauge resistance wire 41 exceeds a preset third threshold.

[0054] When it is determined that the length variation of the strain gauge resistor wire 41 does not exceed the preset third threshold, step S108 is executed.

[0055] In step S108, the collision position is sent and a low risk warning is triggered, and then step S101 is executed, and the cycle continues.

[0056] When it is determined that the length variation of the strain gauge resistance wire 41 exceeds the preset third threshold, step S109 is executed.

[0057] In step S109 , the collision position is sent and a high risk alarm is triggered.

[0058] In the battery pack of the utility model, multiple strain-type resistor wires 41 of the battery pack collision detection device 4 are insulated and arranged between the battery cell group 3 and the box body of the battery pack. When the battery pack is deformed by impact, the strain-type resistor wire 41 corresponding to the impact position is deformed along with the battery pack, and the resistance of the deformed strain-type resistor wire 41 changes. The detection module detects that the resistance value of the deformed strain-type resistor wire 41 changes, thereby confirming that the battery pack position corresponding to the position of the strain-type resistor wire 41 with the changed resistance value is impacted, so as to locate the impacted position of the battery pack.

[0059] In one embodiment, if Figure 2 As shown, the multiple strain-type resistance wires 41 include multiple first resistance wires arranged at intervals along a first direction and multiple second resistance wires arranged at intervals along a second direction. The angle between the first direction and the second direction is not zero, and at least one first resistance wire intersects with multiple second resistance wires to form a resistance wire network.

[0060] The resistance wire network utilizes multiple strain-type resistance wires 41 to establish coordinates within the detection area corresponding to the battery cell group 3, so as to locate the collision position through the intersection of the first resistance wire and the second resistance wire. Compared with arranging multiple strain-type resistance wires 41 in parallel, which can only confirm that a collision occurs in the direction indicated by the strain-type resistance wire 41 whose resistance value changes, the resistance wire network can confirm a more accurate collision position.

[0061] For example, the resistance wire network labels a plurality of first resistance wires arranged at intervals along a first direction with serial numbers L1, L2, L3, ..., L6, and labels a plurality of second resistance wires arranged at intervals along a second direction with serial numbers R1, R2, R3, ..., R6. Figure 3 It is a schematic diagram of the battery pack collision alarm device after being impacted. When the battery pack is impacted, the strain gauge resistor wires 41 numbered L3, L4, R3 and R4 are deformed, and the detection module detects that the resistance values ​​of L3, L4, R3 and R4 change, thereby determining that a collision occurs at the battery pack position corresponding to the intersection of L3, L4, R3 and R4, so as to determine the collision position.

[0062] In one embodiment, the first direction is perpendicular to the second direction.

[0063] In one embodiment, if Figure 5 As shown, the strain gauge resistor wire 41 includes an inner core 411 and an insulating layer 412 wrapped around the outer periphery of the inner core 411 .

[0064] In one embodiment, the inner core 411 may be a metal wire or a strain-type resistor material such as a semiconductor.

[0065] In one embodiment, the melting point of the material of the insulating layer 412 is in the range of 80° C. to 250° C.

[0066] In one embodiment, if Figure 4 As shown, the strain gauge resistor wire 41 includes a first part 42 and a second part 43 that are intertwined, the first end of the first part 42 in the length direction is integrally connected to the first end of the second part 43 in the length direction, the end face of the second end of the first part 42 in the length direction is arranged side by side with the end face of the second end of the second part 43 in the length direction, so that the single strain gauge resistor wire 41 is wound end to end to form a twisted pair, the inner core 411 of the first part 42 and the inner core 411 of the second part 43 are insulated by an insulating layer 412, so that the head and tail ends of the single strain gauge resistor wire 41 are located at the same end of the twisted pair, so that the acquisition line connected to the head and tail ends of the strain gauge resistor wire 41 can be arranged at the same end of the twisted pair to simplify the line.

[0067] The detection module is used to detect the resistance change of the strain gauge resistance wire 41 when the insulating layer 412 is melted and the inner core 411 of the first part 42 and the inner core 411 of the second part 43 are short-circuited, so as to locate the thermal runaway position.

[0068] When the battery has thermal runaway, the insulating layer 412 of the strain gauge resistor wire 41 corresponding to the thermal runaway position melts, causing the inner core 411 of the first part 42 and the inner core 411 of the second part 43 of the twisted pair to short-circuit at the thermal runaway position. The detection module detects that the resistance value of the short-circuited strain gauge resistor wire 41 becomes smaller, thereby determining that the position corresponding to the strain gauge resistor wire 41 with the reduced resistance value is the thermal runaway position.

[0069] Specifically, the second confirmation module compares the resistance difference value of all strain gauge resistor wires 41 according to the second threshold value, and when the resistance difference value of the twisted pair is less than the second threshold value of the second confirmation module, the serial number of the twisted pair whose resistance difference is less than the second threshold value is captured to determine the battery thermal runaway position. Usually, the second threshold value is zero.

[0070] In one embodiment, if Figure 6 As shown, the power supply circuit includes a power supply and multiple reference resistors 7. The power supply provides a constant voltage for the power supply circuit. The reference resistors 7 have a set resistance. The reference resistors 7 are electrically connected between the power supply and one end of the corresponding strain gauge resistance wire 41. The other end of the strain gauge resistance wire 41 is grounded.

[0071] Specifically, based on the principle that the current in a series circuit is equal everywhere, the ratio of the voltage across the strain gauge wire 41 to the voltage across the reference resistor 7 is the same as the ratio of the resistance value of the strain gauge wire 41 to the resistance value of the reference resistor 7. Under the conditions that the voltage provided by the power supply, the resistance value of the reference resistor 7 and the voltage across the strain gauge wire 41 are known, the resistance of the strain gauge wire 41 can be calculated.

[0072] In other embodiments, the resistance of the strain gauge resistance wire 41 may be calculated by measuring the current of the power supply circuit and the voltage of the strain gauge resistance wire 41 .

[0073] In one embodiment, the power source is a power chip, which is integrated into a battery management system. The power chip distributes the power of the battery pack to the power supply circuit without connecting an additional power source.

[0074] In one embodiment, if Figure 6 As shown, the detection module is a single chip microcomputer, and one end of the strain gauge resistor wire 41 is connected to the ADC interface of the single chip microcomputer, so that the single chip microcomputer can obtain the voltage of all strain gauge resistor wires 41 in real time according to the set frequency, thereby obtaining the resistance change of the strain gauge resistor wire 41.

[0075] It should be noted that a plurality of strain gauge resistor wires 41 may be connected to one power chip, or each strain gauge resistor wire 41 may be connected to one power chip. Figure 6 In the electrical connection diagram shown, one end of all strain gauge resistor wires 41 of the battery pack collision detection device 4 is connected to the same power chip, so that the power chip provides voltage for the entire battery pack collision detection device 4 .

[0076] In one embodiment, a plurality of battery cell groups 3 are provided, a plurality of battery pack collision detection devices 4 are provided, and a plurality of strain gauge resistor wires 41 of each battery pack collision detection device are insulated and arranged between the corresponding battery cell group 3 and the box.

[0077] In one embodiment, if Figure 1 As shown, two battery cell groups 3 are provided, and two battery pack collision detection devices 4 are provided. Figure 1 Only one battery pack collision detection device 4 is shown.

[0078] In one embodiment, the box body includes a tray 5, a liquid cooling plate 2, a buffer layer 6 and an upper cover plate 1. The top side of the tray 5 has an opening, a battery cell slot is formed in the tray 5, the battery cell group 3 is placed in the battery cell slot, the upper cover plate 1 covers the top side opening of the tray 5, the liquid cooling plate 2 is arranged between the battery cell group 3 and the upper cover plate 1, and the buffer layer 6 is arranged at the bottom of the tray 5.

[0079] In addition, the battery pack collision detection device 4 may also have an alarm function, which is implemented by one or more of the multimedia components and the communication components. The multimedia components may include a screen and an audio component. The screen may be, for example, a touch screen, and the information detected by the battery pack collision detection device 4 may be displayed on the screen. The audio component is used to output and / or input audio signals. For example, the audio component may include a microphone, and the microphone is used to receive external audio signals. The received audio signals may be further stored in a memory or sent through a communication component. The audio component also includes at least one speaker for outputting audio signals.

[0080] The communication component can realize wired communication or wireless communication of the multimedia component, and the communication component can include: Wi-Fi module, Bluetooth module, NFC module, etc.

[0081] In other embodiments, the plurality of strain gauge resistor wires 41 may be arranged in parallel or inclined at a certain angle.

[0082] In other embodiments, the angle between the first direction and the second direction can be adjusted according to the actual shape of the battery cell group 3 or detection requirements, and the angle can be 30°, 60°, etc.

[0083] In other embodiments, the power chip can be replaced by a battery, the reference resistor 7 is connected between the positive electrode of the battery and one end of the corresponding strain gauge resistor wire 41, the other end of the strain gauge resistor wire 41 is electrically connected to the negative electrode of the battery, and the battery provides a constant voltage for the power supply circuit.

[0084] In other embodiments, the strain gauge resistor wire 41 may only include the inner core 411 . In this case, two layers of insulating pads may be added, and all the strain gauge resistor wires 41 may be disposed between the two layers of insulating pads.

[0085] In addition, an embodiment of the present invention provides a battery pack collision detection device 4 , the structure of which is the same as the structure of the battery pack collision detection device 4 in any of the above embodiments, and will not be described in detail herein.

[0086] In addition, an embodiment of the utility model provides an electrical device, including the battery pack collision detection device 4 or the battery pack of the above embodiment, and the electrical device is not limited to electric vehicles, speedboats, etc.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack collision detection device, characterized in that: It comprises a detection module, a power supply circuit and a plurality of strain gauge resistor wires (41), wherein the plurality of strain gauge resistor wires (41) are suitable for being arranged in an insulated manner between a battery cell group (3) of a battery pack and a box body, and each of the strain gauge resistor wires (41) is electrically connected to the power supply circuit; The power supply circuit is used to provide voltage to the strain gauge resistance wire (41); The detection module is used to detect the change in resistance value of the deformed strain-type resistance wire (41) to locate the impacted position of the battery pack.

2. The battery pack collision detection device according to claim 1, characterized in that: The plurality of strain-type resistance wires (41) include a plurality of first resistance wires arranged at intervals along a first direction and a plurality of second resistance wires arranged at intervals along a second direction, the angle between the first direction and the second direction is not zero, and at least one of the first resistance wires intersects with a plurality of the second resistance wires to form a resistance wire network.

3. The battery pack collision detection device according to claim 2, characterized in that: The first direction is perpendicular to the second direction.

4. The battery pack collision detection device according to claim 1, characterized in that: The power supply circuit comprises a power supply and a plurality of reference resistors (7), the power supply provides a constant voltage for the power supply circuit, and the plurality of reference resistors (7) correspond one to one with the plurality of strain gauge resistance wires (41); The reference resistor (7) has a set resistance value, and is electrically connected between the power supply and one end corresponding to the strain gauge resistance wire (41), and the other end of the strain gauge resistance wire (41) is grounded.

5. The battery pack collision detection device according to claim 4, characterized in that: The power source is a power chip, and the power chip is integrated into a battery management system.

6. The battery pack collision detection device according to claim 1, characterized in that: The strain type resistance wire (41) comprises an inner core (411) and an insulating layer (412) wrapped around the outer periphery of the inner core (411).

7. The battery pack collision detection device according to claim 6, characterized in that: The strain gauge resistor wire (41) comprises a first part (42) and a second part (43) which are intertwined with each other, a first end of the first part (42) in the length direction is integrally connected with a first end of the second part (43) in the length direction, and an end surface of the second end of the first part (42) in the length direction is arranged side by side with an end surface of the second end of the second part (43) in the length direction; The detection module is used to detect the resistance change of the strain gauge resistance wire (41) when the insulation layer (412) is melted and the inner core (411) of the first part (42) and the inner core (411) of the second part (43) are short-circuited, so as to locate the thermal runaway position.

8. A battery pack, characterized in that: It comprises a box, a battery cell group (3) and a battery pack collision detection device (4) as claimed in any one of claims 1 to 7, wherein the battery cell group (3) and the battery pack collision detection device (4) are installed in the box.

9. The battery pack according to claim 8, characterized in that: A plurality of the battery cell groups (3) are provided, a plurality of the battery pack collision detection devices (4) are provided, and a plurality of the strain gauge resistance wires (41) of each battery pack collision detection device (4) are insulated and arranged between the corresponding battery cell group (3) and the box.

10. An electrical device, characterized in that: A battery pack collision detection device (4) comprising any one of claims 1 to 7 or a battery pack according to any one of claims 8 to 9.

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