Single-section high-precision lithium battery protection circuit with over-temperature protection

Abstract

The utility model discloses a single-section high-precision lithium battery protection circuit with over-temperature protection, which relates to the field of lithium battery protection circuits and is characterized in that a fuse is connected with the positive electrode of a protection circuit and the positive electrode of a lithium battery; the temperature detection unit is connected with the battery parameter intelligent management module and the negative electrode of the lithium battery; the discharge protection unit is connected with the discharge detection end of the battery parameter intelligent management module, the short-circuit protection unit, the current-limiting protection unit, the lithium battery cathode, the overcurrent detection unit, the de-protection unit, the protection circuit cathode, the charge and discharge unit and the charge protection unit; the charging protection unit is connected with the discharging protection unit and the negative electrode of the protection circuit; the charge-discharge unit is connected with the negative electrode of the lithium battery. The protection circuit has the beneficial effects that the charging and discharging circuit is cut off or opened by detecting overcharging, overdischarging, charging high temperature, discharging temperature loss, charging overcurrent and discharging overcurrent of the lithium battery, so that the safety of the lithium battery is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery protection, in particular to a secondary protection circuit used in a lithium battery charge and discharge protection circuit. Background Art

[0002] As the application range of lithium batteries becomes wider and wider, the safety protection of lithium batteries is becoming more and more important. Rechargeable lithium batteries cannot be overcharged, over-discharged, over-currented, short-circuited, or charged and discharged at ultra-high temperatures due to their own materials. In the existing technology, lithium batteries or lithium battery components are always equipped with charge and discharge protection boards and current fuses.

[0003] Traditional lithium battery protection circuits generally include overcharge protection (overvoltage protection) and over-discharge protection (undervoltage protection). The lithium battery protection circuit is composed of a lithium battery protection IC and two power MOS. The protection IC of the lithium battery protection circuit monitors the battery voltage and controls the corresponding MOSFET to cut off the charging circuit or the discharging circuit when there is overcharge or over-discharge. However, when the lithium battery protection IC fails, it is easy to cause overcharge or over-discharge, thus causing safety hazards. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a circuit designed for a single lithium-ion / lithium polymer secondary battery, including a protection circuit with a temperature detection function, which has high accuracy in detecting overcharge, overdischarge, discharge overcurrent, charge overcurrent and load short circuit.

[0005] In view of the shortcomings of the secondary protection circuit of the source management circuit in the prior art mentioned above, such as high cost, single protection function and poor effect, the utility model provides a new secondary protection circuit, which connects the control end of the field effect tube to the protection output end of the battery parameter intelligent management module, and uses the field effect tube to connect the temperature detection input end and ground of the battery parameter intelligent management module. When the charging circuit has abnormal conditions such as overvoltage, undervoltage, overcharge, over-discharge, overtemperature, low temperature, MOS tube failure, etc., the battery parameter intelligent management module sends a signal to the protection port, and the protection module turns on the field effect tube, causing the temperature protection to be abnormal, and shuts off the charging and discharging MOS tube to achieve the function of secondary protection.

[0006] According to a first aspect of the present invention, a single-cell high-precision lithium battery protection circuit with over-temperature protection comprises: a positive electrode of a protection circuit, a negative electrode of a protection circuit, a battery parameter intelligent management module, a temperature detection unit, a charging protection unit, a discharging protection unit, a current limiting protection unit, a short circuit protection unit, a fuse, a release protection unit, and a charging and discharging unit.

[0007] One end of the fuse is connected to the positive electrode of the protection circuit, and the other end is connected to the positive electrode of the lithium battery;

[0008] The temperature detection unit is used for charging and discharging temperature detection of the lithium battery. The first end of the temperature detection unit is connected to the temperature detection voltage reference end of the battery parameter intelligent management module, the second end of the temperature detection unit is connected to the temperature detection voltage end of the battery parameter intelligent management module, and the third end of the temperature detection unit is connected to the negative electrode of the lithium battery;

[0009] The discharge protection unit is used to protect the lithium battery from discharging below the rated voltage value. The first end of the discharge protection unit is connected to the discharge detection end of the battery parameter intelligent management module, the second end of the discharge protection unit is connected to the first end of the current limiting protection unit, and the third end of the discharge protection unit is connected to the second end of the charging protection unit;

[0010] The charging protection unit is used to protect the lithium battery from charging above the rated voltage value, the first end of the charging protection unit is connected to the charging detection end of the battery parameter intelligent management module, the second end of the charging protection unit is connected to the third end of the discharge protection unit, and the third end of the charging protection unit is connected to the negative electrode of the protection circuit;

[0011] The short-circuit protection unit is used for short-circuit protection, one end of the short-circuit protection unit is connected to the current detection end of the battery parameter intelligent management module, and the other end is connected to one end of the overcurrent detection unit, and the other end of the overcurrent protection unit is connected to the negative electrode of the lithium battery;

[0012] The release protection unit is used for charge protection, discharge protection, short circuit protection, and temperature lower than the rated value or higher than the rated value protection release. One end of the release protection unit is connected to the reverse voltage end of the battery parameter intelligent management module, and the other end is connected to the negative electrode of the protection circuit;

[0013] The first end of the charge and discharge unit is connected to the positive electrode of the lithium battery, and the second end of the charge and discharge unit is connected to the power input end of the battery parameter intelligent management module; the third end of the charge and discharge unit is connected to the negative electrode of the lithium battery, and the fourth end of the charge and discharge unit is connected to the power ground end of the protection module.

[0014] Furthermore, the battery parameter intelligent management module is a chip.

[0015] Furthermore, the temperature detection unit includes: a thermistor, a resistor, and a capacitor; one end of the thermistor is connected to the temperature detection voltage reference end of the battery parameter intelligent management module, and the other end is connected in parallel with the first end of the resistor and capacitor and the temperature detection voltage end of the battery parameter intelligent management module; the other end of the resistor and capacitor is connected in parallel to the negative electrode of the lithium battery.

[0016] Furthermore, the short-circuit protection unit comprises an RS resistor, one end of the RS resistor is connected to the current detection end of the battery parameter intelligent management module, and the other end of the RS resistor is connected to the negative electrode of the lithium battery.

[0017] Furthermore, the current limiting protection unit is an RS resistor, one end of the RS resistor is connected to the negative electrode of the battery, and the other end of the RS resistor is connected to the current detection end of the battery parameter intelligent management module and the second end of the discharge unit.

[0018] Furthermore, the thermistor is an NTC thermistor.

[0019] Furthermore, the charging protection unit is an NMOSFET tube, the first end of the NMOSFET tube is connected to the charging detection end of the battery parameter intelligent management module; the second end of the discharge protection unit is connected to the first end of the current limiting protection unit, and the third end of the discharge protection unit is connected to the second end of the NMOSFET tube.

[0020] Furthermore, the discharge protection unit is an NMOSFET tube, the first end of the NMOSFET tube is connected to the discharge detection end of the battery parameter intelligent management module; the first end of the NMOSFET tube is connected to the negative electrode of the lithium battery, and the second end of the NMOSFET tube is connected to the fifth end of the NMOSFET tube of the charging unit.

[0021] Furthermore, the protection release unit includes a resistor, one end of the resistor is connected to the negative electrode of the protection circuit, and the other end of the resistor is connected to the reverse voltage end of the battery parameter intelligent management module.

[0022] Furthermore, the charging and discharging unit includes: a resistor and a capacitor, wherein the first end of the resistor is connected to the positive electrode of the lithium battery, and the other end of the resistor is connected in parallel with the first end of the capacitor and connected to the power input end of the battery parameter intelligent management module; the other end of the capacitor is connected in parallel to the power ground terminal of the battery parameter intelligent management module, and the negative electrode of the lithium battery is connected to the power ground terminal of the battery parameter intelligent management module.

[0023] The technical solution provided by the embodiment of the present invention is as follows: when the over-discharge detection voltage of the lithium battery is reduced to below the over-discharge voltage value, charging is carried out; when the charging detection voltage of the lithium battery is higher than the charging over-charge voltage value, the charging circuit is disconnected to enter the charging protection state; when the discharge detection current of the lithium battery is higher than the discharge short-circuit current, the discharge circuit is disconnected to enter the discharge protection state; when the charging temperature of the lithium battery exceeds a specified value, the charging protection circuit is disconnected, charging is stopped, and the high-temperature protection state is entered; when the discharge temperature is lower than the specified temperature value, discharging is stopped, and the discharge protection state is entered; when the charging voltage is lower than the charging over-charge voltage or the charging voltage is higher than the over-charge voltage value or the discharge current is lower than the over-discharge current value or the charging temperature is lower than the rated value or the discharge temperature is higher than the minimum rated value, the over-charge and discharge protection function is released to avoid overheating of the lithium battery cell, which is beneficial to the normal operation of the protection chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 This is a circuit block diagram of the utility model;

[0026] Figure 2 This is the circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0028] Reference Figure 1 The utility model discloses a lithium battery secondary protection circuit 100, a protection circuit positive electrode P+, ​​a protection circuit negative electrode P-, a battery parameter intelligent management module U1, a temperature detection unit 1, a charging protection unit 2, a discharging protection unit 3, a current limiting protection unit 4, a short circuit protection unit 5, a fuse 6, a release protection unit 7, and a charging and discharging unit 8;

[0029] One end of the fuse F1 is connected to the positive electrode P+ of the protection circuit, and the other end is connected to the positive electrode of the lithium battery. The function of the fuse is to prevent the protection circuit from failing and disconnect the protection circuit when the charging or discharging current is too large, so as to protect the lithium battery cell from being damaged;

[0030] The temperature detection unit is used for charging and discharging temperature detection of the lithium battery. The first end of the temperature detection unit is connected to the temperature detection reference voltage end of the battery parameter intelligent management module, the second end of the temperature detection unit is connected to the temperature detection voltage end of the intelligent management module, and the third end is connected to the negative electrode of the lithium battery;

[0031] The discharge protection unit is used to protect the lithium battery from discharging below the rated voltage value. The first end of the discharge protection unit is connected to the discharge end of the battery parameter intelligent management module, the second end of the discharge protection unit is connected to the first end of the current limiting protection unit, and the third end of the discharge protection unit is connected to the second end of the charging protection unit;

[0032] The charging protection unit is used to protect the lithium battery from charging above the rated voltage value. The first end of the charging protection unit is connected to the charging end of the battery parameter intelligent management module, the second end of the charging protection unit is connected to the third end of the discharge protection unit, and the third end of the charging protection unit is connected to the negative electrode of the protection circuit;

[0033] The short-circuit protection unit is used for short-circuit protection, one end of the short-circuit protection unit is connected to the short-circuit current detection end of the battery parameter intelligent management module, and the other end is connected to one end of the overcurrent detection unit, and the other end of the overcurrent unit is connected to the negative electrode of the lithium battery;

[0034] The protection release unit is used for charging protection, discharging protection, short circuit protection, and temperature lower than the rated value or higher than the rated value protection release. One end of the protection release unit is connected to the reverse voltage end of the battery parameter intelligent management module, and the other end is connected to the negative electrode of the protection circuit;

[0035] The first end of the charge and discharge unit is connected to the positive electrode of the lithium battery, and the second end of the charge and discharge unit is connected to the power input end of the battery parameter intelligent management module; the third end of the charge and discharge unit is connected to the negative electrode of the lithium battery, and the fourth end of the charge and discharge unit is connected to the power ground end of the battery parameter intelligent management module.

[0036] Specifically, refer to Figure 2 , this embodiment is Figure 1 The circuit diagram further illustrates that the battery parameter intelligent management module can select a lithium battery protection integrated chip, for example, the lithium battery protection chip can be selected as NT1718B; of course, the battery parameter intelligent management module can also be implemented in other ways, such as designing a specific circuit, such as a current detection circuit, a temperature detection circuit, a voltage detection circuit and other specific functions, to meet the corresponding battery parameter detection function. Of course, for multiple lithium battery cells, this circuit can be designed into the protection unit corresponding to the number of lithium batteries, so as to realize the multi-cell lithium battery charging protection circuit.

[0037] In this embodiment, a lithium battery protection chip U1 is included, which is used to provide parameter detection such as charging overcharge voltage, charging overcharge current, discharging overdischarge current, discharging overdischarge voltage, charging overcharge temperature, discharging overdischarge temperature, and discharging short-circuit current. When the above parameters exceed the threshold, the corresponding protection state is entered;

[0038] As the core protection device of this circuit, the charging and discharging protection units can be selected as NMOSFET type; of course, PMOSFET tubes can also be selected. In this embodiment, the charging NMOSFET tube Q2 and the discharging NMOSFET tube Q1; the gate of the charging NMOSFET tube Q2 is connected to the CO pin end of the protection chip U1; the source of the discharging NMOSFET tube Q2 is connected to the negative electrode P- of the protection circuit, and the drain of the charging NMOSFET tube Q2 is connected to the drain of the discharge unit NMOSFET tube Q1;

[0039] The discharge protection unit is an NMOSFET tube Q1, and the gate of the discharge protection unit NMOSFET tube Q1 is connected to the DO terminal of the protection chip; the source of the discharge NMOSFET tube Q1 is connected to the negative electrode B- of the lithium battery, and the drain of the discharge NMOSFET tube Q1 is connected to the drain of the charging unit NMOSFET tube Q2;

[0040] In order to prevent the lithium battery from charging and discharging at too high a temperature or discharging at too low a temperature, the present embodiment designs a temperature detection unit circuit, including: a thermistor R3, a resistor R4, and a capacitor C2; one end of the thermistor R3 is connected to the protection chip VRTH, and the other end is connected in parallel with the resistor R4, the first end of the capacitor C2, and the protection chip VTH end; the other end of the resistor R4 and the capacitor C2 are connected in parallel with the negative electrode B- of the lithium battery. In the present embodiment, the thermistor can be selected as an NTC thermistor. Of course, a PTC thermistor can also be selected.

[0041] In order to prevent the lithium battery charging circuit from being short-circuited or the discharge load from being short-circuited, a short-circuit protection unit circuit is designed, including an RS resistor, one end of the RS resistor is connected to the CS pin of the protection chip, and the other end of the RS resistor is connected to the negative electrode of the lithium battery.

[0042] In order to prevent the charging and discharging current from being too large, a current limiting unit circuit is designed, and an RS resistor is selected to form a current limiting unit circuit device. One end of the RS resistor is connected to the negative electrode of the battery, and the other end of the RS resistor is connected to the CS end of the protection chip and the second end of the discharge unit.

[0043] When the lithium battery charging and discharging or temperature detection enters the protection state, the lithium battery charging and discharging function protection needs to be designed to release the protection unit circuit, including a resistor R2, one end of the resistor R2 is connected to the negative electrode P- of the protection circuit, and the other end of the resistor R2 is connected to the V- end of the protection circuit.

[0044] As a lithium battery charging and discharging circuit, it includes: a resistor R1 and a capacitor C1, wherein the first end of the resistor R1 is connected to the positive electrode of the lithium battery, and the other end of the resistor R1 is connected to the VDD end of the protection chip; the first end of the capacitor C1 is connected in parallel to the VDD end of the protection chip, and the other end of the capacitor is connected in parallel to the VSS end of the protection chip, and the negative electrode of the lithium battery is connected to the VSS end of the protection chip.

[0045] Reference Figure 2 , the specific working process of this embodiment is:

[0046] When the protection chip VDD voltage is higher than the overcharge detection voltage (V DET1 ) and keep this state for more than the overcharge detection delay time (t VDET1 ), the CO terminal level of the protection chip will jump from high level "H" to low level "L", the charging control NMOSFET tube Q2 will have a high drain-source resistance, the charging circuit will be turned off and charging will stop.

[0047] When the protection chip VDD voltage is lower than the overcharge detection voltage (V DET1 ), and the charger is removed and the load is connected, that is, the voltage of the V- terminal of the protection chip is higher than V RELVM1 When the overcharge voltage and charge overcurrent release voltage are reached, this state is maintained for more than the overcharge release time (t VDET1_REL ), the CO terminal level of the protection chip will jump from low level "L" to high level "H", the NMOSFET tube Q2 will be drain-source conductive, turn on the charging control NMOSFET, and release the overcharge protection. The voltage drop of the protection chip VDD can be caused by the discharge of the lithium battery or the battery itself.

[0048] When the protection chip VDD voltage is lower than the overcharge release voltage V REL1 , and the charger is still connected, and this state is maintained for more than the overcharge release time (t VDET1 _ REL ), the CO terminal of the protection chip will jump from low level "L" to high level "H", the drain-source of the NMOSFET tube Q2 will be turned on, turning on the charging control NMOSFET tube Q1 and releasing the overcharge protection.

[0049] When the VDD voltage of the protection chip is lower than the over-discharge detection voltage (V DET2 ) and maintain this state for more than the over-discharge detection delay time (t VDET2), the protection chip discharge DO terminal will jump from high level "H" to low level "L", and the discharge control MOSFET tube Q2 will be turned off (turned off) to stop discharging. In this state, the protection chip V- terminal voltage will be pulled up to VDD by the internal resistance (RVMD) between the protection chip V- terminal and the protection chip VDD terminal.

[0050] When the voltage of the protection chip Vcs terminal is between V DET31,32 [i.e., discharge overcurrent detection voltage -1 or discharge overcurrent detection voltage -2] and V SHORT The load short-circuit detection voltage is maintained for a period exceeding the discharge overcurrent detection delay time (t VDET31,32 ), it will enter the discharge overcurrent protection state. When the protection chip Vcs terminal voltage is higher than V SHORT (i.e. short-circuit voltage value), and maintain this state for more than the load short-circuit delay time (t SHORT ), it will enter the load short-circuit protection state. When the above state occurs, the voltage of the protection chip DO terminal jumps from high level "H" to low level "L", the drain-source of the discharge control MOSFET tube is disconnected, and the discharge circuit will be turned off to stop discharging. At this time, the voltage of the protection chip V- terminal will be pulled down to VSS by the internal resistance (RVMS) between the V- terminal and the VSS terminal.

[0051] The voltage at the V- terminal of the protection chip is inversely proportional to the impedance (Rload) between (P+ and P-). When Rload increases, the voltage at the V- terminal of the protection chip decreases. RELVM2 When the over-discharge current reaches the maximum voltage, it will return to the normal state from the protection state.

[0052] The relationship between the voltage value of the protection chip V- terminal and Rload is as follows

[0053] Where V-<VRELVM2

[0054] When the protection chip Vcs terminal voltage is lower than the charge overcurrent detection voltage (V DET4 ), and keep this state for more than the charge overcurrent detection delay time (t DET4 ), the voltage at the CO terminal of the protection chip changes from high level "H" to low level "L", and the drain-source of the charging control NMOSFET tube Q2 is disconnected, and it will be turned off to stop charging.

[0055] Remove the charger and connect the load (protect the chip V- terminal voltage higher than V RELVM1(maximum value)), the charge overcurrent state can be released. When used with a specific MOSFET (e.g. N-channel MOSFET), the charge overcurrent state can also be released when no load is connected.

[0056] In the discharge state (V DET31,32 (minimum value) > protection chip CS terminal > V CDET (maximum value)), the battery temperature rises, the temperature reaches the discharge over-temperature detection voltage (DOT) and the temperature detection delay time (t VTH ), the voltage of the protection chip DO terminal will jump from high level "H" to low level "L", and the discharge control NMOSFET tube Q2 will be turned off to stop discharging. When the battery temperature drops to the discharge overtemperature release voltage and the temperature release delay time (t VTH_REL ), the voltage at the DO terminal of the protection chip will jump from low level "L" to high level "H", turning on the discharge control NMOSFET tube and releasing the discharge over-temperature protection.

[0057] During charging, the battery temperature rises and reaches the charge over-temperature detection voltage (COT) and the temperature detection delay time (t VTH ), the protection chip CO terminal will jump from high level "H" to low level "L", and the charging control NMOSFET tube Q2 will be turned off to stop charging. When the battery temperature drops to the charging overtemperature release voltage and the temperature release delay time (t VTH_REL ), the voltage at the CO terminal of the protection chip will jump from low level "L" to high level "H", turning on the charging control NMOSFET tube Q2 and releasing the charging over-temperature protection.

[0058] During charging, the battery temperature drops and reaches the charge low temperature detection voltage (CUT) and the temperature detection delay time (t VTH ), the voltage of the protection chip CO terminal will jump from high level "H" to low level "L", and the charging control NMOSFET tube Q2 will be turned off to stop discharging. When the battery temperature rises to the charging low temperature release voltage and the temperature release delay time (t VTH_REL ), the voltage at the CO terminal of the protection chip will jump from low level "L" to high level "H", turning on the charging control NMOSFET tube Q2 and releasing the charging low temperature protection.

[0059] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

[0060] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0062] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A single-cell high-precision lithium battery protection circuit with over-temperature protection, characterized in that: include: Protection circuit positive pole, protection circuit negative pole, battery parameter intelligent management module, temperature detection unit, charging protection unit, discharging protection unit, current limiting protection unit, short circuit protection unit, fuse, release protection unit, charging and discharging unit; One end of the fuse is connected to the positive electrode of the protection circuit, and the other end is connected to the positive electrode of the lithium battery; The temperature detection unit is used for charging and discharging temperature detection of the lithium battery. The first end of the temperature detection unit is connected to the temperature detection voltage reference end of the battery parameter intelligent management module, the second end of the temperature detection unit is connected to the temperature detection voltage end of the battery parameter intelligent management module, and the third end of the temperature detection unit is connected to the negative electrode of the lithium battery; The discharge protection unit is used to protect the lithium battery from discharging below the rated voltage value. The first end of the discharge protection unit is connected to the discharge detection end of the battery parameter intelligent management module, the second end of the discharge protection unit is connected to the first end of the current limiting protection unit, and the third end of the discharge protection unit is connected to the second end of the charging protection unit; The charging protection unit is used to protect the lithium battery from charging above the rated voltage value, the first end of the charging protection unit is connected to the charging detection end of the battery parameter intelligent management module, the second end of the charging protection unit is connected to the third end of the discharge protection unit, and the third end of the charging protection unit is connected to the negative electrode of the protection circuit; The short-circuit protection unit is used for short-circuit protection, one end of the short-circuit protection unit is connected to the current detection end of the battery parameter intelligent management module, and the other end is connected to one end of the overcurrent detection unit, and the other end of the overcurrent detection unit is connected to the negative electrode of the lithium battery; The release protection unit is used for charge protection, discharge protection, short circuit protection, and temperature lower than the rated value or higher than the rated value protection release. One end of the release protection unit is connected to the reverse voltage end of the battery parameter intelligent management module, and the other end is connected to the negative electrode of the protection circuit; The first end of the charge and discharge unit is connected to the positive electrode of the lithium battery, and the second end of the charge and discharge unit is connected to the power input end of the battery parameter intelligent management module; the third end of the charge and discharge unit is connected to the negative electrode of the lithium battery, and the fourth end of the charge and discharge unit is connected to the power ground end of the protection module.

2. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The battery parameter intelligent management module is a chip.

3. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The temperature detection unit includes: a thermistor, a resistor, and a capacitor; one end of the thermistor is connected to the temperature detection voltage reference end of the battery parameter intelligent management module, and the other end is connected in parallel with the first end of the resistor and capacitor and the temperature detection voltage end of the battery parameter intelligent management module; the other end of the resistor and capacitor is connected in parallel to the negative electrode of the lithium battery.

4. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The short-circuit protection unit comprises an RS resistor, one end of the RS resistor is connected to the current detection end of the battery parameter intelligent management module, and the other end of the RS resistor is connected to the negative electrode of the lithium battery.

5. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The current limiting protection unit is an RS resistor, one end of the RS resistor is connected to the negative electrode of the battery, and the other end of the RS resistor is connected to the current detection end of the battery parameter intelligent management module and the second end of the discharge unit.

6. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 3 is characterized in that: The thermistor is an NTC thermistor.

7. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The charging protection unit is an NMOSFET tube, and the first end of the NMOSFET tube is connected to the charging detection end of the battery parameter intelligent management module; the second end of the discharge protection unit is connected to the first end of the current limiting protection unit, and the third end of the discharge protection unit is connected to the second end of the NMOSFET tube.

8. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1 is characterized in that: The discharge protection unit is an NMOSFET tube, the first end of which is connected to the discharge detection end of the battery parameter intelligent management module; the first end of which is connected to the negative electrode of the lithium battery, and the second end of which is connected to the fifth end of the NMOSFET tube of the charging unit.

9. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1, characterized in that: The release protection unit comprises a resistor, one end of which is connected to the negative electrode of the protection circuit, and the other end of which is connected to the reverse voltage end of the battery parameter intelligent management module.

10. The single-cell high-precision lithium battery protection circuit with over-temperature protection according to claim 1, characterized in that: The charging and discharging unit includes: a resistor and a capacitor, wherein the first end of the resistor is connected to the positive electrode of the lithium battery, and the other end of the resistor is connected in parallel with the first end of the capacitor and connected to the power input end of the battery parameter intelligent management module; the other end of the capacitor is connected in parallel to the power grounding end of the battery parameter intelligent management module, and the negative electrode of the lithium battery is connected to the power grounding end of the battery parameter intelligent management module.

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