A battery pack protection circuit, a battery pack, and electronic equipment.

Abstract

The present application provides a battery pack protection circuit, a battery pack and an electronic device, relating to the technical field of battery pack charging protection. The battery pack protection circuit includes a first protection circuit and a second protection circuit connected in series in a charging circuit between the battery pack and a charger. When the temperature of the battery pack exceeds a preset temperature and / or the charging current of the battery pack exceeds a preset charging current, the first protection circuit can directly disconnect the connection between the battery pack and the charger to achieve over-temperature and / or over-current protection of the battery pack, without relying on the battery management system to detect the operating parameters of the battery pack. When the battery management system detects that the charging voltage of the battery pack exceeds a preset charging voltage, the connection between the battery pack and the charger is disconnected through the first protection circuit or the second protection circuit to achieve over-voltage protection of the battery pack. Through the redundant design of the first protection circuit and the second protection circuit, it is possible to avoid the situation where the battery pack gets out of control due to the failure of the first protection circuit, with high reliability and good safety.

Description

Technical Field

[0001] This application relates to the field of battery pack charging protection technology, and in particular to a battery pack protection circuit, a battery pack, and electronic equipment. Background Technology

[0002] With the rapid development of battery technology, battery packs have been widely used in various mobile devices, electric vehicles, and energy storage systems. However, during use, battery packs may experience abnormal situations such as current overload (overcurrent), abnormal temperature rise due to loose connections or external temperature (overtemperature), and continued charging after reaching the voltage threshold (overvoltage). If corresponding protective measures are not taken in time, these abnormal situations may lead to thermal runaway, fire, or even explosion of the battery pack, resulting in serious safety risks. Therefore, it is crucial to take effective protective measures for battery packs to ensure their safe and stable operation.

[0003] Currently, battery pack protection primarily relies on the Battery Management System (BMS) to monitor various operating parameters of the battery pack. When the BMS detects that a certain operating parameter of the battery pack has reached a corresponding threshold set by the BMS, it sends a command to the corresponding execution unit (such as a relay or smart fuse) to trigger protection measures, such as cutting off the circuit. However, existing protection schemes rely excessively on the BMS and execution units. In the event of a BMS failure or execution unit malfunction, the battery pack will be in an uncontrolled state, posing a significant safety hazard. Furthermore, the execution unit control circuit in existing technologies requires frequent power-on and power-off operations, which can easily cause damage; while smart fuses, although capable of handling overcurrent situations, are prone to misjudgment due to their instantaneous melting characteristic, and are also costly.

[0004] Therefore, in existing battery pack protection technologies, how to enhance the reliability of protection devices and reduce the risks caused by actuator failures while ensuring efficient detection has become an urgent problem to be solved. Utility Model Content

[0005] This application provides a battery pack protection circuit, a battery pack, and an electronic device, which can efficiently detect the battery pack and quickly disconnect the battery pack from the charger in the event of over-temperature, over-current, and / or over-voltage. It has high reliability and good safety.

[0006] In a first aspect, this application provides a battery pack protection circuit, including a first protection circuit and a second protection circuit;

[0007] The first terminal of the first protection circuit is electrically connected to the first terminal of the battery pack, the second terminal of the first protection circuit is electrically connected to the second terminal of the battery pack, the third terminal of the first protection circuit is electrically connected to the first terminal of the charger, and the fourth terminal of the first protection circuit is electrically connected to the first terminal of the battery management system.

[0008] The first terminal of the second protection circuit is electrically connected to the first terminal of the battery pack, the second terminal of the second protection circuit is electrically connected to the second terminal of the charger, and the third terminal of the second protection circuit is electrically connected to the second terminal of the battery management system.

[0009] The first protection circuit is used to disconnect the battery pack from the charger when the battery pack temperature is greater than a preset temperature and / or the battery pack charging current is greater than a preset charging current.

[0010] The second protection circuit is used to disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than a preset charging voltage;

[0011] The first protection circuit is also used to disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than the preset charging voltage and the second protection circuit fails.

[0012] In this embodiment, the battery pack protection circuit includes a first protection circuit and a second protection circuit. The first and second protection circuits are connected in series in the charging circuit between the battery pack and the charger. When the battery pack temperature exceeds a preset temperature and / or the battery pack charging current exceeds a preset charging current, the first protection circuit can directly disconnect the battery pack from the charger, achieving over-temperature and / or over-current protection for the battery pack, without relying on the battery management system to detect the battery pack's operating parameters. When the battery management system detects that the battery pack charging voltage exceeds a preset charging voltage and the second protection circuit is effective, it disconnects the battery pack from the charger through the second protection circuit, achieving overvoltage protection for the battery pack. If the second protection circuit fails, it disconnects the battery pack from the charger through the first protection circuit, continuing to achieve overvoltage protection for the battery pack. The redundant design of the first and second protection circuits avoids battery pack runaway due to the failure of the first protection circuit, resulting in high reliability and good safety.

[0013] In one possible design, the first protection circuit includes a temperature-controlled fuse and a control circuit.

[0014] The first end of the temperature-controlled fuse is electrically connected to the second end of the battery pack, and the second end of the temperature-controlled fuse is electrically connected to the first end of the charger; the temperature-controlled fuse is used to disconnect the battery pack from the charger when the temperature of the temperature-controlled fuse is greater than a preset melting point.

[0015] The first terminal of the control circuit is electrically connected to the first terminal of the battery pack, the second terminal of the control circuit is electrically connected to the second terminal of the battery pack, and the third terminal of the control circuit is electrically connected to the first terminal of the battery management system. The control circuit is used to control the temperature of the temperature control fuse to be greater than the preset melting point and disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than the preset charging voltage and the second protection circuit fails.

[0016] In one possible design, the temperature-controlled fuse comprises a low-melting-point alloy;

[0017] The first end of the low-melting-point alloy is electrically connected to the second end of the battery pack, and the second end of the low-melting-point alloy is electrically connected to the first end of the charger.

[0018] In one possible design, the control circuit includes a first controller, a first switch, and a heater;

[0019] The first terminal of the first controller is electrically connected to the first terminal of the battery pack, the second terminal of the first controller is electrically connected to the second terminal of the battery pack, the third terminal of the first controller is electrically connected to the first terminal of the battery management system, and the fourth terminal of the first controller is electrically connected to the first terminal of the first switch.

[0020] The second terminal of the first switch is electrically connected to the first terminal of the battery pack, the third terminal of the first switch is electrically connected to the first terminal of the heater, and the second terminal of the heater is electrically connected to the second terminal of the battery pack.

[0021] The first controller is used to receive a battery pack overvoltage signal sent by the battery management system, and control the first switch to turn on based on the battery pack overvoltage signal, so that the heater heats up and the temperature of the temperature control fuse is greater than the preset melting point, thereby disconnecting the battery pack from the charger; the battery pack overvoltage signal is sent to the first controller by the battery management system when it detects that the battery pack charging voltage is greater than the preset charging voltage and the second protection circuit fails.

[0022] In one possible design, the heater is located next to the temperature-controlled fuse.

[0023] In one possible design, the control circuit also includes a thermal fuse;

[0024] The first end of the temperature fuse is electrically connected to the third end of the first switch, and the second end of the temperature fuse is electrically connected to the first end of the heater.

[0025] In one possible design, the second protection circuit includes a second controller, a second switch, and a third switch;

[0026] The first terminal of the second controller is electrically connected to the first terminal of the battery pack, the second terminal of the second controller is electrically connected to the second terminal of the charger, and the third terminal of the second controller is electrically connected to the second terminal of the battery management system.

[0027] The first end of the second switch is electrically connected to the first end of the battery pack, the second end of the second switch is electrically connected to the first end of the third switch, the second end of the third switch is electrically connected to the second end of the charger, and the third ends of the second switch and the third end of the third switch are respectively electrically connected to the fourth end of the second controller.

[0028] In one possible design, the preset melting point is less than or equal to 232°C.

[0029] Secondly, this application provides a battery pack including the battery pack protection circuit in the first aspect and any possible design of the first aspect.

[0030] Thirdly, this application provides an electronic device including the battery pack protection circuit described in the second aspect above. The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them according to the content of the specification, and to make the above and other objects, features, and advantages of the embodiments of this application more apparent and understandable, specific embodiments of this application are described below. Attached Figure Description

[0031] Figure 1 This is a circuit block diagram of a battery pack protection circuit provided in an embodiment of this application.

[0032] Figure 2 A circuit block diagram of another battery pack protection circuit provided in an embodiment of this application.

[0033] Figure 3 A circuit block diagram of another battery pack protection circuit provided in the embodiments of this application.

[0034] Figure 4 A circuit block diagram of another battery pack protection circuit provided in an embodiment of this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. First protection circuit;

[0037] 101. Temperature-controlled fuse; 102. Control circuit;

[0038] 1021. First controller; 1022. First switch; 1023. Heater; 1024. Thermal fuse;

[0039] 20. Second protection circuit;

[0040] 201. Second controller; 202. Second switch; 203. Third switch;

[0041] 30. Battery pack;

[0042] 40. Charger;

[0043] 50. Battery Management System. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0046] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0047] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0048] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).

[0049] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" or "joining" in mechanical structures can refer to a physical connection, such as a fixed connection, for example, a connection fixed by a partition, such as a connection fixed by screws, bolts, or other partitions; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0051] Figure 1 This is a circuit block diagram illustrating a battery pack protection circuit, a battery pack, and an electronic device, as provided in an embodiment of this application. Figure 1 As shown, the battery pack protection circuit includes a first protection circuit 10 and a second protection circuit 20.

[0052] The first terminal of the first protection circuit 10 is electrically connected to the first terminal of the battery pack 30, the second terminal of the first protection circuit 10 is electrically connected to the second terminal of the battery pack 30, the third terminal of the first protection circuit 10 is electrically connected to the first terminal of the charger 40, and the fourth terminal of the first protection circuit 10 is electrically connected to the first terminal of the battery management system 50.

[0053] The first terminal of the second protection circuit 20 is electrically connected to the first terminal of the battery pack 30, the second terminal of the second protection circuit 20 is electrically connected to the second terminal of the charger 40, and the third terminal of the second protection circuit 20 is electrically connected to the second terminal of the battery management system 50.

[0054] The first end of the battery pack 30 is the positive terminal of the battery pack 30, and the second end of the battery pack 30 is the negative terminal of the battery pack 30.

[0055] It should be noted that, since the second terminal of the first protection circuit 10 is electrically connected to the second terminal of the battery pack 30, and the third terminal of the first protection circuit 10 is electrically connected to the first terminal of the charger 40, it can be seen that the first protection circuit 10 is connected in series between the battery pack 30 and the charger 40. Similarly, since the first terminal of the second protection circuit 20 is electrically connected to the first terminal of the battery pack 30, and the second terminal of the second protection circuit 20 is electrically connected to the second terminal of the charger 40, it can be seen that the second protection circuit 20 is also connected in series between the battery pack 30 and the charger 40.

[0056] The first protection circuit 10 and the second protection circuit 20 have both on and closed states. When both the first protection circuit 10 and the second protection circuit 20 are on, the battery pack 30 is connected to the charger 40, and the battery pack 30 is charged; when either the first protection circuit 10 or the second protection circuit 20 is off, the battery pack 30 is disconnected from the charger 40, and charging of the battery pack 30 stops.

[0057] The battery management system 50 is used to detect the charging status of the battery pack 30.

[0058] It should be noted that when the battery management system 50 detects an abnormal charging state of the battery pack 30, the battery management system 50 sends the abnormal charging state of the battery pack 30 to the first protection circuit 10 or the second protection circuit 20, so that the connection between the battery pack 30 and the charger 40 can be quickly disconnected through the first protection circuit 10 or the second protection circuit 20, thereby realizing the charging protection of the battery pack 30.

[0059] The first protection circuit 10 is used to disconnect the battery pack 30 from the charger 40 when the battery pack temperature is greater than a preset temperature and / or the battery pack charging current is greater than a preset charging current.

[0060] The battery pack temperature is affected by multiple factors, including the battery pack charging and discharging current, the battery pack internal resistance, the external ambient temperature, and the battery pack heat dissipation performance.

[0061] The preset temperature can be set by the user, and this embodiment does not impose specific limitations on it. For example, the preset temperature is 240℃.

[0062] In this embodiment, the battery pack temperature is directly detected by the first protection circuit 10, and automatically switched to the disconnect state when the battery pack temperature is greater than the preset temperature, so that the battery pack 30 is disconnected from the charger 40, thereby realizing over-temperature protection for the battery pack 30.

[0063] It should be noted that in other embodiments, the battery management system 50 can also detect the battery pack temperature, and when the battery management system 50 detects that the battery pack temperature is greater than the preset temperature, the battery management system 50 sends a battery pack over-temperature signal to the first protection circuit 10, so that the first protection circuit 10 is in the off state, the battery pack 30 is disconnected from the charger 40, and the over-temperature protection of the battery pack 30 is achieved.

[0064] The preset charging current can be set by the user, and this embodiment does not impose specific limitations on it. For example, the preset charging current is 5A.

[0065] In this embodiment, during the charging process of the battery pack, the magnitude of the charging current directly affects the temperature of the battery pack. Therefore, the first protection circuit 10 can determine whether the charging current of the battery pack is greater than a preset charging current based on the magnitude of the current flowing through the first protection circuit 10, and automatically switch to the disconnected state if the charging current of the battery pack is greater than the preset charging current, thereby disconnecting the battery pack 30 from the charger 40 and realizing over-temperature protection for the battery pack 30.

[0066] It should be noted that in other embodiments, the battery management system 50 can also detect the battery pack charging current, and when the battery management system 50 detects that the battery pack charging current is greater than the preset charging current, the battery management system 50 sends a battery pack overcurrent signal to the first protection circuit 10 to make the first protection circuit 10 open, and the battery pack 30 is disconnected from the charger 40, thereby realizing overcurrent protection for the battery pack 30.

[0067] The second protection circuit 20 is used to disconnect the battery pack 30 from the charger 40 when the battery management system 50 detects that the battery pack charging voltage is greater than the preset charging voltage.

[0068] The preset charging power can be set by the user, and this embodiment does not impose specific limitations on it.

[0069] It should be noted that the battery management system 50 can detect the battery pack charging voltage through the voltage detection module and compare the battery pack charging voltage with the preset charging voltage.

[0070] If the battery pack charging voltage is greater than the preset charging voltage, it indicates that the battery pack is over-voltage. At this time, the battery management system 50 sends a battery pack over-voltage signal to the second protection circuit 20 to make the second protection circuit 20 disconnected, thereby disconnecting the battery pack 30 from the charger 40 and realizing over-voltage protection for the battery pack 30.

[0071] If the battery pack charging voltage is less than or equal to the preset charging voltage, the battery management system 50 continues to detect the battery pack charging voltage.

[0072] The first protection circuit 10 is also used to disconnect the battery pack 30 from the charger 40 when the battery management system 50 detects that the battery pack charging voltage is greater than the preset charging voltage and the second protection circuit 20 fails.

[0073] It should be noted that when the battery management system 50 sends a battery pack overvoltage signal to the second protection circuit 20, if the second protection circuit 20 fails, the battery management system will send a battery pack overvoltage signal to the first protection circuit 10 to put the first protection circuit 10 in an open state, thereby disconnecting the battery pack 30 from the charger 40 and achieving overvoltage protection for the battery pack 30.

[0074] In this embodiment, when the battery management system 50 detects that the battery pack charging voltage is greater than the preset charging voltage, if the second protection circuit is effective, the connection between the battery pack 30 and the charger 40 is disconnected by the second protection circuit; if the second protection circuit fails, the connection between the battery pack 30 and the charger 40 is disconnected by the first protection circuit. This design effectively reduces the safety risks caused by the failure of a single protection circuit, ensuring that the battery pack will not be damaged by overvoltage, and preventing safety hazards such as battery thermal runaway, fire, or even explosion caused by battery pack overvoltage.

[0075] This application provides a battery pack protection circuit, including a first protection circuit and a second protection circuit. The first and second protection circuits are connected in series in the charging circuit between the battery pack and the charger. When the battery pack temperature exceeds a preset temperature and / or the battery pack charging current exceeds a preset charging current, the first protection circuit can directly disconnect the battery pack from the charger, achieving over-temperature and / or over-current protection for the battery pack, without relying on the battery management system to detect the battery pack's operating parameters. When the battery management system detects that the battery pack charging voltage exceeds a preset charging voltage and the second protection circuit is effective, it disconnects the battery pack from the charger through the second protection circuit, achieving overvoltage protection for the battery pack. If the second protection circuit fails, it disconnects the battery pack from the charger through the first protection circuit, continuing to achieve overvoltage protection for the battery pack. The redundant design of the first and second protection circuits avoids battery pack runaway due to the failure of the first protection circuit, resulting in high reliability and good safety.

[0076] Figure 2 A circuit block diagram illustrating another battery pack protection circuit provided in an embodiment of this application. (See diagram below.) Figure 2 As shown, in some embodiments, the first protection circuit 10 includes a temperature-controlled fuse 101 and a control circuit 102.

[0077] The first end of the temperature-controlled fuse 101 is electrically connected to the second end of the battery pack 30, and the second end of the temperature-controlled fuse 101 is electrically connected to the first end of the charger 40.

[0078] The temperature-controlled fuse 101 is used to disconnect the battery pack 30 from the charger 40 when the temperature of the temperature-controlled fuse 101 is greater than the preset melting point.

[0079] In some embodiments, the temperature-controlled fuse 101 comprises a low-melting-point alloy. A first end of the low-melting-point alloy is electrically connected to a second end of the battery pack 30, and the second end of the low-melting-point alloy is electrically connected to a first end of the charger 40.

[0080] It should be noted that the preset melting point is the melting point of a low-melting-point alloy. The low-melting-point alloy can be selected by the user, and this example does not specifically limit it.

[0081] In some embodiments, the preset melting point is less than or equal to 232°C.

[0082] It should be noted that low melting point alloys are alloys with a melting point of less than or equal to 232℃.

[0083] Among them, the temperature-controlled fuse 101 is an electrical protection device used to automatically disconnect the battery pack 30 from the charger 40 when the temperature of the battery pack 30 or the temperature of the temperature-controlled fuse 101 exceeds the melting point of the temperature-controlled fuse 101.

[0084] In this embodiment, the temperature-controlled fuse 101 can directly detect the battery pack temperature. When the battery pack 30 overheats due to abnormal ambient temperature or loose circuit connections, causing its temperature to exceed a preset temperature (the preset temperature is the melting point of the temperature-controlled fuse 101), the temperature-controlled fuse 101 automatically melts, thereby disconnecting the battery pack 30 from the charger 40 and preventing the battery pack 30 from overheating and posing a danger. Furthermore, when the battery pack charging current exceeds a preset charging current, the charging current will also flow through the temperature-controlled fuse 101. Due to the internal resistance of the temperature-controlled fuse 101, it heats up. When the temperature of the temperature-controlled fuse 101 exceeds its melting point, the temperature-controlled fuse 101 automatically melts, thereby disconnecting the battery pack 30 from the charger 40 and providing overcurrent protection for the battery pack 30.

[0085] In this embodiment, when the battery pack 30 is protected against over-temperature and over-current by the temperature-controlled fuse 101, it does not rely on the detection of the battery pack by the battery management system 50, nor does it rely on the control of the battery management system. It has a high degree of automation and independence, ensuring that the battery pack 30 can be disconnected in time when there is over-temperature or over-current, so as to avoid safety problems such as damage to the battery pack 30 or fire.

[0086] like Figure 2 As shown, the first terminal of the control circuit 102 is electrically connected to the first terminal of the battery pack 30, the second terminal of the control circuit 102 is electrically connected to the second terminal of the battery pack 30, and the third terminal of the control circuit 102 is electrically connected to the first terminal of the battery management system 50.

[0087] The control circuit 102 is used to control the temperature of the temperature control fuse 101 to be higher than the preset melting point when the battery management system 50 detects that the battery pack charging voltage is greater than the preset charging voltage and the second protection circuit 20 fails, thereby disconnecting the battery pack 30 from the charger 40.

[0088] It should be noted that the function of the control circuit 102 is to disconnect the battery pack 30 from the charger 40 when the battery management system 50 detects that the battery pack charging voltage exceeds the preset charging voltage and the second protection circuit 20 fails, by controlling the operation of the temperature-controlled fuse 101 to ensure that the temperature of the temperature-controlled fuse 101 rises above the preset melting point. By setting the control circuit 102, even if the second protection circuit 20 fails to work properly, the control circuit 102 can still provide additional overvoltage protection for the battery pack 30 through the temperature-controlled fuse 101, thereby reducing the safety hazards caused by overcharging of the battery pack 30.

[0089] Understandably, if the second protection circuit 20 does not fail, the battery management system 50 can also disconnect the battery pack 30 from the charger 40 through the first protection circuit 10.

[0090] In this embodiment, in the event of battery pack overvoltage, the connection between battery pack 30 and charger 40 can be disconnected via the second protection circuit 20, or via the first protection circuit 10. The core component in the first protection circuit 10 used to disconnect the connection between battery pack 30 and charger 40 is a temperature-controlled fuse 101. The temperature-controlled fuse 101 has a melting time of approximately 15 seconds, and compared to existing smart fuses, it reduces the risk of misjudgment and has high reliability. Simultaneously, it effectively reduces the frequency of power-on / off operations of the second protection circuit 20, extending its service life.

[0091] Figure 3 A circuit block diagram illustrating another battery pack protection circuit provided in an embodiment of this application. (See diagram below.) Figure 3 As shown, in some embodiments, the control circuit 102 includes a first controller 1021, a first switch 1022, and a heater 1023.

[0092] The first terminal of the first controller 1021 is electrically connected to the first terminal of the battery pack 30, the second terminal of the first controller 1021 is electrically connected to the second terminal of the battery pack 30, the third terminal of the first controller 1021 is electrically connected to the first terminal of the battery management system 50, and the fourth terminal of the first controller 1021 is electrically connected to the first terminal of the first switch 1022.

[0093] It should be noted that the first controller 1021 can be a microcontroller. The third terminal of the first controller 1021 is electrically connected to the first terminal of the third controller in the battery management system 50, and the first controller 1021 is used to receive overvoltage signals sent by the third controller.

[0094] The second end of the first switch 1022 is electrically connected to the first end of the battery pack 30, the third end of the first switch 1022 is electrically connected to the first end of the heater 1023, and the second end of the heater 1023 is electrically connected to the second end of the battery pack 30.

[0095] It should be noted that the first switch 1022 can be a heating relay, and the first switch 1022 is controlled by the first controller 1021.

[0096] The heater 1023 can be a heating element, a heating resistance wire, or other components with heating function; this embodiment does not specifically limit this.

[0097] The first controller 1021 is used to receive the battery pack overvoltage signal sent by the battery management system 50, and control the first switch 1022 to turn on based on the battery pack overvoltage signal, so that the heater 1023 heats up, making the temperature of the temperature control fuse 101 greater than the preset melting point, and disconnecting the battery pack 30 from the charger 40.

[0098] Among them, the battery pack overvoltage signal is sent to the first controller by the battery management system when it detects that the battery pack charging voltage is greater than the preset charging voltage and the second protection circuit fails.

[0099] It should be noted that when the first controller 1021 receives a battery pack overvoltage signal sent by the battery management system 50, the first controller 1021 outputs a warning signal, which is used to alert the user that the battery pack is overvoltage.

[0100] In some embodiments, the heater 1023 is located next to the temperature control fuse 101.

[0101] It should be noted that placing the heater 1023 next to the temperature-controlled fuse 101 allows the temperature of the fuse 101 to be rapidly increased by the heat from the heater 1023. Thus, when the battery pack 30 experiences overvoltage, the first controller 1021 controls the heater 1023 to heat up, enabling the temperature-controlled fuse 101 to reach its melting point more quickly. This accelerates the operation of the fuse 101, allowing for a more timely disconnection between the battery pack 30 and the charger 40, preventing safety hazards caused by overvoltage in the battery pack 30.

[0102] In this embodiment, when the first controller 1021 receives a battery pack overvoltage signal sent by the third controller, the first controller 1021 controls the first switch 1022 to turn on. At this time, the heater 1023 starts to heat up. The temperature control fuse 101 located next to the heater 1023 is affected by the heat generated by the heater 1023, and the temperature of the temperature control fuse 101 gradually increases until the temperature of the temperature control fuse 101 reaches the melting point of the temperature control fuse 101. The temperature control fuse 101 automatically disconnects, that is, the connection between the battery pack 30 and the charger 40 is disconnected, thus realizing the overvoltage protection of the battery pack 30 by the first protection circuit 10.

[0103] Figure 4 A circuit block diagram illustrating another battery pack protection circuit provided in this application embodiment. (See diagram below.) Figure 4 As shown, in some embodiments, the control circuit 102 further includes a thermal fuse 1024.

[0104] The first end of the thermal fuse 1024 is electrically connected to the third end of the first switch 1022, and the second end of the thermal fuse 1024 is electrically connected to the first end of the heater 1023.

[0105] In this embodiment, after the first controller 1021 receives the battery pack overvoltage signal sent by the battery management system 50 and controls the temperature control fuse 101 to disconnect the battery pack 30 from the charger 40 based on the battery pack overvoltage signal, the resistance of the control circuit 102 is greater than 200MΩ. At this time, the temperature fuse 1024 is disconnected to protect the first controller 1021 and the first switch 1022 from damage caused by the overvoltage of the battery pack 30.

[0106] In some embodiments, the second protection circuit 20 includes a second controller 201, a second switch 202, and a third switch 203.

[0107] The first terminal of the second controller 201 is electrically connected to the first terminal of the battery pack 30, the second terminal of the second controller 201 is electrically connected to the second terminal of the charger 40, and the third terminal of the second controller 201 is electrically connected to the second terminal of the battery management system 50.

[0108] It should be noted that the second controller 201 can be a microcontroller. The third terminal of the second controller 201 is electrically connected to the second terminal of the third controller in the battery management system 50, and the first controller 1021 is used to receive the overvoltage signal sent by the third controller.

[0109] The first end of the second switch 202 is electrically connected to the first end of the battery pack 30, the second end of the second switch 202 is electrically connected to the first end of the third switch 203, the second end of the third switch 203 is electrically connected to the second end of the charger 40, and the third ends of the second switch 202 and the third ends of the third switch 203 are respectively electrically connected to the fourth end of the second controller 201.

[0110] The second switch 202 and the third switch 203 are relays, and both the second switch 202 and the third switch 203 are controlled by the second controller 201.

[0111] It should be noted that when the battery management system 50 detects that the battery pack charging voltage exceeds the preset charging voltage and the second protection circuit 20 has not failed, the third controller of the battery management system 50 sends an overvoltage signal to the second controller 201. The second controller 201 controls the second switch 202 and the third switch 203 to open based on the overvoltage signal, thereby disconnecting the connection between the battery pack 30 and the charger 40.

[0112] In the embodiments of this application, when the battery pack experiences overcurrent, overtemperature, or overvoltage, and the battery management system and / or the second protection circuit fails, the high-voltage main circuit where the battery pack is located can be promptly cut off by the first protection circuit to prevent the battery pack from going out of control.

[0113] Specifically, in the event of overcurrent or overtemperature in the battery pack, the first protection circuit is passively disconnected; in the event of overvoltage in the battery pack, the first protection circuit is actively disconnected. The battery pack protection circuit provided by this application embodiment can effectively reduce the probability of battery pack failure when safety issues arise. Compared with existing battery pack protection circuits, it achieves dual protection and has significant advantages.

[0114] This application also provides a battery pack, including the battery pack protection circuit provided in the foregoing embodiments.

[0115] This application also provides an electronic device, including the battery pack provided in the foregoing embodiments.

[0116] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery pack protection circuit, characterized by, The protection circuit includes a first protection circuit and a second protection circuit; The first terminal of the first protection circuit is electrically connected to the first terminal of the battery pack, the second terminal of the first protection circuit is electrically connected to the second terminal of the battery pack, the third terminal of the first protection circuit is electrically connected to the first terminal of the charger, and the fourth terminal of the first protection circuit is electrically connected to the first terminal of the battery management system. The first terminal of the second protection circuit is electrically connected to the first terminal of the battery pack, the second terminal of the second protection circuit is electrically connected to the second terminal of the charger, and the third terminal of the second protection circuit is electrically connected to the second terminal of the battery management system. The first protection circuit is used to disconnect the battery pack from the charger when the battery pack temperature is greater than a preset temperature and / or the battery pack charging current is greater than a preset charging current. The second protection circuit is used to disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than a preset charging voltage; The first protection circuit is also used to disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than the preset charging voltage and the second protection circuit fails.

2. The circuit of claim 1, wherein, The first protection circuit includes a temperature-controlled fuse and a control circuit; The first end of the temperature-controlled fuse is electrically connected to the second end of the battery pack, and the second end of the temperature-controlled fuse is electrically connected to the first end of the charger; the temperature-controlled fuse is used to disconnect the battery pack from the charger when the temperature of the temperature-controlled fuse is greater than a preset melting point. The first terminal of the control circuit is electrically connected to the first terminal of the battery pack, the second terminal of the control circuit is electrically connected to the second terminal of the battery pack, and the third terminal of the control circuit is electrically connected to the first terminal of the battery management system. The control circuit is used to control the temperature of the temperature control fuse to be greater than the preset melting point and disconnect the battery pack from the charger when the battery management system detects that the charging voltage of the battery pack is greater than the preset charging voltage and the second protection circuit fails.

3. The circuit of claim 2, wherein, The temperature-controlled fuse comprises a low-melting-point alloy; The first end of the low-melting-point alloy is electrically connected to the second end of the battery pack, and the second end of the low-melting-point alloy is electrically connected to the first end of the charger.

4. The circuit of claim 2, wherein, The control circuit includes a first controller, a first switch, and a heater; The first terminal of the first controller is electrically connected to the first terminal of the battery pack, the second terminal of the first controller is electrically connected to the second terminal of the battery pack, the third terminal of the first controller is electrically connected to the first terminal of the battery management system, and the fourth terminal of the first controller is electrically connected to the first terminal of the first switch. The second terminal of the first switch is electrically connected to the first terminal of the battery pack, the third terminal of the first switch is electrically connected to the first terminal of the heater, and the second terminal of the heater is electrically connected to the second terminal of the battery pack. The first controller is used to receive a battery pack overvoltage signal sent by the battery management system, and control the first switch to turn on based on the battery pack overvoltage signal, so that the heater heats up and the temperature of the temperature control fuse is greater than the preset melting point, thereby disconnecting the battery pack from the charger; the battery pack overvoltage signal is sent to the first controller by the battery management system when it detects that the battery pack charging voltage is greater than the preset charging voltage and the second protection circuit fails.

5. The circuit of claim 4, wherein, The heater is located next to the temperature-controlled fuse.

6. The circuit of claim 4, wherein, The control circuit also includes a temperature fuse; The first end of the temperature fuse is electrically connected to the third end of the first switch, and the second end of the temperature fuse is electrically connected to the first end of the heater.

7. The circuit of claim 1, wherein, The second protection circuit includes a second controller, a second switch, and a third switch; The first terminal of the second controller is electrically connected to the first terminal of the battery pack, the second terminal of the second controller is electrically connected to the second terminal of the charger, and the third terminal of the second controller is electrically connected to the second terminal of the battery management system. The first terminal of the second switch is electrically connected to the first terminal of the battery pack, the second terminal of the second switch is electrically connected to the first terminal of the third switch, the second terminal of the third switch is electrically connected to the second terminal of the charger, and the third terminals of the second switch and the third terminal of the third switch are respectively electrically connected to the fourth terminal of the second controller.

8. The circuit of claim 2, wherein, The preset melting point is less than or equal to 232°C.

9. A battery pack, characterized by, Includes the battery pack protection circuit as described in any one of claims 1 to 8.

10. An electronic device, comprising: Includes the battery pack as described in claim 9.

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