Battery packs, power tool systems and charging kits

Abstract

The application discloses a battery pack, an electric tool system and a charging combination, which comprises a shell, a battery cell assembly, a plurality of non-cylindrical battery cell units in the battery cell assembly, a layering arrangement of the battery cell units, an elastic battery cell component on at least one side of the battery cell assembly to protect the battery cell assembly, a battery pack interface electrically connected with the battery cell assembly, a switch connected between the battery cell assembly and the battery pack interface, a deformation sensor on one side of the elastic battery cell component for detecting a parameter related to a deformation amount of the battery cell assembly, and a controller configured to output a control signal for turning off the switch to cut off the electrical connection between the battery cell assembly and the battery pack interface when the parameter related to the deformation amount of the battery cell assembly detected by the sensor meets a preset condition. The above technical scheme can reduce the safety hazard of explosion caused by the internal deformation of the battery pack and improve the safety and reliability of the battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to a battery pack, a power tool system and a charging combination. BACKGROUND

[0002] Based on the use demand of portability, more and more power tools currently use battery packs as power sources.

[0003] The existing battery pack for powering the power tool mostly uses cylindrical lithium cells, and connects multiple cylindrical lithium cells in series and parallel to ensure sufficient power output to improve the endurance and work efficiency of the power tool.

[0004] During the charging process of the cylindrical lithium cell, a small amount of gas will be generated in the battery due to the evaporation of the lithium ion electrolyte. Under normal circumstances, this part of gas will be absorbed when the battery is discharged. However, if the charging and discharging current is too large due to long-time charging, the gas generation will be intensified, the internal pressure of the battery will be increased, and the battery swelling phenomenon will occur. Moreover, the battery may be swollen and deformed during the manufacturing process and the collision with external force, which will affect the battery characteristics, and further affect the service life and stability of the battery. With the development of battery technology, pouch batteries have emerged, but they usually use flexible shells, so the pouch battery is more likely to swell and deform during the charging and discharging process. At the same time, in the worst case, flammable gases such as electrolyte or broken materials may be discharged outward, which may cause fire or explosion.

[0005] Therefore, in the power tool using the battery pack for power supply, there is a safety hazard of explosion caused by the swelling and deformation of the battery pack. SUMMARY

[0006] In order to solve the problems of the prior art, the purpose of the present application is to provide a battery pack, a power tool system and a charging system, which can reduce the safety hazard of explosion caused by the internal deformation of the battery pack, and improve the safety and reliability of the battery pack.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] A battery pack, comprising: a housing comprising an upper housing and a lower housing assembled at a boundary surface to form an inner cavity; a cell assembly disposed in the inner cavity; the cell assembly comprising a plurality of non-cylindrical cell units; the cell units being arranged in a stack; a cell elastic member disposed around the cell assembly to seal the cell assembly; a battery pack interface electrically connected to at least the cell assembly; a switch connected between the cell assembly and the battery pack interface; a deformation sensor located on one side of the cell elastic member and configured to detect a parameter related to a deformation amount of the cell assembly; and a controller configured to output a control signal to turn off the switch to cut off the electrical connection between the cell assembly and the battery pack interface when the sensor detects that the parameter related to the deformation amount of the cell assembly meets a preset condition.

[0009] Optionally, the sensor is located on the upper side of the cell elastic member and has a preset distance from the upper surface of the cell elastic member.

[0010] Optionally, the preset distance is greater than or equal to 1 mm and less than or equal to 6 mm.

[0011] Optionally, the battery pack further comprises a first support plate located on the upper side of the lower housing, the first support plate and the lower housing forming a receiving space for receiving the cell assembly; and the sensor is disposed on the lower surface of the first support plate.

[0012] Optionally, the battery pack further comprises a second support plate comprising an elastic plate having a certain elastic coefficient, the second support plate being disposed between the cell assembly and the first support plate and configured to support the sensor.

[0013] Optionally, the second support plate is fixedly connected to the lower housing by an elastic arm.

[0014] Optionally, the battery pack further comprises an alarm connected to the controller; and the controller is configured to output an alarm signal to trigger the alarm to alarm when the sensor detects that the parameter related to the deformation amount of the cell assembly meets the preset condition.

[0015] Optionally, the sensor comprises a detection terminal; and the controller is configured to acquire a voltage of the detection terminal; and output the control signal to turn off the switch to cut off the electrical connection between the cell assembly and the battery pack interface when the voltage is less than or equal to a first preset voltage.

[0016] Optionally, the sensor comprises a detection terminal; and the controller is configured to acquire a voltage of the detection terminal; and output the control signal to turn off the switch to cut off the electrical connection between the cell assembly and the battery pack interface when the voltage is greater than a second preset voltage.

[0017] Optionally, the battery core elastic member is formed around the battery core assembly by glue injection.

[0018] A power tool system comprises: a power tool including functional parts and a motor for driving the functional parts; a battery pack for providing power to the power tool; the battery pack comprising: a shell including an upper shell and a lower shell assembled at a boundary surface to form an inner cavity; a cell assembly arranged in the inner cavity; the cell assembly including a plurality of non-cylindrical cell units; the cell units being arranged in a stacked manner; a cell elastic member arranged around the cell assembly to seal the cell assembly; a battery pack interface electrically connected to the cell assembly and to the power tool to provide power to the power tool; the cell assembly, the battery pack interface and the motor constitute a discharge circuit, and the motor consumes the power of the cell assembly; a sensor located on one side of the cell elastic member for detecting parameters related to the deformation of the cell assembly; the power tool system further comprises: a switch arranged on the discharge circuit; a controller configured to output a control signal to disconnect the switch to cut off the discharge circuit when the sensor detects that the parameters related to the deformation of the cell assembly meet a preset condition.

[0019] A charging combination includes: a charger including a charging circuit; a battery pack for providing electrical energy to an electric tool; the battery pack includes: a shell including an upper shell and a lower shell assembled at a boundary surface to form an inner cavity; a cell assembly arranged in the inner cavity; the cell assembly includes a plurality of non-cylindrical cell units; the cell units are arranged in a stacked manner; a cell elastic member is arranged around the cell assembly to seal the cell assembly; a battery pack interface is electrically connected to the cell assembly and to the charging circuit to provide electrical energy to the cell assembly; the cell assembly, the battery pack interface, and the charging circuit constitute a charging circuit; a sensor is located on one side of the cell elastic member and is used to detect parameters related to the deformation of the cell assembly; the charging combination also includes: a switch arranged on the charging circuit; a controller is configured to: output a control signal to disconnect the switch to cut off the charging circuit when the sensor detects that the parameters related to the deformation of the cell assembly meet preset conditions.

[0020] The benefit of the present invention is that it can provide a battery pack and an electric tool using the battery pack, reducing the safety hazard of explosion caused by internal deformation of the battery pack and effectively improving the safety and reliability of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the power tool system provided in Example 1;

[0022] Figure 2 yesFigure 1 The structural stereogram of the power tool in FIG;

[0023] Figure 3 is a structural diagram of the battery pack provided in Example 1;

[0024] Figure 4 yes Figure 3 The schematic diagram of the structure of the battery pack shown is without the upper shell;

[0025] Figure 5 yes Figure 3 The schematic diagram of the internal structure of the battery pack shown here is excluding the shell and the cell elastic parts;

[0026] Figure 6 yes Figure 3 The battery cell assembly shown includes a schematic diagram of the internal structure of some battery cell elastic parts;

[0027] Figure 7 is a schematic diagram of the internal structure between the lower housing and the first support plate of Example 1;

[0028] Figure 8 is a schematic diagram of the internal structure between the lower housing and the first support plate of the second embodiment;

[0029] Figure 9 is a block diagram of a protection circuit for a battery pack according to the first embodiment;

[0030] Figure 10 is a block diagram of a protection circuit for a battery pack according to a second embodiment;

[0031] Figure 11 is a block diagram of a protection circuit for a power tool system according to the first embodiment;

[0032] Figure 12 This is a block diagram of a protection circuit for a charging assembly according to the first embodiment. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Figure 1 FIG. 1 shows a power tool system 100 including a power tool 10 and a battery pack 20 adapted to the power tool 10 to power the power tool 10. Figure 1 In the embodiment, the power tool 10 is an impact wrench. Although this embodiment relates to an impact wrench, it should be understood that the present application is not limited to the disclosed embodiment and is applicable to other types of power tools 10, such as garden tools such as lawn mowers, pruners, hair dryers, and chainsaws; torque output tools such as electric drills and electric hammers; sawing tools such as electric circular saws, jigsaws, and reciprocating saws; and grinding tools such as angle grinders and sanders.

[0035] Referring to Figure 2 As shown, the power tool 10 includes a tool body 11 and a tool interface 12 and a tool mating portion 13 disposed on the tool body 11.

[0036] The tool body 11 includes a motor 111, an output shaft 112 and an impact mechanism 113. The output shaft 112 is driven by the motor 111; the impact mechanism 113 connects the motor 111 and the output shaft 112, and the impact mechanism 113 is driven by the motor 111 and exerts an impact force on the output shaft 112. The power tool 10 body further includes a handle 114, which can be held by a user to operate the power tool 10. A trigger switch 115 is also provided on the handle, which is used to be driven by the user of the power tool 10 to start or stop the motor 111 from running. In addition, the power tool 10 is also provided with the tool interface 12 and the tool mating portion 13 at the lower end of the handle 114, which is used for detachable connection with the battery pack 20. In some embodiments, the tool mating portion 13 is configured such that the battery pack 20 can be detached therefrom when the user slides the battery pack 20 towards the front of the power tool 10 body.

[0037] In the following description, the up-down, front-back directions are described in the directions indicated by the arrows in the following figure. Figure 3

[0038] Referring to Figures 3 to 5 As shown, the battery pack 20 includes a housing 23, a battery cell assembly 24, a battery pack coupling portion 22 and a battery pack interface 21. The voltage of the battery pack 20 is usually 10.8V, 24V, 36V, 48V, 56V or 80V, and the capacity of the battery pack 20 is greater than or equal to 5Ah, and further, the capacity of the battery pack is greater than or equal to 9Ah. The battery pack 20 is configured with the battery pack interface 21 and the battery pack coupling portion 22. The battery pack interface 21 is used to adapt the tool interface 12 to power the power tool 10, and the battery pack interface 21 can also adapt the charger to charge the battery pack 20. The battery pack coupling portion 22 can be detachably connected with the tool mating portion 13 or the charger, so that the battery pack 20 can power the power tool 10 or the charger can charge the battery cell assembly 24.

[0039] The housing 23 includes an upper housing 231 and a lower housing 232 assembled at a boundary surface to form an inner cavity; the inner cavity formed by the assembly of the upper housing 231 and the lower housing 232 is used to fix and accommodate the battery cell assembly 24.

[0040] ​The electric cell assembly 24 is disposed in the inner cavity formed by the shell 23. The electric cell assembly 24 includes a plurality of electric cell units 241. The electric cell unit 241 includes an electric cell tab 242, which further includes an electric cell unit positive electrode 2421 and an electric cell unit negative electrode 2422, for outputting electric energy of the electric cell unit 241 or inputting electric energy to charge the electric cell unit 241. The electric cell assembly 24 further includes an electric cell assembly positive electrode terminal and an electric cell assembly negative electrode terminal, for outputting electric energy of the electric cell assembly 24 or inputting electric energy to charge the electric cell assembly 24. The electric cell assembly positive electrode terminal is connected in series between at least one of the electric cell unit positive electrodes and the battery pack positive electrode terminal, and the electric cell assembly negative electrode terminal is connected in series between at least one of the electric cell unit negative electrodes and the battery pack negative electrode terminal. Generally, the plurality of electric cell units 241 are connected in series, in parallel, or in a combination of series and parallel to form the electric cell assembly 24. The voltage of a single electric cell unit 241 is 4.2V. In some embodiments, the electric cell unit 241 is in a cylindrical structure, such as a 18650 battery. In other embodiments, the electric cell unit 241 is in a flat bag structure, and a plurality of electric cell units 241 are arranged in sequence in the up-down direction. The electric cell unit 241 can also be curved into an arc structure, such as a soft pack battery. The electric cell unit 241 further includes an electric cell unit 241 housing. The cylindrical battery generally uses a steel shell as the electric cell unit 241 housing, and the soft pack battery generally uses an aluminum plastic film as the electric cell unit 241 housing. It can be understood that the present application is not limited to the disclosed embodiments, and the structure of the electric cell unit 241 is not limited herein.

[0041] The battery pack interface 21 is formed on an upper surface of the shell 23 and is electrically connected to at least the electric cell assembly 24, for establishing physical and electrical connection with the power tool. Specifically, the battery pack interface 21 is formed on the upper surface of the upper shell 231. In some embodiments, the battery pack interface 21 includes a power supply positive interface 211, a power supply negative interface 212, and a power supply communication interface 213. The battery pack 20 outputs electric energy through the power supply positive interface 211 and the power supply negative interface 212; and the battery pack 20 communicates with the attached power tool or charger through the power supply communication interface 213. In a specific embodiment, the shell is provided with 2 power supply positive interfaces 211 and 2 power supply negative interfaces 212. It can be understood that the shell 23 can be provided with more or fewer power supply positive interfaces 211 and power supply negative interfaces 212 according to the electrical characteristics of the battery pack.

[0042] The battery pack further includes a first support plate 25, a main circuit board 26, and a terminal assembly 27.

[0043] The first support plate 25 is located on the upper side of the lower housing 232 and forms a receiving space with the lower housing 232 to receive the battery cell assembly 24. The first support plate 25 is detachably connected with the lower housing 232 to form the receiving space to receive the battery cell assembly 24. Similarly, the first support plate 25 also forms a receiving space with the upper housing 231 to receive the main circuit board 26, the terminal assembly 27 and other components. Specifically, the first support plate 25 has a flat plate structure.

[0044] The terminal assembly 27 includes a plurality of battery pack terminals and a terminal support seat 271. The terminal support seat 271 is used to receive and fix the plurality of battery pack terminals on the first support plate 25. The plurality of battery pack terminals further include a battery pack positive terminal 272, a battery pack negative terminal 273 and a battery pack communication terminal 274. The battery pack positive terminal 272 is electrically connected with the positive terminal of the battery cell assembly, i.e. the positive terminal of at least one battery cell unit, which is located in the power supply positive interface 211. The battery pack negative terminal 273 is electrically connected with the negative terminal of the battery cell assembly, i.e. the negative terminal of at least one battery cell unit, which is located in the power supply negative interface 212. The battery pack positive terminal 272 and the battery pack negative terminal 273 are configured to cooperate with the tool terminals of the power tool 10 to output the electric energy of the battery cell assembly 24 to the power tool 10. Specifically, the electric energy of the battery cell assembly 24 passes through the positive terminal of the battery cell assembly, the battery pack positive terminal 272, the tool interface 12 of the power tool, the motor 111, and then passes through the battery pack negative terminal 273, the negative terminal of the battery cell assembly back to the battery cell assembly 24. Therefore, the battery cell assembly 24, the plurality of battery pack terminals in the battery pack interface, and the motor 111 of the power tool form a discharge circuit, and the motor 111 consumes the electric energy of the battery cell assembly 24 through the discharge circuit. In addition, the battery pack communication terminal 274 is located in the power supply communication interface 213 and is used for communication with the connected power tool 10 or charger. As a specific embodiment, the battery pack terminals are respectively clamped on the tool terminals from both sides in the left-right direction by elastic force. Therefore, the tool terminals of the power tool are guided by the battery pack interface to be inserted into the battery pack terminals during the process of installing the battery pack into the power tool, so that the tool terminals are clamped by the battery pack terminals, thereby realizing the electrical connection between the power tool 10 and the battery pack 20.

[0045] The main circuit board 26 is arranged on the upper side of the first support plate 25 and is connected in series between the cell assembly 24 and the battery pack interface 21, and is used to collect electrical signals related to the battery pack 20. In some embodiments, the main circuit board 26 is connected in series between the cell assembly 24 and the battery pack communication terminal 274, and is used to transmit battery pack information to the power tool 10 attached to the battery pack 20 through the battery pack communication terminal 274. The battery pack information includes the discharge current of the battery pack, the temperature of the cell assembly 24 and / or the cell unit 241, the voltage of the cell unit 241, the internal resistance value of the cell unit 241, etc. Generally, the battery pack information is detected by a sensor, and therefore the battery pack 20 further includes a detection sensor. The number of detection sensors can be one or more. In some embodiments, the detection sensor can be a temperature sensor arranged on the surface of the cell assembly 24 or the surface of the cell unit 241, and the temperature sensor can be a thermistor. The detection sensor can also be a voltage sensor for detecting the voltage of the cell unit 241.

[0046] Referring to Figure 5 As shown, the battery pack 20 further includes a detection circuit board 28, and the detection sensor is integrated on the detection circuit board 28. In order to facilitate detection, the detection circuit board 28 is arranged on the side of the cell assembly where the cell tab 242 is located, i.e. on the side of the cell assembly 24 where the cell unit positive electrode 2421 and the cell unit negative electrode 2422 are located. It can be understood that the battery pack 20 further includes other types of sensors, so that the detection circuit board 28 can collect battery pack information through various sensors, and at the same time transmit the collected battery pack information to the main circuit board 26 and transmit to the attached power tool 10 or charger through the battery pack communication terminal 274. In some embodiments, the cell tab 242, i.e. the cell unit positive electrode 2421 and the cell unit negative electrode 2422, is arranged on the front end face or the rear end face of the cell unit 241.

[0047] Referring to Figure 6As shown, the battery pack 20 further comprises a cell elastic member 201, which is arranged on at least one side of the cell assembly 24 to protect the cell assembly 24. The cell assembly 24 has an upper surface and a lower surface, a front end surface and a rear end surface arranged between the upper surface and the lower surface, and a left side surface and a right side surface arranged on both sides of the first end surface. Among them, the front end surface and the rear end surface are oppositely arranged. In some embodiments, the cell elastic member 201 is arranged around the cell assembly 24, that is, the cell elastic member 201 is arranged around the upper surface, the lower surface, the front end surface, the rear end surface, the left side surface and the right side surface of the cell assembly 24 to seal the cell assembly 24 to achieve waterproof, dustproof and other functions. In other embodiments, the cell elastic member 201 is arranged at both ends of the cell assembly, and at least part of the cell elastic member 201 encapsulates the tab to fix the tab. In this way, the cell elastic member 201 is used to protect the cell assembly 24, prevent relative displacement between the cell units 241 due to bumps or vibrations, and avoid the occurrence of extrusion or folding of the cell units 241 or the tab. Therefore, the cell elastic member 201 can improve the anti-falling and shock-absorbing performance of the battery pack 20, thereby improving the reliability of the battery pack 20; and the cell elastic member 201 is an elastic member that can better adapt to the swelling property of the battery pack 20. Moreover, the cell elastic member 201 can also improve the heat dissipation performance of the battery pack 20.

[0048] In some embodiments, the cell elastic member 201 encapsulates and fixes the cell assembly 24, the detection circuit board 28 and other connecting lines. In order to output or input electric energy from the cell assembly 24, the positive and negative lead-out sheets 243 and 244 of the cell assembly 24 extend out of the cell elastic member 201 and protrude from the cell elastic member 201, and are electrically connected with the battery pack positive terminal 272 and the battery pack negative terminal 273, respectively. In some embodiments, the cell elastic member 201 is formed around the cell assembly 24 in a glue injection manner. Specifically, the cell assembly 24 is placed in the lower shell 232, and the cell elastic member 201 is formed on the outer surface of the entire cell assembly 24 in a glue injection manner to seal the cell assembly 24 and achieve waterproof, dustproof and other functions.

[0049] Referring to Figure 7 As shown, the battery pack 20 further comprises a deformation sensor 202 arranged on one side of the cell elastic member 201 for detecting a parameter related to the deformation amount of the cell assembly 24. Specifically, the deformation sensor 202 is located on the upper side of the cell elastic member 201 and is spaced apart from the upper surface of the cell elastic member 201 by a predetermined distance. The deformation sensor 202 is arranged between the cell elastic member 201 and the first support plate 25, and in some embodiments, the deformation sensor 202 is specifically arranged on the lower surface of the first support plate 25 and is spaced apart from the upper surface of the cell elastic member 201 by 1 to 6 millimeters, that is, the predetermined distance is greater than or equal to 1 millimeter and less than or equal to 6 millimeters.

[0050] In this embodiment, the deformation sensor 202 is connected to the main circuit board 26 through the first connecting line 203 to output the sensing signal of the deformation sensor 202 to the main circuit board 26. As an embodiment, the deformation sensor 202 is a pressure sensor, which is capable of outputting the sensing signal when subjected to pressure. Specifically, referring to FIG. 2, when the battery cell assembly 24 is deformed, for example, the battery cell assembly 24 is expanded to increase the first thickness H1, the battery cell elastic member 201 is deformed to protrude upward to contact the deformation sensor 202, the deformation sensor 202 senses the pressure from the battery cell elastic member 201 to output the sensing signal, and the sensing signal is transmitted to the main circuit board 26 through the first connecting line. In this way, the deformation sensor 202 and the first connecting line are arranged outside the battery cell elastic member 201, which facilitates the maintenance and replacement of the deformation sensor 202 when it fails. Figure 5

[0051] On the one hand, since the battery cell assembly 24 will be deformed to a certain extent when it is in normal operation, a preset distance is reserved between the deformation sensor 202 and the battery cell elastic member 201 to ensure the deformation interval when the battery cell assembly 24 is in normal operation, thereby improving the reliability of the deformation sensor 202 and reducing the probability of false triggering. On the other hand, since the battery cell elastic member 201 surrounds the battery cell assembly 24 to form a sealed cavity, the temperature change of the battery pack during operation can cause the air in the sealed cavity to expand, resulting in an increase in air pressure in the sealed cavity. Therefore, arranging the deformation sensor 202 outside the battery cell elastic member 201 can also avoid the influence of the sealed cavity formed by the battery cell elastic member 201 on the deformation detection of the battery cell assembly 24, thereby improving the reliability of the deformation sensor 202 and the safety and reliability of the battery pack. In addition, the first support plate 25 is arranged between the battery cell assembly 24 and the main circuit board 26, so that even if the battery cell assembly 24 is deformed, the first support plate 25 can effectively hinder the deformation of the battery cell assembly 24 to protect the main circuit board 26 and prevent the main circuit board 26 from being damaged by the deformation of the battery cell assembly 24.

[0052] In other embodiments, referring to Figure 8 ​As shown, the battery pack 20 further comprises a second support plate 204, which comprises an elastic plate with a certain elastic coefficient. The second support plate 204 is arranged between the cell assembly 24 and the first support plate 25, and is used to support the deformation sensor 202. In this embodiment, the second support plate 204 is fixedly connected to the lower shell 232 through elastic arms with a certain elastic coefficient. The second support plate 204 further comprises a plurality of elastic arms, which are detachably connected to the lower shell 232 through screws. It can be understood that the second support plate 204 can be made of an elastic material, as long as it can be deformed along with the deformation of the cell assembly 24, which is not limited herein. Specifically, the deformation sensor 202 is arranged on the upper surface of the second support plate 204, and is spaced apart from the upper surface of the cell elastic member 201 covering the outer surface of the cell assembly 24 by 1-6 mm.

[0053] In this embodiment, the deformation sensor 202 is connected to the detection circuit board 28 through the second connecting line 205 to output the sensing signal of the deformation sensor 202 to the detection circuit board 28. Specifically, when the cell assembly 24 deforms, for example, the cell assembly 24 expands to increase the first thickness H1, the cell elastic member 201 deforms and protrudes upward to contact the second support plate 204, and the deformation sensor 202 arranged on the second support plate 204 also protrudes upward until it contacts the first support plate 25. Therefore, the deformation sensor 202 senses the pressure from the first support plate 25 and the second support plate 204 and outputs a sensing signal, which is transmitted to the detection circuit board 28 through the second connecting line 205. The detection circuit board 28 collects the sensing signal and transmits it to the main circuit board 26. The specific shape of the first connecting line 203 and the second connecting line 205 can be set according to the specific structure of the battery pack, which is not limited herein.

[0054] Figure 9 A block diagram of the protection circuit of the battery pack is shown. As shown in Figure 9 The battery pack protection circuit 30 comprises a cell assembly 31, a switch 32, a controller 33, a battery pack positive terminal 341, a battery pack negative terminal 342, and a deformation sensor 33. The battery pack positive terminal 341 and the battery pack negative terminal 342 are arranged in the battery pack interface 34, and the cell assembly 31 further comprises a cell assembly positive terminal 311 and a cell assembly negative terminal 312.

[0055] The switch 32 is connected between the battery cell assembly 31 and the battery pack interface 34, and is used to turn on or turn off the electrical connection between the battery cell assembly 31 and the battery pack interface 34. The on and off of the switch 32 is controlled by the controller 33. In some embodiments, the switch is arranged between the positive terminal 311 of the battery cell assembly and the positive terminal 341 of the battery pack; in other embodiments, the switch is arranged between the negative terminal 312 of the battery cell assembly and the negative terminal 342 of the battery pack. Specifically, the switch 32 is arranged on a circuit board, and the switch 32 can be a metal oxide semiconductor transistor, and can also be an insulated gate bipolar transistor, a relay, or other electronic switch.

[0056] The controller 33 is connected with the deformation sensor 35 and configured to output a control signal to turn off the switch 32 to cut off the electrical connection between the battery cell assembly 31 and the battery pack interface 34 when the deformation sensor 35 detects that a parameter related to the deformation of the battery cell assembly 31 meets a preset condition. In some embodiments, the deformation sensor 35 includes at least a detection terminal 351 connected with the controller 33. In some embodiments, the parameter related to the deformation of the battery cell assembly 31 is a voltage parameter, and specifically, the output voltage of the detection terminal 351 changes constantly with the pressure on the deformation sensor 35 after the deformation sensor 35 is powered on. Therefore, the controller 33 is specifically configured to obtain the voltage of the detection terminal 351 and output a control signal to turn off the switch 32 to cut off the electrical connection between the battery cell assembly 31 and the battery pack interface 34 when the voltage of the detection terminal 351 is less than or equal to a first preset voltage. In this embodiment, since the resistance of the deformation sensor 35 decreases with the increasing pressure on the battery cell assembly 31, the voltage of the detection terminal 351 decreases constantly with the increasing pressure on the deformation sensor 35, and the controller 33 determines that the battery cell assembly 31 is deformed to turn off the switch 32 when the voltage decreases to the first preset voltage, thereby cutting off the electrical connection between the battery cell assembly 31 and the battery pack interface 21 to protect the safety of the battery pack. Specifically, the deformation sensor 35 can be one of a strain pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric pressure sensor, an inductive pressure sensor, or a Hall pressure sensor. Therefore, according to the selected deformation sensor 35, the parameter related to the deformation of the battery cell assembly 31 obtained by the controller 33 can also be a resistance value, a current value, an inductance value, etc., which are not limited herein. It can be understood that the present application includes but is not limited to the disclosed embodiments, and the preset condition for the controller 33 to control the switch 32 to turn on or off can also be different according to the specific circuit of the deformation sensor 35. For example, the controller 33 can also be configured to output a control signal to turn off the switch 32 to cut off the electrical connection between the battery cell assembly 31 and the battery pack interface 21 when the voltage of the detection terminal 351 is greater than or equal to the first preset voltage to protect the safety of the battery pack.

[0057] In some embodiments, the parameter related to the deformation of the battery cell assembly 31 is a voltage parameter, and specifically, the output voltage of the detection terminal 351 changes constantly with the pressure on the deformation sensor 35 after the deformation sensor 35 is powered on. Therefore, the controller 33 is specifically configured to obtain the voltage of the detection terminal 351 and output a control signal to turn off the switch 32 to cut off the electrical connection between the battery cell assembly 31 and the battery pack interface 34 when the voltage of the detection terminal 351 is less than or equal to a first preset voltage. Figure 10As shown, the battery pack protection circuit 40 comprises an alarm 46 which can be triggered to alarm. The controller 43 is configured to output an alarm signal to trigger the alarm 46 to alarm when the parameter related to the deformation amount of the battery cell assembly 41 detected by the deformation sensor 45 meets a preset condition. Specifically, the deformation sensor 45 comprises at least a detection terminal 451 connected to the controller 43, and the controller 43 is specifically configured to acquire the voltage of the detection terminal 451 and output an alarm signal to trigger the alarm 46 to alarm when the voltage is less than or equal to a first preset voltage. In this embodiment, since the resistance of the deformation sensor 45 gradually decreases as the pressure on the deformation sensor 45 increases due to the continuous deformation of the battery cell assembly 41, the voltage of the detection terminal 451 continuously decreases as the pressure on the deformation sensor 45 increases, until the voltage decreases to the first preset voltage, at which time the controller 43 determines that the battery cell assembly 41 deforms and outputs an alarm signal to trigger the alarm 46 to alarm. The alarm 46 can be a buzzer which emits a buzzing sound to remind the user that there is a safety hazard in the battery pack. The alarm 46 can also be other electronic devices, such as an LED lamp, which can be triggered to flash to remind the user that the battery cell assembly 41 deforms and there is a safety hazard.

[0058] To further improve the reliability of the deformation sensor 45, the controller 43 needs to determine whether the deformation sensor 45 is reliable before determining whether the battery cell assembly 41 deforms. Therefore, the controller 43 is configured to acquire the voltage of the detection terminal 451 and output a control signal to turn off the switch to cut off the electrical connection between the battery cell assembly 41 and the battery pack interface 44 when the voltage is greater than a second preset voltage. In this embodiment, if the deformation sensor 45 is reliable, the voltage should be less than or equal to the second preset voltage; if the voltage of the detection terminal 451 is greater than the second preset voltage, it indicates that the deformation sensor 45 is open, and thus the deformation sensor 45 is determined to be invalid. To ensure the safety of the battery pack, the controller 43 turns off the switch to cut off the electrical connection between the battery cell assembly 41 and the battery pack interface 44. Conversely, if the voltage of the detection terminal 451 is less than or equal to the second preset voltage, it indicates that the deformation sensor 45 is reliable, and the voltage is continuously determined to be less than or equal to the first preset voltage to determine whether the battery cell assembly 41 deforms. The first preset voltage is less than the second preset voltage.

[0059] In other embodiments, the switch of the battery pack protection circuit is arranged in the power tool system, specifically on the discharge circuit. Figure 11 A protection circuit block diagram of a power tool system in an embodiment is shown, which is described with reference to Figure 11As shown, the power tool system includes a power tool 50 and a battery pack 60. The battery pack 60 is attached to the power tool 50, and the battery pack positive terminal 641 and the battery pack negative terminal 642 cooperate with the tool positive terminal 531 and the tool negative terminal 532 of the power tool to output the electric energy of the battery cell assembly 61 to the power tool 50, and the battery pack communication terminal and the tool communication terminal are connected to communicate with the power tool. In this embodiment, the switch 51 is arranged on a discharge circuit formed by the battery cell assembly 61, the battery pack interface 64, and the motor 52 of the power tool, and is used at least to turn on or turn off the electrical connection between the battery pack and the motor 52 of the power tool. The on and off of the switch 51 is also controlled by the controller 63, and specifically, the controller 63 sends a control signal to turn off the switch 51 through the battery pack communication terminal. The controller 63 is configured to output the control signal to turn off the switch 51 to cut off the discharge circuit when the parameter related to the deformation amount of the battery cell assembly 61 detected by the deformation sensor 62 meets the preset condition, thereby protecting the safety of the power tool system. The deformation sensor 62 at least includes a detection terminal 621 connected to the controller 63, and the controller 63 is specifically used to obtain the voltage of the detection terminal 621 and output the control signal to turn off the switch 51 to cut off the discharge circuit when the voltage is less than or equal to a first preset voltage. Since the resistance of the deformation sensor 62 gradually decreases as the pressure borne by the battery cell assembly 61 increases with continuous deformation, the voltage of the detection terminal 621 continuously decreases as the pressure borne by the deformation sensor 62 increases, until the voltage decreases to the first preset voltage, at which time the controller 63 determines that the deformation of the battery cell assembly 61 causes the switch 51 to turn off, thereby cutting off the discharge circuit and protecting the safety of the battery pack. It is worth noting that although the switch 51 is arranged in the power tool in this embodiment, the switch 51 can also be arranged in the battery pack, which is not limited herein.

[0060] In order to further improve the reliability of the deformation sensor 62, the controller 63 determines whether the deformation sensor 62 is reliable before determining whether the battery cell assembly 61 deforms. The controller 63 is configured to obtain the voltage of the detection terminal 621 and output the control signal to turn off the switch 51 to cut off the discharge circuit when the voltage is greater than a second preset voltage. In this embodiment, if the deformation sensor 62 is reliable, the voltage should be less than or equal to the second preset voltage; if the voltage of the detection terminal 621 is greater than the second preset voltage, it indicates that the deformation sensor 62 is open, thereby determining that the deformation sensor 62 is invalid. In order to ensure the safety of the battery pack, the controller 63 turns off the switch 51, thereby cutting off the discharge circuit. Conversely, if the voltage of the detection terminal 621 is less than or equal to the second preset voltage, it indicates that the deformation sensor 62 is reliable, and the voltage is further determined whether it is less than or equal to the first preset voltage to determine whether the battery cell assembly 61 deforms. The first preset voltage is less than the second preset voltage.

[0061] Figure 12 A protection circuit block diagram for the charging combination is shown in FIG. 8, and reference is made to Figure 12 As shown, the charging combination includes the battery pack 60 and the charger 80.

[0062] The charger 80 is configured to charge the battery pack. Exemplarily, the charger 80 includes a charging circuit 82 and a direct current output interface 83, and the charging circuit 82 includes an alternating current input interface and an alternating-direct current conversion circuit. Specifically, the alternating current input interface is configured to access alternating current, and in some embodiments, the alternating current input interface is connected with a power plug which is plugged into an alternating current socket to access alternating current from a power grid. The alternating current accessed by the alternating current input interface has a value ranging from 110V to 130V or from 210V to 230V. The alternating-direct current conversion circuit is electrically connected with the alternating current input interface to convert the alternating current into direct current, and the direct current output interface 83 is electrically connected with the alternating-direct current conversion circuit to output the direct current. The direct current output interface 83 further includes a charger positive terminal 831 and a charger negative terminal 832. The charger positive terminal 831 and the charger negative terminal 832 are configured to cooperate with the battery pack positive terminal 641 and the battery pack negative terminal 642 to provide electric energy to the cell assembly 61, and a charger communication terminal 833 and a battery pack communication terminal 643 are connected to communicate with the battery pack. In the present embodiment, a switch 81 is arranged on a charging loop formed by the cell assembly 61, the battery pack interface 64 and the charging circuit 82, and is configured to at least turn on or turn off the electrical connection between the battery pack and the charging circuit 82. The turning on and turning off of the switch is also controlled by the controller 63, and specifically, the controller 63 sends a control signal to turn off the switch through the battery pack communication terminal. The controller 63 is configured to output the control signal to turn off the switch to cut off the charging loop when the deformation sensor 62 detects that a parameter related to the deformation of the cell assembly 61 meets a preset condition, thereby protecting the safety of the charging combination. Specifically, the deformation sensor 62 at least includes a detection terminal 621, and the detection terminal 621 is connected with the controller 63, and the controller 63 is specifically configured to acquire the voltage of the detection terminal 621, and output the control signal to turn off the switch 81 to cut off the charging loop when the voltage is less than or equal to a first preset voltage. Since the resistance of the deformation sensor 62 decreases with the increase of the pressure, the voltage of the detection terminal 621 continuously decreases with the increase of the pressure of the deformation sensor 62, and until the voltage decreases to the first preset voltage, it is determined that the cell assembly 61 is deformed at this time, and the controller 63 turns off the switch 81 to cut off the charging loop, thereby protecting the safety of the battery pack. It is worth noting that although the present embodiment discloses that the switch is arranged in the charger 80, the switch can also be arranged in the battery pack, and there is no limitation herein.

[0063] In order to further improve the reliability of the deformation sensor 62, the controller 63 judges whether the deformation sensor 62 is reliable before judging whether the cell assembly 61 is deformed. The controller 63 is configured to obtain the voltage of the detection terminal 621, and output a control signal for turning off the switch 81 to cut off the charging circuit when the voltage is greater than a second preset voltage. In this embodiment, if the deformation sensor 62 is reliable, the voltage should be less than or equal to the second preset voltage. If the voltage of the detection terminal 621 is greater than the second preset voltage, it indicates that the deformation sensor 62 is open, and thus the deformation sensor 62 is judged to be invalid. In order to ensure the safety of the battery pack, the controller 63 turns off the switch 81 to cut off the charging circuit. Conversely, if the voltage of the detection terminal 621 is less than or equal to the second preset voltage, it indicates that the deformation sensor 62 is reliable, and the voltage is continuously judged to be less than or equal to a first preset voltage to judge whether the cell assembly 61 is deformed. The first preset voltage is less than the second preset voltage.

[0064] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the above embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A battery pack comprising: a housing comprising an upper housing and a lower housing assembled at an interface to form an inner cavity; A battery cell assembly is disposed in the inner cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are stacked and arranged; A battery core elastic member, located on at least one side of the battery core assembly to protect the battery core assembly; A battery pack interface, electrically connected to at least the battery cell assembly; A switch connected between the battery cell assembly and the battery pack interface; A deformation sensor, located on one side of the battery core elastic member, for detecting parameters related to the deformation of the battery core assembly; The controller is configured as: When the deformation sensor detects that the parameter related to the deformation amount of the battery cell assembly meets a preset condition, it outputs a control signal to disconnect the switch to cut off the electrical connection between the battery cell assembly and the battery pack interface; The battery core elastic member is arranged around the battery core assembly to seal the battery core assembly; The deformation sensor is located on the upper side of the battery core elastic member and is spaced a preset distance from the upper surface of the battery core elastic member; The range of the preset distance is greater than or equal to 1 mm and less than or equal to 6 mm.

2. The battery pack according to claim 1, wherein: include: a first support plate, located on the upper side of the lower housing, wherein the first support plate and the lower housing form an accommodating space for accommodating the battery cell assembly; The deformation sensor is arranged on the lower surface of the first support plate.

3. The battery pack according to claim 1, wherein: include: a first support plate, located on the upper side of the lower housing, wherein the first support plate and the lower housing form an accommodating space for accommodating the battery cell assembly; The second support plate includes an elastic plate with an elastic coefficient, is arranged between the battery core assembly and the first support plate, and is used to support the deformation sensor.

4. The battery pack according to claim 3, wherein: The second supporting plate is fixedly connected to the lower shell through an elastic arm.

5. The battery pack according to claim 1, wherein: include: an alarm, connected to the controller; The controller is configured to: When the deformation sensor detects that the parameters related to the deformation amount of the battery core component meet the preset conditions, an alarm signal is output to trigger the alarm device to alarm.

6. The battery pack according to claim 1, wherein: The deformation sensor includes a detection terminal; The controller is configured to: obtaining the voltage of the detection terminal; When the voltage is less than or equal to a first preset voltage, a control signal is output to disconnect the switch to cut off the electrical connection between the battery cell assembly and the battery pack interface.

7. The battery pack according to claim 1, wherein: The deformation sensor includes a detection terminal; The controller is configured to: obtaining the voltage of the detection terminal; When the voltage is greater than a second preset voltage, a control signal is output to disconnect the switch to cut off the electrical connection between the battery cell assembly and the battery pack interface.

8. The battery pack according to claim 1, wherein: The battery core elastic member is formed around the battery core assembly in a glue injection manner.

9. A power tool system comprising: An electric tool comprising an output shaft and a motor for driving the output shaft; a battery pack, providing electrical energy for the power tool; The battery pack includes: a housing comprising an upper housing and a lower housing assembled at an interface to form an inner cavity; A battery cell assembly is disposed in the inner cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are stacked and arranged; A battery core elastic member, located on at least one side of the battery core assembly to protect the battery core assembly; a battery pack interface, electrically connected to the battery core assembly and connected to the power tool to provide power to the power tool; The battery cell assembly, the battery pack interface, and the motor form a discharge circuit, and the motor consumes the electric energy of the battery cell assembly; A deformation sensor, located on one side of the battery core elastic member, for detecting parameters related to the deformation of the battery core assembly; The electric tool system further comprises: A switch is provided on the discharge circuit; The controller is configured as: When the deformation sensor detects that the parameter related to the deformation amount of the battery cell assembly meets a preset condition, outputting a control signal to disconnect the switch to cut off the discharge circuit; The battery core elastic member is arranged around the battery core assembly to seal the battery core assembly; The deformation sensor is located on the upper side of the battery core elastic member and is spaced apart from the upper surface of the battery core elastic member by a preset distance, wherein the preset distance ranges from greater than or equal to 1 mm to less than or equal to 6 mm.

10. A charging assembly comprising: a charger, including a charging circuit; Battery packs, which provide power to power tools; The battery pack includes: a housing comprising an upper housing and a lower housing assembled at an interface to form an inner cavity; A battery cell assembly is disposed in the inner cavity; the battery cell assembly comprises a plurality of non-cylindrical battery cell units; the battery cell units are stacked and arranged; A battery core elastic member, located on at least one side of the battery core assembly to protect the battery core assembly; a battery pack interface, electrically connected to the battery cell assembly and connected to the charging circuit to provide power to the battery cell assembly; The battery cell assembly, battery pack interface, and charging circuit constitute a charging circuit; A deformation sensor, located on one side of the battery core elastic member, for detecting parameters related to the deformation of the battery core assembly; The charging combination further comprises: A switch, provided on the charging circuit; The controller is configured as: When the deformation sensor detects that the parameter related to the deformation amount of the battery cell assembly meets a preset condition, outputting a control signal to disconnect the switch to cut off the charging circuit; The battery core elastic member is arranged around the battery core assembly to seal the battery core assembly; The deformation sensor is located on the upper side of the battery core elastic member and is spaced apart from the upper surface of the battery core elastic member by a preset distance, wherein the preset distance ranges from greater than or equal to 1 mm to less than or equal to 6 mm.

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