Lead-acid battery protection device

Abstract

The invention provides a lead-acid battery protection device, and relates to the field of storage batteries, and the lead-acid battery protection device comprises a microcontroller, a DCDC power supply, a thermal fusing fuse and a lead-acid battery, the microcontroller is connected with the thermal fusing fuse and the DCDC power supply; the thermal fusing fuse is connected with the lead-acid battery; the microcontroller is used for controlling the charging input, the main loop output and the secondary loop output of the storage battery system; the DCDC power supply is used for providing output voltage; the first path of output voltage is adjusted by the first path of secondary loop control circuit, and 12V voltage and 200mA-limited current are output; the second path of output voltage controls the second path of secondary loop control circuit to adjust, and 12V voltage and 6A current are output; the third path of output voltage is used for outputting 5V voltage and 500mA current so as to supply power to the microcontroller; and the microcontroller is also used for closing the thermal fusing fuse so as to close the charging and discharging functions of the lead-acid battery when the storage battery system is abnormal. The over-temperature protection device can meet the requirements of new national standard discharge current and play a role in over-temperature protection.

Description

Technical Field

[0001] The invention relates to the field of storage batteries, and in particular to a lead-acid battery protection device. Background Art

[0002] In recent years, the electrical safety of electric bicycles has been continuously improved. The battery system currently available on the market, which consists of lead-acid batteries and protective devices, is simple in function and cannot meet the requirements of the new national standard.

[0003] The lead-acid battery protection circuit with publication number CN216530609U can realize the control of voltage, temperature, current, and charge and discharge ports, but cannot achieve short-circuit protection of the main circuit and the secondary circuit, as well as separate control of charging and discharging. Therefore, it cannot meet the requirements of 4.4 voltage and discharge current of the new national standard.

[0004] In response to the requirements of the new national standard, the lead-acid battery pack protection system with publication number CN105743188B has a charging and discharging drive module, a charging and discharging module, a control module, and a voltage and current acquisition module. The circuit can only realize charging and discharging control, but cannot realize over-temperature protection and protection device failure protection. Summary of the invention

[0005] The purpose of the present invention is to provide a lead-acid battery protection device to solve the problem that the discharge current requirement of the new national standard cannot be met and over-temperature protection cannot be achieved.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A lead-acid battery protection device comprises: a microcontroller, a DCDC power supply, a thermal fuse and a lead-acid battery;

[0008] The microcontroller is connected to the thermal cutoff fuse and the DCDC power supply; the thermal cutoff fuse is also connected to the lead-acid battery;

[0009] The microcontroller is used to control the charging input, main circuit output and secondary circuit output of the battery system; the DCDC power supply is used to provide output voltage; the first output voltage is adjusted by the first secondary circuit control circuit to output 12V voltage and 200mA current; the second output voltage controls the adjustment of the second secondary circuit control circuit to output 12V voltage and 6A current; the third output voltage is used to output 5V voltage and 500mA current to power the microcontroller; the microcontroller is also used to turn off the thermal fuse to turn off the charging and discharging function of the lead-acid battery when an abnormality occurs in the battery system.

[0010] Optionally, it also includes: a charging control circuit, a main loop control circuit, two secondary loop control circuits, a communication circuit, a temperature sensor, a battery voltage acquisition circuit, and a battery charge and discharge current acquisition circuit connected to the microcontroller;

[0011] The DCDC power supply is respectively connected to the charging control circuit, the thermal fuse, the main loop control circuit and the secondary loop control circuit;

[0012] The DCDC power supply includes a control circuit and a power supply circuit; the control circuit is connected to the two secondary loop control circuits; and the power supply circuit is connected to the microprocessor.

[0013] Optionally, the control circuit specifically includes:

[0014] The charging control circuit is connected to the positive electrode of the diode D1 and one end of the thermistor RT1; the negative electrode of the diode D1 is connected to one end of the capacitor C1, one end of the capacitor C2, one end of the resistor R1 and the second end of the switch tube Q1; the other end of the thermistor RT1, the other end of the capacitor C1 and the other end of the capacitor C2 are grounded; the first end of the switch tube Q1 is connected to the positive electrode of the diode D2 and one end of the resistor R2; the negative electrode of the diode D2 is connected to the 9th interface of the first controller; the other end of the resistor R2 is connected to the 1st interface of the first controller; the third end of the first switch tube Q1 is connected to one end of the first parallel structure, the 8th interface of the first controller and the negative electrode of the Schottky diode; the positive electrode of the Schottky diode is grounded;

[0015] The other end of the resistor R1 is connected to one end of the resistor R3, one end of the capacitor C3 and the second interface of the first controller; the other end of the resistor R3 is connected to the cathode of the diode D3; the other end of the capacitor C3 is connected to one end of the capacitor C4, one end of the resistor R4, one end of the resistor R5, one end of the resistor R6, the other end of the first parallel structure, one end of the inductor L1 and the sixth interface and the seventh interface of the first controller; the positive electrode of the capacitor D3 is connected to the other end of the resistor R5, the other end of the inductor L1 and the first end of the second parallel structure; the second end of the second parallel structure is grounded; the third end of the second parallel structure is connected to the two-way sub-loop control circuit and the microcontroller, and the third end of the second parallel structure is used to provide a 12V voltage to the two-way sub-loop control circuit and the microcontroller; the first parallel structure includes parallel resistors R8, R9, R10, R11 and R12; the parallel structure includes capacitors C5, C6, C7, C8 and resistor R13.

[0016] Optionally, the first secondary loop control circuit specifically includes:

[0017] The third end of the second parallel structure is connected to one end of the capacitor C9, one end of the resistor R14 and the source of the switch tube Q2; the other end of the capacitor C9 is connected to one end of the resistor R15, the other end of the resistor R14 and the gate of the switch tube Q2; the other end of the resistor R15 is connected to the source of the switch tube Q3; the gate of the switch tube Q3 is connected to one end of the resistor R16 and one end of the resistor R17; the drain of the switch tube Q3 is connected to the other end of the resistor R16 and is grounded;

[0018] The drain of the switch tube Q3 is connected to one end of the capacitor C10, one end of the resistor R18 and the third interface of the second controller; the other end of the capacitor C10 is grounded; the other end of the resistor R18 is connected to one end of the resistor R19 and the first interface of the second controller; the other end of the resistor R19 is connected to the second interface and the fourth interface of the second controller;

[0019] The 12V voltage is adjusted by the first secondary loop control circuit to output a 12V voltage and a current limited to 200mA.

[0020] Optionally, the second secondary loop control circuit specifically includes:

[0021] The third end of the second parallel structure is connected to one end of the capacitor C12, one end of the resistor R20 and the source of the switch tube Q4; the other end of the capacitor C12 is connected to the other end of the resistor R20, one end of the resistor R21 and the gate of the switch tube Q4; the drain of the switch tube Q4 is connected to one end of the capacitor C12 and one end of the capacitor C13; the other end of the capacitor C12 and the other end of the capacitor C13 are grounded;

[0022] The other end of the resistor R21 is connected to the source of the switch tube Q5; the gate of the switch tube is connected to one end of the resistor R22 and one end of the resistor R23; the drain of the switch tube Q5 is connected to the other end of the resistor R22 and is grounded.

[0023] Optionally, the power supply circuit specifically includes:

[0024] The third end of the second parallel structure is connected to the positive electrode of the diode D4; the negative electrode of the diode D4 is connected to the second end of the variable resistor D5, one end of the capacitor C14, one end of the capacitor C15, one end of the resistor R24 ​​and the fifth interface of the third controller; the first end of the variable resistor D5, one end of the capacitor C14 and one end of the capacitor C15 are grounded; the other end of the resistor R24 ​​is connected to one end of the capacitor C16 and the fourth interface of the third controller; the other end of the capacitor C16 is grounded;

[0025] The sixth interface of the third controller is connected to one end of the inductor L2 and one end of the capacitor C17; the other end of the capacitor C7 is connected to the first interface of the third controller; the other end of the inductor L2 is connected to one end of the resistor R25, one end of the capacitor C18, one end of the capacitor C19 and one end of the capacitor C20; the other end of the capacitor C19 and the other end of the capacitor C20 are connected and grounded;

[0026] The other end of the resistor R25 is connected to the other end of the capacitor C18, the third interface of the third controller, and one end of the resistor R26; the other end of the resistor R26 is grounded.

[0027] Optionally, when the charging control circuit is operating, the microprocessor communicates with the charging control circuit, and the microprocessor closes a charging switch in the charging control circuit to supply power to the lead-acid battery.

[0028] Optionally, the charging switch is a normally open relay; and the microcontroller periodically detects whether the charging switch is abnormal.

[0029] Optionally, the microprocessor collects the temperature of the temperature sensor in real time. When the temperature of the temperature sensor is greater than a set temperature, it is determined that an abnormality occurs in the protection system, and the thermal cutoff fuse blows to prevent the lead-acid battery from continuing to discharge.

[0030] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the present invention provides a lead-acid battery protection device, which provides three output voltages through a DCDC power supply, the first output voltage is adjusted by the first sub-loop control circuit, and outputs a 12V voltage and a current limited to 200mA to achieve low-voltage 200mA current limiting protection, and the second output voltage controls the adjustment of the second sub-loop control circuit to output a 12V voltage and a 6A current to meet the requirements of the new national standard discharge current; in addition, the present invention is also provided with a thermal fuse, and when the temperature is too high, the thermal fuse is melted to prevent the lead-acid battery from continuous discharge, thereby playing a role of over-temperature protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A schematic diagram of the connection relationship of the lead-acid battery protection device provided by the present invention;

[0033] Figure 2 This is a schematic diagram of the main circuit and secondary circuit control part provided by the present invention;

[0034] Figure 3 This is a schematic diagram of the charging control part provided by the present invention;

[0035] Figure 4 A control circuit diagram provided by the present invention;

[0036] Figure 5 A first-way secondary loop control circuit diagram provided by the present invention;

[0037] Figure 6 A second secondary loop control circuit diagram provided by the present invention;

[0038] Figure 7 A power supply circuit diagram provided by the present invention;

[0039] Figure 8 This is a schematic diagram of the over-temperature protection connection provided by the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] The purpose of the present invention is to provide a lead-acid battery protection device that can meet the requirements of the new national standard discharge current and play a role in over-temperature protection.

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figure 1As shown, the present invention provides a lead-acid battery protection device, comprising: a microcontroller, a DCDC power supply, a thermal fuse and a lead-acid battery; the microcontroller is connected to the thermal fuse and the DCDC power supply; the thermal fuse is also connected to the lead-acid battery; the microcontroller is used to control the charging input, main circuit output and secondary circuit output of the battery system; the DCDC power supply is used to provide output voltage; the first output voltage is adjusted by the first secondary circuit control circuit to output 12V voltage and 200mA current; the second output voltage controls the second secondary circuit control circuit to adjust and output 12V voltage and 6A current; the third output voltage is used to output 5V voltage and 500mA current to power the microcontroller; the microcontroller is also used to turn off the thermal fuse to turn off the charging and discharging function of the lead-acid battery when an abnormality occurs in the battery system; the battery system comprises a lead-acid battery and a protection device.

[0044] In practical applications, it also includes: a charging control circuit (i.e. Figure 1 Charging control in the main circuit control circuit (i.e. Figure 1 The main circuit control in the two-way secondary circuit control circuit (i.e. Figure 1 Secondary loop control 1 and secondary loop control 2), communication circuit (i.e. Figure 1 Communication in), temperature sensor, battery voltage acquisition circuit (i.e. Figure 1 The battery voltage acquisition in the battery charging and discharging current acquisition circuit (i.e. Figure 1 The DCDC power supply is respectively connected to the charging control circuit, the thermal fuse, the main loop control circuit and the secondary loop control circuit; the DCDC power supply includes a control circuit and a power supply circuit; the control circuit is connected to the two secondary loop control circuits; the power supply circuit is connected to the microprocessor.

[0045] In practical applications, lead-acid batteries (i.e. Figure 1 The lead-acid battery pack in the system provides power for the entire system. With the microprocessor as the core, it controls the charging input, main circuit and secondary circuit output of the battery system; communicates with external charger controller instruments, etc.; and collects the voltage, charge and discharge current, battery temperature and battery compartment temperature of the lead-acid battery; when the system is abnormally shut down and the fuse is blown, the lead-acid battery charging and discharging function is completely shut down.

[0046] like Figure 2 As shown, in the main circuit and secondary circuit control part, the microprocessor detects the closed state of K1:

[0047] The main circuit control is the same as the charging port, which uses relay control. At the same time, the microprocessor regularly detects whether the relay is abnormal, preventing the main circuit from abnormal discharge, over-discharge, etc., which may cause safety hazards.

[0048] The secondary loop control circuit converts the battery voltage to 12V through the DCDC circuit, and then powers the external low-voltage equipment. To meet the requirements of the new national standard, the secondary loop voltage cannot exceed DC35V / AC16V at any time, and when the electric door lock is closed, the secondary loop current cannot exceed 200mA.

[0049] When the battery system is used in the car, the electric door lock is opened, Q4 will be turned on to power external devices, and the current will exceed 200mA. When the electric door lock is closed, Q4 will be turned off to output 200mA. When the current exceeds 200mA, the chip will be current limited and the secondary circuit output will be closed.

[0050] When the battery system is a single entity, Q2 and Q4 are both in the off state, and the secondary circuit output is zero. The charging port and the main circuit output port are also zero to prevent the port discharge from causing abnormalities in the battery system.

[0051] like Figure 3 As shown, for the charging control part, when the charger is inserted into the charging port, the microprocessor will communicate with the charger. When the charger matches the entire battery system, the microprocessor will close the connection of the K2 charging port to power the lead-acid battery pack. K2 uses a normally open relay. The charging handshake is successfully closed, and it is disconnected at other times to prevent the charging port from leaking electricity / short circuit. Wrong connection and misuse of the charger will cause the vehicle to catch fire. At the same time, the processor will regularly detect whether the relay is abnormal.

[0052] In practical applications, such as Figure 4 As shown, the control circuit specifically includes: the charging control circuit is connected to the positive electrode of the diode D1 and one end of the thermistor RT1; the negative electrode of the diode D1 is connected to one end of the capacitor C1, one end of the capacitor C2, one end of the resistor R1 and the second end of the switch tube Q1; the other end of the thermistor RT1, the other end of the capacitor C1 and the other end of the capacitor C2 are grounded; the first end of the switch tube Q1 is connected to the positive electrode of the diode D2 and one end of the resistor R2; the negative electrode of the diode D2 is connected to the 9th interface of the first controller; the other end of the resistor R2 is connected to the 1st interface of the first controller; the third end of the first switch tube Q1 is connected to one end of the first parallel structure, the 8th interface of the first controller and the negative electrode of the Schottky diode (MBRD20100CT); the positive electrode of the Schottky diode is grounded.

[0053] The other end of the resistor R1 is connected to one end of the resistor R3, one end of the capacitor C3 and the second interface of the first controller; the other end of the resistor R3 is connected to the cathode of the diode D3; the other end of the capacitor C3 is connected to one end of the capacitor C4, one end of the resistor R4, one end of the resistor R5, one end of the resistor R6, the other end of the first parallel structure, one end of the inductor L1 and the sixth interface and the seventh interface of the first controller; the positive electrode of the capacitor D3 is connected to the other end of the resistor R5, the other end of the inductor L1 and the first end of the second parallel structure; the second end of the second parallel structure is grounded; the third end of the second parallel structure is connected to the two-way sub-loop control circuit and the microcontroller, and the third end of the second parallel structure is used to provide a 12V voltage to the two-way sub-loop control circuit and the microcontroller; the first parallel structure includes parallel resistors R8, R9, R10, R11 and R12; the parallel structure includes capacitors C5, C6, C7, C8 and resistor R13.

[0054] In practical applications, such as Figure 5 As shown, the first secondary loop control circuit specifically includes: the third end of the second parallel structure is connected to one end of the capacitor C9, one end of the resistor R14 and the source of the switch tube Q2; the other end of the capacitor C9 is connected to one end of the resistor R15, the other end of the resistor R14 and the gate of the switch tube Q2; the other end of the resistor R15 is connected to the source of the switch tube Q3; the gate of the switch tube Q3 is connected to one end of the resistor R16 and one end of the resistor R17; the drain of the switch tube Q3 is connected to the other end of the resistor R16 and grounded.

[0055] The drain of the switch tube Q3 is interconnected with one end of the capacitor C10, one end of the resistor R18 and the third interface of the second controller; the other end of the capacitor C10 is grounded; the other end of the resistor R18 is interconnected with one end of the resistor R19 and the first interface of the second controller; the other end of the resistor R19 is connected to the second interface and the fourth interface of the second controller; the 12V voltage is adjusted by the first secondary loop control circuit, and the 12V voltage and the current limited to 200mA are output.

[0056] In practical applications, such as Figure 6As shown, the second sub-loop control circuit specifically includes: the third end of the second parallel structure is connected to one end of the capacitor C12, one end of the resistor R20 and the source of the switch tube Q4; the other end of the capacitor C12 is connected to the other end of the resistor R20, one end of the resistor R21 and the gate of the switch tube Q4; the drain of the switch tube Q4 is connected to one end of the capacitor C12 and one end of the capacitor C13; the other end of the capacitor C12 and the other end of the capacitor C13 are grounded.

[0057] The other end of the resistor R21 is connected to the source of the switch tube Q5; the gate of the switch tube is connected to one end of the resistor R22 and one end of the resistor R23; the drain of the switch tube Q5 is connected to the other end of the resistor R22 and is grounded.

[0058] In practical applications, such as Figure 7 As shown, the power supply circuit specifically includes: the third end of the second parallel structure is connected to the positive electrode of the diode D4; the negative electrode of the diode D4 is interconnected with the second end of the variable resistor D5, one end of the capacitor C14, one end of the capacitor C15, one end of the resistor R24 ​​and the 5th interface of the third controller; the first end of the variable resistor D5, one end of the capacitor C14 and one end of the capacitor C15 are grounded; the other end of the resistor R24 ​​is interconnected with one end of the capacitor C16 and the 4th interface of the third controller; the other end of the capacitor C16 is grounded.

[0059] The 6th interface of the third controller is interconnected with one end of the inductor L2 and one end of the capacitor C17; the other end of the capacitor C7 is connected to the 1st interface of the third controller; the other end of the inductor L2 is interconnected with one end of the resistor R25, one end of the capacitor C18, one end of the capacitor C19 and one end of the capacitor C20; the other end of the capacitor C19 and the other end of the capacitor C20 are connected and grounded.

[0060] The other end of the resistor R25 is connected to the other end of the capacitor C18, the third interface of the third controller, and one end of the resistor R26; the other end of the resistor R26 is grounded.

[0061] In practical applications, when the charging control circuit is working, the microprocessor communicates with the charging control circuit, and the microprocessor closes the charging switch in the charging control circuit to supply power to the lead-acid battery.

[0062] In practical applications, the charging switch is a normally open relay; the microcontroller periodically detects whether the charging switch is abnormal.

[0063] In actual applications, the microprocessor collects the temperature of the temperature sensor in real time. When the temperature of the temperature sensor is greater than the set temperature, it is determined that an abnormality occurs in the protection system, and the thermal fuse blows to prevent the lead-acid battery from continuing to discharge.

[0064] like Figure 8 As shown, a thermal cutout fuse will be installed at the output end of the battery. When the protection system is abnormal, the microprocessor will activate the thermal cutout fuse to prevent the battery from continuously discharging and causing safety hazards.

[0065] A sampling resistor is added to the negative end of the battery, and the microprocessor supports differential ADC sampling, which can collect the discharge and charging current of the battery. The microprocessor also detects the battery voltage, battery compartment ambient temperature, and battery surface temperature in real time, making the battery safer in use.

[0066] In actual applications, the microprocessor calculates the battery current and health indexes such as aging in real time, and transmits the data to controllers, instruments and other equipment through the communication port.

[0067] Based on the fact that electric bicycles meet the requirements of the new national standard during use, the lead-acid battery protection device provided by the present invention can realize high-voltage to low-voltage conversion and low-voltage 200mA current limiting protection. The battery charging and discharging current, voltage, working environment temperature, charging and discharging temperature, external communication abnormality alarm, charging mutual recognition and coordination and other functions can better protect the battery and avoid fires caused by battery over-discharge, overcharging, short circuit, abnormal temperature, etc., which may cause loss of life and property. At the same time, the power, aging, and health status of the lead-acid battery can also be accurately calculated.

[0068] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0069] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A lead-acid battery protection device, characterized in that: include: Microcontroller, DCDC power supply, thermal fuse and lead-acid battery; The microcontroller is connected to the thermal cutoff fuse and the DCDC power supply; the thermal cutoff fuse is also connected to the lead-acid battery; The microcontroller is used to control the charging input, primary circuit output and secondary circuit output of the battery system; the DCDC power supply is used to provide an output voltage; The first output voltage is adjusted by the first sub-loop control circuit to output a 12V voltage and a current limited to 200mA; the second output voltage controls the adjustment of the second sub-loop control circuit to output a 12V voltage and a 6A current; the third output voltage is used to output a 5V voltage and a 500mA current to power the microcontroller; the microcontroller is also used to turn off the thermal fuse to turn off the charging and discharging functions of the lead-acid battery when an abnormality occurs in the battery system.

2. The lead-acid battery protection device according to claim 1, characterized in that: Also includes: A charging control circuit, a main loop control circuit, two secondary loop control circuits, a communication circuit, a temperature sensor, a battery voltage acquisition circuit, and a battery charge and discharge current acquisition circuit connected to the microcontroller; The DCDC power supply is respectively connected to the charging control circuit, the thermal fuse, the main loop control circuit and the secondary loop control circuit; The DCDC power supply includes a control circuit and a power supply circuit; the control circuit is connected to the two secondary loop control circuits; and the power supply circuit is connected to the microprocessor.

3. The lead-acid battery protection device according to claim 2, characterized in that: The control circuit specifically comprises: The charging control circuit is connected to the positive electrode of the diode D1 and one end of the thermistor RT1; the negative electrode of the diode D1 is connected to one end of the capacitor C1, one end of the capacitor C2, one end of the resistor R1 and the second end of the switch tube Q1; the other end of the thermistor RT1, the other end of the capacitor C1 and the other end of the capacitor C2 are grounded; the first end of the switch tube Q1 is connected to the positive electrode of the diode D2 and one end of the resistor R2; the negative electrode of the diode D2 is connected to the 9th interface of the first controller; the other end of the resistor R2 is connected to the 1st interface of the first controller; the third end of the first switch tube Q1 is connected to one end of the first parallel structure, the 8th interface of the first controller and the negative electrode of the Schottky diode; the positive electrode of the Schottky diode is grounded; The other end of the resistor R1 is connected to one end of the resistor R3, one end of the capacitor C3 and the second interface of the first controller; the other end of the resistor R3 is connected to the cathode of the diode D3; the other end of the capacitor C3 is connected to one end of the capacitor C4, one end of the resistor R4, one end of the resistor R5, one end of the resistor R6, the other end of the first parallel structure, one end of the inductor L1 and the sixth interface and the seventh interface of the first controller; the positive electrode of the capacitor D3 is connected to the other end of the resistor R5, the other end of the inductor L1 and the first end of the second parallel structure; the second end of the second parallel structure is grounded; the third end of the second parallel structure is connected to the two-way sub-loop control circuit and the microcontroller, and the third end of the second parallel structure is used to provide a 12V voltage to the two-way sub-loop control circuit and the microcontroller; the first parallel structure includes parallel resistors R8, R9, R10, R11 and R12; the parallel structure includes capacitors C5, C6, C7, C8 and resistor R13.

4. The lead-acid battery protection device according to claim 2, characterized in that: The first secondary loop control circuit specifically includes: The third end of the second parallel structure is connected to one end of the capacitor C9, one end of the resistor R14 and the source of the switch tube Q2; the other end of the capacitor C9 is connected to one end of the resistor R15, the other end of the resistor R14 and the gate of the switch tube Q2; the other end of the resistor R15 is connected to the source of the switch tube Q3; the gate of the switch tube Q3 is connected to one end of the resistor R16 and one end of the resistor R17; the drain of the switch tube Q3 is connected to the other end of the resistor R16 and is grounded; The drain of the switch tube Q3 is connected to one end of the capacitor C10, one end of the resistor R18 and the third interface of the second controller; the other end of the capacitor C10 is grounded; the other end of the resistor R18 is connected to one end of the resistor R19 and the first interface of the second controller; the other end of the resistor R19 is connected to the second interface and the fourth interface of the second controller; The 12V voltage is adjusted by the first secondary loop control circuit to output a 12V voltage and a current limited to 200mA.

5. The lead-acid battery protection device according to claim 2, characterized in that: The second secondary loop control circuit specifically includes: The third end of the second parallel structure is connected to one end of the capacitor C12, one end of the resistor R20 and the source of the switch tube Q4; the other end of the capacitor C12 is connected to the other end of the resistor R20, one end of the resistor R21 and the gate of the switch tube Q4; the drain of the switch tube Q4 is connected to one end of the capacitor C12 and one end of the capacitor C13; the other end of the capacitor C12 and the other end of the capacitor C13 are grounded; The other end of the resistor R21 is connected to the source of the switch tube Q5; the gate of the switch tube is connected to one end of the resistor R22 and one end of the resistor R23; the drain of the switch tube Q5 is connected to the other end of the resistor R22 and is grounded.

6. The lead-acid battery protection device according to claim 2, characterized in that: The power supply circuit specifically comprises: The third end of the second parallel structure is connected to the positive electrode of the diode D4; the negative electrode of the diode D4 is connected to the second end of the variable resistor D5, one end of the capacitor C14, one end of the capacitor C15, one end of the resistor R24 ​​and the fifth interface of the third controller; the first end of the variable resistor D5, one end of the capacitor C14 and one end of the capacitor C15 are grounded; the other end of the resistor R24 ​​is connected to one end of the capacitor C16 and the fourth interface of the third controller; the other end of the capacitor C16 is grounded; The sixth interface of the third controller is connected to one end of the inductor L2 and one end of the capacitor C17; the other end of the capacitor C7 is connected to the first interface of the third controller; the other end of the inductor L2 is connected to one end of the resistor R25, one end of the capacitor C18, one end of the capacitor C19 and one end of the capacitor C20; the other end of the capacitor C19 and the other end of the capacitor C20 are connected and grounded; The other end of the resistor R25 is connected to the other end of the capacitor C18, the third interface of the third controller, and one end of the resistor R26; the other end of the resistor R26 is grounded.

7. The lead-acid battery protection device according to claim 2, characterized in that: When the charging control circuit is working, the microprocessor communicates with the charging control circuit, and the microprocessor closes the charging switch in the charging control circuit to supply power to the lead-acid battery.

8. The lead-acid battery protection device according to claim 7, characterized in that: The charging switch is a normally open relay; the microcontroller periodically detects whether the charging switch is abnormal.

9. The lead-acid battery protection device according to claim 2, characterized in that: The microprocessor collects the temperature of the temperature sensor in real time. When the temperature of the temperature sensor is greater than a set temperature, it is determined that an abnormality occurs in the protection system, and the thermal cutoff fuse blows to prevent the lead-acid battery from continuously discharging.

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