Battery pack control device based on self-locking protection

Abstract

The utility model provides a battery pack control device based on self-locking protection, which is connected with a battery pack formed by at least two batteries connected in parallel, and each battery in the battery pack forms a corresponding charging and discharging loop with a charger and a load respectively. Comprising a state identification unit and a self-locking unit, and the state identification unit is arranged on the charging and discharging loop of the corresponding battery. The control switch is used for replacing an isolation diode to control charging and discharging of the battery pack, the problems of energy utilization rate reduction and energy accumulation are avoided, meanwhile, in the running process, the running state of the battery is recognized, the on-off of the control switch is further controlled through the self-locking unit, the risk of mutual charging is avoided, and the service life of the battery pack is prolonged. And safe operation of the battery pack under abnormal conditions such as mutual charging of the battery pack is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery pack control technical field especially is the battery pack control device based on self locking protection. BACKGROUND

[0002] Traditional electronic equipment or electric product often only marks a battery pack, needs charging to recover its use ability after its electric quantity is exhausted. With the increase of charge and discharge cycle number, the actual capacity of battery will drop, leads to the emergence of battery not durable, for this, commonly through the mode for using spare battery pack, prolongs the continuous use time of equipment. But in actual operation process, cannot guarantee the consistency of the voltage of two battery packs installed together, along with the use of battery pack, easy to appear the situation that the voltage difference of two is big. And because the internal resistance of battery is milliohm level, smaller voltage difference can produce very big mutual charging current, exists the risk of battery burning and even explosion combustion, influences the use safety. For the multi-battery scene existing mutual charging risk, commonly through the mode for using diode to avoid the mutual charging phenomenon between two or more battery packs, but when the load current is big, the isolation diode will consume part of energy due to heat, leads to the decrease of energy utilization rate, when facing inductive load, also easy to cause energy accumulation because of the unidirectional conduction of diode, influences the operation safety. UTILIZATIONAL CONTENT

[0003] The utility model discloses a battery pack control device based on self locking protection to control switch instead of isolation diode control battery pack's charge and discharge, avoid the emergence of energy utilization rate reduction and energy accumulation problem, simultaneously in the operation process, to the battery operating state identification, and further through the self locking unit control switch's on-off control, avoid mutual charging risk, guarantee the operation safety of battery pack under the abnormal condition such as battery pack mutual charging.

[0004] The utility model discloses a battery pack control device based on self locking protection to control switch instead of isolation diode control battery pack's charge and discharge, avoid the emergence of energy utilization rate reduction and energy accumulation problem, simultaneously in the operation process, to the battery operating state identification, and further through the self locking unit control switch's on-off control, avoid mutual charging risk, guarantee the operation safety of battery pack under the abnormal condition such as battery pack mutual charging.

[0005] The battery pack control device based on self-locking protection is connected with a battery pack composed of at least two batteries in parallel, each battery in the battery pack is connected with a charger and a load to form a corresponding charging and discharging circuit, and the battery pack control device comprises control switches arranged on each charging and discharging circuit in the battery pack and a plurality of control sub-modules consistent with the number of batteries in the battery pack, each control sub-module comprises a state recognition unit and a self-locking unit, the state recognition unit is arranged on the charging and discharging circuit of the corresponding battery and electrically connected with the corresponding self-locking unit, the self-locking unit is also electrically connected with the control switch, the state recognition unit recognizes the running state of the battery pack by collecting electrical data on the charging and discharging circuit of the corresponding battery, and controls the self-locking unit to open or close the control switch to control the closing or opening of each charging and discharging circuit of the battery pack.

[0006] The on-resistance of the control switch is extremely low, and compared with the isolation diode for realizing charging and discharging control by using unidirectional conductivity, the energy loss is smaller, and the energy utilization rate can be effectively improved. Moreover, the control switch supports external signal control, and has higher control flexibility and accuracy, and can adapt to the change of the load to avoid the problem of energy accumulation due to the change of the load. At the same time, the state recognition unit is arranged to collect the electrical data of the battery in real time to accurately judge the running state of the battery pack, and once the abnormal condition such as mutual charging is detected, the self-locking unit will respond immediately to quickly cut off the corresponding charging and discharging circuit through the control switch to effectively prevent the battery from being damaged and ensure the safe operation of the battery pack.

[0007] Further, the state recognition unit at least comprises a detection element and a state recognition circuit, the detection element is arranged on the charging and discharging circuit of the corresponding battery, and the state recognition circuit is connected in parallel across the detection element to collect the electrical data on the charging and discharging circuit of the corresponding battery and recognize the running state of the battery pack.

[0008] Further, the state recognition unit at least comprises an operational amplifier, the first input end and the second input end of the operational amplifier are connected to the two ends of the detection element, and the output end of the operational amplifier is connected with the self-locking unit.

[0009] Further, each self-locking unit at least comprises a first triode and a second triode which are mutually self-locked, the base of the first triode and the collector of the second triode are connected to a first port, the first port is connected with the output end of the state recognition unit, and the emitter of the second triode is connected with the control end of the control switch.

[0010] The self-locking unit is arranged to control the control switch, and the self-locking function of the self-locking unit ensures that the control switch can be re-closed only when manual reset or specific conditions are met after triggering the shutdown action, thereby ensuring the safe operation of the battery pack.

[0011] Further, a voltage reduction circuit is further included, an input end of the voltage reduction circuit is connected with the positive pole of each battery in the battery pack, and an output end of the voltage reduction circuit is connected with the state recognition unit and the self-locking unit in each control sub-module respectively to provide corresponding working voltage.

[0012] Further, a voltage reduction circuit is further included, an input end of the voltage reduction circuit is connected with the positive pole of each battery in the battery pack, and an output end of the voltage reduction circuit is connected with the state recognition unit and the self-locking unit in each control sub-module respectively to provide corresponding working voltage.

[0013] Further, a protection unit is further included, the protection unit at least includes an anti-sparking circuit, an input end of the anti-sparking circuit is connected with the charger, and an output end of the anti-sparking circuit is connected with the positive pole of each battery in the battery pack through a corresponding isolation diode.

[0014] Further, the protection unit further includes a plurality of safety tubes consistent with the number of batteries in the battery pack, and each safety tube is connected in series with the positive pole of a corresponding battery.

[0015] The utility model discloses the beneficial effect is:

[0016] (1) the on-resistance of control switch is extremely low, compared with the isolation diode for realizing the charge and discharge control by using the unidirectional conductivity, the energy loss is smaller, and the energy utilization rate can be effectively improved.

[0017] (2) the self-locking unit is arranged to control the control switch, and the self-locking function of the self-locking unit ensures that the control switch can be re-closed only when manual reset or specific conditions are met after triggering the shutdown action, thereby ensuring the operation safety of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of the utility model.

[0019] Figure 2 is a charging current path schematic diagram of the battery pack in a normal state of the embodiment of the utility model.

[0020] Figure 3 is a discharging current path schematic diagram of the battery pack in a normal state of the embodiment of the utility model.

[0021] Figure 4is a discharge current path schematic diagram of a battery pack under an abnormal discharge state according to an embodiment of the utility model;

[0022] Figure 5 is a state recognition unit circuit schematic diagram according to an embodiment of the utility model;

[0023] Figure 6 is a self-locking unit circuit schematic diagram according to an embodiment of the utility model;

[0024] Figure 7 is a voltage reduction circuit schematic diagram according to an embodiment of the utility model;

[0025] Figure 8 is a control switch and its peripheral circuit schematic diagram according to an embodiment of the utility model;

[0026] Figure 9 is an energy recovery current path schematic diagram according to an embodiment of the utility model.

[0027] Mark in the drawing: 1, the control switch corresponding to battery A, 2, the control switch corresponding to battery B, 31, the state recognition unit corresponding to battery A, 311, the sampling resistance corresponding to battery A, 312, the operational amplifier corresponding to battery A, 32, the self-locking unit corresponding to battery A, 41, the state recognition unit corresponding to battery B, 411, the sampling resistance corresponding to battery B, 412, the operational amplifier corresponding to battery B, 42, the self-locking unit corresponding to battery B, 5, the anti-arcing circuit, 6, the isolation diode, 7, the safety tube corresponding to battery A, 8, the safety tube corresponding to battery B, 9, the charger, 10, the voltage reduction circuit, 11, the load. DETAILED DESCRIPTION

[0028] The utility model is further described below in combination with the drawings and embodiments.

[0029] Embodiment:

[0030] Please refer to Figure 1 , Figure 1 The battery pack control device provided by the embodiment takes the battery pack composed of battery A and battery B as an example, and provides a structural schematic diagram of the battery pack control device under a battery pack charging and discharging control scene.

[0031] The battery pack control device based on self-locking protection is connected with a battery pack composed of at least two batteries in parallel, each battery in the battery pack is connected with a charger and a load to form a corresponding charging and discharging circuit, and the battery pack control device comprises control switches arranged on each charging and discharging circuit in the battery pack and a plurality of control sub-modules consistent with the number of batteries in the battery pack, each control sub-module comprises a state recognition unit and a self-locking unit, the state recognition unit is arranged on the charging and discharging circuit of the corresponding battery and is electrically connected with the corresponding self-locking unit, the self-locking unit is also electrically connected with the control switch, the state recognition unit recognizes the running state of the battery pack by collecting electrical data on the charging and discharging circuit of the corresponding battery, and the self-locking unit is controlled to open or close the control switch, thereby controlling the closing or opening of each charging and discharging circuit in the battery pack.

[0032] For the battery pack with multiple batteries, each battery in the battery pack forms an independent charging and discharging circuit with the charger and the load, so that even if one of the batteries has a problem, the running of the entire battery pack will not be affected.

[0033] Considering that the voltage difference between the batteries in the battery pack is likely to be large during use of the battery pack, the control switches independent of each other are arranged in the charging and discharging circuits. Meanwhile, the state recognition unit is used to monitor the running state of the battery pack in real time, so that when the electrical data of one of the batteries is abnormal, the corresponding control switch can be closed in time to cut off the corresponding charging and discharging circuit, thereby ensuring the running safety.

[0034] The control switch can be a MOS tube, an IGBT element or the like, and can be controlled to be turned on or off according to an external signal. In this embodiment, an N-type MOS tube with a built-in diode is used as the circuit switch to omit an external diode, thereby further simplifying the circuit.

[0035] Further, the self-locking unit is arranged to control the control switch. The self-locking function of the self-locking unit ensures that after the control switch is triggered to be closed, the control switch can be closed again only when a manual reset is performed or a specific condition is met, thereby ensuring the running safety of the battery pack.

[0036] In combination Figure 1 with the structure shown in the structural schematic diagram, the battery pack including battery A and battery B is taken as an example. In a normal state, the charging current path and the discharging current path of the battery pack are as shown in Figure 2 and Figure 3 .

[0037] As shown in Figure 2 , in a normal charging state, the current flows out from the charger, enters the positive electrode of the battery after passing through the anti-sparking circuit and the isolation diode, and then flows out from the negative electrode of the battery back to the negative electrode of the charger, thereby forming a complete charging circuit.

[0038] As shown inFigure 3 It can be seen that under normal discharge conditions, after the battery is connected to the load, the control switch is turned on by default, the discharge circuit is closed, the current flows out from the positive terminal of the battery, enters the load after passing through the fuse, and then returns to the negative terminal of the battery after passing through the sampling resistor and the control switch.

[0039] In an abnormal discharge state, i.e., when mutual charging occurs and the voltage of battery A is higher than that of battery B, the discharge current path of the battery pack is as follows: Figure 4 As shown.

[0040] The status recognition unit includes at least a detection element and a status recognition circuit. The detection element is disposed on the charging and discharging circuit of the corresponding battery, and the status recognition circuit is connected in parallel across the two ends of the detection element to collect electrical data on the charging and discharging circuit of the corresponding battery and identify the operating status of the battery pack.

[0041] The status recognition unit can collect electrical data such as voltage and current on the charging and discharging circuit of the corresponding battery through detection elements, and then analyze and identify abnormal conditions based on the above data to realize the drive control of the self-locking circuit.

[0042] The detection element can be a sampling resistor, sampling capacitor, or other components.

[0043] In this embodiment, voltage value is specifically used as an identification parameter to determine the battery's operating status.

[0044] Based on this, the state recognition unit includes at least an operational amplifier, the first input terminal and the second input terminal of the operational amplifier are respectively connected to the two ends of the detection element, and the output terminal of the operational amplifier is connected to the self-locking unit.

[0045] Taking the status recognition unit installed on the charging and discharging circuit of one of the batteries, A, as an example, its overall circuit is as follows: Figure 5 As shown, it includes a sampling resistor R1, an operational amplifier U1, resistors R2, R3, R4, R5, R6, and R7, which are installed in the charging and discharging circuit of battery A.

[0046] Depend on Figure 5 It can be seen that the sampling resistor R1 is connected in series in the charging and discharging circuit of battery A. The MS1 terminal of the sampling resistor R1 is connected to the positive terminal of battery A, and the GND1 terminal of the sampling resistor R1 is connected to the negative terminal of battery A. The output terminal MS1_OUT of the operational amplifier U1 is the output terminal of the corresponding state recognition unit, which is connected to the corresponding self-locking unit.

[0047] Each of the self-locking units comprises at least a first triode and a second triode which are mutually self-locked, the base of the first triode and the collector of the second triode are connected to a first port, the first port is connected to the output of the state recognition unit, and the emitter of the second triode is connected to the control end of the control switch.

[0048] Taking the self-locking unit arranged on the charge-discharge circuit of one of the batteries A as an example, the overall circuit is as shown in the figure Figure 6 , which is composed of two triodes and related resistors and capacitors, and specifically comprises a first triode Q1, a second triode Q2, a resistor R8, a capacitor C1 and a capacitor C2.

[0049] As can be seen from the figure Figure 6 , the self-locking unit further combines the resistor R8, the capacitor C1 and the capacitor C2 to realize the mutual locking of the first triode Q1 and the second triode Q2, and the base of the first triode Q1 and the collector of the second triode Q2 are commonly connected to the first port, which is the node for the self-locking unit to interact with the external circuit and can receive the control signal from the corresponding state recognition unit, i.e., the first port is connected to the output MS1_OUT of the operational amplifier U1 to receive the control signal sent by the operational amplifier U1.

[0050] The emitter of the second triode Q2 is the output OCP1 of the self-locking unit and is connected to the control end of the control switch, which can output the control signal for controlling the on-off of the control switch.

[0051] The circuit structures of the state recognition units and the self-locking units arranged on the charge-discharge circuits of the remaining batteries are consistent with those of the state recognition unit of the battery A.

[0052] As can be seen from the figure Figures 1-6 , taking the battery A as an example, when the battery A is in a normal charging state, the charging current will flow from the negative electrode GND1 of the battery A to the ground GND, so the voltage V MS1 at the first input end of the operational amplifier in the corresponding state recognition unit of the battery A is greater than the voltage V GND at the second input end, and after amplification, it is also less than the set self-locking circuit opening voltage, so the self-locking circuit will not be triggered, and the control switch is opened by default.

[0053] However, when an abnormal condition occurs, i.e., the batteries A and B are in a mutual charging state, the voltage V BUS2 of the battery B is much greater than the voltage V BUS1 of the battery A, at this time, the current will flow out from the positive electrode MS2 of the battery B, flow into the positive electrode MS1 of the battery A, and then flow out from the negative electrode GND1 of the battery A, pass through the corresponding control switch and sampling resistor of the battery A, and then pass through the corresponding sampling resistor and control switch of the battery B, and finally return to the negative electrode GND2 of the battery B, at this time, the voltage V MS1Much greater than the voltage V at the second input terminal GND And the first input terminal V of the operational amplifier in the state recognition unit corresponding to battery B MS2 Less than the voltage V at the second input terminal GND After being amplified by the operational amplifier, the output voltage V of the state recognition unit corresponding to battery A is... MS1_out It will be greater than the set self-locking circuit opening voltage.

[0054] The output voltage V of the state recognition unit MS1_out When the voltage exceeds the set self-locking circuit activation voltage, the first transistor Q1 corresponding to battery A will be turned on, thereby pulling the base of the second transistor Q2 to a low level, thus turning on the second transistor Q2. Then, the base voltage of the first transistor Q1 will be pulled to a high level, realizing the interlocking of the two transistors and keeping the self-locking unit circuit in the open state. Then, the control terminal of the control switch corresponding to battery A will be pulled to a low level through the self-locking unit, so that the control switch will be turned off, realizing the disconnection of the corresponding charging and discharging circuit.

[0055] The input terminal of the step-down circuit is connected to the positive terminal of each battery in the battery pack, and the output terminal of the step-down circuit is connected to the status recognition unit and self-locking unit in each control submodule to provide the corresponding operating voltage.

[0056] The control submodules are powered directly by the battery's charge. Taking a battery pack including battery A and battery B as an example, the corresponding step-down circuit is as follows: Figure 7 As shown, the circuit includes a step-down chip U2, diodes D1, D2, and D3, resistor R9, voltage regulator capacitors C3, C4, C5, and C6. The step-down circuit reduces the battery voltage to VCC to power the control switches and various control submodules.

[0057] The control switch is also connected to a voltage divider element, and the control terminal of the control switch is connected to the output terminal of the step-down circuit and ground through the corresponding voltage divider element.

[0058] A voltage divider element is used to further provide the required voltage for the control switch to turn on and off. Taking the control switch corresponding to battery A as an example, its control switch and its peripheral circuit are as follows: Figure 8 As shown, it includes control switch Q. A Resistors R10 and R11 are used, where the gate of the control switch is its control terminal, which is connected to the self-locking unit.

[0059] To further ensure the safe operation of the battery pack, a protection unit is also provided. The protection unit includes at least an anti-sparking circuit. The input terminal of the anti-sparking circuit is connected to the charger, and the output terminal of the anti-sparking circuit is connected to the positive terminal of each battery in the battery pack through corresponding isolation diodes.

[0060] The protection unit also includes a number of fuse tubes consistent with the number of batteries in the battery pack, each fuse tube is connected in series to the positive electrode of the corresponding battery.

[0061] The anti-sparking circuit can prevent sparking when connecting or disconnecting the charger, which can protect the battery pack and charger from instantaneous high voltage or high current. The input of the anti-sparking circuit is directly connected to the charger and receives power from the charger. Its output is connected to the positive electrode of each battery in the battery pack through the corresponding isolation diode. This design ensures that each battery can safely receive charging power, while avoiding direct electrical connection between batteries, reducing the risk of short circuit.

[0062] The isolation diode acts as a one-way conductor, allowing power to flow from the charger through the anti-sparking circuit to the battery pack, but preventing power from the battery pack from flowing back to the charger or other batteries. This helps maintain electrical isolation within the battery pack and improves system safety.

[0063] In addition, a fuse tube is connected in series in the charge and discharge circuit of each battery. When a short circuit, overload or other abnormal condition occurs in a battery or the entire system, the fuse tube will quickly melt and cut off the circuit, preventing current from continuing to flow and potentially causing a fire or equipment damage. This way of configuring a fuse tube for each battery allows more precise control of the current for each battery, improving the safety and reliability of the entire battery pack.

[0064] Through the control switches and control sub-modules, in addition to avoiding abnormal conditions of mutual charging between batteries, energy recovery for loads powered by the battery pack can also be achieved depending on the flexibility and controllability of the control switches.

[0065] In addition to external loads, the loads powered by the battery pack also include related elements in the control device powered by the battery pack and the main control circuit board of the external load, etc.

[0066] When the external load is an inductive load such as a brushed motor or a brushless motor, the motor will generate a reverse electromotive force of varying energy at each stage of operation. Energy recovery mainly occurs during the deceleration and gradual stop of the motor, and the main control drive circuit of the motor has been cut off without driving current, but the motor is still rotating with inertia, at this time a reverse electromotive force will be generated. If the energy is not recovered or effectively consumed, it may accumulate on the total power supply, raising the power supply voltage, causing overvoltage damage to components directly connected to the power supply, or causing the system to misjudge.

[0067] Therefore, by energy recovery, the generated reverse electromotive force can be recovered to the battery for storage, that is, to prevent the system from being damaged, and the energy is recovered and stored, and the resources are fully utilized. The whole energy recovery process is similar to the process of taking the inductive load as a generator and charging the battery pack by the generator.

[0068] Similarly, taking the battery pack including battery A and battery B as an example, the energy recovery current path thereof is as shown in Figure 9

[0069] The working process of the battery pack control device based on self-lock protection provided by the embodiment is as follows:

[0070] Collecting electrical data of each charging and discharging circuit, identifying the running state of the battery pack according to the corresponding electrical data;

[0071] When identifying that the battery pack is in the abnormal running state of battery mutual charging, starting the corresponding self-lock unit, turning off the control switch, and controlling the corresponding charging circuit to be disconnected.

[0072] The electrical data of each charging and discharging circuit is collected by the state identification unit, and the electrical data includes voltage, current, temperature and other key parameters. The abnormal state analysis can be performed based on the voltage value through the operational amplifier as described in the embodiment, or the abnormal state analysis can be performed through the additional control chip combined with multi-dimensional parameters.

[0073] When identifying the abnormal running state, the corresponding self-lock unit can be automatically started, and the control switch is turned off in time to control the corresponding charging circuit to be disconnected.

[0074] And since each control sub-module is independent of each other, the identification of the abnormal running state can be accurate to the specific battery, and then only the corresponding self-lock unit is started, and the corresponding control switch is turned off, without affecting the operation of other normal batteries, thereby ensuring the power supply reliability of the whole battery pack.

[0075] Among them, identifying the running state of the battery pack according to the corresponding electrical data includes:

[0076] Obtaining the output voltage of each battery corresponding charging and discharging circuit according to the electrical data;

[0077] When the output voltage is greater than or equal to the preset self-lock unit opening voltage, it is judged that the battery pack is in the abnormal running state of battery mutual charging;

[0078] When the output voltage is less than the preset self-lock unit opening voltage, it is judged that the battery pack is in a normal running state.

[0079] ​In the identification process of the battery pack operating state, the state identification of each battery corresponding to the charging and discharging circuit is independent, and only when the output voltage corresponding to the collected self-locking unit is higher than the opening voltage, it is judged that the battery pack is in the abnormal operating state of battery mutual charging, and the specific abnormal battery is directly located.

[0080] If the control switch is turned off due to false triggering, the normal operation of the battery pack can be directly restored after the battery pack is reconnected to the load, and if the normal operation cannot be restored, the battery pack is further checked and replaced.

[0081] The above-described embodiments are only a preferred scheme of the present application, and do not limit the present application in any form, and there are other variants and modifications without exceeding the technical scheme recorded in the claims.

Claims

1. A battery pack control device based on self-locking protection, connected to a battery pack consisting of at least two batteries connected in parallel, wherein each battery in the battery pack forms a corresponding charging and discharging circuit with a charger and a load, characterized in that, The system includes control switches installed on each charging and discharging circuit within the battery pack, as well as several control sub-modules corresponding to the number of batteries in the battery pack. Each control sub-module includes a status identification unit and a self-locking unit. The status identification unit is installed on the charging and discharging circuit of the corresponding battery and is electrically connected to the corresponding self-locking unit. The self-locking unit is also electrically connected to the control switch. The status identification unit identifies the operating status of the battery pack by collecting electrical data from the charging and discharging circuit of the corresponding battery, and controls the self-locking unit accordingly to open or close the control switch, thereby controlling the closure or opening of each charging and discharging circuit of the battery pack.

2. The battery pack control device based on self-locking protection according to claim 1, characterized in that, The status recognition unit includes at least a detection element and a status recognition circuit. The detection element is disposed on the charging and discharging circuit of the corresponding battery, and the status recognition circuit is connected in parallel across the two ends of the detection element to collect electrical data on the charging and discharging circuit of the corresponding battery and identify the operating status of the battery pack.

3. The battery pack control device based on self-locking protection according to claim 2, characterized in that, The state recognition unit includes at least an operational amplifier, with the first and second input terminals of the operational amplifier connected to the two ends of the detection element, and the output terminal of the operational amplifier connected to the self-locking unit.

4. The battery pack control device based on self-locking protection according to claim 1, characterized in that, Each of the self-locking units includes at least a first transistor and a second transistor that are mutually self-locked. The base of the first transistor and the collector of the second transistor are connected to a first port, which is connected to the output terminal of the status recognition unit. The emitter of the second transistor is connected to the control terminal of the control switch.

5. The battery pack control device based on self-locking protection according to claim 1, characterized in that, It also includes a step-down circuit, the input of which is connected to the positive terminal of each battery in the battery pack, and the output of which is connected to the status recognition unit and the self-locking unit in each control submodule to provide the corresponding operating voltage.

6. The battery pack control device based on self-locking protection according to claim 5, characterized in that, The control switch is also connected to a voltage divider element, and the control terminal of the control switch is connected to the output terminal of the step-down circuit and ground through the corresponding voltage divider element.

7. The battery pack control device based on self-locking protection according to claim 1, characterized in that, It also includes a protection unit, which includes at least an anti-sparking circuit. The input terminal of the anti-sparking circuit is connected to the charger, and the output terminal of the anti-sparking circuit is connected to the positive terminal of each battery in the battery pack through corresponding isolation diodes.

8. The battery pack control device based on self-locking protection according to claim 7, characterized in that, The protection unit also includes several fuses, the same number as the number of batteries in the battery pack, with each fuse connected in series with the positive terminal of the corresponding battery.

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