Battery protection circuit and battery pack

Abstract

The present invention belongs to the field of battery technology, and in particular, relates to a battery protection circuit and a battery pack. The battery protection circuit includes a recoverable circuit breaker control circuit and a first controller; the recoverable circuit breaker control circuit includes an active switch connected to the first controller and a recoverable circuit breaker connected to a battery cell; the first controller is also used to control the active switch to conduct when it is detected that the temperature of the battery cell is greater than or equal to the preset battery temperature, or the current of the battery cell is greater than or equal to the first preset current, or the voltage of the battery cell is greater than or equal to the first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker. In the present invention, the recoverable circuit breaker control circuit can be reused after being actuated, and the battery protection circuit is used as a secondary protection circuit or a tertiary protection circuit of the battery cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to a battery protection circuit and a battery pack. Background Art

[0002] Secondary protection devices such as mobile phone batteries, laptop batteries, and tablet batteries on the market generally use solutions such as positive temperature coefficient resistors (PTCs) and temperature fuses. Among them, the positive temperature coefficient resistor (PTC) is a polymer material, and its internal resistance cannot be completely restored after each action. At the same time, its material is affected by the temperature, humidity, corrosive gases, etc. in the use environment. After a period of use, the internal resistance of the positive temperature coefficient resistor (PTC) will increase, resulting in a decrease in the usable capacity of the battery and an increase in the direction loss of the battery itself. In addition, after the temperature fuse is activated, it cannot be restored to use, resulting in a waste of resources, and further causing the use of the terminal to be scrapped. Summary of the invention

[0003] The present invention solves the technical problem in the prior art that a secondary battery protection device cannot be reused after being actuated, and provides a battery protection circuit and a battery pack.

[0004] An embodiment of the present invention provides a battery protection circuit, comprising a restorable circuit breaker control circuit and a first controller; the restorable circuit breaker control circuit comprises an active switch and a restorable circuit breaker; one end of the active switch is connected to the first controller, the other end of the active switch is connected to the restorable circuit breaker and an external device, and the end of the restorable circuit breaker away from the external device is connected to a battery cell;

[0005] The first controller is used to detect the temperature, current and voltage of the battery cell in real time;

[0006] The first controller is also used to control the active switch to turn on when it is detected that the temperature of the battery cell is greater than or equal to a preset battery temperature, or the current of the battery cell is greater than or equal to a first preset current, or the voltage of the battery cell is greater than or equal to a first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker; wherein the recoverable circuit breaker remains disconnected when the operating temperature is greater than or equal to the preset operating temperature, and is turned on when the operating temperature is less than the preset operating temperature.

[0007] Optionally, the first controller is further used to control the active switch to disconnect when it is detected that the temperature of the battery cell is lower than a preset battery temperature, the current of the battery cell is lower than a first preset current, and the voltage of the battery cell is lower than a first preset voltage.

[0008] Optionally, the restorable circuit breaker includes a passive switch component and a first heating element, and the restorable circuit breaker control circuit also includes a second heating element; the first heating element and the passive switch component are connected in parallel between the battery cell and the external device, one end of the second heating element is connected to the active switch, and the other end of the second heating element is connected to the connection line between the first heating element and the external device; one end of the active switch away from the second heating element is connected to the first controller;

[0009] The second heating element is used to increase the temperature of the passive switch component to the preset operating temperature when the active switch is turned on.

[0010] Optionally, the first heating element is a first PTC resistor, and the second heating element is a second PTC resistor.

[0011] Optionally, the battery protection circuit further comprises a charging protection switch connected to the first controller, and the battery cell is connected to a charging device sequentially through the recoverable circuit breaker and the charging protection switch;

[0012] The first controller is further configured to, when detecting that the charging device is charging the battery cell, control the charging protection switch to be disconnected and continuously detect the voltage of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the voltage of the battery cell is greater than a second preset voltage; wherein the second preset voltage is less than the first preset voltage;

[0013] The first controller is also used to control the active switch to conduct when it is detected that the voltage of the battery cell is greater than or equal to the first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

[0014] Optionally, the battery protection circuit further comprises a charging protection switch connected to the first controller, and the battery cell is connected to a charging device sequentially through the recoverable circuit breaker and the charging protection switch;

[0015] The first controller is further configured to, when detecting that the charging device is charging the battery cell, control the charging protection switch to be disconnected and continuously detect the current of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the current of the battery cell is greater than or equal to a second preset current; wherein the second preset current is less than the first preset current;

[0016] The first controller is also used to control the active switch to conduct when it is detected that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

[0017] Optionally, the battery protection circuit further comprises a discharge protection switch connected to the first controller, and the battery cell is connected to the electrical equipment in sequence through the recoverable circuit breaker and the discharge protection switch;

[0018] The first controller is further configured to, when it is detected that the battery cell is discharging to the electrical equipment, control the discharge protection switch to be disconnected and continuously detect the current of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the voltage of the battery cell is greater than a third preset voltage; wherein the third preset voltage is less than the first preset voltage;

[0019] The first controller is also used to control the active switch to conduct when it is detected that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

[0020] Optionally, the battery protection circuit further comprises a discharge protection switch connected to the control module, and the battery cell is connected to the electrical equipment in sequence through the recoverable circuit breaker and the discharge protection switch;

[0021] The first controller is further configured to, when it is detected that the battery cell is discharging to the electrical equipment, control the discharge protection switch to be disconnected and continuously detect the current of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the current of the battery cell is greater than a third preset current; the third preset current is less than the first preset current;

[0022] The first controller is also used to control the active switch to conduct when it is detected that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

[0023] Optionally, the battery cell is connected to a charging device via the recoverable circuit breaker; the battery protection circuit further comprises a second controller, the second controller being connected to the battery cell and the active switch;

[0024] The second controller is used for controlling the active switch to conduct when it is detected that the voltage of the battery cell is greater than or equal to a limit preset voltage; wherein the limit preset voltage is greater than the first preset voltage.

[0025] In the present invention, the first controller is also used to control the active switch to be turned on when it is detected that the temperature of the battery cell is greater than or equal to the preset battery temperature, or the current of the battery cell is greater than or equal to the first preset current, or the voltage of the battery cell is greater than or equal to the first preset voltage; after the active switch is turned on, the operating temperature of the recoverable circuit breaker will continue to increase during the operation of the battery cell. When the temperature of the recoverable circuit breaker rises to the preset operating temperature, the recoverable circuit breaker will switch from the on state to the off state according to its own characteristics, and as long as the temperature of the recoverable circuit breaker is greater than or equal to the preset operating temperature, or the high current and high voltage state of the battery cell is not released, the recoverable circuit breaker will always remain in the off state. At this time, the battery cell will not continue to charge or discharge at a large current or voltage, thereby avoiding accidents such as explosion and spontaneous combustion of the battery cell caused by excessive current or voltage of the battery cell. When the temperature of the recoverable circuit breaker is lower than the preset action temperature and the high current and high voltage state of the battery cell is released, the recoverable circuit breaker remains in the on state and the resistance of the recoverable circuit breaker will not change, so that the recoverable circuit breaker can be reused. In addition, the recoverable circuit breaker control circuit is used as a secondary protection circuit or a tertiary protection circuit of the battery cell.

[0026] Another embodiment of the present invention further provides a battery pack, comprising a battery and the above-mentioned battery protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] Figure 1 A schematic diagram of a battery protection circuit provided by a first embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a battery protection circuit provided by a second embodiment of the present invention;

[0030] Figure 3 A schematic diagram of a battery protection circuit provided in accordance with a first embodiment of the present invention;

[0031] Figure 4 A schematic diagram of a battery protection circuit provided by a third embodiment of the present invention;

[0032] Figure 5 A schematic diagram of a battery protection circuit provided by a fourth embodiment of the present invention;

[0033] Figure 6 This is a flowchart of the battery protection circuit provided in the fourth embodiment of the present invention.

[0034] The reference numerals in the specification are as follows:

[0035] 1. Recoverable circuit breaker control circuit; 11. Active switch; 12. Recoverable circuit breaker; 121. Passive switch assembly; 122. First heating element; 13. Second heating element; 2. First controller; 3. Charging protection switch; 4. Discharging protection switch; 5. Second controller; 6. Battery cell; 7. Charging equipment; 8. Electrical equipment. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] It should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "back", and "middle" are based on the directions or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation of the present invention.

[0038] like Figures 1 to 3 As shown, a battery protection circuit provided by an embodiment of the present invention includes a recoverable circuit breaker control circuit 1 and a first controller 2; the recoverable circuit breaker control circuit 1 includes an active switch 11 and a recoverable circuit breaker 12; one end of the active switch 11 is connected to the first controller 2, the other end of the active switch 11 is connected to the recoverable circuit breaker 12 and an external device, and the end of the recoverable circuit breaker 12 away from the external device is connected to a battery cell 6; it can be understood that the recoverable circuit breaker 12 can be installed inside a battery pack; and the external device includes but is not limited to a charging device 7 and an electrical device 8.

[0039] The first controller 2 is used to detect the temperature, current and voltage of the battery cell 6 in real time; it can be understood that the first controller 2 can detect the temperature of the battery cell 6 through a temperature detection sensor, etc., and can detect the voltage and current of the battery cell 6 through a power meter. It should be noted that the first controller 2 is always in a state of detecting the temperature, voltage and current of the battery cell 6.

[0040] The first controller 2 is also used to control the active switch 11 to conduct when it is detected that the temperature of the battery cell 6 is greater than or equal to the preset battery temperature, or the current of the battery cell 6 is greater than or equal to the first preset current, or the voltage of the battery cell 6 is greater than or equal to the first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker 12 to the preset operating temperature, thereby disconnecting the recoverable circuit breaker 12; wherein the recoverable circuit breaker 12 remains disconnected when the operating temperature is greater than or equal to the preset operating temperature, and conducts when the operating temperature is less than the preset operating temperature. It can be understood that the preset battery temperature, the first preset voltage, and the first preset current can all be determined according to actual needs; and the preset operating temperature is determined by the characteristics of the recoverable circuit breaker control circuit 1 itself. Further, when the current of the battery cell 6 is in a high current state, the first controller 2 controls the active switch 11 to be turned on. After the active switch 11 is turned on, the temperature of the recoverable circuit breaker 12 rises to the preset action temperature. After the temperature of the recoverable circuit breaker 12 rises to the preset action temperature, the recoverable circuit breaker 12 remains in a disconnected state; that is, when the battery cell 6 is in a high current state, the recoverable circuit breaker 12 will always be in a disconnected state; or when the voltage of the battery cell 6 is in a high voltage state, the first controller 2 will also control the active switch 11 to be turned on. After the active switch 11 is turned on, the temperature of the recoverable circuit breaker 12 rises to the preset action temperature. After the temperature of the recoverable circuit breaker 12 rises to the preset action temperature, the recoverable circuit breaker 12 remains in a disconnected state; that is, when the battery cell 6 is in a high current state, the recoverable circuit breaker 12 will always be in a disconnected state. When the high current and / or high voltage state of the battery cell 6 is released, the first controller 2 will control the active switch 11 to disconnect. At this time, the temperature of the recoverable circuit breaker 12 will drop below the preset action temperature, and the recoverable circuit breaker 12 will be in the on state.

[0041] Specifically, during the charging process of the battery cell 6, if the first controller 2 detects that the voltage of the battery cell 6 is greater than the first preset voltage, or detects that the current of the battery cell 6 is greater than the first preset current, the first controller 2 will control the active switch 11 to be turned on; thereafter, during the charging process of the battery protection circuit, the temperature of the recoverable circuit breaker 12 will continue to rise, and when the temperature of the recoverable circuit breaker 12 rises to the preset action temperature, the recoverable circuit breaker 12 will switch from the on state to the off state according to its own characteristics, and as long as the temperature of the recoverable circuit breaker 12 is greater than or equal to the preset action temperature, the recoverable circuit breaker 12 will always remain in the off state (that is, the high current or high voltage of the battery cell 6). When the high pressure is not released, the first controller controls the active switch 11 to be turned on, so that the temperature of the recoverable circuit breaker 12 is maintained above the preset action temperature, and then the recoverable circuit breaker 12 remains in the disconnected state). At this time, it can be avoided that the charging device 7 continues to charge the battery cell 6 with a large current or voltage, which may cause the battery cell 6 to explode, spontaneously combust, and other accidents; when the large current or high voltage of the battery cell 6 is released, the first controller 2 will control the active switch 11 to be disconnected, and the temperature of the recoverable circuit breaker 12 will drop below the preset action temperature. At this time, the recoverable circuit breaker 12 will switch from the disconnected state to the on state, and remain in the on state, so that the recoverable circuit breaker 12 can be reused.

[0042] During the discharge of the battery cell 6, when the first controller 2 detects that the voltage of the battery cell 6 is greater than or equal to the first preset voltage, or detects that the current of the battery cell 6 is greater than or equal to the first preset current, the first controller 2 will control the active switch 11 to turn on; thereafter, the working principle of the recoverable circuit breaker 12 is consistent with the working principle during the charging process, and will not be repeated here. The recoverable circuit breaker 12 avoids the battery cell 6 from continuously supplying power to the electrical equipment 8 with a large current or voltage, which may cause the battery cell 6 to explode, spontaneously combust, or other accidents.

[0043] It should be noted that during the charging or discharging process of the battery cell 6 , the temperature of the battery cell 6 will increase. When the first controller 2 detects that the temperature of the battery cell 6 is greater than the preset battery temperature, the first controller 2 will control the active switch 11 to be turned on.

[0044] In one embodiment, the first controller 2 is further used to control the active switch 11 to disconnect when it is detected that the temperature of the battery cell 6 is lower than the preset battery temperature, the current of the battery cell 6 is lower than the first preset current, and the voltage of the battery cell 6 is lower than the first preset voltage. It can be understood that during the operation of the battery cell 6, only when the temperature of the battery cell 6 is lower than the preset battery temperature, the current of the battery cell 6 is lower than the first preset current, and the voltage of the battery cell 6 is lower than the first preset voltage, the first controller 2 will control the active switch 11 to disconnect. At this time, during the operation of the battery cell 6, the recoverable circuit breaker 12 will not rise to the preset operating temperature at the operating temperature; that is, the battery protection circuit is in a normal charging and discharging state.

[0045] In the present invention, the first controller 2 is also used to control the active switch 11 to be turned on when it is detected that the temperature of the battery cell 6 is greater than or equal to the preset battery temperature, or the current of the battery cell 6 is greater than or equal to the first preset current, or the voltage of the battery cell 6 is greater than or equal to the first preset voltage; after the active switch 11 is turned on, the operating temperature of the recoverable circuit breaker 12 will continue to increase during the operation of the battery cell 6. When the temperature of the recoverable circuit breaker 12 rises to the preset operating temperature, the recoverable circuit breaker 12 will switch from the on state to the off state according to its own characteristics, and as long as the temperature of the recoverable circuit breaker 12 is greater than or equal to the preset operating temperature, or the high current and high voltage state of the battery cell 6 is not released, the recoverable circuit breaker 12 will always remain in the off state. At this time, the battery cell 6 will not continue to charge or discharge with a large current or voltage, thereby avoiding the battery cell 6 from exploding, spontaneously combusting, or other accidents caused by the current or voltage of the battery cell 6 being too high. When the temperature of the restorable circuit breaker 12 is lower than the preset operating temperature and the high current and high voltage state of the battery cell 6 is released, the restorable circuit breaker 12 remains in the on state and the resistance of the restorable circuit breaker 12 will not change, so that the restorable circuit breaker 12 can be reused. In addition, the restorable circuit breaker control circuit 1 is used as a secondary protection circuit or a tertiary protection circuit of the battery cell 6.

[0046] In one embodiment, if Figures 1 to 3As shown, the recoverable circuit breaker 12 includes a passive switch component 121 and a first heating element 122, and the recoverable circuit breaker control circuit 1 also includes a second heating element 13; the first heating element 122 and the passive switch component 121 are connected in parallel between the battery cell 6 and the external device, one end of the second heating element 13 is connected to the active switch 11, and the other end of the second heating element 13 is connected to the connection line between the first heating element 122 and the external device; the end of the active switch 11 away from the second heating element 13 is connected to the first controller 2; it can be understood that the first heating element 122 and the second heating element 13 both include but are not limited to heating resistors, etc., preferably, the first heating element is a first PTC resistor, and the second heating element is a second PTC resistor. That is, the first heating element 122 and the second heating element 13 are both PTC (Positive Temperature Coefficient) heating resistors.

[0047] The first heating element 122 is used to maintain the passive switch component 121 in the current on state; the second heating element 13 is used to heat the passive switch component 121 to the preset operating temperature when the active switch 11 is turned on. Specifically, during the charging process of the battery cell 6, when the first controller 2 controls the active switch 11 to be turned off, the battery cell 6 is connected to the charging device 7 through the passive switch component 121, and the first heating element 122 is short-circuited by the passive switch component 121; at this time, the battery cell 6 can perform normal charging. When the first controller 2 controls the active switch 11 to be turned on, part of the current or voltage of the charging device 7 enters the battery cell 6 through the switch 121, and the other part of the current or voltage flows out through the second heating element 13, and the current or voltage entering the battery cell 6 will be greatly reduced. At the same time, after the current passes through the second heating element 13, the temperature of the second heating element 13 will rise sharply, so that the temperature of the passive switch component 121 reaches its preset action temperature, so that the second heating element 13 can assist the passive switch component 121 to heat up quickly and disconnect it, avoiding the charging device 7 from continuously charging the battery cell 6 with a large current or voltage, thereby avoiding accidents in the battery cell 6 process, and also avoiding explosions, spontaneous combustion and other accidents caused by excessive charging voltage of the battery cell 6. After the passive switch assembly 121 is disconnected, part of the current of the charging device 7 can return to the negative electrode of the charging device 7 through the second heating element 13 and the active switch 11, and the other part of the current enters the battery cell 7 of the battery cell group through the first heating element 122; because the first heating element 122 and the second heating element 13 are PTC, positive temperature coefficient resistors. At the preset action temperature, that is, the resistance value increases significantly, when the voltage of the external charging device remains unchanged, the current of the entire charging circuit is reduced to 1% to 1‰ before the action; the continuous energy input of the battery cell 6 is reduced to ensure the safety of the battery cell 6; in addition, during the charging process of the battery cell 6, the first heating element 122 can play a role of voltage division and the second heating element 13 can play a role of current diversion, thereby preventing the battery cell 6 from being overcharged.

[0048] Furthermore, during the discharge of the battery cell 6, when the first controller 2 controls the active switch 11 to be disconnected, the current of the battery cell 6 flows directly into the electrical device 8 through the passive switch component 121, and the first heating element 122 is short-circuited by the passive switch component 121. At this time, the battery cell 6 can perform a normal discharge function. When the first controller 2 detects that the voltage of the battery cell 6 is greater than the first preset voltage, or the current of the battery cell 6 is greater than the first preset current, the first controller 2 controls the active switch 11 to be turned on, and part of the current or voltage of the battery cell 6 charges the electrical device 8 through the passive switch component 121, and the other part of the current or voltage passes through the second heating element 13; because the resistance of the second heating element 13 is very low at room temperature, and the current flowing through it is very large, the heat generated by the second heating element 13 is very large; thereby, the temperature of the passive switch component 121 rises To the preset action temperature, thereby disconnecting the passive switch component; then the current flows through the first heating element 122 and then enters the second heating element 13 and the electrical equipment 8. The first heating element 122 and the second heating element 13 are both PTC resistors. After the temperature of the first heating element 122 and the second heating element 13 rises, their resistance increases, the current flowing through them decreases, and the external output power is reduced to 1‰. At the same time, the first heating element 122 divides the voltage, reducing the external voltage output; thereby avoiding the battery cell 6 continuously supplying power to the electrical equipment 8 with a large voltage or current, which may cause safety accidents such as explosion and spontaneous combustion.

[0049] In one embodiment, the passive switch component 121 includes a first end, a second end and a bimetallic strip. When the passive switch component 121 is below a preset operating temperature, the first end and the second end are connected; when the passive switch component is above the preset operating temperature, the first end and the second end are disconnected due to spatial displacement caused by a change in the deformation state of the bimetallic strip; the battery cell 6 is connected to the first end, and the charging device 7 or the electrical device 8 is connected to the second end; the first heating element 122 is connected between the first end and the second end. It can be understood that the bimetallic strip is formed by stacking metal strips of different materials on both sides; when the temperature of the bimetallic strip rises, the deformation amount is different due to the different thermal expansion coefficients of the two materials, so that the bimetallic strip will bend and other deformations. When the first controller 2 controls the active switch 11 to turn on and current passes through the second heating element 13, the operating temperature of the bimetallic strip reaches the preset operating temperature, and the bimetallic strip will deform and cause the input end and the output end to be disconnected. At this time, the battery cell 6 is connected to the charging device 7 or the electrical device 8 through the first heating element 122; and when the operating temperature of the bimetallic strip is greater than the preset operating temperature, the passive switch remains in the disconnected state. When the high current or high voltage of the battery cell 6 is released, the first controller 2 will control the active switch 11 to disconnect. At this time, no current will flow through the second heating element 13, no current will flow through the first heating element 122, the temperature of the bimetallic strip will drop below the preset action temperature, the bimetallic strip will return to its original state, the first end and the second end will be connected, and at this time, the battery cell 6 is connected to the charging device 7 or the power-consuming device 8 through the input end, the bimetallic strip, and the second end; and when the temperature of the bimetallic strip is lower than the preset action temperature, the passive switch remains in the on state. In this embodiment, after the passive switch component 121 is actuated, the first heating element 122 and the second heating element 13 can return to their original state, and the resistance of the passive switch will not change, so that the passive switch component 121 can be reused.

[0050] In the related art of the present application, when the ambient temperature of the restorable circuit breaker 12 reaches the preset operating temperature of the restorable circuit breaker 12, the passive switch component 121 can be disconnected, so that the first end and the second end of the passive switch component 121 are disconnected, thereby disconnecting the charge and discharge circuit of the battery cell 6, so as to avoid safety risks of the battery when the ambient temperature of the restorable circuit breaker 12 is too high due to the excessive ambient temperature or the excessive battery temperature. And when the ambient temperature of the restorable circuit breaker 12 changes to a temperature lower than the operating temperature of the restorable circuit breaker 12, the restorable circuit breaker 12 will be restored to the conducting state (that is, the first end and the second end are connected through the contact point), thereby closing the battery charge and discharge circuit. However, there is a situation where the ambient temperature of the recoverable circuit breaker 12 drops below the operating temperature, but the battery still has safety risks, and thus the recoverable circuit breaker 12 in the related art cannot effectively reduce the battery safety risk. Therefore, this case proposes to use the cooperation of the first controller 2 with the active switch 11 and the second heating element 13 to enable the recoverable circuit breaker 12 to accurately disconnect the battery charging and discharging circuit when the battery has a safety risk (that is, the first controller 2 is used to control the active switch 11 to be turned on, and when current flows through the second heating element 13, the heat emitted by the second heating element 13 assists the recoverable circuit breaker 12 The temperature of the restorable circuit breaker 12 rises to the preset action temperature, so that the restorable circuit breaker 12 will be disconnected), and the battery charging and discharging circuit is restored when the safety risk is eliminated (that is, when the high voltage or high current of the charging and discharging circuit of the battery cell 6 is in contact, the first controller 2 controls the active switch 11 to break, and no current will flow through the second heating element, and the temperature of the restorable circuit breaker 12 will drop below the preset action temperature, so that the restorable circuit breaker 12 is closed), thereby avoiding the battery from exploding, spontaneously combusting and other safety accidents caused by charging and discharging the battery at a higher voltage or current, thereby improving the safety of the battery.

[0051] In one embodiment, if Figure 4 and Figure 5 As shown, the battery protection circuit also includes a charging protection switch 3 connected to the first controller 2, and the battery cell 6 is connected to the charging device 7 through the recoverable circuit breaker 12 and the charging protection switch 3 in sequence; it can be understood that the charging protection switch 3 is a primary protection switch of the battery cell 6.

[0052] The first controller 2 is also used to control the charging protection switch 3 to be disconnected and continuously detect the voltage of the battery cell 6 when it is detected that the charging device 7 is charging the battery cell 6, if the recoverable circuit breaker 12 is turned on and the active switch 11 is turned off, and it is detected that the voltage of the battery cell 6 is greater than the second preset voltage; wherein the second preset voltage is less than the first preset voltage. It can be understood that the first preset voltage is the critical voltage at which the first controller 2 controls the active switch 11 to be turned on or off during the charging process of the battery cell 6, which generally refers to the voltage value of the safe voltage of the battery charging. When the battery voltage reaches this safe voltage, the battery is prone to explosion, fire and other risks, thereby causing a safety accident. The second preset voltage is the critical voltage at which the first controller 2 controls the charging protection switch 3 to be turned on or off during the charging process of the battery cell 6. It generally refers to the battery protection voltage of the battery cell 6. When the charging voltage of the battery cell 6 reaches or exceeds the battery protection voltage, it can ensure that the battery 6 can be charged normally and will not damage the battery. However, when the charging voltage of the battery cell 6 is less than the battery protection voltage, the battery cell 6 may damage its service life due to overcharging and other reasons. In the normal battery charging process, the charging protection switch 3 and the passive switch component 121 are in a normally closed state, and the active switch 11 is in a normally open state to ensure that the charging device 7 can charge the battery stably. Furthermore, the second preset voltage can be set according to actual needs. In this application, when it is detected that the voltage of the battery 6 is greater than the second preset voltage and less than the first preset voltage, the first controller controls the charging protection switch 3 to disconnect to avoid the battery voltage from continuing to rise and damaging the battery life. Furthermore, when the voltage of the battery cell 6 is between the second preset voltage and the first preset voltage, the voltage of the battery cell 6 may cause damage to the battery cell 6, but will not cause safety accidents such as explosion and spontaneous combustion of the battery cell 6.

[0053] Specifically, during the charging process of the battery cell 6, when the first controller 2 detects that the voltage of the battery cell 6 is greater than the second preset voltage and less than the first preset voltage; at this time, if the charging device 7 continues to charge the battery cell 6, the battery cell 6 may be damaged due to excessive voltage and other accidents such as its service life; therefore, the first controller 2 controls the charging protection switch 3 to turn off, so that the charging device 7 will not charge the battery cell 6, thereby avoiding the battery cell 6 from being affected by the excessive charging voltage and affecting its service life. It should be noted that when the voltage of the battery cell 6 is less than the second preset voltage, the charging device 7 charges the battery cell 6 normally through the passive switch component 121 and the charging protection switch 3.

[0054] The first controller 2 is also used to control the active switch 11 to turn on when it detects that the voltage of the battery cell 6 is greater than or equal to the first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker 12 to the preset operating temperature, thereby disconnecting the recoverable circuit breaker 12, thereby disconnecting the entire battery charging circuit, preventing the battery voltage from continuing to increase, and avoiding the risk of fire, explosion, etc. It can be understood that when the first controller 2 controls the charging protection switch 3 to be disconnected, the charging protection switch 3 is not actually disconnected; thus, the charging device 7 will continue to charge the battery cell 6, and the charging voltage of the battery cell 6 will continue to increase; when the first controller 2 detects that the charging voltage of the battery cell 6 is greater than or equal to the first preset voltage, the first controller 2 controls the active switch 11 to be turned on; at this time, a part of the current or voltage of the charging device 7 enters the battery cell 6 through the passive switch component 121, and another part of the current or voltage flows out through the second heating element 13, and the current flowing through the second heating element 13 causes the temperature of the second heating element 13 to rise sharply, so that the heat of the second heating element 13 causes the temperature of the passive switch component 121 to reach the preset action temperature, and the passive switch component 121 will automatically disconnect; after the passive switch component 121 is disconnected, a part of the current of the charging device 7 flows through the first heating element 122 into the battery cell 6, and another part of the current flows out through the second heating element 13. Since the first heating element 121 and the second heating element 13 are PTC resistors, when current flows through them, the first heating element 121 and the second heating element 13 can maintain the passive switch component in a disconnected state, so that the first heating element 122 will play a technical effect of voltage division and current limiting, avoiding accidents such as spontaneous combustion and explosion due to excessive battery voltage.

[0055] In one embodiment, if Figure 4 and Figure 5 As shown, the battery protection circuit further includes a charging protection switch 3 connected to the first controller 2 , and the battery cell 6 is connected to a charging device 7 via the recoverable circuit breaker 12 and the charging protection switch 3 in sequence.

[0056] The first controller 2 is also used to control the charging protection switch 3 to be disconnected and continuously detect the current of the battery cell 6 when the charging device 7 is detected to be charging the battery cell 6, if the recoverable circuit breaker 12 is turned on and the active switch 11 is turned off, and when it is detected that the current of the battery cell 6 is greater than or the second preset current and less than the first preset current. It can be understood that the first preset current is the critical current at which the first controller 2 controls the active switch 11 to be turned on or off during the charging process of the battery cell 6, which generally refers to the current value of the safe current of the battery charging. When the battery charging current reaches the safe current, the battery is prone to explosion, fire and other risks, thereby causing a safety accident. The second preset current is the critical current at which the first controller 2 controls the charging protection switch 3 to be turned on or off during the charging process of the battery cell 6, and the second preset current can be set according to actual needs, generally referring to the battery protection current of the battery charging. When the battery charging current reaches below the battery protection current, it can ensure that the battery is charged normally and will not damage the battery, but when the battery charging current is greater than the battery protection current, the battery may damage its service life. Furthermore, the second preset current can be set according to actual needs. In the present application, when it is detected that the charging current of the battery 6 is greater than the second preset current and less than the first preset current, the first controller controls the charging protection switch 3 to disconnect, so as to avoid the battery current from continuing to increase and damaging the battery life. Furthermore, when the charging current of the battery cell 6 is between the second preset current and the first preset current, the current of the battery cell 6 may cause damage to the battery cell 6, but will not cause safety accidents such as explosion and spontaneous combustion of the battery cell 6.

[0057] Specifically, during the charging process of the battery cell 6, when the first controller 2 detects that the current of the battery cell 6 is greater than the second preset current and less than the first preset current; at this time, if the charging device 7 continues to charge the battery cell 6, the battery cell 6 may be damaged due to the excessive charging current and its service life accident; therefore, the first controller 2 controls the charging protection switch 3 to turn off, so that the charging device 7 will not charge the battery cell 6, thereby avoiding the battery cell 6 from being affected by the excessive charging voltage and affecting its service life. It should be noted that when the charging current of the battery cell 6 is less than the second preset current, the charging device 7 charges the battery cell 6 through the passive switch component 121 and the charging protection switch 3.

[0058] The first controller 2 is also used to control the active switch 11 to turn on when it detects that the current of the battery cell 6 is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker 12 to the preset operating temperature, thereby disconnecting the recoverable circuit breaker 12, thereby disconnecting the entire battery charging circuit, preventing the battery current from continuing to increase, and avoiding the risk of fire, explosion, etc. It can be understood that when the first controller 2 controls the charging protection switch 3 to be disconnected, the charging protection switch 3 is not actually disconnected; thus, the charging device 7 will continue to charge the battery cell 6, and the charging current of the battery will continue to increase; the first controller 2 controls the active switch 11 to be turned on; at this time, a part of the current or voltage of the charging device 7 enters the battery cell 6 through the passive switch component 121, and another part of the current or voltage flows out through the second heating element 13, and the current flowing through the second heating element 13 causes the temperature of the second heating element 13 to rise sharply, so that the heat of the second heating element 13 makes the temperature of the passive switch component 121 reach the preset action temperature, and the passive switch component 121 will automatically disconnect; after the passive switch is disconnected, a part of the current of the charging device 7 flows through the first heating element 122 into the battery cell 6, and another part of the current flows out through the second heating element 13. Since the first heating element 121 and the second heating element 13 are PTC resistors, when current flows through them, the first heating element 121 and the second heating element 13 can maintain the passive switch component in a disconnected state, so that the first heating element 122 will play a technical effect of shunting, avoiding accidents such as spontaneous combustion and explosion caused by excessive current of the battery voltage. And since after the passive switch component 121 is disconnected, the first heating element 122 and the second heating element 13 can always maintain the passive switch component 121 disconnected, thereby improving the safety of the battery, avoiding the continuous increase of the battery charging current, and reducing the risk of battery fire or even explosion.

[0059] In one embodiment, if Figure 4 and Figure 5 As shown, the battery protection circuit also includes a discharge protection switch 4 connected to the first controller 2, and the battery cell 6 is connected to the electrical equipment 8 through the recoverable circuit breaker 12 and the discharge protection switch 4 in sequence; it can be understood that the discharge protection switch 4 is a primary protection switch of the battery cell 6.

[0060] The first controller 2 is also used to control the discharge protection switch 4 to be disconnected and continuously detect the current of the battery cell 6 when it is detected that the battery cell 6 is discharging to the electrical equipment 8, if the recoverable circuit breaker 12 is turned on and the active switch 11 is turned off, and the voltage of the battery cell 6 is less than the third preset voltage; wherein the third preset voltage is less than the first preset voltage; it can be understood that the third preset voltage is the critical voltage at which the first controller 2 controls the discharge protection switch 4 to be turned on or off during the discharge of the battery cell 6; it generally refers to the battery protection voltage of the discharged battery cell 6. When the discharge voltage of the battery cell 6 is above the third preset voltage and below the first preset voltage, it can ensure that the battery 6 can be discharged normally and will not be damaged; but when the discharge voltage of the battery cell 6 is below the second preset voltage, the battery cell 6 will be damaged in its service life due to excessive discharge. The discharge protection switch 4 and the passive switch component 121 are in a normally closed state, and the active switch 11 is in a normally open state; that is, when the battery cell 6 is in a normal discharge process, the discharge protection switch 4 and the passive switch component 121 are in a conductive state, and the active switch 11 is in a disconnected state. Furthermore, the third preset voltage can be set according to actual needs; and the battery cell 6 is normally discharged at a constant current or constant power. The present application controls the discharge protection switch 4 to disconnect when it is detected that the discharge voltage of the battery 6 is less than the third preset voltage, so as to avoid the battery voltage from continuing to decrease and damaging the battery life.

[0061] Specifically, during the discharge of the battery cell 6, when the first controller 2 detects that the voltage of the battery cell 6 is greater than the third preset voltage; at this time, if the battery cell 6 continues to discharge the electrical device 8, the battery cell 6 may bulge, leak, and other accidents; at this time, the first controller 2 controls the discharge protection switch 4 to turn off, so that the battery cell 6 will not discharge the electrical device 8, avoiding the battery cell 6 from having a low voltage due to continuous discharge, and then bulging, leaking accidents. It should be noted that when the voltage of the battery cell 6 is less than the third preset voltage, the battery cell 6 discharges normally to the electrical device 8 through the passive switch and the discharge protection switch 4.

[0062] The first controller 2 is also used to control the active switch 11 to turn on when it detects that the current of the battery cell 6 is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker 12 to the preset operating temperature, thereby disconnecting the recoverable circuit breaker 12, thereby disconnecting the entire battery discharge circuit, preventing the battery from continuing to discharge with a large current, and avoiding the risk of fire, explosion, etc. of the battery. It can be understood that when the first controller 2 controls the discharge protection switch 4 to disconnect, the discharge protection switch 4 is not actually disconnected; thus, the battery cell 6 will continue to discharge the electrical equipment 8 with a large current, and the voltage of the battery cell 6 will continue to decrease; when the first controller 2 detects that the current of the battery cell 6 is greater than or equal to the first preset current, the first controller 2 controls the active switch 11 to turn on, at which time, part of the current of the battery cell 6 enters the electrical equipment 8 through the passive switch component 121, and the other part of the current flows out through the passive switch component 122 and the second heating element 13; thereafter, the passive Current flows through the switch component 122 and the second heating element 13, so that the temperature of the first heating element 122 and the second heating element 13 will increase, thereby making the operating temperature of the passive switch component 121 reach the preset operating temperature, and the passive switch component 121 automatically disconnects; after the passive switch component 121 automatically disconnects, part of the current of the battery cell 6 flows into the electrical device 8 through the first heating element 122, and the other part of the current flows back to the battery cell through the first heating element 122 and the second heating element 13, thereby avoiding the battery cell 6 continuously discharging to the electrical device 8 with a large current, which may cause explosion, spontaneous combustion and other accidents.

[0063] In one embodiment, if Figure 3 and Figure 4 As shown, the battery protection circuit further includes a discharge protection switch 4 connected to the first controller 2 , and the battery cell 6 is connected to the electrical device 8 via the recoverable circuit breaker 12 and the discharge protection switch 4 in sequence.

[0064] The first controller 2 is also used to control the discharge protection switch 4 to be disconnected and continuously detect the current of the battery cell 6 when it is detected that the battery cell 6 is discharging to the electrical equipment 8, if the recoverable circuit breaker 12 is turned on and the active switch 11 is turned off, and the current of the battery cell 6 is greater than the third preset current; the third preset current is less than the first preset current; it can be understood that the third preset current is the critical current at which the first controller 2 controls the discharge protection switch 4 to be turned on or off during the discharge of the battery cell 6; it generally refers to the battery protection current of the battery discharge. When the discharge current of the battery cell 6 is below the battery protection current, it can ensure that the battery 6 can be discharged normally and will not damage the battery; but when the discharge current of the battery cell 6 is above the battery protection current, the battery cell 6 will be damaged due to excessive current discharge. The first preset current is the critical current at which the first controller controls the active switch 11 to turn on or off during the discharge of the battery cell 6; it generally refers to the current value of the safe current of the battery discharge. When the battery discharge current is above the safe current, the battery is prone to explosion, fire and other risks, thereby causing a safety accident. The third preset current can be set according to actual needs. In this application, when it is detected that the discharge current of the battery 6 is greater than the third preset current and less than the first preset current, the first controller controls the discharge protection switch 4 to disconnect, so as to avoid the battery discharge current from continuing to increase and damaging the battery life. Furthermore, when the discharge current of the battery cell 6 is between the third preset current and the first preset current, the discharge current of the battery cell 6 may cause damage to the battery cell 6, but will not cause safety accidents such as explosion and spontaneous combustion of the battery cell 6.

[0065] Specifically, during the discharge of the battery cell 6, when the first controller 2 detects that the current of the battery cell 6 is greater than the third preset current and less than the first preset current; at this time, if the battery cell 6 continues to discharge the electrical equipment 8 at a higher current, the battery cell 6 may be damaged due to the excessive discharge current and its service life; therefore, the first controller 2 controls the discharge protection switch 4 to turn off, so that the battery cell 6 will not discharge the electrical equipment 8, thereby avoiding the battery cell 6 from affecting its service life due to the excessive discharge current.

[0066] The first controller 2 is also used to control the active switch 11 to turn on when it is detected that the current of the battery cell 6 is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker 12 to the preset operating temperature, thereby disconnecting the recoverable circuit breaker 12, thereby disconnecting the entire battery discharge circuit, preventing the battery from continuing to discharge with a large current, and avoiding the risk of fire, explosion, etc. of the battery. It can be understood that when the first controller 2 controls the discharge protection switch 4 to turn off, the discharge protection switch 4 is not actually disconnected; thus, the battery cell 6 will continue to discharge to the electrical device 8 with a large current, and the battery cell 6 will continue to generate electricity. The first controller 2 controls the active switch 11 to turn on. At this time, part of the current of the battery cell 6 enters the electrical device 8 through the passive switch component 121, and the other part of the current returns to the negative electrode of the battery cell 6 through the first heating element 122 and the second heating element 13; thereafter, the first heating element 122 and the second heating element 13, current flows through both the first heating element 122 and the second heating element 13, so that the heat of the first heating element 122 and the second heating element 13 will make the operating temperature of the passive switch component 121 reach the preset operating temperature, thereby driving the passive switch component 121 to disconnect; after the passive switch component 121 is disconnected, part of the current of the battery cell 6 flows into the electrical device 8 through the first heating element 122, and the other part of the current flows back to the battery cell through the first heating element 122 and the second heating element 13, thereby avoiding the battery cell 6 continuously discharging to the electrical device 8 with a large current, which may cause explosion, spontaneous combustion and other accidents.

[0067] In one embodiment, if Figure 4 and Figure 5 As shown, the battery cell 6 is connected to the charging device 7 through the recoverable circuit breaker 12; the battery protection circuit also includes a second controller 5, and the second controller 5 is connected to the battery cell 6 and the active switch 11; it can be understood that the second controller 5 and the first controller 2 can both control the active switch 11 to be turned on and off.

[0068] The second controller 5 is used to control the active switch 11 to turn on when it is detected that the voltage of the battery cell 6 is greater than or equal to the limit preset voltage; wherein the limit preset voltage is greater than the first preset voltage. It can be understood that the limit preset voltage is the critical voltage at which the second controller 5 controls the active switch 11 to turn on or off during the charging of the battery cell 6, which generally refers to the limit voltage of battery charging. When the battery voltage reaches this limit voltage, the battery is very likely to explode, catch fire, and cause a safety accident. It should be noted that the limit preset voltage is greater than the first preset voltage, and the first preset voltage is greater than the second preset voltage. The second preset voltage is the critical voltage at which the first controller 2 controls the charging protection switch 3 to be turned on or off during the charging of the battery cell 6, and generally refers to the battery protection voltage of the battery charging (that is, when the charging cell is below the second preset voltage, the battery can perform normal charging without damaging its service life; when the charging cell is above the second preset voltage, the battery does not damage its service life due to the excessive charging voltage). The first preset voltage is the critical voltage at which the first controller 2 controls the active switch 11 to be turned on or off during the charging of the battery cell 6, and generally refers to the safe voltage of the battery charging (that is, when the charging cell is above the first preset voltage, the battery is prone to explosion, spontaneous combustion and other accidents due to the excessive charging voltage). Further, when the charging voltage of the battery is greater than the limit preset voltage, the probability of the battery exploding, spontaneously combusting and other accidents is very high, and when the charging voltage of the battery is between the first preset voltage and the limit preset voltage, the battery explodes. The probability of accidents such as spontaneous combustion is relatively high; when the charging voltage of the battery is between the second preset voltage and the first preset voltage, the battery will be damaged during charging, and safety accidents such as explosion and spontaneous combustion will not occur; or the probability of safety accidents such as explosion and spontaneous combustion is relatively low; when the charging voltage of the battery is below the second preset voltage, the battery can be charged normally.Specifically, during the process of charging the battery cell 6 by the charging device 7, when the first controller 2 detects that the voltage of the battery cell 6 is greater than the first preset voltage, the first controller 2 turns on the first active switch 11, so that the first heating element 122 will play a technical effect of voltage division and current limiting, thereby preventing the battery cell 6 from spontaneous combustion, explosion and other accidents due to excessive voltage; if the first controller 2 fails due to other reasons, the active switch 11 is not turned on when the voltage of the battery cell 6 is greater than or equal to the first preset voltage; at this time, the voltage of the battery cell 6 will further increase, and when the second controller 5 detects that the voltage of the battery cell 6 is greater than or equal to the limit preset voltage, the second controller 5 will control the active switch 11 to turn on, so that the first heating element 122 and the second heating element 13 are both connected to the charging circuit of the battery cell 6, thereby avoiding accidents such as spontaneous combustion and explosion caused by excessive voltage of the battery cell 6.

[0069] Furthermore, each battery pack is composed of a plurality of the battery cells 6, and each of the battery cells 6 will share a portion of the total voltage of the charging device 7; during the assembly of the battery pack, when a voltage signal is disconnected in one or more battery cells 6 in the battery pack, due to the detection reasons inside the first controller 2, the voltage value detected by the first controller 2 is higher than the actual battery cell voltage value and will cause a false operation. At this time, when the second controller 5 detects that the voltage value is higher than the preset limit voltage, the second controller 5 controls the active switch 11 to turn on, and then the battery protection circuit will be connected with the recoverable circuit breaker 12. When the voltage of the battery cell is too high, the recoverable circuit breaker 12 will cause the passive switch to disconnect, thereby causing the voltage of the battery cell 6 to continue to increase; because the recoverable circuit breaker 12 is used, it can be restored after it is connected normally without damaging the battery pack.

[0070] What needs to be clarified is Figure 3 In the battery protection circuit shown in FIG. 1 , the charging protection switch 3 and the discharging protection switch 4 are the primary protection switches of the battery pack, and the recoverable disconnection control circuit 1 is the secondary protection switch of the battery pack. In addition, each battery cell 6 also needs to be designed with a tertiary protection switch. Figure 4 In the embodiment shown, one of the three-stage protection switches is the recoverable circuit breaker control circuit 1, which can play the role of the three-stage protection switch and the two-stage protection switch, thereby reducing one two-stage protection switch in the battery protection circuit, reducing the problems of tight space layout and concentrated thermal reaction of the battery protection circuit.

[0071] Another embodiment of the present invention further provides a battery pack, comprising a battery and the above-mentioned battery protection circuit. It can be understood that the battery can be provided with a plurality of the battery cells 6 according to actual needs.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery protection circuit, characterized in that: It includes a restorable circuit breaker control circuit and a first controller; the restorable circuit breaker control circuit includes an active switch and a restorable circuit breaker; one end of the active switch is connected to the first controller, the other end of the active switch is connected to the restorable circuit breaker and an external device, and the end of the restorable circuit breaker away from the external device is connected to a battery cell; The first controller is used to detect the temperature, current and voltage of the battery cell in real time; The first controller is further used to control the active switch to conduct when it is detected that the temperature of the battery cell is greater than or equal to a preset battery temperature, or the current of the battery cell is greater than or equal to a first preset current, or the voltage of the battery cell is greater than or equal to a first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker to a preset operating temperature, thereby disconnecting the recoverable circuit breaker; wherein the recoverable circuit breaker remains disconnected when the operating temperature is greater than or equal to the preset operating temperature, and is turned on when the operating temperature is less than the preset operating temperature; The restorable circuit breaker includes a passive switch assembly and a first heating element, and the restorable circuit breaker control circuit also includes a second heating element; the first heating element and the passive switch assembly are connected in parallel between the battery cell and the external device, one end of the second heating element is connected to the active switch, and the other end of the second heating element is connected to the connection line between the first heating element and the external device; the end of the active switch away from the second heating element is connected to the first controller; The second heating element is used to heat the passive switch component to the preset operating temperature when the active switch is turned on; The battery cell is connected to a charging device via the recoverable circuit breaker; the battery protection circuit further comprises a second controller, the second controller being connected to the battery cell and the active switch; The second controller is used for controlling the active switch to conduct when it is detected that the voltage of the battery cell is greater than or equal to a limit preset voltage; wherein the limit preset voltage is greater than the first preset voltage.

2. The battery protection circuit according to claim 1, characterized in that: The first controller is further configured to control the active switch to be disconnected when it is detected that the temperature of the battery cell is lower than a preset battery temperature, the current of the battery cell is lower than a first preset current, and the voltage of the battery cell is lower than a first preset voltage.

3. The battery protection circuit according to claim 1, characterized in that: The first heating element is a first PTC resistor, and the second heating element is a second PTC resistor.

4. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a charging protection switch connected to the first controller, and the battery cell is connected to a charging device in sequence through the recoverable circuit breaker and the charging protection switch; The first controller is further configured to, when detecting that the charging device is charging the battery cell, control the charging protection switch to be disconnected and continuously detect the voltage of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the voltage of the battery cell is greater than a second preset voltage; wherein the second preset voltage is less than the first preset voltage; The first controller is also used to control the active switch to conduct when it is detected that the voltage of the battery cell is greater than or equal to the first preset voltage, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

5. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit further includes a charging protection switch connected to the first controller, and the battery cell is connected to a charging device in sequence through the recoverable circuit breaker and the charging protection switch; The first controller is further configured to, when detecting that the charging device is charging the battery cell, control the charging protection switch to be disconnected and continuously detect the current of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the current of the battery cell is greater than or equal to a second preset current; wherein the second preset current is less than the first preset current; The first controller is also used to control the active switch to conduct when it is detected that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

6. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit further comprises a discharge protection switch connected to the first controller, and the battery cell is connected to the electrical equipment in sequence through the recoverable circuit breaker and the discharge protection switch; The first controller is further used to detect that when the battery cell discharges the electrical equipment, if the recoverable circuit breaker is turned on and the active switch is turned off, and the voltage of the battery cell is less than a third preset voltage, then control the discharge protection switch to turn off and continue to detect the current of the battery cell; wherein the third preset voltage is less than the first preset voltage; The first controller is also used to control the active switch to conduct when it detects that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

7. The battery protection circuit according to claim 1, characterized in that: The battery protection circuit also includes a discharge protection switch connected to the control module, and the battery cell is connected to the electrical equipment in sequence through the recoverable circuit breaker and the discharge protection switch; The first controller is further configured to, when it is detected that the battery cell is discharging to the electrical equipment, control the discharge protection switch to be disconnected and continuously detect the current of the battery cell if the recoverable circuit breaker is turned on and the active switch is turned off, and the current of the battery cell is greater than a third preset current; the third preset current is less than the first preset current; The first controller is also used to control the active switch to conduct when it is detected that the current of the battery cell is greater than or equal to the first preset current, so as to increase the operating temperature of the recoverable circuit breaker to the preset operating temperature, thereby disconnecting the recoverable circuit breaker.

8. A battery pack, characterized in that: The invention comprises a battery and a battery protection circuit as claimed in any one of claims 1 to 7.

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