Car lithium battery intelligent control board

Abstract

The invention relates to an on-vehicle lithium battery intelligent control board, which comprises IC1 and IC2 chips and peripheral components to form a lithium battery protection board, wherein the positive input terminal and the negative input terminal of the lithium battery protection board are respectively connected to the positive terminal and the negative terminal of the lithium battery, and a switch circuit composed of field effect tubes T100 and T101 and peripheral components is also connected in series between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, and the lithium battery protection board controls the on-off of charging and discharging, and a charging current sensor is connected between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, and the positive input terminal and the negative input terminal of the variable load charging management circuit are connected to the positive terminal of the lithium battery and the negative input terminal of the lithium battery of the protection board, and the charging current sampling terminal thereof is connected to the negative terminal of the lithium battery, and the output terminal thereof is connected to the charging control terminal of the lithium battery protection board. The invention uses an electronic circuit to be connected to an existing lithium battery protection board circuit, and together solves the problem that an automobile generator charges a large-capacity lithium battery pack, so that the automobile generator runs at full load for a long time, and the generator is overheated and damaged under specific high temperature environmental conditions.

Description

Technical Field

[0001] The invention relates to a vehicle lithium battery control system, in particular to an on-vehicle lithium battery intelligent control panel. Background Art

[0002] Truck drivers live in their vehicles for a long time during long-distance transportation, especially when resting in the car at night. In summer, they need external air conditioning for cooling, and often carry other household appliances. However, when the vehicle is parked for a rest, the lead-acid battery of the vehicle cannot meet the daily electricity needs, and it is easy to run out of battery power. As a result, the vehicle cannot be started normally the next day, which brings many inconveniences to the truck driver and even affects road safety, causing great trouble.

[0003] For this reason, the current conventional practice is to use lithium batteries to replace the original lead-acid batteries. Lithium batteries are used for automotive energy storage. Compared with lead-acid batteries, lead-acid batteries are not durable, which causes truck drivers to basically spend money to replace lead-acid batteries every two years. At the same time, lead-acid batteries cannot fully meet the daily 8-10 hours or even longer air conditioning power supply of large truck drivers, and at the same time meet the needs of daily electricity consumption. The newly replaced lead-acid batteries can temporarily meet the needs for a period of time. This satisfaction is a temporary satisfaction replaced by the service life of the lead-acid battery, which is even more a state of putting the cart before the horse. The use of lithium batteries can change the above phenomenon, help users reduce the cost of use, and meet the needs at the same time; its high energy density, small size, and light weight have attracted attention, and it can store the idle power generation capacity of automobile generators, which can be used to add on-board electrical appliances, improve driving comfort, and facilitate travel life. There is a wide range of application space and huge market demand, such as large trucks with on-board air conditioners, carrying electric appliances for boiling water and cooking, and during long-distance operations, parking and resting time periods, drivers can enjoy their daily electricity consumption.

[0004] In recent years, many players have used lithium batteries for automotive energy storage, but none of them have done a good job. Some have damaged the car's electrical appliances, such as burning the generator, burning the circuit, burning the lithium battery, and some have run out of power and been unable to start the car, and so on.

[0005] The main reasons for the above-mentioned negative impacts are:

[0006] (1) The matching problem between the car generator and the lithium battery. The original car battery is lead-acid, with a small capacity and soft charging characteristics. The charging voltage is easy to rise and the charging current is easy to drop. The generator enters the light load state soon after running at full load. The car generator is designed based on the specific high temperature conditions of the car's use environment, and can run reliably at full load for a short time. Therefore, the car generator cannot run continuously for a long time under specific high temperature conditions. After installing a large-capacity lithium battery, the charging characteristics of the lithium battery are relatively hard, and the voltage does not rise for a long time, which makes the car generator run at full load for a long time. The lower the output voltage of the car generator, the greater the output current, and the more heat the generator generates. When the ambient temperature is low, there is no big problem. Under specific high temperature conditions, the generator will overheat and be damaged.

[0007] (2) Damage to the voltage regulator of the car generator further burns the car circuit. Failure of the voltage regulator will cause the power generation voltage to be out of control. The voltage regulator inside the car generator is the most vulnerable component. After the voltage regulator is damaged due to overheating or other factors, if the generator is connected to a lead-acid battery, the fault can be expanded to the point where the battery is damaged and the car cannot start. Only the generator needs to be repaired and the battery replaced; if the damaged car generator is connected to a lithium battery, the charging will be terminated when the lithium battery is fully charged, that is, it will be separated from the generator in the charging circuit. At this time, the generator voltage will exceed 100V, which will damage other car electrical appliances and the lithium battery protection board, and then damage the lithium battery.

[0008] (3) Truck drivers often carry other electrical appliances and rely on conventional lithium batteries to meet their daily electricity needs. This can easily cause the lithium battery to run out of power. The voltage is insufficient and the lithium battery cannot meet the starting requirements. The vehicle cannot start normally, causing a lot of inconvenience to the truck driver and even affecting road safety, which will cause great trouble.

[0009] Conventional 24V lithium iron phosphate battery control board such as Figure 1 As shown, V1-V8 are 8 single lithium batteries, two BM3451 chips and their peripheral components form a lithium battery protection board, P+ and P- are common ports for charging and discharging of lithium batteries, and field effect transistors T100 and T101 are turned on in the charging or discharging state. When fully charged, the chip controls T100 to turn off and stop charging. When the power is exhausted, the chip controls T101 to turn off and terminate discharge.

[0010] In response to this problem, some people have previously suggested replacing it with a larger generator, but the car generator is installed on the engine, and its surroundings are very compact, making it difficult to accommodate the structural space for a larger model. Moreover, the combination of the car engine and the generator is almost unique in terms of appearance and structure, and other appearances cannot be installed.

[0011] Based on the above factors, the lithium battery pack composed of lithium batteries and protection boards currently on the market is not suitable for application in automobile starting and energy storage. Summary of the invention

[0012] The purpose of the present invention is to provide an intelligent control board for a vehicle-mounted lithium battery, which uses an electronic circuit and an existing lithium battery protection board to solve the problem that when a car generator charges a large-capacity lithium battery pack, the car generator runs at full load for a long time, which may cause the generator to overheat and be damaged under specific high temperature environmental conditions.

[0013] To achieve the above purpose, the following technical solutions are adopted:

[0014] A vehicle-mounted lithium battery intelligent control board includes IC1 and IC2 chips and peripheral components to form a lithium battery protection board, wherein the positive input terminal and the negative input terminal of the lithium battery protection board are respectively connected to the positive terminal and the negative terminal of the lithium battery, and a switching circuit composed of field effect tubes T100 and T101 and peripheral components is also connected in series between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, and the lithium battery protection board controls the on-off of charging and discharging, and is characterized in that: a charging current sensor is connected between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, the positive input terminal and the negative input terminal of the variable load charging management circuit are connected to the positive terminal of the lithium battery and the negative input terminal of the lithium battery of the protection board, the charging current sampling terminal of the variable load charging management circuit is connected to the negative terminal of the lithium battery, and the output terminal of the variable load charging management circuit is connected to the charging control terminal of the lithium battery protection board.

[0015] The variable load charging management circuit uses the negative input terminal of the lithium battery of the protection board as the zero potential terminal, the resistance of the connecting line between the zero potential terminal and the negative terminal of the lithium battery is the charging current detection resistor R0, the negative terminal of the lithium battery is also connected to the resistor R108, the other end of the resistor R108 is connected to the resistor R107, the positive input terminal of the operational amplifier IC101 and the cathode of the diode D104, the anode of the diode D104 and the other end of the resistor R107 are connected to the zero potential terminal, the output terminal and the reverse input terminal of the operational amplifier IC101 are connected to the resistor R105, the reverse input terminal is also connected to the resistor R106 and the thermistor RT, the other end of the resistor R106 and the thermistor RT are connected to the zero potential terminal, the output terminal of the operational amplifier IC101 is connected to the resistor R103, and is also connected to the resistor R102, and the other end of the resistor R102 is connected to the diode D 103 cathode, the other end of resistor R103 and the anode of diode D103 are connected to the reverse input end of operational amplifier IC102, the positive end of the lithium battery is connected to resistor R109, the other end of resistor R109 is connected to the positive power supply of operational amplifier IC101 and resistor R101, the other end of resistor R101 is connected to the positive input end of operational amplifier IC102 and resistor R100, the positive input end of operational amplifier IC102 and the zero potential end are connected in parallel with resistor R104, the reverse input end of operational amplifier IC102 and the zero potential end are connected in parallel with capacitor C101, and the negative power supply of operational amplifier IC102 is connected to the zero potential end; the other end of the resistor R100 is connected to the output end of operational amplifier IC102 and the cathode of diode D102, and the anode of diode D102 is connected to the charging control of the lithium battery protection board.

[0016] A voltage runaway protection circuit is also connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board.

[0017] The voltage out-of-control protection circuit includes a voltage stabilizing protection circuit and a discharge and alarm circuit. The voltage stabilizing protection circuit includes a voltage stabilizing tube D112, a voltage stabilizing tube D113, a voltage stabilizing tube D115, a diode D114, a diode D116, a resistor R119, a resistor R120, a resistor R121, a transistor T106 and a relay J101. The cathodes of the voltage stabilizing tubes D112 and D115 are connected to the positive input end of the lithium battery protection board, the anode of the voltage stabilizing tube D112 is connected to the negative input end of the lithium battery protection board, the anode of the voltage stabilizing tube D115 is connected to the anode of the diode D114, the cathode of the voltage stabilizing tube D113 and the resistor R119, the anode of the voltage stabilizing tube D113 and the other end of the resistor R119 are connected to the negative input end of the lithium battery protection board, and the cathode of the diode D114 is connected to the resistor R120. 0, the other end of the resistor R120 is connected to the gate of the field effect tube T107, and a resistor R121 and a capacitor C105 are connected in parallel between the gate of the field effect tube T107 and the negative input terminal of the lithium battery protection board; the drain of the field effect tube T107 is connected to the anode of the relay J101 and the diode D116, the other end of the relay J101 and the cathode of the diode D116 are connected to the positive input terminal of the lithium battery protection board, and the alarm circuit is connected between the positive input terminal and the negative input terminal of the lithium battery protection board. The alarm circuit includes a control switch K101 of the relay J101, one end of the control switch K101 is connected to the positive input terminal of the lithium battery protection board, and the other end of the control switch K101 is connected to the speaker and one end of the resistor R122, and the other end of the speaker and the resistor R122 is connected to the negative input terminal of the lithium battery protection board.

[0018] A pre-discharge management circuit is also connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board.

[0019] The pre-discharge management circuit includes an optocoupler, a triode, a field effect transistor, a plurality of resistors, a self-reset start button and a capacitor. The positive input end of the lithium battery protection board is connected to the optocoupler G100, the resistor R123, the resistor R110, the resistor R116, the anode of the diode D111 and the cathode of the voltage regulator tube D106. The other end of the optocoupler G100 and the resistor R123 is connected to the resistor R114. The other end of the resistor R114 is connected to the drain of the field effect tube T104. The source of the field effect tube T104 is connected to the cathode of the diode D109. The gate of the field effect tube T104 is connected to the anode of the voltage regulator tube D107 and the resistor R112. The other end of the resistor R112 is connected to the cathode of the diode D109. The cathode of the voltage regulator tube D107 is connected to the capacitor C103, the resistor R113, the resistor R110 and the drain of the field effect tube T103; the cathode of the diode D111 is connected to the resistor R117, the capacitor C104 and The emitter of transistor T106 and the other end of capacitor C104 are connected to the zero potential end, the other end of resistor R117 is connected to resistor R116 and the base of transistor T106, the collector of transistor T106 is connected to resistor R118, the other end of resistor R118 is connected to the anode of voltage regulator D106, the gate of field effect transistor T103 and resistor R111, the other end of resistor R111 is connected to the source of field effect transistor T103 and the cathode of diode D109, the cathode of diode D109 is connected to the anode of diode D108, the cathode of diode D108 is connected to the zero potential end and resistor R115, the other end of resistor R115 is connected to the base of transistor T105, the collector of transistor T105 is connected to resistor R113, the emitter of transistor T105 is connected to the anode of diode D110, and the cathode of diode D110 is connected to the negative input end of the lithium battery protection board.

[0020] The present invention selects a suitable connection line between the zero potential end and the negative electrode of the lithium battery as a charging current detection resistor, and the current sampling end is at the negative electrode terminal of the lithium battery V1;

[0021] When the electronic circuit of the present invention detects that the charging current is very large, a set of signals is given to the lithium battery protection board to allow it to charge and stop charging for about 50% of the time;

[0022] When the electronic circuit of the present invention detects that the charging current is relatively large, a group of signals is given to the lithium battery protection board to charge the battery for about 75% of the time, and the charging is stopped for about 25%. As the charging current decreases, the charging stop time also decreases.

[0023] When the electronic circuit of the present invention detects that the charging current is small, no signal is given to the lithium battery protection board, and the lithium battery protection board manages it by itself;

[0024] The ambient temperature information detected by the electronic circuit of the present invention is used to adjust the time ratio between charging and stopping charging, and the higher the temperature, the shorter the charging time;

[0025] The maximum adjustment amount of the charging stop time during the high-current charging is about 50%. Combined with the power load of the automobile electrical appliances, the automobile generator can be reduced by about 30%. Due to the continuous change of the automobile load, the charging current is also constantly changing, and there is a certain difference in the control time. This difference does not affect the operation of the whole vehicle and can meet the requirements of the generator load reduction adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a circuit schematic diagram of a lithium battery protection board in the prior art;

[0027] Figure 2 The schematic diagram of the circuit of the lithium battery intelligent control board of the present invention is shown in FIG. DETAILED DESCRIPTION

[0028] like Figure 2 As shown, an on-vehicle lithium battery intelligent control board includes IC1 and IC2 chips and their peripheral components to form a lithium battery protection board, the positive input terminal and the negative input terminal of the lithium battery protection board are respectively connected to the positive terminal and the negative terminal of the lithium battery, and a switching circuit composed of field effect tubes T100 and T101 and peripheral components is also connected in series between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery. The lithium battery protection board controls the on-off of charging and discharging, a charging current sensor is connected between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, the positive input terminal and the negative input terminal of the variable load charging management circuit are connected to the positive terminal of the lithium battery and the negative input terminal of the lithium battery of the protection board, the charging current sampling terminal of the variable load charging management circuit is connected to the negative terminal of the lithium battery, and the output terminal of the variable load charging management circuit is connected to the charging control terminal of the lithium battery protection board.

[0029] The variable load charging management circuit uses the negative input terminal of the lithium battery of the protection board as the zero potential terminal, the resistance of the connecting line between the zero potential terminal and the negative terminal of the lithium battery is the charging current detection resistor R0, the negative terminal of the lithium battery is also connected to the resistor R108, the other end of the resistor R108 is connected to the resistor R107, the positive input terminal of the operational amplifier IC101 and the cathode of the diode D104, the anode of the diode D104 and the other end of the resistor R107 are connected to the zero potential terminal, the output terminal and the reverse input terminal of the operational amplifier IC101 are connected to the resistor R105, the reverse input terminal is also connected to the resistor R106 and the thermistor RT, the other end of the resistor R106 and the thermistor RT are connected to the zero potential terminal, the output terminal of the operational amplifier IC101 is connected to the resistor R103, and is also connected to the resistor R102, and the other end of the resistor R102 is connected to the diode D 103 cathode, the other end of resistor R103 and the anode of diode D103 are connected to the reverse input end of operational amplifier IC102, the positive end of the lithium battery is connected to resistor R109, the other end of resistor R109 is connected to the positive power supply of operational amplifier IC101 and resistor R101, the other end of resistor R101 is connected to the positive input end of operational amplifier IC102 and resistor R100, the positive input end of operational amplifier IC102 and the zero potential end are connected in parallel with resistor R104, the reverse input end of operational amplifier IC102 and the zero potential end are connected in parallel with capacitor C101, and the negative power supply of operational amplifier IC102 is connected to the zero potential end; the other end of the resistor R100 is connected to the output end of operational amplifier IC102 and the cathode of diode D102, and the anode of diode D102 is connected to the charging control of the lithium battery protection board.

[0030] (1) The negative input terminal of the lithium battery intelligent control board, that is Figure 2 The port on the side of Rsense that connects Rsense and the negative electrode of the lithium battery V1 is the zero potential end. Select a suitable zero potential end and the connection line of the negative electrode of the lithium battery V1 as the charging current detection resistor. The current sampling end is at the negative electrode terminal of the lithium battery V1.

[0031] (2) When the electronic circuit of the present invention detects that the charging current is very large, a set of signals is given to the lithium battery protection board to allow it to charge and stop charging for about 50% of the time;

[0032] (3) When the electronic circuit of the present invention detects that the charging current is relatively large, a set of signals is sent to the lithium battery protection board to allow it to charge for about 75% of the time, and the charging is stopped for about 25% of the time. As the charging current decreases, the charging stop time also decreases;

[0033] (4) When the electronic circuit of the present invention detects that the charging current is small, no signal is given to the lithium battery control board, and the lithium battery protection board manages it by itself;

[0034] (5) Using the ambient temperature information detected by the electronic circuit of the present invention to adjust the time ratio between charging and stopping charging, the higher the temperature, the shorter the charging time;

[0035] (6) The maximum adjustment amount of the stop charging time during the high current charging is about 50%. Combined with the power load of the automobile electrical appliances, the automobile generator can be reduced by about 30%. Due to the continuous change of the automobile load, the charging current is also constantly changing, and there is a certain difference in the control time. This difference does not affect the operation of the whole vehicle and can meet the requirements of the generator load reduction regulation.

[0036] R0 is the charging current detection resistor, which is connected to the zero potential end of the lithium battery intelligent control board and the negative terminal of the lithium battery V1. The charging current flows from the negative terminal of the lithium battery V1 to the zero potential end of the lithium battery intelligent control board through R0. The voltage drop generated by R0 is divided by R108 and R107 and added to the input terminal of the operational amplifier IC101+. R106, RT, and R105 determine the amplification factor. Select appropriate R0, R108, R107, RT, R105, and R106. 06. The charging current changes from 0 to 50A, and the voltage at the output end of IC101 changes from about 0 to 20V. Then, through R100, R101, R102, R103, R104, R105, C101, D102, D103, and IC102, a charging stop signal can be generated. That is, when the electronic circuit of the present invention detects that the charging current is very large (about 60A or more), a group of signals are given to the lithium battery protection board to charge and stop charging. The time is about 50% each; when the electronic circuit described in the present invention detects a large charging current (about 40-50A), a group of signals are given to the lithium battery protection board to allow it to charge for about 75% of the time, and the charging is stopped for about 25% of the time; when the electronic circuit described in the present invention detects a small charging current (below about 40A), no control signal is given to the lithium battery, and the lithium battery protection board manages it by itself; the charging stop signal generated by IC102 controls the 3-pin COIN of the BM3451 chip through D102, and the end turns off its 11-pin CO output voltage, thereby turning off T100 and stopping charging; the negative temperature coefficient thermistor RT, the higher the ambient temperature, the smaller the resistance, the greater the current amplification factor of IC101, and the longer the charging is stopped; when the lithium battery stops charging suddenly, the normal generator will also generate a certain short-term impact voltage, and the parallel C106 can absorb a large part of it. By selecting a suitable capacity, the requirements for automobile power supply can be met.

[0037] The present invention also has a voltage runaway protection circuit connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board; when the voltage of the automobile generator is out of control, it is generally because the excitation current of the voltage regulator cannot be adjusted and is directly turned on. When the lithium battery intelligent control board is in the charging state, it will not be affected. The generator is only generating electricity at full load. When the lithium battery is fully charged and stops charging, the generator load is suddenly reduced and the voltage will have different rising amplitudes according to the load size at that time. The smaller the load, the higher the voltage, which may exceed 100V, and it is continuous for a long time, which will damage other automobile electrical appliances, and also damage the lithium battery protection board, and then damage the lithium battery. The present invention uses electronic circuits and existing lithium battery protection boards to provide a solution to this fault: a method for protecting the voltage of an on-board lithium battery automobile generator from runaway;

[0038] The voltage out-of-control protection circuit includes a voltage stabilizing protection circuit and an alarm circuit. The voltage stabilizing protection circuit includes a voltage stabilizing tube D112, a voltage stabilizing tube D113, a voltage stabilizing tube D115, a diode D114, a diode D116, a resistor R119, a resistor R120, a resistor R121, a transistor T107 and a relay J101. The cathodes of the voltage stabilizing tubes D112 and D115 are connected to the positive input end of the lithium battery protection board, the anode of the voltage stabilizing tube D112 is connected to the negative input end of the lithium battery protection board, the anode of the voltage stabilizing tube D115 is connected to the anode of the diode D114, the cathode of the voltage stabilizing tube D113 and the resistor R119, the anode of the voltage stabilizing tube D113 and the other end of the resistor R119 are connected to the negative input end of the lithium battery protection board, the cathode of the diode D114 is connected to the resistor R120, the resistor R121 is connected to the negative input end of the lithium battery protection board, and the cathode of the diode D114 is connected to the resistor R120. The other end of R120 is connected to the gate of the field effect tube T107, and a resistor R121 and a capacitor C105 are connected in parallel between the gate of the field effect tube T107 and the negative input terminal of the lithium battery protection board; the drain of the field effect tube T107 is connected to the anode of the relay J101 and the diode D116, and the other end of the relay J101 and the cathode of the diode D116 are connected to the positive input terminal of the lithium battery protection board, and the alarm circuit is connected between the positive input terminal and the negative input terminal of the lithium battery protection board. The alarm circuit includes a control switch K101 of the relay J101, one end of the control switch K101 is connected to the positive input terminal of the lithium battery protection board, and the other end of the control switch K101 is connected to the speaker and one end of the resistor R122, and the other end of the speaker L101 and the resistor R122 is connected to the negative input terminal of the lithium battery protection board.

[0039] When the lithium battery is fully charged and charging is terminated or the lithium battery intelligent control board changes load and stops charging, transistor T100 is turned off, and the generator output voltage rises rapidly. The voltage regulator diodes D115 and D113 have a total voltage regulation value of about 35V. When the voltage rises above 35V, the voltage on R119 is about 5V, which charges C105 through D114 and R120. At the same time, transistor T107 is turned on, relay J101 is energized, and its contact K101 is closed. The current of the generator is discharged through R122, and the alarm horn L101 sounds an alarm. The parameters of C105 and R121 determine the maintenance relay opening time. After a few minutes, T107 is turned off. Since the discharge current of R122 is greater than the power generation current of the generator, part of the lithium battery current can also be discharged. After T107 is turned off, the generator can charge the lithium battery again, and this cycle continues. The driver stops the car immediately after hearing the alarm, and turns on the on-board electrical discharge for a period of time, and then it can be driven, and then repaired.

[0040] After parking, if some onboard electrical appliances are forgotten to be turned off, or other electrical appliances are used, the lithium battery may be accidentally exhausted and the car cannot be started, which will cause great trouble. The present invention uses electronic circuits and existing lithium battery protection boards to provide a solution to this unexpected phenomenon: a pre-discharge management method in a lithium battery intelligent control board.

[0041] A pre-discharge management circuit is also connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board; the pre-discharge management circuit includes an optocoupler, a triode, a field effect transistor, a plurality of resistors, a self-reset start button and a capacitor. The positive input terminal of the lithium battery protection board is connected to the optocoupler G100, the resistor R123, the resistor R110, the resistor R116, the anode of the diode D111 and the cathode of the voltage regulator tube D106, and the other end of the optocoupler G100 and the resistor R123 is connected to the resistor R114, the other end of the resistor R114 is connected to the drain of the field effect transistor T104, the source of the field effect transistor T104 is connected to the cathode of the diode D109, the gate of the field effect transistor T104 is connected to the anode of the voltage regulator tube D107 and the resistor R112, the other end of the resistor R112 is connected to the cathode of the diode D109, the cathode of the voltage regulator tube D107 is connected to the capacitor C103, the resistor R113, the resistor R110 and the drain of the field effect transistor T103; the diode D111 The cathode is connected to the resistor R117, the capacitor C104 and the emitter of the transistor T106, the other end of the capacitor C104 is connected to the zero potential end, the other end of the resistor R117 is connected to the resistor R116 and the base of the transistor T106, the collector of the transistor T106 is connected to the resistor R118, the other end of the resistor R118 is connected to the anode of the voltage regulator tube D106, the gate of the field effect tube T103 and the resistor R111, and the other end of the resistor R111 is connected to the field effect tube T10 3 is connected to the source of transistor T105 and the cathode of diode D109, the cathode of diode D109 is connected to the anode of diode D108, the cathode of diode D108 is connected to the zero potential end and resistor R115, the other end of resistor R115 is connected to the base of transistor T105, the collector of transistor T105 is connected to resistor R113, the emitter of transistor T105 is connected to the anode of diode D110, and the cathode of diode D110 is connected to the negative input terminal of lithium battery protection board.

[0042] The discharge termination voltage of the lithium iron phosphate battery pack is about 20V. Since the generator starting current is very large, in order to meet the requirements of multiple starts, about 10% of the power must be reserved, that is, at a threshold voltage of about 25V, the discharge is terminated in advance. When the engine needs to be started or other electricity is needed for a short time, pressing the start button of the lithium battery can supply power for a few minutes to complete the engine start operation; when the lithium battery voltage is higher than 25V, the voltage regulator D106 is turned on, T103 is turned on, and T104 is turned off. This circuit does not affect the original lithium battery The operation of the protection board, when the lithium battery voltage is lower than 25V, T103 is turned off, and the lithium battery charges C103 through R110. After C103 reaches a certain voltage, D107 is turned on, and T104 is also turned on. The voltage of P+ forms a current through the optocoupler G100, R114, T104, and D108. The G100 transistor is partially turned on, short-circuiting the emitter junction of P1, turning off P1, and the discharge signal of the DO pin of the IC2 chip is cut off. The IC1 chip DOIN cannot get the discharge signal, so its DO output signal is turned off. Turn off T101 to shut down the lithium battery in advance; when you need to use electricity temporarily, press the K102 self-reset start button, the charge of C103 is released through R113 and K102, T104 is turned off, the protection board turns on T101, and the lithium battery control board resumes power supply; after releasing the button, the lithium battery charges C103 through R110 again, and after a few minutes, it reaches a certain voltage. D107 turns on, T104 turns on, and the lithium battery protection board turns off the power supply again, and this cycle repeats; once the engine is started, the large current of the starter will cause the lithium battery to be significantly The voltage is reduced (greater than 2V), and the charge in C104 is discharged to the lithium battery through the emitter junction of T106 and R116, thereby turning on T106. The charge in C104 is then turned on T103 through T106 and R118, releasing the charge just charged by C103, which further extends the power recovery time. After turning off the starter, the lithium battery voltage will recover, and the lithium battery will charge C104 through D111. When the next start is started, T103 will be turned on to discharge C103. If the engine is started multiple times in a row, the lithium battery control board will continue to supply power.

[0043] If the engine is started, the generator is running, and the lithium battery is in a charging state, if T101 is still turned off, the charging current will pass through D101 of T101 and cause a voltage drop. Long-term operation will damage T101. The present invention transfers this voltage drop through R115, T105, and D110, turns on T105, and releases the charge in C103 through R113, T104, and D109. T104 turns off and T101 turns on, and normal charging begins. The voltage slowly rises, and this cycle continues. When the voltage exceeds a threshold voltage of about 25V, the pre-discharge management stops running, and the lithium battery enters a normal charge and discharge state.

Claims

1. An on-board lithium battery intelligent control board, including IC1 and IC2 chips and their peripheral components to form a lithium battery protection board, the positive input terminal and the negative input terminal of the lithium battery protection board are respectively connected to the positive terminal and the negative terminal of the lithium battery, and a switch circuit composed of field effect tubes T100 and T101 and peripheral components is also connected in series between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery. The lithium battery protection board controls the on and off of charging and discharging, and is characterized in that: A charging current sensor is connected between the negative input terminal of the lithium battery protection board and the negative terminal of the lithium battery, the positive input terminal and the negative input terminal of the variable load charging management circuit are respectively connected to the positive terminal of the lithium battery and the negative input terminal of the lithium battery of the protection board, the charging current sampling terminal of the variable load charging management circuit is connected to the negative terminal of the lithium battery, and the output terminal of the variable load charging management circuit is connected to the charging control terminal of the lithium battery protection board; a voltage runaway protection circuit is also connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board; The variable load charging management circuit uses the negative input terminal of the lithium battery of the protection board as the zero potential terminal, the resistance of the connecting line between the zero potential terminal and the negative terminal of the lithium battery is the charging current detection resistor R0, the negative terminal of the lithium battery is also connected to the resistor R108, the other end of the resistor R108 is connected to the resistor R107, the positive input terminal of the operational amplifier IC101 and the cathode of the diode D104, the anode of the diode D104 and the other end of the resistor R107 are connected to the zero potential terminal, the output terminal and the reverse input terminal of the operational amplifier IC101 are connected to the resistor R105, the reverse input terminal is also connected to the resistor R106 and the thermistor RT, the other end of the resistor R106 and the thermistor RT are connected to the zero potential terminal, the output terminal of the operational amplifier IC101 is connected to the resistor R103, and is also connected to the resistor R102, and the other end of the resistor R102 is connected to the diode D 103 cathode, the other end of the resistor R103 and the anode of the diode D103 are connected to the reverse input end of the operational amplifier IC102, the positive end of the lithium battery is connected to the resistor R109, the other end of the resistor R109 is connected to the positive power supply of the operational amplifier IC101 and the resistor R101, the other end of the resistor R101 is connected to the positive input end of the operational amplifier IC102 and the resistor R100, the resistor R104 is connected in parallel between the positive input end and the zero potential end of the operational amplifier IC102, the capacitor C101 is connected in parallel between the reverse input end and the zero potential end of the operational amplifier IC102, and the negative power supply of the operational amplifier IC102 is connected to the zero potential end; the other end of the resistor R100 is connected to the output end of the operational amplifier IC102 and the cathode of the diode D102, and the anode of the diode D102 is connected to the charging control of the lithium battery protection board; The voltage out-of-control protection circuit includes a voltage stabilizing protection circuit and a discharge and alarm circuit. The voltage stabilizing protection circuit includes a voltage stabilizing tube D112, a voltage stabilizing tube D113, a voltage stabilizing tube D115, a diode D114, a diode D116, a resistor R119, a resistor R120, a resistor R121, a transistor T106 and a relay J101. The cathodes of the voltage stabilizing tubes D112 and D115 are connected to the positive input end of the lithium battery protection board, the anode of the voltage stabilizing tube D112 is connected to the negative input end of the lithium battery protection board, the anode of the voltage stabilizing tube D115 is connected to the anode of the diode D114, the cathode of the voltage stabilizing tube D113 and the resistor R119, the anode of the voltage stabilizing tube D113 and the other end of the resistor R119 are connected to the negative input end of the lithium battery protection board, and the cathode of the diode D114 is connected to the resistor R120. 0, the other end of the resistor R120 is connected to the gate of the field effect tube T107, and a resistor R121 and a capacitor C105 are connected in parallel between the gate of the field effect tube T107 and the negative input terminal of the lithium battery protection board; the drain of the field effect tube T107 is connected to the anode of the relay J101 and the diode D116, the other end of the relay J101 and the cathode of the diode D116 are connected to the positive input terminal of the lithium battery protection board, and the alarm circuit is connected between the positive input terminal and the negative input terminal of the lithium battery protection board. The alarm circuit includes a control switch K101 of the relay J101, one end of the control switch K101 is connected to the positive input terminal of the lithium battery protection board, and the other end of the control switch K101 is connected to the speaker and one end of the resistor R122, and the other end of the speaker and the resistor R122 is connected to the negative input terminal of the lithium battery protection board.

2. The vehicle-mounted lithium battery intelligent control board according to claim 1, characterized in that: A pre-discharge management circuit is also connected in parallel between the positive input terminal and the negative input terminal of the lithium battery protection board.

3. The vehicle-mounted lithium battery intelligent control board as claimed in claim 2, characterized in that: The pre-discharge management circuit includes an optocoupler, a triode, a field effect transistor, a plurality of resistors, a self-reset start button and a capacitor. The positive input end of the lithium battery protection board is connected to the optocoupler G100, the resistor R123, the resistor R110, the resistor R116, the anode of the diode D111 and the cathode of the voltage regulator tube D106. The other end of the optocoupler G100 and the resistor R123 is connected to the resistor R114. The other end of the resistor R114 is connected to the drain of the field effect tube T104. The source of the field effect tube T104 is connected to the cathode of the diode D109. The gate of the field effect tube T104 is connected to the anode of the voltage regulator tube D107 and the resistor R112. The other end of the resistor R112 is connected to the cathode of the diode D109. The cathode of the voltage regulator tube D107 is connected to the capacitor C103, the resistor R113, the resistor R110 and the drain of the field effect tube T103; the cathode of the diode D111 is connected to the resistor R117, the capacitor C104 and The emitter of transistor T106 and the other end of capacitor C104 are connected to the zero potential end, the other end of resistor R117 is connected to resistor R116 and the base of transistor T106, the collector of transistor T106 is connected to resistor R118, the other end of resistor R118 is connected to the anode of voltage regulator D106, the gate of field effect transistor T103 and resistor R111, the other end of resistor R111 is connected to the source of field effect transistor T103 and the cathode of diode D109, the cathode of diode D109 is connected to the anode of diode D108, the cathode of diode D108 is connected to the zero potential end and resistor R115, the other end of resistor R115 is connected to the base of transistor T105, the collector of transistor T105 is connected to resistor R113, the emitter of transistor T105 is connected to the anode of diode D110, and the cathode of diode D110 is connected to the negative input end of the lithium battery protection board.

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