Battery protection device and battery

Abstract

The present application discloses a battery protection device and a battery, belonging to the field of batteries. The battery protection device comprises: a mainboard and a battery protection chip, wherein the battery protection chip comprises a main control logic circuit and an over-discharge protection circuit, wherein: the mainboard is electrically connected to the main control logic circuit, and the main control logic circuit is electrically connected to the over-discharge protection circuit, wherein the over-discharge protection circuit provides at least two over-discharge protection voltages of different sizes for selection.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery protection device and a battery. Background Art

[0002] At present, with the continuous upgrading of electronic products, silicon-carbon negative electrode batteries have been introduced into the market because they have the advantage of high battery energy density compared to graphite negative electrode batteries under the same volume.

[0003] However, silicon-carbon negative electrode batteries have the characteristic of storing electricity at low voltage (that is, there is still a lot of electricity available at low voltage). Therefore, during the use of silicon-carbon negative electrode batteries, there is a problem of low battery utilization efficiency. Utility Model Content

[0004] The present application discloses a battery protection device and a battery, which can improve the use efficiency of the battery.

[0005] In a first aspect, an embodiment of the present application discloses a battery protection device, comprising: a main board and a battery protection chip, wherein the battery protection chip comprises a main control logic circuit and an over-discharge protection circuit, wherein: the main board is electrically connected to the main control logic circuit, and the main control logic circuit is electrically connected to the over-discharge protection circuit, wherein the over-discharge protection circuit provides at least two over-discharge protection voltages of different sizes for selection.

[0006] In a second aspect, an embodiment of the present application discloses a battery, comprising the battery protection device described in the first aspect.

[0007] An embodiment of the present application provides a battery protection device, including a main board and a battery protection chip, the battery protection chip including a main control logic circuit and an over-discharge protection circuit, the main board is electrically connected to the main control logic circuit, the main control logic circuit is electrically connected to the over-discharge protection circuit, the over-discharge protection circuit provides at least two over-discharge protection voltages of different sizes for selection, and the battery protection device disclosed in the present application is used, a control signal is sent to the main control logic circuit in the battery protection chip through the main board, and the main control logic circuit determines the minimum over-discharge protection voltage from at least two over-discharge protection voltages of different sizes for selection provided by the over-discharge protection circuit according to the received control signal, and over-discharge protection is performed with the minimum over-discharge protection voltage, which can improve the use efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A schematic diagram of the structure of a battery protection device disclosed in an embodiment of the present application;

[0009] Figure 2 A schematic diagram of the structure of a battery protection chip disclosed in an embodiment of the present application;

[0010] Figure 3A pin diagram of a battery protection chip disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0012] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0013] The present application discloses a battery protection device and a battery. Figure 1 is a schematic diagram of the structure of a battery protection device disclosed in an embodiment of the present application, Figure 2 A schematic diagram of the structure of a battery protection chip disclosed in an embodiment of the present application.

[0014] like Figure 1 and Figure 2 As shown, the battery protection device disclosed in the present application includes: a mainboard 110 and a battery protection chip 120, the battery protection chip 120 includes a main control logic circuit 121 and an over-discharge protection circuit 122, wherein: the mainboard 110 is electrically connected to the main control logic circuit 121, the main control logic circuit 121 is electrically connected to the over-discharge protection circuit 122, wherein the over-discharge protection circuit 122 provides at least two over-discharge protection voltages of different sizes for selection.

[0015] In the present application, a control signal is outputted through the mainboard 110 to the main control logic circuit 121 of the battery protection chip 120. The main control logic circuit 121 determines an over-discharge protection voltage from at least two over-discharge protection voltages of different sizes provided by the over-discharge protection circuit 122 according to the received control signal, and performs over-discharge protection with the over-discharge protection voltage.

[0016] Exemplarily, the over-discharge protection circuit 122 provides at least two over-discharge protection voltages of different sizes for selection, including over-discharge protection voltage 1 and over-discharge protection voltage 2, and the over-discharge protection voltage 1 is greater than the over-discharge protection voltage 2. When it is necessary to solve the problem of low-voltage gas production of the battery, the main board 110 can send a first control signal to the main control logic circuit 121, and the main control logic circuit 121 selects the over-discharge protection voltage 1 for over-discharge protection according to the received first control signal. When it is necessary to improve the battery usage efficiency and solve the problem of low-voltage power storage of the battery, the main board 110 can send a second control signal to the main control logic circuit 121, and the main control logic circuit 121 selects the over-discharge protection voltage 2 for over-discharge protection according to the received second control signal.

[0017] The embodiment of the present application provides a battery protection device, including a mainboard 110 and a battery protection chip 120, the battery protection chip 120 includes a main control logic circuit 121 and an over-discharge protection circuit 122, the mainboard 110 is electrically connected to the main control logic circuit 121, the main control logic circuit 121 is electrically connected to the over-discharge protection circuit 122, the over-discharge protection circuit 122 provides at least two over-discharge protection voltages of different sizes for selection, using the battery protection device disclosed in the present application, the mainboard 110 sends a control signal to the main control logic circuit 121 in the battery protection chip 120, the main control logic circuit 121 determines the minimum over-discharge protection voltage from the at least two over-discharge protection voltages of different sizes for selection provided by the over-discharge protection circuit 122 according to the received control signal, and performs over-discharge protection with the minimum over-discharge protection voltage, which can improve the use efficiency of the battery.

[0018] In the embodiments of the present application, Figure 2 As shown, the battery protection chip 120 may further include a detection circuit 123, the input end of the detection circuit 123 is electrically connected to the main board 110, and the output end of the detection circuit 123 is electrically connected to the main control logic circuit 121. The detection circuit 123 is used to determine what kind of control signal is sent by the main board 110, and send the determination result to the main control logic circuit 121, and the main control logic circuit 121 performs a control operation corresponding to the control signal sent by the main board 110. By adopting the solution of the embodiment of the present application, the original main control logic circuit on the battery protection chip can be reused.

[0019] In one implementation, Figure 2As shown, the over-discharge protection circuit 122 may include a first resistor R1, a second resistor R2, a first comparator COM1, a level conversion device, a first on-off device Q1, a second on-off device Q2, a first voltage source VI1 and a second voltage source VI2, wherein: a first end of the first resistor R1 is electrically connected to a cell voltage detection pin VDD of the battery protection chip 120, a second end of the first resistor R1 is electrically connected to a first end of the second resistor R2, and a second end of the second resistor R2 is electrically connected to a ground terminal; a first input end of the first comparator COM1 is electrically connected to a second end of the first resistor R1, a second input end of the first comparator COM1 is electrically connected to a first end of the first on-off device Q1 and a first end of the second on-off device Q2, respectively, and an output end of the first comparator COM1 is electrically connected to the main control logic circuit. The first on-off device Q1 is electrically connected to the positive electrode of the first voltage source VI1, the negative electrode of the first voltage source VI1 is electrically connected to the ground, and the control end of the first on-off device Q1 is electrically connected to the main control logic circuit 121; the second end of the second on-off device Q2 is electrically connected to the positive electrode of the second voltage source VI2, and the negative electrode of the second voltage source VI2 is electrically connected to the ground; the input end of the level conversion device is electrically connected to the main control logic circuit 121, and the output end of the level conversion device is electrically connected to the control end of the second on-off device Q2; wherein the control end of the first on-off device Q1 and the input end of the level conversion device are connected to the same end of the main control logic circuit 121, and the voltage value provided by the first voltage source VI1 is different from the voltage value provided by the second voltage source VI2.

[0020] In the present application, the first comparator COM1 is an over-discharge comparator. In addition, the first on-off device Q1 and the second on-off device Q2 are on-off devices with the same structure. Exemplarily, the first on-off device Q1 and the second on-off device Q2 can be N-type metal oxide semiconductor (Negative channel-Metal-Oxide-Semiconductor, NMOS) field effect transistors, or the first on-off device Q1 and the second on-off device Q2 can be P-type metal oxide semiconductor (Positive channel-Metal-Oxide-Semiconductor, PMOS) field effect transistors. In addition, the first on-off device Q1 and the second on-off device Q2 can also be triodes, which are not specifically limited in the present application. The level conversion device can be an inverter. In addition, the second end of the second resistor R2 can be electrically connected to the common ground pin VSS of the battery protection chip 120.

[0021] Exemplarily, when the voltage signal output by the mainboard 110 is V1 and the duration is longer than T1, the main control logic circuit 121 sends a high level to the control end of the first on-off device Q1 and the input end of the level conversion device, the electrical connection between the first end and the second end of the first on-off device Q1 is turned on, and the voltage corresponding to the first voltage source VI1 is used as the over-discharge protection voltage of the over-discharge protection circuit 122; when the voltage signal output by the mainboard 110 is V2 and the duration is longer than T2, the main control logic circuit 121 sends a low level to the control end of the first on-off device Q1 and the input end of the level conversion device, the electrical connection between the first end and the second end of the second on-off device Q2 is turned on, and the voltage corresponding to the second voltage source VI2 is used as the over-discharge protection voltage of the over-discharge protection circuit 122. In the present application, the voltage value provided by the first voltage source VI1 is greater than the voltage value provided by the second voltage source VI2.

[0022] In one implementation, Figure 2 As shown, the over-discharge protection circuit 122 may further include a buffer, the input end of the buffer is electrically connected to the main control logic circuit 121, and the output end of the buffer is electrically connected to the control end of the first on-off device Q1. In other words, the signal sent by the main control logic circuit 121 reaches the control end of the first on-off device Q1 after passing through the buffer, and the buffer is used to delay the signal sent by the main control logic circuit 121, and plays a role of coordination and buffering.

[0023] It should be noted that by connecting a plurality of the circuit structures connected to the second input end of the first comparator COM1 as described above to the second input end of the first comparator COM1, the over-discharge protection circuit 122 can provide a plurality of selectable over-discharge protection voltages of different magnitudes.

[0024] In one implementation, when the over-discharge protection circuit 122 includes a first resistor R1, a second resistor R2, a first comparator COM1, a level conversion device, a first on-off device Q1, a second on-off device Q2, a first voltage source VI1 and a second voltage source VI2, the detection circuit 123 may include a second comparator COM2, a third voltage source VI3, a third resistor R3 and a control circuit, wherein the mainboard 110 is electrically connected to the first input terminal of the second comparator COM2 and the first end of the third resistor R3, respectively, the second input terminal of the second comparator COM2 is electrically connected to the positive electrode of the third voltage source VI3, the negative electrode of the third voltage source VI3 is electrically connected to the ground, the output terminal of the second comparator COM2 is electrically connected to the input terminal of the control circuit, the second end of the third resistor R3 is electrically connected to the ground, and the output terminal of the control circuit is electrically connected to the main control logic circuit 121.

[0025] In the embodiments of the present application, Figure 2As shown, the main control logic circuit 121 is electrically connected to the pin DO of the discharge control field effect tube of the battery protection chip 120, and the charger and load detection pin VM of the battery protection chip 120, respectively. That is to say, the main control logic circuit 121 can control the DO pin and the VM pin according to the signal sent by the mainboard 110. Exemplarily, when the voltage signal output by the mainboard 110 is V3 and the duration is greater than T3, the main control logic circuit 121 sends a low level to the DO pin, disconnects the MOS tube connected to the DO pin that controls the discharge, and pulls up the voltage of the VM pin to a predetermined threshold value. The main control logic circuit 121 controls to shut down all circuits inside the battery protection chip 120, so that the battery consumption current is reduced to a minimum, infinitely close to zero power consumption, and enters the low power consumption mode of the whole machine, so that the battery storage time is longer.

[0026] In one implementation, when the over-discharge protection circuit 122 includes a first resistor R1, a second resistor R2, a first comparator COM1, a level conversion device, a first on-off device Q1, a second on-off device Q2, a first voltage source VI1 and a second voltage source VI2, and the main control logic circuit 121 can control the DO pin and the VM pin according to the signal sent by the mainboard 110, the detection circuit 123 may include a second comparator COM2, a third comparator COM3, a third voltage source VI3, a fourth voltage source VI4, a third resistor R3 and a control circuit, wherein: the mainboard 110 is respectively connected to the first input terminal of the second comparator COM2, the first input terminal of the third comparator COM3 and the The first end of the third resistor R3 is electrically connected; the second input end of the second comparator COM2 is electrically connected to the positive electrode of the third voltage source VI3, the negative electrode of the third voltage source VI3 is electrically connected to the ground, and the output end of the second comparator COM2 is electrically connected to the input end of the control circuit; the second input end of the third comparator COM3 is electrically connected to the positive electrode of the fourth voltage source VI4, the negative electrode of the fourth voltage source VI4 is electrically connected to the ground, and the output end of the third comparator COM3 is electrically connected to the input end of the control circuit; the second end of the third resistor R3 is electrically connected to the ground; the output end of the control circuit is electrically connected to the main control logic circuit 121; wherein, the voltage value provided by the third voltage source VI3 is less than the voltage value provided by the fourth voltage source VI4.

[0027] In the embodiments of the present application, Figure 2As shown, the main control logic circuit 121 is electrically connected to the pin CO of the control charging field effect tube of the battery protection chip 120. That is, the main control logic circuit 121 can control the CO pin according to the signal sent by the mainboard 110. Exemplarily, when the voltage signal output by the mainboard 110 is V4 and the duration is greater than T4, the main control logic circuit 121 sends a low level to the DO pin and the CO pin, disconnects the MOS tube connected to the DO pin for controlling discharge, disconnects the MOS tube connected to the CO pin for controlling charging, and prohibits the battery from charging and discharging, which is convenient for the assembly test of the whole machine and the test of the mainboard leakage.

[0028] In one implementation, the over-discharge protection circuit 122 includes a first resistor R1, a second resistor R2, a first comparator COM1, a level conversion device, a first on-off device Q1, a second on-off device Q2, a first voltage source VI1, and a second voltage source VI2, and the main control logic circuit 121 can control the DO pin and the VM pin according to the signal sent by the mainboard 110, and the main control logic circuit 121 can control the CO pin according to the signal sent by the mainboard 110. Figure 2As shown, the detection circuit 123 may include a second comparator COM2, a third comparator COM3, a fourth comparator COM4, ​​a third voltage source VI3, a fourth voltage source VI4, a fifth voltage source VI5, a third resistor R3 and a control circuit, wherein: the mainboard 110 is electrically connected to the first input terminal of the second comparator COM2, the first input terminal of the third comparator COM3, the first input terminal of the fourth comparator COM4 and the first end of the third resistor R3 respectively; the second input terminal of the second comparator COM2 is electrically connected to the positive electrode of the third voltage source VI3, the negative electrode of the third voltage source VI3 is electrically connected to the ground, the output terminal of the second comparator COM2 is electrically connected to the input terminal of the control circuit; the second input terminal of the third comparator COM3 is electrically connected to the first input terminal of the fourth comparator COM4 and the positive electrode of the third voltage source VI3 is electrically connected to the ground terminal, and the output terminal of the second comparator COM2 is electrically connected to the input terminal of the control circuit; the second input terminal of the third comparator COM3 is electrically connected to the first input terminal of the fourth comparator COM4 and the positive electrode of the third voltage source VI3 is electrically connected to the ground terminal. The positive electrode of the fourth voltage source VI4 is electrically connected, the negative electrode of the fourth voltage source VI4 is electrically connected to the ground, and the output end of the third comparator COM3 is electrically connected to the input end of the control circuit; the second input end of the fourth comparator COM4 is electrically connected to the negative electrode of the fifth voltage source VI5, the positive electrode of the fifth voltage source VI5 is electrically connected to the battery cell voltage detection pin, and the output end of the fourth comparator COM4 is electrically connected to the input end of the control circuit; the second end of the third resistor R3 is electrically connected to the ground; the output end of the control circuit is electrically connected to the main control logic circuit 121; wherein, the voltage value provided by the third voltage source VI3 is less than the voltage value provided by the fourth voltage source VI4, and the voltage value provided by the fourth voltage source VI4 is less than the voltage value provided by the fifth voltage source VI5. The voltage value provided by the fifth voltage source VI5 is slightly less than the battery cell voltage. For example, the voltage value provided by the fifth voltage source VI5 can be 0.2V less than the battery cell voltage.

[0029] It should be noted that, based on the connection method of the fifth voltage source VI5 described above, the voltage value provided by the fifth voltage source VI5 can change dynamically.

[0030] Alternatively, if Figure 2 As shown, the detection circuit 123 may further include a third on-off device Q3, a control end of the third on-off device Q3 is electrically connected to the main control logic circuit 121, a first end of the third on-off device Q3 is electrically connected to the second end of the third resistor R3, and a second end of the third on-off device Q3 is electrically connected to the ground. It should be noted that when the detection circuit 123 is in the working state, the main control logic circuit 121 controls the electrical connection between the first end and the second end of the third on-off device Q3 to remain on.

[0031] In this application, if Figure 2As shown, the mainboard 110 can be electrically connected to the first input end of the second comparator COM2, the first input end of the third comparator COM3, the first input end of the fourth comparator COM4 and the first end of the third resistor R3 through the control pin CTL of the battery protection chip 120. It should be noted that the CTL pin can be a pin newly added on the battery protection chip 120, for example, Figure 3 As shown, the CTL pin can be added at the bottom of the battery protection chip 120. This method is compatible with the original 6-pin packaging effect and has higher layout compatibility.

[0032] In the present application, when the voltage signals output by the mainboard 110 of the above-mentioned battery protection device are V1, V2, V3 and V4, four application scenarios may be corresponded, as shown in the following table.

[0033]

[0034]

[0035] When the voltage signal output by the mainboard 110 is V1 and the duration is greater than T1, that is, the voltage of the CTL pin V1 < VI3 and the duration is > T1, the control circuit feeds back to the main control logic circuit 121, and the main control logic circuit 121 sends a high level to the control end of the first on-off device Q1 and the input end of the level conversion device, the electrical connection between the first end and the second end of the first on-off device Q1 is turned on, and the voltage corresponding to the first voltage source VI1 is used as the over-discharge protection voltage of the over-discharge protection circuit 122 (that is, over-discharge protection voltage 1); when there is no input to the CTL pin, the CTL pin is pulled down to the ground end by default, 0 < VI3, the control circuit feeds back to the main control logic circuit 121, and the main control logic circuit 121 controls the over-discharge protection circuit 122 to execute the over-discharge protection voltage 1. In this scenario, the release condition is that the plug-in charger is activated or the battery cell voltage is automatically restored after it rises to the recovery voltage of the over-discharge protection voltage 1.

[0036] When the voltage signal output by the mainboard 110 is V2 and the duration is greater than T2, that is, the voltage VI3 of the CTL pin is less than V2 and less than VI4, and the duration is greater than T2, the control circuit feeds back to the main control logic circuit 121, and the main control logic circuit 121 sends a low level to the control end of the first on-off device Q1 and the input end of the level conversion device, and the electrical connection between the first end and the second end of the second on-off device Q2 is turned on, and the voltage corresponding to the second voltage source VI2 is used as the over-discharge protection voltage of the over-discharge protection circuit 122 (that is, over-discharge protection voltage 2). In this scenario, the release condition is that the plug-in charger is activated or the battery cell voltage is automatically restored after it rises to the recovery voltage of the over-discharge protection voltage 1.

[0037] When the voltage signal output by the mainboard 110 is V3 and the duration is greater than T3, that is, the voltage VI4 of the CTL pin is less than V3 and less than VI5, and the duration is greater than T3, the control circuit feeds back to the main control logic circuit 121, and the main control logic circuit 121 sends a low level to the DO pin, disconnects the MOS tube connected to the DO pin that controls the discharge, and pulls up the voltage of the VM pin to a predetermined threshold. The main control logic circuit 121 controls the shutdown of all circuits inside the battery protection chip 120, so that the current consumption is reduced to a minimum, and the whole machine enters a low power consumption mode, so that the battery storage time is longer. The release condition is activated by inserting a charger. It should be noted that the predetermined threshold here is a value that can perform recovery detection (i.e., determine whether the VM pin is connected to a charger or a load). When the VM pin is connected to a charger or a load, the voltage of the VM pin will drop.

[0038] When the voltage signal output by the mainboard 110 is V4 and lasts longer than T4, that is, the voltage VI5 of the CTL pin is less than V4 and lasts longer than T4, the control circuit feeds back to the main control logic circuit 121, and the main control logic circuit 121 sends a low level to the DO pin and the CO pin, disconnects the MOS tube connected to the DO pin for controlling discharge, disconnects the MOS tube connected to the CO pin for controlling charging, and prohibits charging and discharging of the battery, which is convenient for assembly and testing of the whole machine and more effective detection of the power consumption of the mainboard.

[0039] The present application also discloses a battery, comprising the battery protection device described above.

[0040] The above embodiments of the present application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0041] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A battery protection device, characterized in that: include: Mainboard and battery protection chip, the battery protection chip includes a main control logic circuit and an over-discharge protection circuit, wherein: The mainboard is electrically connected to the main control logic circuit, and the main control logic circuit is electrically connected to the over-discharge protection circuit, wherein the over-discharge protection circuit provides at least two over-discharge protection voltages of different sizes for selection; The battery protection chip further includes a detection circuit, an input end of the detection circuit is electrically connected to the main board, and an output end of the detection circuit is electrically connected to the main control logic circuit; The over-discharge protection circuit includes a first resistor, a second resistor, a first comparator, a level conversion device, a first on-off device, a second on-off device, a first voltage source and a second voltage source, wherein: the first end of the first resistor is electrically connected to the cell voltage detection pin of the battery protection chip, the second end of the first resistor is electrically connected to the first end of the second resistor, and the second end of the second resistor is electrically connected to the ground; the first input end of the first comparator is electrically connected to the second end of the first resistor, the second input end of the first comparator is electrically connected to the first end of the first on-off device and the first end of the second on-off device respectively, and the output end of the first comparator is electrically connected to the main control logic circuit; the first The second end of the on-off device is electrically connected to the positive electrode of the first voltage source, the negative electrode of the first voltage source is electrically connected to the ground, and the control end of the first on-off device is electrically connected to the main control logic circuit; the second end of the second on-off device is electrically connected to the positive electrode of the second voltage source, and the negative electrode of the second voltage source is electrically connected to the ground; the input end of the level conversion device is electrically connected to the main control logic circuit, and the output end of the level conversion device is electrically connected to the control end of the second on-off device; wherein the control end of the first on-off device and the input end of the level conversion device are connected to the same end of the main control logic circuit, and the voltage value provided by the first voltage source is different from the voltage value provided by the second voltage source; The main control logic circuit is electrically connected to the pins of the control discharge field effect transistor of the battery protection chip, and the charger and load detection pins of the battery protection chip respectively; The main control logic circuit is electrically connected to the pin of the control charging field effect transistor of the battery protection chip; The detection circuit includes a second comparator, a third comparator, a fourth comparator, a third voltage source, a fourth voltage source, a fifth voltage source, a third resistor and a control circuit, wherein: the mainboard is electrically connected to the first input terminal of the second comparator, the first input terminal of the third comparator, the first input terminal of the fourth comparator and the first terminal of the third resistor respectively; the second input terminal of the second comparator is electrically connected to the positive electrode of the third voltage source, the negative electrode of the third voltage source is electrically connected to the ground terminal, the output terminal of the second comparator is electrically connected to the input terminal of the control circuit; the second input terminal of the third comparator is electrically connected to the positive electrode of the fourth voltage source, and the The negative electrode of the fourth voltage source is electrically connected to the ground, and the output end of the third comparator is electrically connected to the input end of the control circuit; the second input end of the fourth comparator is electrically connected to the negative electrode of the fifth voltage source, the positive electrode of the fifth voltage source is electrically connected to the battery cell voltage detection pin, and the output end of the fourth comparator is electrically connected to the input end of the control circuit; the second end of the third resistor is electrically connected to the ground; the output end of the control circuit is electrically connected to the main control logic circuit; wherein, the voltage value provided by the third voltage source is smaller than the voltage value provided by the fourth voltage source, and the voltage value provided by the fourth voltage source is smaller than the voltage value provided by the fifth voltage source.

2. The battery protection device according to claim 1, characterized in that: The over-discharge protection circuit further includes a buffer, an input end of the buffer is electrically connected to the main control logic circuit, and an output end of the buffer is electrically connected to the control end of the first switching device.

3. The battery protection device according to claim 1, characterized in that: The detection circuit also includes a third on-off device, a control end of the third on-off device is electrically connected to the main control logic circuit, a first end of the third on-off device is electrically connected to the second end of the third resistor, and a second end of the third on-off device is electrically connected to the ground.

4. The battery protection device according to claim 1, characterized in that: The mainboard is electrically connected to the first input end of the second comparator, the first input end of the third comparator, the first input end of the fourth comparator and the first end of the third resistor respectively through the control pin of the battery protection chip.

5. A battery, characterized in that: A battery protection device comprising the battery protection device according to any one of claims 1 to 4.

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