Battery and charging protection circuit

Abstract

A battery (10) and a charging protection circuit (12), which can effectively reduce the possibility of overcharging while reducing volume and production costs. The battery comprises: at least one battery cell (11); and a charging protection circuit, connected to the at least one battery cell. The charging protection circuit comprises a comparison circuit (121) and an on-off circuit (122). The comparison circuit is configured to receive a first input voltage (U1) and a second input voltage (U2) during charging, and to output a comparison signal on the basis of a comparison result of the first input voltage and the second input voltage. The first input voltage indicates a charging voltage threshold, and the second input voltage indicates voltages of some of the battery cells among the at least one battery cell. The on-off circuit is configured to cut off a charging loop of the battery when the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage. The number of comparison circuits is greater than the number of on-off circuits.

Description

Battery and charging protection circuit Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411102976.X, filed on August 12, 2024, entitled “Battery and charging protection circuit”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a battery and a charging protection circuit. BACKGROUND

[0003] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. In this case, electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0004] In the development of battery technology, overcharging is a major difficulty. Overcharging often leads to problems such as performance degradation, life attenuation, and even thermal runaway of the battery, which in turn causes huge personal and property losses. Therefore, how to effectively solve the problem of overcharging of the battery is an urgent problem to be solved. SUMMARY

[0005] The embodiments of the present application provide a battery and a charging protection circuit, which can effectively reduce the possibility of overcharging of the battery while reducing the volume of the battery and the production cost of the battery.

[0006] In a first aspect, a battery is provided, comprising: at least one battery cell; a charging protection circuit connected with the at least one battery cell, the charging protection circuit comprising a comparison circuit and a pass-fail circuit; wherein the comparison circuit is configured to receive a first input voltage and a second input voltage during charging, and output a comparison signal according to a comparison result of the first input voltage and the second input voltage, the first input voltage indicating a charging voltage threshold, and the second input voltage indicating a voltage of part of the at least one battery cell; the pass-fail circuit is configured to cut off a charging loop of the battery when the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage; and the number of comparison circuits is greater than the number of pass-fail circuits.

[0007] The charging protection circuit includes a comparison circuit and a switch circuit, the comparison circuit is connected with the battery monomer, and is configured to receive a first input voltage indicating a charging voltage threshold and a second input voltage indicating a battery monomer voltage; and the switch circuit can cut off the charging circuit of the battery in time when the voltage of the battery monomer is greater than or equal to the charging voltage threshold, thereby reducing the possibility of overcharging of the battery, improving the performance of the battery, and reducing the probability of safety hazards caused by overcharging of the battery to a certain extent. Further, the number of comparison circuits is greater than the number of switch circuits, which on the one hand reduces the space of the battery occupied by the charging protection circuit, thereby effectively reducing the volume of the battery, and on the other hand reduces the production cost of the battery.

[0008] In some possible implementation manners, each of the at least one battery monomer is connected with each of the comparison circuits respectively.

[0009] The above technical solution sets the number of comparison circuits to be less than the number of battery monomers, and the comparison circuits are connected with part of the at least one battery monomer, so that the cost and volume of the battery can be further reduced.

[0010] In some possible implementation manners, the number of comparison circuits is less than the number of the at least one battery monomer, and the comparison circuits are connected with part of the at least one battery monomer.

[0011] In this way, each battery monomer is connected with a comparison circuit, so that the switch circuit can quickly respond to overcharging and cut off the charging circuit in time when the voltage of any battery monomer reaches the voltage threshold, thereby effectively reducing the possibility of overcharging of the battery, further improving the performance of the battery, and reducing the probability of safety hazards caused by overcharging of the battery to a certain extent.

[0012] In some possible implementation manners, the number of switch circuits is one, and the output end of the comparison circuit is connected to one of the switch circuits.

[0013] The above technical solution sets the number of switch circuits to be one, which can reduce the electronic components included in the charging protection circuit to the maximum extent, thereby further reducing the cost of the charging protection circuit and the internal space of the battery occupied by the charging protection circuit, and effectively reducing the cost and volume of the battery.

[0014] In some possible implementation manners, the charging protection circuit further includes: a first voltage dividing circuit, an input end of the first voltage dividing circuit receives a preset voltage output by a preset voltage source, an output end of the first voltage dividing circuit is connected to the first input end of the comparison circuit, and the first voltage dividing circuit is configured to divide the preset voltage into the first input voltage; and / or

[0015] a second voltage dividing circuit, an input end of the second voltage dividing circuit is connected to a positive electrode of the battery cell, an output end of the second voltage dividing circuit is connected to the second input end of the comparison circuit, and the second voltage dividing circuit is configured to divide a voltage of the battery cell into the second input voltage.

[0016] The above technical solution, on the one hand, by arranging the first voltage dividing circuit, the first input voltage input to the first input end of the comparison circuit can more accurately indicate the charging voltage threshold, thereby further reducing the possibility of battery overcharging. On the other hand, by arranging the second voltage dividing circuit, the requirement that the charging voltage threshold is greater than the voltage of the battery cell in a specific scenario (for example, the voltage of the battery cell is converted into the first input voltage through a voltage reduction circuit) can be met, thereby ensuring the normal charging of the battery.

[0017] In some possible implementation manners, the first voltage dividing circuit includes a first resistor and a second resistor, a first end of the first resistor is connected to the preset voltage source, a second end of the first resistor is connected to a first end of the second resistor and the first input end of the comparison circuit, and a second end of the second resistor is grounded; and / or

[0018] The second voltage dividing circuit includes a third resistor and a fourth resistor, a first end of the third resistor is connected to the positive electrode of the battery cell, a second end of the third resistor is connected to a first end of the fourth resistor and the second input end of the comparison circuit, and a second end of the fourth resistor is grounded.

[0019] The first voltage dividing circuit includes two resistors, and / or the second voltage dividing circuit includes two resistors. Since the resistors are relatively cheap, the above technical solution realizes the voltage dividing function at a relatively low cost.

[0020] In some possible implementation manners, the charging protection circuit further includes: a delay circuit, an input end of the delay circuit is connected to the output end of the second voltage dividing circuit, and an output end of the delay circuit is grounded, so as to perform delay processing on the second input voltage.

[0021] The technical solution, by arranging the delay circuit, the first input voltage can be greater than the second input voltage during the charging process, thereby ensuring the normal charging. For example, at the power-on moment, it is ensured that the first input voltage is greater than the second input voltage, thereby preventing the power-on mis-triggering.

[0022] In some possible implementation manners, the charging protection circuit further includes: a first filter circuit, configured to receive the first input voltage at an input end and output the first input voltage to a first input end of the comparison circuit, so as to filter the received first input voltage and output the filtered first input voltage to the first input end of the comparison circuit; and / or

[0023] a second filter circuit, configured to receive the second input voltage at an input end and output the second input voltage to a second input end of the comparison circuit, so as to filter the received second input voltage and output the filtered second input voltage to the second input end of the comparison circuit.

[0024] The above technical solution can filter out high-frequency noise signals in the first input voltage and the second input voltage by arranging the first filter circuit and / or the second filter circuit, thereby effectively improving the robustness of the charging protection circuit.

[0025] In some possible implementation manners, the first filter circuit includes a first filter resistor and a first filter capacitor, a first end of the first filter resistor is configured to receive the first input voltage, a second end of the first filter resistor is connected to a first end of the first filter capacitor and the first input end of the comparison circuit, and a second end of the first filter capacitor is grounded; and / or

[0026] The second filter circuit includes a second filter resistor and a second filter capacitor, a first end of the second filter resistor is configured to receive the second input voltage, a second end of the second filter resistor is connected to a first end of the second filter capacitor and the second input end of the comparison circuit, and a second end of the second filter capacitor is grounded.

[0027] The above technical solution arranges the first filter circuit and / or the second filter circuit to include a resistor and a capacitor, so as to achieve the purpose of filtering out high-frequency noise signals at a relatively low cost.

[0028] In some possible implementation manners, the charging protection circuit further includes: a power supply circuit, an input end of the power supply circuit is connected to a positive electrode of the battery monomer, and an output end of the power supply circuit is connected to the first input end of the comparison circuit, and the power supply circuit is configured to convert the voltage of the battery monomer into the first input voltage.

[0029] The input of the charging protection circuit is usually the voltage of the battery cell connected thereto. The real-time voltage of the battery cell is constantly changing during a charging process, while the charging voltage threshold is a fixed value. Therefore, the technical solution sets the supply circuit for converting the voltage of the battery cell into the first input voltage input signal, so as to set the charging voltage threshold, and then effectively reduce the possibility of overcharging of the battery through the charging voltage threshold.

[0030] In some possible implementation manners, the charging protection circuit further includes a trigger circuit, an input end of the trigger circuit is configured to receive the comparison signal, and an output end of the trigger circuit is connected to the on-off circuit. The trigger circuit is configured to output a control signal to the on-off circuit according to the comparison signal, and the control signal is used to control the on-off of the charging loop. In a case where the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage, the control signal is used to control the on-off circuit to cut off the charging loop.

[0031] The technical solution sets the trigger circuit, so that in a case where the second input voltage is greater than or equal to the first input voltage, the comparison signal output by the comparison circuit can trigger the on-off circuit to timely switch the charging loop, regardless of the form of the on-off circuit. The technical solution not only improves the diversity of application of the charging protection circuit, but also further reduces the possibility of overcharging of the battery.

[0032] In some possible implementation manners, the charging protection circuit further includes a protection circuit including a first capacitor, a diode and a transient voltage suppression diode. A first end of the first capacitor is connected to the positive electrode of the battery cell and a first end of the diode, a second end of the first capacitor is grounded through a second end of the transient voltage suppression diode, and a second end of the diode is connected to a first end of the transient voltage suppression diode to a second input end of the comparison circuit.

[0033] The technical solution sets the protection circuit, which can protect against surge voltage on the bus voltage and prevent reverse connection of the power supply, thereby further improving the performance of the battery.

[0034] In a second aspect, a charging protection circuit is provided, including: a comparison circuit configured to receive a first input voltage and a second input voltage during a charging process, and output a comparison signal according to a comparison result of the first input voltage and the second input voltage, the first input voltage indicating a charging voltage threshold, and the second input voltage indicating a voltage of a battery cell; an on-off circuit configured to cut off a charging loop of the battery in a case where the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage; and wherein the number of comparison circuits is greater than the number of on-off circuits. BRIEF DESCRIPTION OF DRAWINGS

[0035] FIG. 1 shows a schematic diagram of a battery according to an embodiment of the present application.

[0036] FIG. 2 shows an exploded view of a battery cell according to an embodiment of the present application.

[0037] FIG. 3 shows a schematic diagram of a battery according to an embodiment of the present application.

[0038] FIG. 4 shows a schematic diagram of another battery according to an embodiment of the present application.

[0039] FIG. 5 shows a schematic diagram of a power supply circuit according to an embodiment of the present application.

[0040] FIG. 6 shows a schematic diagram of another power supply circuit according to an embodiment of the present application.

[0041] FIG. 7 shows a schematic diagram of yet another power supply circuit according to an embodiment of the present application.

[0042] FIG. 8 shows a schematic diagram of a battery according to an embodiment of the present application.

[0043] FIG. 9 shows a schematic diagram of a battery according to an embodiment of the present application.

[0044] FIG. 10 shows a schematic diagram of a battery according to an embodiment of the present application.

[0045] FIG. 11 shows a schematic diagram of a battery according to an embodiment of the present application.

[0046] FIG. 12 shows a schematic diagram of a trigger circuit according to an embodiment of the present application.

[0047] FIG. 13 shows a schematic diagram of a charge protection circuit according to an embodiment of the present application.

[0048] FIG. 14 shows a schematic diagram of a charge protection circuit according to an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] 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 belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the use herein of terms such as "comprise", "have" and "include" or their conjugates, encompass the presence of the stated features or components but do not preclude the presence of additional features or components. The use herein of terms such as "first", "second" and "third" and the like does not imply a particular order but is used for naming purposes only.

[0051] The positional words appearing in the following description are the directions shown in the drawings, and are not intended to limit the specific structure of the present application. In the description of the present application, it should be further explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0053] In the present application, "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0054] In the field of new energy, batteries can be used as the main power source for electric devices (such as vehicles, ships or spacecraft, etc.). The battery referred to in the embodiments of the present application refers to a single physical module comprising one or more battery monomers to provide higher voltage and capacity. For example, the battery referred to in the present application can include a battery module or a battery pack, etc.

[0055] During the use of the battery, the battery needs to be charged. However, overcharging may occur when the battery is charged. Battery overcharging refers to the situation that, during the charging process of the battery, due to the charging time being too long or the charging voltage being too high, the internal charging reaction of the battery continues, thereby exceeding the normal charging state designed for the battery.

[0056] Battery overcharging can cause a series of problems. On the one hand, it can reduce the service life of the battery. Specifically, battery overcharging can accelerate the progress of the chemical reaction inside the battery, causing physical and chemical changes in the internal structure of the battery, thereby accelerating the aging process of the battery. In addition, overcharging can reduce the number of cycles of the battery, i.e., the number of times the battery can be charged and discharged, thereby shortening the overall service life of the battery. On the other hand, battery overcharging can cause loss of active materials inside the battery, thereby reducing the capacity of the battery and weakening the endurance of the battery. In addition, battery overcharging can increase the internal resistance of the battery, reduce the energy conversion efficiency of the battery, and reduce the energy released by the battery during discharging. On the other hand, battery overcharging can also cause safety hazards. For example, battery overcharging can generate a large amount of heat, which, if not dissipated in time, can cause the temperature of the battery to rise sharply, thereby causing serious safety problems such as smoking, fire, and even explosion. For another example, battery overcharging can also cause the internal gas pressure of the battery to rise, causing the battery shell to expand, and in severe cases, can cause the battery to leak, causing damage to the environment and equipment.

[0057] Based on this, the embodiments of the present application provide a battery, including at least one battery cell and a charging protection circuit connected with the at least one battery cell. Wherein, the charging protection circuit includes a comparison circuit and a on-off circuit, the comparison circuit is configured to receive a first input voltage and a second input voltage during charging, and output a comparison signal according to the comparison result of the first input voltage and the second input voltage, the first input voltage indicates a charging voltage threshold, and the second input voltage indicates the voltage of part of the battery cells in the at least one battery cell, the on-off circuit is configured to cut off the charging loop of the battery in the case that the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage. Wherein, the number of comparison circuits is greater than the number of on-off circuits. In this way, the on-off circuit can cut off the charging loop of the battery in time in the case that the voltage of the battery cell is greater than the charging voltage threshold, reducing the possibility of battery overcharging, not only improving the performance of the battery, but also reducing the probability of safety hazards caused by battery overcharging to a certain extent. Further, the number of comparison circuits is set to be greater than the number of on-off circuits, on the one hand, reducing the space of the battery occupied by the charging protection circuit, thereby effectively reducing the volume of the battery, on the other hand, reducing the production cost of the battery.

[0058] FIG. 1 shows a schematic diagram of a battery 10 according to an embodiment of the present application.

[0059] As shown in FIG. 1, the battery 10 includes at least one battery cell 11 and a charging protection circuit 12 connected with the at least one battery cell 11, the charging protection circuit 12 including a comparison circuit 121 and a switch-off circuit 122. The comparison circuit 121 is configured to receive a first input voltage U1 and a second input voltage U2 during charging, the first input voltage U1 indicating a charging voltage threshold, and the second input voltage U2 indicating a voltage of part of the at least one battery cell 11, and output a comparison signal according to a comparison result of the first input voltage U1 and the second input voltage U2, and the switch-off circuit 122 is configured to cut off a charging loop of the battery 10 when the comparison signal indicates that the second input voltage U2 is greater than or equal to the first input voltage U1.

[0060] In the embodiment, the number of the comparison circuits 121 is greater than the number of the switch-off circuits 122.

[0061] In the embodiment, the charging protection circuit 12 including the comparison circuit 121 and the switch-off circuit 122 is connected with the battery cell 11, and the comparison circuit 121 is configured to receive the first input voltage U1 indicating the charging voltage threshold and the second input voltage U2 indicating the voltage of the battery cell, and the switch-off circuit 122 can timely cut off the charging loop of the battery 10 when the voltage of the battery cell 11 is greater than or equal to the charging voltage threshold, thereby reducing the possibility of overcharging of the battery 10, improving the performance of the battery 10, and reducing the probability of safety hazards caused by overcharging of the battery 10 to a certain extent. Further, the number of the comparison circuits 121 is set to be greater than the number of the switch-off circuits 122, which on one hand reduces the space of the charging protection circuit 12 in the battery 10, thereby effectively reducing the volume of the battery 10, and on the other hand, reduces the production cost of the battery 10.

[0062] As shown in FIG. 2, a structure diagram of a battery cell 11 according to an embodiment of the present application is shown. The battery cell 11 includes one or more electrode assemblies 120, a housing 131, and a cover plate 132. The housing 131 and the cover plate 132 form an outer shell or a battery box 13. The walls of the housing 131 and the cover plate 132 are collectively referred to as the walls of the battery cell 11. The housing 131 is shaped according to the shape of the one or more electrode assemblies 120 combined together. For example, the housing 131 can be a hollow cuboid or a hollow square or a hollow cylinder. One of the faces of the housing 131 has an opening so that the one or more electrode assemblies 120 can be placed inside the housing 131. For example, when the housing 131 is a hollow cuboid or a hollow square, one of the flat faces of the housing 131 is the opening face, i.e., the flat face does not have a wall so that the inside of the housing 131 is in communication with the outside. When the housing 131 is a hollow cylinder, one of the end faces of the housing 131 is the opening face, i.e., the end face does not have a wall so that the inside of the housing 131 is in communication with the outside. The cover plate 132 covers the opening and is connected to the housing 131 to form a closed cavity in which the electrode assembly 120 is placed. The housing 131 is filled with an electrolyte, such as an electrolyte solution.

[0063] The battery cell 11 can further include two electrode terminals 114, which can be arranged on the cover plate 132. The cover plate 132 is generally a flat plate, and the two electrode terminals 114 are fixed to the flat surface of the cover plate 132. The two electrode terminals 114 are respectively a positive electrode terminal 114a and a negative electrode terminal 114b. Each of the electrode terminals 114 is respectively provided with a connecting member 15, which is also referred to as a current collecting member 15, between the cover plate 132 and the electrode assembly 120, for electrically connecting the electrode assembly 120 and the electrode terminal 114.

[0064] As shown in FIG. 2, each of the electrode assemblies 120 has a first tab 121a and a second tab 122a. The first tab 121a and the second tab 122a have opposite polarities. For example, when the first tab 121a is a positive tab, the second tab 122a is a negative tab. The first tab 121a of the one or more electrode assemblies 120 is connected to one of the electrode terminals 114 through one of the connecting members 15, and the second tab 122a of the one or more electrode assemblies 120 is connected to the other of the electrode terminals 114 through the other of the connecting members 15. For example, the positive electrode terminal 114a is connected to the positive tab through one of the connecting members 15, and the negative electrode terminal 114b is connected to the negative tab through the other of the connecting members 15.

[0065] In the battery cell 11, the electrode assemblies 120 can be arranged as a single electrode assembly or multiple electrode assemblies according to actual use requirements. As shown in FIG. 2, the battery cell 11 is provided with four independent electrode assemblies 120.

[0066] A relief mechanism 113 can also be provided on the battery cell 11. The relief mechanism 113 is configured to actuate to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 11 reaches a threshold value.

[0067] The on-off circuit 122 can include, but is not limited to, a fuse, a fuse, a fuse, a self-recovery fuse, etc. Exemplarily, the internal resistance of the on-off circuit 122 can be between 1.5Ω and 2.3Ω.

[0068] The positive electrode of the comparison circuit 121 is configured to receive the first input voltage U1, and the negative electrode is configured to receive the second input voltage U2. The comparison circuit 121 can be, for example, the circuit shown in FIG. 3, or can also be the circuit shown in FIG. 4.

[0069] In some embodiments, the number of comparison circuits 121 is less than the number of at least one battery cell 11, and the comparison circuits 121 are connected to part of the at least one battery cell 11.

[0070] Optionally, the comparison circuit 121 can be connected to any part of the at least one battery cell 11.

[0071] Optionally, the battery cell 11 connected to the comparison circuit 121 can be determined based on certain criteria. For example, the battery cell 11 connected to the comparison circuit 121 can be determined according to the battery state parameters of each battery cell 11 in the at least one battery cell 11. The battery state parameters can include, for example, temperature, state of charge (SOC), state of health (SOH), capacity, etc. For another example, the battery cell 11 connected to the comparison circuit 121 can be determined according to the environment in which the battery 10 is located.

[0072] The above technical solutions set the number of comparison circuits 121 to be less than the number of battery cells 11, and the comparison circuits 121 are connected to part of the at least one battery cell 11. In this way, the cost and volume of the battery 10 can be further reduced.

[0073] Since the high-voltage platform of the battery system is usually composed of hundreds of battery cells in series, it is determined that different battery cells need to be charged with the same current, and the difference in capacity and initial voltage state of the battery cells will cause a difference in the actual charging voltage, that is, part of the battery cells will first reach the overcharge threshold. At this time, continuing to charge will cause harm to the overcharged battery cell.

[0074] Considering the above problems, in some embodiments, each battery cell 11 in the at least one battery cell 11 can be connected to each comparison circuit 121 in the comparison circuit 121, respectively.

[0075] In other words, the comparison circuit 121 corresponds to the battery cell 11 one by one, and the number of the comparison circuit 121 is the same as the number of the battery cell 11.

[0076] In this way, each battery cell 11 is connected with the comparison circuit 121, so that when the voltage of any battery cell 11 reaches the voltage threshold value, the on-off circuit 122 can quickly respond to overcharging and timely cut off the charging circuit, effectively reducing the possibility of overcharging of the battery 10, not only further improving the performance of the battery 10, but also effectively reducing the probability of safety hazards caused by overcharging of the battery 10.

[0077] The number of the on-off circuit 122 can be multiple. For example, the charging protection circuit 12 includes 3 comparison circuits 121, the output ends of 2 comparison circuits 121 are connected to one on-off circuit 122, and the output end of the other comparison circuit 121 is connected to another on-off circuit 122.

[0078] Alternatively, the number of the on-off circuit 122 can be one, and the output ends of the comparison circuits 121 are connected to the common on-off circuit 122.

[0079] The technical solution sets the number of the on-off circuit 122 to one, which can reduce the electronic components included in the charging protection circuit 12 to the greatest extent, thereby further reducing the cost and the internal space of the battery 10 occupied by the charging protection circuit 12, and effectively reducing the cost and the volume of the battery 10.

[0080] Alternatively, the charging voltage threshold value can be a fixed value, that is, the charging voltage threshold value is the same value at any time of charging. The charging voltage threshold value can be obtained by the user based on multiple experiments, or can be a value determined based on experience.

[0081] Alternatively, the charging voltage threshold value can be a variable. For example, the charging voltage threshold value is V1 last time, and the charging voltage threshold value is V2 this time. Illustratively, the charging voltage threshold value can change according to the change of the battery state, or can change according to the change of the external environment, or can change according to the different charging purposes.

[0082] It should be noted that the charging voltage threshold value is a fixed value in the same charging process.

[0083] It should be further noted that "the second input voltage U2 is greater than or equal to the first input voltage U1" of the embodiment of the application means that the second input voltage U2 will be greater than or equal to the first input voltage U1, or the second input voltage U2 has been greater than or equal to the first input voltage U1.

[0084] As an example, the first input of the comparison circuit 121 can be directly connected to a preset voltage source S, and the output of the preset voltage source S is the charging voltage threshold.

[0085] Considering that the input of the charging protection circuit 12 is usually the voltage of the battery cell 11 connected thereto, the real-time voltage of the battery cell 11 changes constantly during a charging process, while the charging voltage threshold is a fixed value. Therefore, as another example, the charging protection circuit 12 can include a power supply circuit 123, an input of which is connected to the positive electrode of the battery cell 11, and an output of which is connected to the first input of the comparison circuit 121. The power supply circuit 123 is configured to convert the voltage of the battery cell 11 into the first input voltage.

[0086] The power supply circuit 123 can be a voltage boosting circuit, a voltage reducing circuit, or other circuits. FIGS. 5-7 show three possible schematic circuit diagrams of the power supply circuit 123 of the embodiments of the present application.

[0087] The above technical solution realizes the setting of the charging voltage threshold by setting the power supply circuit 123 that converts the voltage of the battery cell 11 into the first input voltage input signal, and thus the possibility of overcharging of the battery 10 can be effectively reduced by the charging voltage threshold.

[0088] Further, the charging protection circuit 12 can further include a first voltage dividing circuit 124. An input of the first voltage dividing circuit 124 receives a preset voltage output by the preset voltage source S, and an output of the first voltage dividing circuit 124 is connected to the first input of the comparison circuit 121. The first voltage dividing circuit 124 is configured to divide the preset voltage into the first input voltage U1.

[0089] The preset voltage source S can be the battery cell 11, and the preset voltage can be the voltage of the battery cell 11, or the preset voltage can be the voltage of the battery cell 11 after a diode voltage drop. In the case where the charging protection circuit 12 includes the power supply circuit 123, the preset voltage can be the output signal of the power supply circuit 123.

[0090] By setting the first voltage dividing circuit 124, the first input voltage U1 input to the first input of the comparison circuit 121 can more accurately indicate the charging voltage threshold, thereby further reducing the possibility of overcharging of the battery 10.

[0091] As shown in FIG. 8, the first voltage dividing circuit 124 can include a first resistor R1 and a second resistor R2. A first end of the first resistor R1 is connected to the preset voltage source S, a second end of the first resistor R1 is connected to a first end of the second resistor R2 and the first input of the comparison circuit 121, and a second end of the second resistor R2 is grounded.

[0092] At this time, the charging voltage threshold can satisfy the following formula:

[0093] wherein V th is the charging voltage threshold, V CC1 is the preset voltage. It can be seen that the charging voltage threshold can be changed by adjusting the resistance values of R1 and R2.

[0094] The first voltage dividing circuit 124 includes two resistors. Since the resistors are relatively cheap, the above technical solution realizes the voltage dividing function at a low cost.

[0095] In the case where the power supply circuit 123 is a step-down circuit, the first input voltage, i.e., the charging voltage threshold, is less than the voltage of the battery cell 11, which is contrary to the normal charging condition.

[0096] Therefore, in some embodiments, the charging protection circuit 12 can further include a second voltage dividing circuit 125. The input end of the second voltage dividing circuit 125 is connected to the positive electrode of the battery cell 11, the output end of the second voltage dividing circuit 125 is connected to the second input end of the comparison circuit 121, and the second voltage dividing circuit 125 is configured to divide the voltage of the battery cell 11 into a second input voltage U2.

[0097] By setting the second voltage dividing circuit 125, the requirement that the charging voltage threshold is greater than the voltage of the battery cell 11 in a specific scenario (e.g., the voltage of the battery cell 11 is converted into the first input voltage by the step-down circuit) can be met, thereby ensuring the normal charging of the battery 10.

[0098] Referring again to FIG. 8, the second voltage dividing circuit 125 can include a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the positive electrode of the battery cell 11, the second end of the third resistor R3 is connected to the first end of the fourth resistor R4 and the second input end of the comparison circuit 121, and the second end of the fourth resistor R4 is grounded.

[0099] At this time, the second input voltage U2 can satisfy the following formula:

[0100] wherein U2 indicates the output voltage of the battery cell 11 connected thereto after passing through the second voltage dividing circuit 125, V in is the voltage of the battery cell 11 connected thereto without passing through the second voltage dividing circuit 125. It can be seen that the value of the second input voltage U2 can be changed by adjusting the resistance values of R3 and R4.

[0101] The second voltage dividing circuit 125 includes two resistors. Since the resistors are relatively cheap, the above technical solution realizes the voltage dividing function at a low cost.

[0102] Considering that the first input voltage U1 can have high-frequency noise, further, the charging protection circuit 12 can further include a first filter circuit 126. The first filter circuit 126 is configured to receive the first input voltage U1 at an input end and output the first input voltage U1 to the first input end of the comparison circuit 121 after filtering the first input voltage U1.

[0103] Specifically, as shown in FIG. 9, the first filter circuit 126 can include a first filter resistor R5 and a first filter capacitor C1. The first end of the first filter resistor R5 receives the first input voltage U1, the second end of the first filter resistor R5 is connected to the first end of the first filter capacitor C1 and the first input end of the comparison circuit 121, and the second end of the first filter capacitor C1 is grounded.

[0104] The first filter cutoff frequency of the first filter circuit 126 can be adjusted by adjusting the resistance value of the first filter resistor R5 and the capacitance value of the first filter capacitor C1. The first filter cutoff frequency f1 can satisfy:

[0105] Alternatively, the first filter circuit 126 can include a first filter inductor and a first filter capacitor C1 connected in series between the first filter inductor and the first filter capacitor C1. The input end of the first filter inductor receives the first input voltage U1, and the output end of the first filter capacitor C1 is connected to the first input end of the comparison circuit 121.

[0106] Similar to the first input voltage U1, the second input voltage U2 can also have high-frequency noise. Therefore, the charging protection circuit 12 can also include a second filter circuit 127. The second filter circuit 127 is configured to receive the second input voltage U2 at an input end and output the second input voltage U2 to the second input end of the comparison circuit 121 after filtering the second input voltage U2.

[0107] Specifically, referring again to FIG. 9, the second filter circuit 127 can include a second filter resistor R6 and a second filter capacitor C2. The first end of the second filter resistor R6 receives the second input voltage U2, the second end of the second filter resistor R6 is connected to the first end of the second filter capacitor C2 and the second input end of the comparison circuit, and the second end of the second filter capacitor C2 is grounded.

[0108] The second filter cutoff frequency of the second filter circuit 127 can be adjusted by adjusting the resistance value of the second filter resistor R6 and the capacitance value of the second filter capacitor C2. The second filter cutoff frequency f2 can satisfy:

[0109] Alternatively, the second filter circuit 127 can include a second filter inductor and a second filter capacitor C2 connected in series between each other, an input end of the second filter inductor receiving the second input voltage U2, and an output end of the second filter capacitor C2 connected to the second input end of the comparison circuit 121.

[0110] The above technical solution can filter out high-frequency noise signals in the first input voltage U1 and the second input voltage U2 by arranging the first filter circuit 126 and / or the second filter circuit 127, thereby effectively improving the robustness of the charging protection circuit 12.

[0111] In addition, the first filter circuit 126 and / or the second filter circuit 127 are arranged to include a resistor and a capacitor, thereby achieving the purpose of filtering out high-frequency noise signals at a relatively low cost.

[0112] In the case of normal charging, the first input voltage U1 should be greater than the second input voltage U2. At the moment of power-on, both the first input voltage U1 and the second input voltage U2 start to rise from 0. In order to ensure the normal function of the charging protection circuit 12 and make the first input signal always greater than the second input voltage U2, in some embodiments, the charging protection circuit 12 can further include a delay circuit configured to receive the second input voltage U2 at an input end and connected to the second input end of the comparison circuit 121 to perform delay processing on the received second input voltage U2.

[0113] The technical solution can make the first input voltage U1 greater than the second input voltage U2 during charging by arranging the delay circuit, thereby ensuring the normal charging. For example, at the moment of power-on, it can be ensured that the first input voltage U1 is greater than the second input voltage U2, thereby preventing the power-on from being triggered by mistake.

[0114] In the case where the charging protection circuit 12 includes the second voltage dividing circuit 125, the input end of the delay circuit can be connected to the output end of the second voltage dividing circuit 125, and the output end of the delay circuit is connected to the second input end of the comparison circuit 121.

[0115] If the second voltage dividing circuit 125 includes a third resistor R3 and a fourth resistor R4, a first end of the delay circuit can be connected to a second end of the third resistor R3 and a first end of the fourth resistor R4, and a second end of the delay circuit can be grounded. At this time, the third resistor R3 not only has the function of voltage division, but also can limit the charging speed of the delay circuit, so that the first input voltage U1 is greater than the second input voltage U2.

[0116] Alternatively, the first end of the delay circuit can be connected to the first end of the fourth resistor R4, and the second end of the delay circuit is grounded.

[0117] As an example, as shown in FIG. 10, the delay circuit can include a first delay capacitor C3. Wherein the greater the capacitance value of the first delay capacitor, the longer the delay time.

[0118] In the case where the charging protection circuit 12 includes the second voltage dividing circuit 125 and the second filter circuit 127, and the second voltage dividing circuit 125 includes the third resistor R3 and the fourth resistor R4, and the second filter circuit 127 includes the second filter resistor R6 and the second filter capacitor C2, the delay time t1 of the second input voltage U2 can satisfy the following formula:

[0119] As another example, the delay circuit can include a second delay capacitor and a second delay resistor.

[0120] It should be noted that although the first input end of the comparison circuit 121 is not connected with the delay circuit, due to the parasitic capacitor in the charging protection circuit 12, there is a delay time for the first input voltage U1. In the case where the charging protection circuit 12 includes the first voltage dividing circuit 124 and the first filter circuit 126, and the first voltage dividing circuit 124 includes the first resistor R1 and the second resistor R2, and the first filter circuit 126 includes the first filter resistor R5 and the first filter capacitor C1, the delay time t2 of the first input voltage U1 can satisfy:

[0121] If the on-off circuit 122 is a fuse, the fuse usually needs to be triggered by current. However, the comparison signal output by the comparison circuit 121 is a signal, not a current. At this time, if the comparison signal indicates that the second input voltage U2 is greater than the first input voltage U1, the comparison signal cannot drive the on-off circuit 122, and the on-off circuit 122 cannot timely cut off the charging circuit of the battery 10.

[0122] Therefore, in some embodiments, the charging protection circuit 12 can further include a trigger circuit 128, an input end of the trigger circuit 128 is configured to receive the comparison signal, and an output end of the trigger circuit 128 is connected to the on-off circuit 122. The trigger circuit 128 is configured to output a control signal to the on-off circuit 122 according to the comparison signal, and the control signal is used to control the on-off of the charging circuit.

[0123] Wherein, in the case where the comparison signal indicates that the second input voltage U2 is greater than or equal to the first input voltage U1, the control signal is used to control the on-off circuit 122 to cut off the charging circuit.

[0124] As shown in FIG. 11, the trigger circuit 128 can include a resistor R7, a metal-oxide-semiconductor field-effect transistor (MOSFET), referred to as MOS tube Q1, and an anti-short diode D1.

[0125] Based on the trigger circuit 128 of FIG. 11, when the battery monomer 11 works normally, the first input voltage U1 is greater than the second input voltage U2, the comparison signal is high, at this time, the Q1 source and gate voltage Vgs is 0V, Q1 is cut off, and the on-off circuit 122 is not triggered; when the battery monomer 11 is overcharged, the first input voltage U1 is less than the second input voltage U2, the comparison signal is low, the Q1 source and gate voltage Vgs is VCC1, Q1 is turned on, the on-off circuit 122 is triggered, and the charging loop is cut off.

[0126] It should be noted that the selection of Q1 and the anti-short circuit diode D1 and the wiring of the printed circuit board (PCB) need to meet the requirements of transient overcurrent. If the requirements are not met, large current may cause damage to the devices and lines it passes through.

[0127] The trigger circuit 128 can also not include the anti-short circuit diode D1. In addition, in addition to the circuit shown in FIG. 11, the trigger circuit 128 can also be the circuit shown in FIG. 12. Among them, the direct current / direct current (DC / DC) in FIG. 12 can include common low-dropout regulator (LDO), BUCK circuit, BOOST circuit, BUCK-BOOST, forward, flyback, and other power topologies.

[0128] The above technical solution, by setting the trigger circuit 128, makes the comparison signal output by the comparison circuit 121 can trigger the on-off circuit 122 to switch the charging loop in time, no matter what form the on-off circuit 122 is, as long as the second input voltage U2 is greater than or equal to the first input voltage U1. Not only improves the diversity of the application of the charging protection circuit 12, but also further reduces the possibility of overcharging of the battery 10.

[0129] Further, the charging protection circuit 12 can also include a protection circuit, the input end of the protection circuit is connected to the positive electrode of the battery monomer 11, and the output end is connected to the second input end of the comparison circuit 121, for protecting the surge voltage on the bus voltage and preventing the power supply from being reversed. In this way, the performance of the circuit can be further improved.

[0130] For example, the protection circuit may include a transient voltage suppressor (TVS), a first capacitor C5, and a diode D2. The first terminal of the first capacitor C5 is connected to the positive terminal of the battery cell 11 and the first terminal of the diode D2. The second terminal of the first capacitor C5 is grounded to the second terminal of the transient voltage suppressor (TVS). The second terminal of the diode D2 is connected to the second input terminal of the comparator circuit 121, along with the first terminal of the transient voltage suppressor (TVS).

[0131] TVS is a high-efficiency protection device in the form of a diode. When the two poles of TVS are subjected to a reverse transient high-energy impact, it can change the high impedance between its two poles to a low impedance at a speed on the order of 10 to the power of -12 seconds, absorbing surge power of up to several kilowatts, clamping the voltage between the two poles to a predetermined value, and effectively protecting the precision components in electronic circuits from damage by various surge pulses.

[0132] Figure 13 shows a schematic diagram of a specific charging protection circuit 12 according to an embodiment of this application. As can be seen, the charging protection circuit 12 shown in Figure 13 includes a power supply circuit 123, a first voltage divider circuit 124, a second voltage divider circuit 125, a first filter circuit 126, a second filter circuit 127, a delay circuit, a comparison circuit 121, a trigger circuit 128, an on / off circuit 122, and a safety protection circuit 129.

[0133] Where Vin is the voltage of the battery cell 11 connected to the charging protection circuit 12, and Vi is the voltage after Vin drops by approximately 0.4V through diode D2. C4 can act as a decoupling agent to improve V i Performance, such as smoothing out V i High-frequency small fluctuation signals in the signal.

[0134] Each battery cell can correspond to a power supply circuit 123, a first voltage divider circuit 124, a second voltage divider circuit 125, a first filter circuit 126, a second filter circuit 127, a delay circuit, a comparator circuit 121, a trigger circuit 128, and a safety protection circuit 129. In other words, each battery cell can be configured with all circuits in the charging protection circuit 12 except for the on / off circuit 122, and multiple battery cells share one on / off circuit 122.

[0135] It should be understood that the same symbols in Figure 13 indicate that they are connected together throughout the entire charging protection circuit 12.

[0136] As shown in Figure 14, this embodiment of the application also provides a charging protection circuit 14. As shown in Figure 14, the charging protection circuit 14 includes:

[0137] The comparison circuit 141 is configured to receive a first input voltage and a second input voltage during the charging process, and output a comparison signal according to a comparison result of the first input voltage and the second input voltage, the first input voltage indicating a charging voltage threshold, and the second input voltage indicating a voltage of the battery cell.

[0138] The on-off circuit 142 is configured to cut off a charging loop of the battery when the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage.

[0139] Optionally, in the embodiments of the present application, the number of the comparison circuits 141 is greater than the number of the on-off circuits 142.

[0140] Optionally, in the embodiments of the present application, each of the battery cells is connected to each of the comparison circuits 141.

[0141] Optionally, in the embodiments of the present application, the number of the comparison circuits 141 is less than the number of the battery cells, and the comparison circuits 141 are connected to part of the battery cells.

[0142] Optionally, in the embodiments of the present application, the number of the on-off circuits 142 is one, and the output end of the comparison circuit 141 is connected to one of the on-off circuits 142.

[0143] Optionally, in the embodiments of the present application, the charging protection circuit further comprises: a first voltage dividing circuit, an input end of the first voltage dividing circuit receiving a preset voltage output by a preset voltage source, an output end of the first voltage dividing circuit being connected to a first input end of the comparison circuit 141, the first voltage dividing circuit being configured to divide the preset voltage into the first input voltage; and / or

[0144] a second voltage dividing circuit, an input end of the second voltage dividing circuit being connected to a positive electrode of the battery cell, an output end of the second voltage dividing circuit being connected to a second input end of the comparison circuit 141, the second voltage dividing circuit being configured to divide the voltage of the battery cell into the second input voltage.

[0145] Optionally, in the embodiments of the present application, the first voltage dividing circuit comprises a first resistor and a second resistor, a first end of the first resistor being connected to the preset voltage source, a second end of the first resistor being connected to a first end of the second resistor and the first input end of the comparison circuit 141, and a second end of the second resistor being grounded; and / or

[0146] The second voltage dividing circuit comprises a third resistor and a fourth resistor, a first end of the third resistor is connected to the positive electrode of the battery cell, a second end of the third resistor is connected to a first end of the fourth resistor and a second input end of the comparison circuit 141, and a second end of the fourth resistor is grounded.

[0147] Optionally, in the embodiment of the present application, the charging protection circuit further comprises a delay circuit, an input end of the delay circuit is connected to an output end of the second voltage dividing circuit, and an output end of the delay circuit is grounded, so as to perform delay processing on the second input voltage.

[0148] Optionally, in the embodiment of the present application, the charging protection circuit further comprises a first filter circuit configured to receive the first input voltage at an input end and connected to a first input end of the comparison circuit 141 at an output end, so as to filter the received first input voltage and output the filtered first input voltage to the first input end of the comparison circuit 141; and / or

[0149] a second filter circuit configured to receive the second input voltage at an input end and connected to a second input end of the comparison circuit 141 at an output end, so as to filter the received second input voltage and output the filtered second input voltage to the second input end of the comparison circuit 141.

[0150] Optionally, in the embodiment of the present application, the first filter circuit comprises a first filter resistor and a first filter capacitor, a first end of the first filter resistor receives the first input voltage, a second end of the first filter resistor is connected to a first end of the first filter capacitor and the first input end of the comparison circuit 141, and a second end of the first filter capacitor is grounded; and / or

[0151] the second filter circuit comprises a second filter resistor and a second filter capacitor, a first end of the second filter resistor receives the second input voltage, a second end of the second filter resistor is connected to a first end of the second filter capacitor and the second input end of the comparison circuit 141, and a second end of the second filter capacitor is grounded.

[0152] Optionally, in the embodiment of the present application, the charging protection circuit further comprises a power supply circuit, an input end of the power supply circuit is connected to the positive electrode of the battery cell, an output end of the power supply circuit is connected to the first input end of the comparison, and the power supply circuit is configured to convert the voltage of the battery cell into the first input voltage.

[0153] Optionally, in the embodiment of the present application, the charging protection circuit further comprises a trigger circuit, an input end of the trigger circuit is configured to receive the comparison signal, and an output end of the trigger circuit is connected to the on-off circuit 142, the trigger circuit is configured to output a control signal to the on-off circuit 142 according to the comparison signal, and the control signal is used to control the on-off of the charging loop; wherein, in the case that the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage, the control signal is used to control the on-off circuit 142 to cut off the charging loop.

[0154] Optionally, in the embodiment of the present application, the charging protection circuit further comprises a protection circuit comprising a first capacitor, a diode and a transient voltage suppression diode, wherein a first end of the first capacitor is connected to a positive electrode of the battery monomer and a first end of the diode, a second end of the first capacitor is grounded with a second end of the transient voltage suppression diode, and a second end of the diode is connected to a first end of the transient voltage suppression diode to a second input end of the comparison circuit 141.

[0155] It should be understood that the charging protection circuit 14, the comparison circuit 141 and the on-off circuit 142 may, for example, be the charging protection circuit 12, the comparison circuit 121 and the on-off circuit 122 in FIG. 1, and the related contents can be referred to the description of the charging protection circuit 12, the comparison circuit 121 and the on-off circuit 122, and for the sake of brevity, will not be repeated here.

[0156] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it without departing from the scope of the present application, and equivalent components can be substituted therefor. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery, characterized by, The application relates to a charging protection circuit for at least one battery cell. The charging protection circuit comprises at least one battery cell, a charging protection circuit connected to the at least one battery cell, the charging protection circuit comprising a comparison circuit and a switch circuit. The comparison circuit is configured to receive a first input voltage and a second input voltage during charging, and output a comparison signal according to a comparison result of the first input voltage and the second input voltage, wherein the first input voltage indicates a charging voltage threshold, and the second input voltage indicates a voltage of part of the at least one battery cell. The switch circuit is configured to cut off a charging loop of the battery when the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage. The number of comparison circuits is greater than the number of switch circuits. Each of the at least one battery cell is connected to each of the comparison circuits.

2. The battery of claim 1, wherein, The number of comparison circuits is less than the number of the at least one battery cell, and the comparison circuits are connected to part of the at least one battery cell.

3. The battery of claim 1, wherein, The number of switch circuits is one, and the output end of the comparison circuit is connected to one of the switch circuits.

4. The battery according to any one of claims 1 to 3, characterized in that, The charging protection circuit further comprises:

5. The battery of any one of claims 1 to 4, wherein, a first voltage dividing circuit, wherein an input end of the first voltage dividing circuit receives a preset voltage output by a preset voltage source, an output end of the first voltage dividing circuit is connected to a first input end of the comparison circuit, and the first voltage dividing circuit is configured to divide the preset voltage into the first input voltage; and / or a second voltage dividing circuit, wherein an input end of the second voltage dividing circuit is connected to a positive electrode of the battery cell, an output end of the second voltage dividing circuit is connected to a second input end of the comparison circuit, and the second voltage dividing circuit is configured to divide a voltage of the battery cell into the second input voltage. The first voltage dividing circuit comprises a first resistor and a second resistor, a first end of the first resistor is connected to the preset voltage source, a second end of the first resistor is connected to a first end of the second resistor and the first input end of the comparison circuit, and a second end of the second resistor is grounded; and / or 6. The battery of claim 5, wherein, The second voltage dividing circuit comprises a third resistor and a fourth resistor, a first end of the third resistor is connected to the positive electrode of the battery cell, a second end of the third resistor is connected to a first end of the fourth resistor and the second input end of the comparison circuit, and a second end of the fourth resistor is grounded. The charging protection circuit further comprises:

7. The battery according to claim 5 or 6, characterized in that a delay circuit, wherein an input end of the delay circuit is connected to an output end of the second voltage dividing circuit, and an output end of the delay circuit is grounded to perform delay processing on the second input voltage. The charging protection circuit further comprises:

8. The battery of any one of claims 1 to 7, wherein, a first filter circuit, wherein an input end of the first filter circuit receives the first input voltage, and an output end of the first filter circuit is connected to the first input end of the comparison circuit, so that the first filter circuit filters the received first input voltage and outputs the filtered first input voltage to the first input end of the comparison circuit; and / or a second filter circuit, wherein an input end of the second filter circuit receives the second input voltage, and an output end of the second filter circuit is connected to the second input end of the comparison circuit, so that the second filter circuit filters the received second input voltage and outputs the filtered second input voltage to the second input end of the comparison circuit. A second filter circuit is configured to receive the second input voltage at an input end and output the filtered second input voltage to a second input end of the comparison circuit.

9. The battery of claim 8, wherein, The first filter circuit includes a first filter resistor and a first filter capacitor, a first end of the first filter resistor receives the first input voltage, a second end of the first filter resistor is connected to a first end of the first filter capacitor and a first input end of the comparison circuit, and a second end of the first filter capacitor is grounded; and / or The second filter circuit includes a second filter resistor and a second filter capacitor, a first end of the second filter resistor receives the second input voltage, a second end of the second filter resistor is connected to a first end of the second filter capacitor and a second input end of the comparison circuit, and a second end of the second filter capacitor is grounded.

10. The battery of any one of claims 1 to 9, wherein, The charging protection circuit further includes: A power supply circuit, an input end of the power supply circuit is connected to the positive electrode of the battery cell, and an output end of the power supply circuit is connected to the first input end of the comparison circuit, configured to convert the voltage of the battery cell into the first input voltage.

11. The battery of any one of claims 1-10, wherein, The charging protection circuit further includes: A trigger circuit, an input end of the trigger circuit is configured to receive the comparison signal, and an output end of the trigger circuit is connected to the on-off circuit, the trigger circuit is configured to output a control signal to the on-off circuit according to the comparison signal, and the control signal is used to control the on-off of the charging circuit. In the case where the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage, the control signal is used to control the on-off circuit to cut off the charging circuit.

12. The battery of any one of claims 1-11, wherein, The charging protection circuit further includes: A protection circuit including a first capacitor, a diode and a transient voltage suppression diode, wherein a first end of the first capacitor is connected to the positive electrode of the battery cell and a first end of the diode, a second end of the first capacitor is grounded with a second end of the transient voltage suppression diode, and a second end of the diode is connected to a first end of the transient voltage suppression diode and a second input end of the comparison circuit.

13. A charge protection circuit, characterized by, It includes: A comparison circuit configured to receive a first input voltage and a second input voltage during charging, and output a comparison signal according to the comparison result of the first input voltage and the second input voltage, the first input voltage indicating a charging voltage threshold, and the second input voltage indicating a voltage of a battery cell; An on-off circuit configured to cut off a charging circuit of the battery in the case where the comparison signal indicates that the second input voltage is greater than or equal to the first input voltage; Wherein the number of comparison circuits is greater than the number of on-off circuits.

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