Energy storage battery system and BMS self-power-off control circuit thereof

Abstract

The utility model provides a BMS self-power-off control circuit, which comprises an isolating switch, a main circuit with an output side and a driving circuit with an input side, and is characterized in that the main circuit is connected in series in a power supply loop of a DCDC power supply module of a BMS; when the driving circuit has a driving current, the isolation switch is in a conducting state. The auxiliary battery cell BAT1 is connected with the driving circuit and the resistor R1 to form a driving loop and is used for providing an initial starting power supply for the driving circuit; the switching tube Q1 is connected with a controller of the BMS and used for connecting or disconnecting the driving loop, and the switching tube Q1 is disconnected to enable the BMS to be powered off; and the external key SW is arranged in parallel with the switching tube Q1 and is used for conducting the driving loop and triggering the energy storage battery system to start up. The self-power-off control circuit provided by the utility model can realize a BMS self-power-off function under specific conditions, and improves the standby time, safety and cycle life of the battery.

Description

Energy storage battery system and its BMS automatic power-off control circuit Technical Field

[0001] This utility model belongs to the field of battery management system technology, and in particular relates to an energy storage battery system and its BMS self-power-off control circuit. Background Technology

[0002] In a typical battery energy storage system, the battery management system (BMS) is one of the core components. Its main functions include monitoring, protecting, balancing, and communicating with external systems to ensure the safe operation of the battery, extend battery life, and maintain system performance.

[0003] Currently, the common method for BMS (Battery Management System) to draw power from the battery itself has several key issues. Firstly, because the BMS needs to operate continuously to monitor and manage the battery's state in real time, it will continuously draw power from the battery as long as the battery energy storage system is in operation. Secondly, the battery's charge gradually decreases during discharge, and the BMS's continuous power drawing leads to additional battery drain.

[0004] Typical battery management systems (BMS) only protect against undervoltage. If undervoltage protection is triggered, the BMS will actively disconnect the load circuit to prevent further discharge of the battery pack. However, the BMS circuit remains connected to the battery pack at this time. Since its own circuit components are still powered by the battery, over time, this can directly pull the cell voltage down to an over-discharged state. At this point, the battery voltage is too low to activate the charging control circuit, resulting in a charging failure. Even if the cells are charged directly, the over-discharge will cause lithium plating, increasing the battery's internal resistance, severely damaging its lifespan, and in extreme cases, even leading to fire or explosion.

[0005] In related technologies, some battery management systems (BMS) enter a low-power mode for depleted lithium battery packs. However, this so-called low-power mode still consumes power; it only extends the standby time of the lithium battery pack and cannot achieve a zero-power mode. Furthermore, existing battery management systems have a restart mechanism to restart the system after shutdown. However, the reliability and safety of existing restart mechanisms are low, lacking a robust protection mechanism, which may lead to safety hazards. Summary of the Invention

[0006] This utility model aims to at least partially solve one of the technical problems in related technologies. Therefore,

[0007] According to embodiments of this disclosure, a BMS self-power-off control circuit is provided, comprising:

[0008] The isolating switch has a main circuit on the output side and a drive circuit on the input side. The main circuit is connected in series in the power supply circuit of the DC-DC power module of the BMS. When there is a drive current on the drive circuit, the isolating switch is in the on state.

[0009] The auxiliary battery cell BAT1 is connected to the drive circuit and resistor R1 to form a drive circuit, which is used to provide initial startup power to the drive circuit.

[0010] Switch Q1 is connected to the controller of the BMS and is used to turn the drive circuit on or off. When switch Q1 is turned off, the BMS is de-energized.

[0011] An external button SW is connected in parallel with the switching transistor Q1 to turn on the drive circuit and trigger the energy storage battery system to start.

[0012] The above technical solution has the following advantages or beneficial effects: the self-power-off control circuit composed of isolating switch, auxiliary cell, switching tube and external button realizes the function of automatically cutting off BMS power under specific conditions, realizing 0A current consumption, effectively reducing the power consumption of energy storage battery system after power failure, and extending battery life and standby time.

[0013] According to embodiments of this disclosure, the BMS self-power-off control circuit further includes:

[0014] Diode D1, whose anode is connected to the first output terminal of the DC-DC power module;

[0015] Diode D2 is connected in series in the driving circuit. The cathode of diode D2 and the cathode of diode D1 are connected to the input terminal of the driving circuit. The anode of diode D2 is connected to the positive terminal of the auxiliary cell BAT1. The first voltage output from the first output terminal causes diode D2 to be reverse-biased and cut off.

[0016] The above technical solution has the following advantages or beneficial effects: by utilizing the characteristics of diodes, at the instant the external button SW is pressed, the driving circuit of the isolating switch is powered by the auxiliary battery cell BAT1. After the DC-DC power module is started, the driving circuit starts to be powered by the output of the DC-DC power module, avoiding the consumption of BAT1's power and allowing BAT1 to be used for a longer time.

[0017] According to embodiments of this disclosure, the BMS self-power-off control circuit further includes a BAT1 charging circuit connected to the auxiliary battery cell BAT1, used to charge the auxiliary battery cell BAT1, the BAT1 charging circuit including:

[0018] The battery cell charging chip U1 has its output terminal connected to the auxiliary battery cell BAT1;

[0019] Switch Q4 is used to turn on or off the power supply circuit of the battery cell charging chip U1. The control terminal of switch Q4 is connected to the controller, the input terminal of switch Q4 is connected to the first output terminal of the DC-DC power module, and the output terminal of switch Q4 is connected to the power supply terminal of the battery cell charging chip U1.

[0020] The above technical solution has the following advantages or beneficial effects: by setting up the BAT1 charging circuit and controlling the switch Q4 by the controller to turn on or off the power supply circuit of the battery cell charging chip U1, intelligent charging management of the auxiliary battery cell BAT1 is realized, ensuring that the auxiliary battery cell can provide sufficient power when needed, avoiding damage to the auxiliary battery cell caused by overcharging or undercharging, and further improving the charging efficiency and safety of the auxiliary battery cell.

[0021] According to an embodiment of this disclosure, the BMS self-power-off control circuit further includes a voltage detection circuit connected to the controller for detecting the voltage of the auxiliary battery cell BAT1.

[0022] The above technical solution has the following advantages or beneficial effects: adding a voltage detection circuit connected to the controller enables the BMS to monitor the voltage of the auxiliary cell BAT1 in real time, providing the controller with accurate voltage data so that it can judge the status of the auxiliary cell in a timely manner and take corresponding charging or protection measures, thereby further improving the intelligent management level and safety of the energy storage battery system.

[0023] According to an embodiment of this disclosure, the voltage detection circuit includes:

[0024] Voltage divider resistors R2 and R3 are connected in series with the negative terminal of the auxiliary cell BAT1 to divide the voltage of BAT1.

[0025] Operational amplifier U4 has its non-inverting input connected to the middle node of voltage divider resistors R2 and R3, and its inverting input and output are both connected to the AD sampling port of the controller.

[0026] Operational amplifier U3 has its non-inverting input connected to the positive terminal of the auxiliary battery cell BAT1, and its inverting input and output are connected to the end of the voltage divider resistor R2 furthest from the middle node.

[0027] The above technical solution has the following advantages or beneficial effects: Operational amplifiers U3 and U4 are used to perform two-stage voltage follower function and impedance matching. Together with voltage divider resistors and controller, they monitor the voltage of BAT1 battery, which improves the accuracy and reliability of BMS monitoring the voltage of auxiliary cells.

[0028] According to embodiments of this disclosure, the BMS self-power-off control circuit further includes a protection circuit, the protection circuit comprising:

[0029] The battery cell protection chip U2 is electrically connected to the auxiliary battery cell BAT1;

[0030] The switching transistor Q2, whose control terminal is connected to the cell protection chip U2, is used to turn on or off the discharge circuit of the auxiliary cell BAT1;

[0031] The switching transistor Q3, whose control terminal is connected to the cell protection chip U2, is used to turn on or off the charging circuit of the auxiliary cell BAT1;

[0032] In this circuit, the switching transistor Q3 and the switching transistor Q2 are connected in series to form a first branch. The input terminal of the first branch is connected to the negative terminal of the auxiliary battery cell BAT1, and the output terminal of the first branch is connected to the ground signal.

[0033] The above technical solution has the following advantages or beneficial effects: by introducing the cell protection chip U2, the auxiliary cell voltage is monitored in real time. When the voltage is lower than the working voltage or exceeds the safe voltage, the auxiliary cell is protected by disconnecting the discharge circuit or the charging circuit, respectively, so that it enters a low-power standby state or a charging prohibited state. This enhances the protection function of the auxiliary cell and the entire system, and improves the safety and reliability of the system.

[0034] According to embodiments of this disclosure, the disconnecting switch is an optical MOS relay, the driving circuit is a light-emitting diode, and the main circuit includes a MOSFET.

[0035] The above technical solution has the following advantages or beneficial effects: by using an optical MOS relay as an isolating switch and providing initial startup power from the auxiliary battery cell, effective isolation and control between the main battery BAT2 and the DC-DC power module are achieved. The optical MOS relay has good electrical isolation performance and fast response capability, which improves the safety and control accuracy of the system, while also ensuring stable power supply to the isolating switch drive circuit.

[0036] According to an embodiment of this disclosure, the DC-DC power module includes an isolation unit DC-DC1 and a power supply unit DC-DC2. The input terminal of the isolation unit DC-DC1 is connected to the main battery BAT2 through the main circuit. The input terminal of the power supply unit DC-DC2 is connected to the first output terminal of the isolation unit DC-DC1 to convert the first voltage output by the isolation unit DC-DC1 into a second voltage. The output terminal of the power supply unit DC-DC2 is connected to the power supply terminal of the controller.

[0037] The above technical solution has the following advantages or beneficial effects: dividing the DC-DC power module into an isolation unit and a power supply unit realizes a stable and safe power supply from the main battery BAT2 to the BMS controller. The isolation unit can effectively isolate the electrical interference between the main battery BAT2 and the power supply unit, improving the stability and reliability of the power supply. At the same time, the power supply unit can convert the input voltage into a voltage suitable for the operation of the BMS controller, ensuring the normal operation of the system.

[0038] According to embodiments of this disclosure, the BMS self-power-off control circuit further includes a key state detection circuit connected to the controller, used to monitor the state of the external key SW, the key state detection circuit including:

[0039] Resistor R4, one end of which is connected to the first output terminal of the isolation unit DC-DC1;

[0040] Resistor R5 is connected between resistor R4 and the I / O input port of the controller. One end of the external button SW is connected to the ground signal, and the other end is connected between resistor R4 and resistor R5.

[0041] Diode D4, the anode of which is connected between resistor R4 and resistor R5, and the cathode of diode D4 is connected to one end of the external button SW;

[0042] Diode D3 is connected to the discharge circuit of the auxiliary battery cell BAT1. The cathode of diode D3 is connected to the external button SW and the cathode of diode D4. The anode of diode D3 is connected to the input terminal of the switch Q1.

[0043] The above technical solution has the following advantages or beneficial effects: By using a simple combination of components such as resistors and diodes, the button status detection circuit accurately monitors the external button status while preventing the drive current of the isolating switch from flowing directly through resistor R5 to the controller before the button SW is closed, thus preventing false triggering. The BMS controller can respond promptly based on the button status, improving the system's response speed and reliability to user operations.

[0044] Another aspect of this application provides an energy storage battery system comprising:

[0045] External communication power supply;

[0046] The battery pack includes a battery management system (BMS) and a main battery (BAT2). The main battery (BAT2) is electrically connected to the external communication power supply via a main circuit, allowing the external communication power supply to charge and discharge it. The battery management system (BMS) includes:

[0047] The communication module is connected to the external communication power supply.

[0048] The controller is connected to the communication module;

[0049] The DC-DC power module is connected to the main battery BAT2 and the controller to supply power to the controller.

[0050] The battery pack also includes the BMS self-power-off control circuit described in any of the above technical solutions. The self-power-off control circuit is connected to the controller, and the main circuit of the disconnect switch is connected in series in the power supply circuit between the DC-DC power module and the main battery BAT2.

[0051] The above technical solution has the following advantages or beneficial effects: the self-power-off control circuit composed of isolating switch, auxiliary cell, switching tube and external button can control the automatic disconnection of BMS power supply under specific conditions of energy storage battery system, realize 0A current consumption, effectively reduce the power consumption of energy storage battery system after power failure, and extend battery life and standby time. Attached Figure Description

[0052] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0053] Figure 1 is a circuit diagram of the self-power-off control circuit according to the embodiment of this application;

[0054] Figure 2 is a structural block diagram of the energy storage battery system according to an embodiment of this application;

[0055] Figure 3 is a flowchart of the BMS self-power-off control method according to the embodiments of this application;

[0056] Figure 4 is a flowchart of the control logic for BMS self-power-off according to the embodiment of this application;

[0057] Figure 5 is a flowchart of the control logic for starting up the energy storage battery system according to the embodiment of this application.

[0058] In the above figures, the energy storage battery system is 10; the external communication power supply is 1; the battery PACK is 2; the DC-DC power module is 21; the communication module is 22; the sampling module is 23; the controller is 24; the drive module is 25; the self-power-off control circuit is 3; the voltage detection circuit is 31; the button status detection circuit is 32; the protection circuit is 33; and the disconnect switch is 34. Detailed Implementation

[0059] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0060] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0061] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0062] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0063] This utility model provides a BMS self-power-off control circuit 3 for an energy storage battery system, which can automatically cut off the BMS power supply under specific conditions to achieve 0A current consumption, effectively improving the battery's standby time, as well as safety and cycle life.

[0064] Referring to Figure 1, the BMS self-power-off control circuit 3 may include an isolating switch 34. The isolating switch 34 has a main circuit on the output side and a drive circuit on the input side. The main circuit is connected in series in the power supply circuit of the BMS's DC-DC power module 21, which is powered by the main battery BAT2.

[0065] When there is a driving current in the driving circuit, the isolating switch 34 is in the on state; when there is no current flowing in the driving circuit, the isolating switch 34 is in the off state.

[0066] Understandably, when the isolating switch 34 is open, the power supply circuit of the DC-DC power module 21 is cut off.

[0067] The BMS self-power-off control circuit 3 may include an auxiliary battery cell BAT1. The auxiliary battery cell BAT1 is connected to the drive circuit and resistor R1 to form a drive circuit, which is used to provide initial start-up power to the drive circuit.

[0068] The BMS self-power-off control circuit 3 may include a switching transistor Q1, which is connected to the BMS controller 24 and is used to turn the drive circuit on or off. Specifically, when the switching transistor Q1 is turned off, the isolating switch 34 is in the open state, thereby de-energizing the BMS.

[0069] The BMS self-power-off control circuit 3 may include an external button SW, which is connected in parallel with the switching transistor Q1 to conduct the drive circuit and trigger the energy storage battery system to start.

[0070] Referring to Figure 1, the negative terminal of the auxiliary battery cell BAT1 is connected to the ground signal, and the positive terminal of the auxiliary battery cell BAT1 is connected to the ground signal in sequence through the driving circuit of the isolating switch 34, the resistor R1, the parallel switch Q1, and the external button SW to form a driving circuit.

[0071] In this embodiment, the self-power-off control circuit, composed of isolating switch 34, auxiliary battery cell, switching transistor and external button SW, realizes the function of automatically cutting off BMS power under specific conditions, achieving 0A current consumption, effectively reducing the power consumption of the energy storage battery system after power failure, and extending the battery's service life and standby time.

[0072] When the energy storage battery system needs to be shut down, the controller 24 sends a shutdown command, which controls the switch Q1 to disconnect. At this time, the drive circuit cannot be turned on, the main circuit of the isolating switch 34 is disconnected, the power supply circuit of the DC-DC power module 21 is cut off, the BMS is powered off, and the energy storage battery system achieves 0A power consumption.

[0073] Furthermore, continuing to refer to Figure 1, the BMS self-power-off control circuit 3 also includes a diode D1. The anode of diode D1 is connected to the first output terminal of the DC-DC power module 21.

[0074] The BMS self-power-off control circuit 3 also includes diode D2, which is connected in series in the drive circuit. The cathode of diode D2 and the cathode of diode D1 are both connected to the input terminal of the drive circuit, and the anode of diode D2 is connected to the positive terminal of the auxiliary battery cell BAT1. The first voltage output from the first output terminal causes diode D2 to be reverse-biased and cut off.

[0075] In other words, referring to Figure 1, the auxiliary battery cell BAT1 is connected to the drive circuit of the opto-MOS relay through diode D2 and is powered by the first output terminal of the DC-DC power module 21 through diode D1 and is powered by the drive circuit of the opto-MOS relay.

[0076] Specifically, when the external button SW is pressed, the DC-DC power module 21 is activated and outputs a first voltage to diode D1. The first voltage cuts off the power supply path of the auxiliary battery cell BAT1 through diodes D1 and D2, so that the drive circuit of the opto-MOS relay is powered by the DC-DC power module 21.

[0077] In this embodiment, by utilizing the characteristics of diodes, the driving circuit of the isolation switch 34 is powered by the auxiliary battery cell BAT1 at the instant the external button SW is pressed. After the DC-DC power module 21 is started, the driving circuit starts to be powered by the output of the DC-DC power module 21, thus avoiding the consumption of BAT1's power and allowing BAT1 to be used for a longer period of time.

[0078] BAT1 serves as an auxiliary power source, operating only briefly when the system is woken up. The power supply circuit of the DC-DC power module 21 and the linkage with the BMS are dynamically adjusted by the controller 24 based on the status of the main battery BAT2, forming a complete low-power control closed loop to achieve high-efficiency energy saving and reliable protection of the energy storage battery system 10.

[0079] In some embodiments of this application, the DC-DC power module 21 includes an isolation unit DC-DC1 and a power supply unit DC-DC2. The input terminal of the isolation unit DC-DC1 is connected to the main battery BAT2 through the main circuit. The input terminal of the power supply unit DC-DC2 is connected to the first output terminal of the isolation unit DC-DC1 to convert its output first voltage into a second voltage. The output terminal of the power supply unit DC-DC2 is connected to the power supply terminal of the controller 24 so that the second voltage supplies power to the controller 24.

[0080] In this embodiment, the DC-DC power module 21 is divided into an isolation unit and a power supply unit, which realizes a stable and safe power supply from the main battery BAT2 to the controller 24 of the BMS. The isolation unit can effectively isolate the electrical interference between the main battery BAT2 and the power supply unit, improve the stability and reliability of the power supply, and at the same time, the power supply unit can convert the input voltage into a voltage suitable for the operation of the controller 24 of the BMS, ensuring the normal operation of the system.

[0081] Referring back to Figure 1, the energy storage battery system is in the off state, with no power-consuming modules. When the external button SW is pressed, the drive circuit is activated, BAT1 begins to discharge, and the isolating switch 34 is driven to open the main circuit. The isolation unit DC-DC1 begins to output 5V_1, and DC-DC2 outputs 3.3V to power the MCU. Simultaneously, the 5V_1 output from the first output terminal cuts off the output of the auxiliary cell BAT1 through the characteristics of diodes D1 and D2. In other words, after the isolation unit DC-DC1 starts outputting 5V_1, the drive circuit of the isolating switch 34 begins to be powered by 5V_1. The auxiliary cell BAT1 only provides the initial startup voltage, that is, it only works briefly when the system wakes up, avoiding the consumption of BAT1's power and extending its usage time.

[0082] Furthermore, after the energy storage battery system is powered on, the controller 24 sends a command to close the switch Q1, so that even if the external button SW bounces back, the drive circuit will not be disconnected, thus maintaining the power supply circuit of the BMS.

[0083] In some embodiments of this application, the BMS self-power-off control circuit 3 further includes a BAT1 charging circuit, which is connected to the auxiliary battery cell BAT1 and is used to charge the auxiliary battery cell BAT1.

[0084] The BAT1 charging circuit may include a cell charging chip U1, the output of which is connected to the auxiliary cell BAT1. The cell charging chip U1 has a constant voltage-constant current charging function, used to charge the auxiliary battery BAT1 during startup.

[0085] The BAT1 charging circuit may include a switching transistor Q4, which is used to turn on or off the power supply circuit of the battery cell charging chip U1. The control terminal of the switching transistor Q4 is connected to the controller 24, meaning that the switching transistor Q4 is controlled by the controller 24 to close or open.

[0086] Referring to Figure 1, the input terminal of the switching transistor Q4 is connected to the first output terminal of the DC-DC power module 21, and the output terminal of the switching transistor Q4 is connected to the power supply terminal of the battery cell charging chip U1, so that the first voltage output from the first output terminal powers the battery cell charging chip U1 through the switching transistor Q4.

[0087] In this embodiment, by setting up a BAT1 charging circuit and controlling the switch Q4 by the controller 24 to turn on or off the power supply circuit of the battery cell charging chip U1, intelligent charging management of the auxiliary battery cell BAT1 is realized, ensuring that the auxiliary battery cell can provide sufficient power when needed, avoiding damage to the auxiliary battery cell caused by overcharging or undercharging, and further improving the charging efficiency and safety of the auxiliary battery cell.

[0088] In some embodiments, the BMS self-power-off control circuit 3 further includes a voltage detection circuit 31, which is connected to the controller 24 and is used to detect the voltage of the auxiliary battery cell BAT1.

[0089] In this embodiment, the addition of a voltage detection circuit 31 connected to the controller 24 enables the BMS to monitor the voltage of the auxiliary cell BAT1 in real time, providing the controller 24 with accurate voltage data so that it can promptly determine the status of the auxiliary cell and take corresponding charging or protection measures, thereby further improving the intelligent management level and safety of the energy storage battery system.

[0090] Specifically, referring to Figure 1, the voltage detection circuit 31 may include voltage divider resistors R2 and R3, which are connected in series in series at the negative terminal of the auxiliary cell BAT1 to divide the voltage of BAT1.

[0091] The voltage detection circuit 31 may include an operational amplifier U4. The non-inverting input of the operational amplifier U4 is connected to the middle node of the voltage divider resistors R2 and R3, and the inverting input and output of the operational amplifier U4 are connected to the AD sampling port of the controller 24.

[0092] The voltage detection circuit 31 may include an operational amplifier U3. The non-inverting input of the operational amplifier U3 is connected to the positive terminal of the auxiliary battery cell BAT1, and the inverting input and output of the operational amplifier U3 are connected to the end of the voltage divider resistor R2 furthest from the intermediate node.

[0093] In this embodiment, operational amplifiers U3 and U4 are used to perform two-stage voltage follower function and impedance matching. Together with voltage divider resistors R2 and R3, they are used to sample the voltage of BAT1, enabling the controller 24 to monitor the voltage of BAT1 in real time, thereby improving the accuracy and reliability of the BMS in monitoring the voltage of the auxiliary battery cells.

[0094] Furthermore, the controller 24 acquires the BAT1 voltage through operational amplifiers U3 and U4 and voltage divider resistors R2 and R3, and dynamically controls the on / off state of Q4 according to thresholds V1 and V2 to ensure that BAT1 is within a safe voltage range.

[0095] In some embodiments of this application, the BMS self-power-off control circuit 3 further includes a protection circuit 33 for protecting the health of the auxiliary battery cell BAT1.

[0096] Specifically, referring to Figure 1, the protection circuit 33 may include a cell protection chip U2, which is electrically connected to the auxiliary cell BAT1. The cell protection chip U2 can detect the voltage of the auxiliary cell BAT1.

[0097] The protection circuit 33 may include a switching transistor Q2, the control terminal of which is connected to the cell protection chip U2, for turning on or off the discharge circuit of the auxiliary cell BAT1.

[0098] The protection circuit 33 may include a switching transistor Q3, the control terminal of which is connected to the cell protection chip U2, for turning on or off the charging circuit of the auxiliary cell BAT1.

[0099] In this circuit, switching transistors Q3 and Q2 are connected in series to form the first branch. The input terminal of the first branch is connected to the negative terminal of the auxiliary battery cell BAT1, and the output terminal of the first branch is connected to the ground signal.

[0100] In this embodiment, by introducing a cell protection chip U2, the voltage of the auxiliary cell is monitored in real time. When the voltage is lower than the working voltage or exceeds the safe voltage, the auxiliary cell is protected by disconnecting the discharge circuit or the charging circuit, respectively, so that it enters a low-power standby state or a charging-prohibited state. This enhances the protection function of the auxiliary cell and the entire system, and improves the safety and reliability of the system.

[0101] The battery cell protection chip U2, together with the switching transistors Q2 and Q3, forms an auxiliary protection circuit 33 for charging and discharging the battery cell, which has overvoltage, undervoltage, and overcurrent protection functions.

[0102] Specifically, the cell protection chip U2 acquires the voltage of the auxiliary cell in real time. When the voltage of the auxiliary cell is lower than its own operating voltage, the cell protection chip U2 disconnects the discharge circuit of the auxiliary cell through the switching transistor Q2, so that the cell protection chip U2 enters an extremely low power consumption state to wait for the auxiliary cell to charge.

[0103] When the voltage of the auxiliary battery cell exceeds its own safe voltage, the battery cell protection chip U2 disconnects the charging circuit of the auxiliary battery cell through the switching transistor Q3, so that the auxiliary battery cell enters a state where charging is prohibited.

[0104] For example, referring to Figure 1, the disconnecting switch 34 can be a photoelectric MOS relay. The driving circuit is a light-emitting diode, and the main circuit includes a MOSFET. The specific structure and working principle of the photoelectric MOS relay are existing technologies and will not be described in detail here.

[0105] In this embodiment, an optical MOS relay is used as the isolating switch 34, and the auxiliary battery cell provides the initial start-up power, which realizes effective isolation and control between the main battery BAT2 and the DC-DC power module 21. The optical MOS relay has good electrical isolation performance and fast response capability, which improves the safety and control accuracy of the system, and also ensures the stable power supply of the isolating switch 34 drive circuit.

[0106] In some embodiments of this application, the BMS self-power-off control circuit 3 further includes a key status detection circuit, which is connected to the controller 24 and is used to monitor the status of the external key SW.

[0107] Referring again to Figure 1, the button status detection circuit 32 is connected between the controller 24 and the DC-DC power module 21, and the button status detection circuit 32 is connected to the external button SW.

[0108] The button status detection circuit 32 may include a resistor R4. One end of the resistor R4 is connected to the first output terminal of the isolation unit DCDC1. The resistor R4 serves as a pull-up resistor.

[0109] The button status detection circuit 32 may include a resistor R5, which is connected between the resistor R4 and the I / O input port of the BMS controller 24.

[0110] The button status detection circuit 32 may include a diode D4. The anode of diode D4 is connected between resistors R4 and R5, and the cathode of diode D4 is connected to one end of the external button SW. The other end of the external button SW is connected to ground.

[0111] Diode D4 prevents the drive current of the opto-MOS relay from flowing through resistor R5 and then through controller 24 before button SW is closed, thus preventing false triggering.

[0112] The button status detection circuit 32 may include a diode D3, which is connected to the discharge circuit of the auxiliary battery cell BAT1, and the cathode of diode D3 is connected to the connection point between the cathode of diode D4 and the external button SW.

[0113] Referring again to Figure 1, the anode of diode D3 is connected between the external button SW and the switching transistor Q1. The function of diode D3 is to prevent the SW_test signal from being pulled low after the switching transistor Q1 is turned on, thus ensuring accurate detection of the SW state by the controller 24.

[0114] In other words, regardless of whether SW is open or closed, diode D3 can prevent the Sw_test signal from always being 0, thus preventing the failure to detect the state of SW.

[0115] In this embodiment, the key status detection circuit 32, using a simple combination of components such as resistors and diodes, accurately monitors the status of external keys while preventing the drive current of the isolating switch 34 from flowing directly through resistor R5 to the controller 24 before the key SW is closed, thus preventing false triggering. The BMS controller 24 can respond promptly based on the key status, improving the system's response speed and reliability to user operations.

[0116] In this embodiment, resistor R4 is a pull-up resistor, which pulls the voltage up to the first voltage (5V). Resistor R5 acts as a current-limiting resistor to send the voltage signal Sw_test into the level detection I / O port of controller 24.

[0117] When the external button SW is pressed, Sw_test is connected to the ground signal through the button SW, and the voltage is pulled down to close to 0.3V (determined by the voltage drop of diode D3 and the circuit resistance). At this time, the controller 24 detects a low level, indicating that SW is in the closed state.

[0118] When the external button SW rebounds, the signal line Sw_test is pulled up to 5.0V through the pull-up resistor R4. The controller 24 detects a high level, indicating that SW is in the off state.

[0119] In another aspect, this application also provides an energy storage battery system, which includes the BMS self-power-off control circuit 3 described in any of the above claims.

[0120] The energy storage battery system 10 may include a battery pack and an external communication power supply. The external communication power supply 1 is connected to the battery pack 2 and is used to charge and discharge the battery pack 2. The battery pack can be connected to the power grid and load via the external communication power supply.

[0121] The external communication power supply 1 can be a DC power supply with communication capabilities or an energy storage power conversion system (PCS). Selecting a DC power supply with communication capabilities or an energy storage power conversion system (PCS) as the external communication power supply 1 can meet the needs of all application scenarios.

[0122] A DC power supply with communication capabilities is selected as the external communication power supply 1, which can provide a stable voltage output. Furthermore, DC power supplies typically support a wide input voltage range, adapting to different power grid conditions. An energy storage power conversion system (PCS) is selected as the external communication power supply 1, enabling bidirectional conversion between DC and AC power, allowing for both charging and discharging, thus improving system flexibility.

[0123] Referring to Figures 1 and 2, the battery PACK2 may include a battery management system (BMS) and a main battery (BAT2) connected to the BMS. The main battery (BAT2) stores electrical energy, the BMS monitors and protects the main battery (BAT2) and communicates with the external power supply 1, and the BMS self-power-off control circuit 3 connects the main battery (BAT2) and the BMS.

[0124] The main battery BAT2 is electrically connected to the external communication power supply 1 through the main circuit, so that the external communication power supply 1 can charge and discharge the main battery BAT2 through the main circuit.

[0125] The main circuit includes a positive switch K2 and a negative switch K3. The positive switch K2 is connected to the positive terminal of the main battery BAT2, and the negative switch K3 is connected to the negative terminal of the main battery BAT2. The positive switch K2, negative switch K3, and pre-charge switch K1 can be relays.

[0126] The main circuit includes a pre-charge circuit. By setting up the pre-charge circuit, the main battery BAT2, external communication power supply 1, and switching devices can be effectively protected from damage due to overcurrent, thus extending the service life of the main battery BAT2, external communication power supply 1, and switching devices.

[0127] The precharge circuit includes a branch formed by connecting the precharge resistor R and the precharge switch K1 in series. The branch is connected in parallel with one of the positive and negative switches of the main circuit.

[0128] In other words, the branch can be connected in parallel with the positive switch K2, and the branch can also be connected in parallel with the negative switch K3. Understandably, different circuit architectures in battery PACK2 can be selected based on actual application scenarios and design requirements. For example, a circuit architecture with the pre-charge resistor R connected in parallel to the positive switch K2 may be more suitable for scenarios requiring strict control of the positive current, while a circuit architecture with the pre-charge resistor R connected in parallel to the negative switch K3 may be more suitable for simplifying the design of the negative circuit.

[0129] In this embodiment, the cooperation between the pre-charge resistor R and the pre-charge switch K1 can limit the current magnitude in the early stage of charging, avoid instantaneous large current surges caused by voltage differences, and improve the safety and reliability of the charging process.

[0130] Referring to Figure 2, the battery management system (BMS) may include a communication module 22. The communication module is used for data interaction with an external communication power source 1.

[0131] The communication module 22 enables bidirectional communication between the battery PACK2 and the external communication power supply 1. The communication module 22 can be a CAN communication module or a 485 communication module; this application does not limit the communication method of the communication module 22.

[0132] The BMS may include a DC-DC power module 21, the input of which is connected to the main battery BAT2 to power the BMS.

[0133] Furthermore, the battery management system (BMS) may include a sampling module 23. The sampling module 23 is connected to the main battery (BAT2) and is used to collect battery parameters in real time during the charging and discharging process. These battery parameters include at least the voltage, charging current, discharging current, cell temperature, cell voltage, and cell impedance of battery PACK2.

[0134] The sampling module 23 may include an AFE (analog front end), which in BMS specifically refers to a battery sampling chip used to collect battery voltage, current, cell voltage, cell temperature, etc. The sampling module 23 may also include a separate sampling circuit.

[0135] The battery management system (BMS) may include a controller 24, which is connected to a communication module 22 and a sampling module 23. The controller 24 may be an MCU.

[0136] In some embodiments, referring to FIG2, the battery management system may include a drive module 25, which is used to drive the main circuit and the precharge circuit to be turned on or off.

[0137] Specifically, the input terminal of the drive module 25 is connected to the output terminal of the controller 24, and the output terminal of the drive module 25 is connected to the controlled terminals of the positive switch K2, the negative switch K3, and the precharge switch K1. The drive module drives the positive switch K2, the negative switch K3, and the precharge switch K1 to open or close according to the drive commands issued by the controller 24.

[0138] In this embodiment, by setting the drive module 25, the battery management system can accurately and timely control the connection or disconnection of the main circuit and the precharge circuit, thereby improving the safety and reliability of the battery system when switching between different working states.

[0139] The controller 24 includes a processor and a memory communicatively connected to the processor; wherein the memory stores instructions executable by the processor, which are executed by the processor to enable the processor to perform the BMS self-power-off control method.

[0140] Referring to Figure 3, the BMS automatic power-off control method may include the following steps:

[0141] Step S1: Under normal operating conditions, the BMS monitors the voltage or SOC value of the main battery BAT2 in real time.

[0142] Step S2: When the voltage or SOC value is lower than the preset threshold, the BMS sends a forced charging command to the external communication power supply 1 and starts timer T1.

[0143] Step S3: If T1 times out or PCS does not meet the charging conditions, the BMS sends a shutdown command to the self-power-off control circuit 3 to control the disconnection switch 34 to cut off the power supply circuit between the main battery BAT2 and the DC-DC power module 21, so that the BMS enters the zero power consumption state.

[0144] Step S4: When the energy storage battery system 10 is in the off state, the external button SW of the self-power-off control circuit 3 is used to open the discharge circuit of the auxiliary cell BAT1 to the isolation switch 34. The auxiliary cell BAT1 drives the isolation switch 34 to open, so that the DC-DC power module 21 is started and wakes up the BMS, and the energy storage battery system 10 is turned on.

[0145] In this embodiment, the voltage or SOC value of the main battery BAT2 is monitored in real time by the BMS. When it is lower than the preset threshold, a forced charging command is sent and a timer is started. If the timeout occurs or the charging conditions are not met, the BMS controls the disconnection switch 34 to cut off the power supply of the DC-DC power module 21, so that the BMS enters a zero power consumption state, effectively reducing the power consumption of the energy storage battery system 10, extending the system's service life, improving energy utilization efficiency, and enhancing the system's stability and reliability.

[0146] The above technical solution effectively solves the problem that when the power supply is interrupted or the main battery is low, the BMS cannot automatically control the system to enter a low-power state, resulting in high power consumption and severe battery undervoltage affecting the normal operation of the system.

[0147] Furthermore, when the energy storage battery system 10 is powered off, there are no power-consuming modules. The auxiliary cell BAT1 is connected to the disconnect switch 34 via a drive circuit to provide initial current to the drive circuit of the disconnect switch 34. An external button SW is connected to the discharge circuit of the auxiliary cell BAT1 to control the on / off state of the discharge circuit.

[0148] When the external button SW is pressed, the discharge circuit of the auxiliary battery cell BAT1 is activated, and BAT1 begins to discharge, driving the isolating switch 34 to turn on, thereby restoring the power supply circuit of the DC-DC power module 21. At this time, the DC-DC power module 21 begins to output a first voltage and a second voltage, with the second voltage used to power the BMS controller.

[0149] When the energy storage battery system 10 is in the off state, and it is necessary to turn on the energy storage battery system 10, the discharge circuit of the auxiliary cell BAT1 is turned on by the external button SW. The auxiliary cell BAT1 provides the initial start-up power to the drive circuit of the isolation switch 34, so as to turn on the isolation switch 34, so that the DC-DC power module 21 is started to wake up the BMS and complete the power-on of the energy storage battery system 10.

[0150] It is understandable that the self-power-off control circuit 3 is electrically connected to the main battery BAT2 and the DC-DC power module 21. The DC-DC power module 21 can draw power from the main battery BAT2; that is, the DC-DC power module 21 is powered by the main battery BAT2.

[0151] In some embodiments of this application, the BMS self-power-off control method further includes:

[0152] When the external button is pressed, the switch Q1 connected in parallel with the external button SW is closed to keep the drive circuit of the isolating switch 34 in the conducting state.

[0153] In this embodiment, by controlling the closed switch Q1, the driving circuit of the isolating switch 34 is kept in the conducting state. Even if the button SW rebounds, the driving circuit of the isolating switch 34 will not be disconnected, thus maintaining the power supply circuit and improving the stability and reliability of the system during and after power-on.

[0154] The BMS self-power-off control method also includes: controlling the switch Q1 to disconnect, so that the isolating switch 34 is disconnected, thereby cutting off the power supply circuit between the main battery BAT2 and the DC-DC power module 21.

[0155] In some embodiments of this application, the BMS self-power-off control method further includes:

[0156] The BMS monitors the voltage of the auxiliary cell BAT1 in real time. When the voltage of the auxiliary cell BAT1 is lower than the preset first threshold V1, it controls the cell charging chip U1 of the self-power-off control circuit 3 to charge the auxiliary cell BAT1 until the charging voltage of BAT1 reaches the preset second threshold V2 and then stops charging.

[0157] In this embodiment, when the voltage of the auxiliary cell BAT1 is lower than the preset first threshold V1, BAT1 is charged to maintain its high charge level, effectively maintaining the charge level of the auxiliary cell and ensuring its normal operation. This provides stable power support for the control and startup of the energy storage battery system 10, extends the service life of the auxiliary cell, and avoids the problem that the voltage of the auxiliary cell may be too low, which may cause the isolation switch 34 to fail to drive properly, thus avoiding affecting the normal operation and startup of the energy storage battery system 10.

[0158] It should be noted that the preset first threshold V1 is defined as the minimum operating voltage of BAT1 driving the isolating switch 34, and the preset second threshold V2 is defined as the maximum operating voltage of BAT1.

[0159] In some embodiments, the BMS self-power-off control method further includes:

[0160] When the voltage of BAT1 is lower than the preset first threshold V1, the BMS sends a charging command to control the switching transistor Q4 to turn on. The DC-DC power module 21 supplies power to the cell charging chip U1 so that the cell charging chip U1 can charge the auxiliary cell BAT1.

[0161] When the charging voltage of the auxiliary cell BAT1 reaches the preset second threshold V2, the BMS sends a stop charging command to control the shutdown of the switch Q4, so that the DC-DC power module 21 disconnects the power supply to the cell charging chip U1. At this time, the cell charging chip U1 stops charging the auxiliary cell BAT1.

[0162] In this embodiment, the precise control of the switching transistor Q4 by the BMS makes the charging process of the auxiliary battery cell more controllable, avoiding damage to the auxiliary battery cell caused by overcharging or undercharging, and further improving the charging efficiency and safety of the auxiliary battery cell.

[0163] In some embodiments of this application, after the energy storage battery system 10 is powered on, the BMS controller collects the voltage of the auxiliary cell BAT1 through the voltage detection circuit 31. The controller 24 collects the voltage of BAT1 through operational amplifiers U3 and U4 and voltage divider resistors R2 and R3, and dynamically controls the on / off state of Q4 according to thresholds V1 and V2 to ensure that BAT1 is within a safe voltage range.

[0164] In some embodiments of this application, the BMS self-power-off control method further includes:

[0165] The cell protection chip U2 acquires the voltage of the auxiliary cell in real time;

[0166] When the voltage of the auxiliary battery cell is lower than its own operating voltage, the battery cell protection chip U2 disconnects the discharge circuit of the auxiliary battery cell through the switching transistor Q2, so that the battery cell protection chip U2 enters an extremely low power consumption state to wait for the auxiliary battery cell to charge.

[0167] When the voltage of the auxiliary battery cell exceeds its own safe voltage, the battery cell protection chip U2 disconnects the charging circuit of the auxiliary battery cell through the switching transistor Q3, so that the auxiliary battery cell enters a state where charging is prohibited.

[0168] In this embodiment, by introducing a cell protection chip U2, the voltage of the auxiliary cell is monitored in real time. When the voltage is lower than the working voltage or exceeds the safe voltage, the auxiliary cell is protected by disconnecting the discharge circuit or the charging circuit, respectively, so that it enters a low-power standby state or a charging-prohibited state. This enhances the protection function of the auxiliary cell and the entire system, and improves the safety and reliability of the system.

[0169] Referring to Figures 4 and 5, taking the external communication power supply 1 as the PCS and the disconnecting switch 34 as an optical MOS relay as an example, the BMS self-power-off control method of the energy storage battery system 10 will be described in detail.

[0170] Referring to Figure 4, under normal operating conditions, when the main battery voltage or SOC is low (below the corresponding preset threshold), a low SOC warning is triggered. At this time, the BMS sends a forced charging command to the PCS. It checks whether the PCS has the necessary charging conditions and whether the waiting time t does not exceed T1. If yes, the charging process for the main battery BAT2 begins. If not, the BMS determines that power consumption needs to be reduced to protect the main battery and prevent severe undervoltage from causing the energy storage system to malfunction. The BMS sends a shutdown command, at which point the switching transistor Q1 is disconnected, the drive circuit of the opto-MOS relay cannot conduct, the main circuit of the opto-MOS relay is disconnected, the power supply circuit of the isolation module DCDC1 is cut off, the BMS is powered off, and the energy storage system achieves 0A power consumption.

[0171] Referring to Figure 5, when the energy storage battery system is in the off state, there are no power-consuming modules. To restart the energy storage battery system, manually press the external button SW. The discharge circuit is then activated. At this time, the auxiliary cell BAT1 powers the photoelectric MOS relay, the isolation unit DC-DC1 is energized and begins outputting 5V_1, and the power supply unit DC-DC2 is energized and outputs 3.3V to the MCU. The auxiliary cell BAT1 stops supplying power, and the 5V_1 drives the photoelectric MOS relay. The MCU is then powered on, and the energy storage battery system is successfully powered on. At this time, the MCU sends a command to close the switch Q1. The closed switch Q1 keeps the drive circuit of the photoelectric MOS relay conducting.

[0172] After the energy storage battery system is powered on, the MCU detects the voltage of BAT1 through operational amplifiers U3 and U4, and determines whether the preset first threshold V1 is not greater than the voltage Vbat1 of the auxiliary cell BAT1. If so, the MCU sends a stop charging command for BAT1, the switching transistor Q4 is turned off, and the cell charging chip U1 stops charging. If not, the MCU sends a charging command for BAT1. Furthermore, when the cell charging chip U1 charges BAT1, it determines whether the preset second threshold V2 is not greater than the voltage Vbat1 of the auxiliary cell BAT1. If so, the MCU sends a stop charging command for BAT1; if not, the MCU continues to send charging commands for BAT1.

[0173] The BMS self-power-off control circuit 3 provided by this utility model can promptly cut off the power supply circuit of the DC-DC power module 21 when the voltage or SOC of the main battery BAT2 is low and cannot be charged in time, thereby de-energizing the BMS and achieving 0A power consumption in the energy storage battery system. Simultaneously, it features a low-power, high-reliability self-starting mechanism, allowing the system to be woken up by an external button after the energy storage battery system is powered off. This effectively solves the problem of static current consumption in the BMS during standby, which leads to a continuous decrease in the main battery's charge, shortening standby time and cycle life.

[0174] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A BMS self-power-off control circuit, characterized in that, include: The isolating switch has an output-side main circuit and an input-side drive circuit. The main circuit is connected in series in the power supply circuit of the BMS's DC-DC power module. When there is a drive current in the drive circuit, the isolating switch is in the ON state. The auxiliary cell BAT1 is connected to the drive circuit and resistor R1 to form a drive circuit, which is used to provide initial startup power to the drive circuit. The switching transistor Q1 is connected to the controller of the BMS and is used to turn the drive circuit on or off. When the switching transistor Q1 is off, the BMS is de-energized. The external button SW is connected in parallel with the switching transistor Q1 and is used to turn on the drive circuit and trigger the start-up of the energy storage battery system.

2. The BMS self-power-off control circuit as described in claim 1, characterized in that, Also includes: Diode D1 has its anode connected to the first output terminal of the DC-DC power module; Diode D2 is connected in series in the drive circuit, and the cathode of diode D2 and the cathode of diode D1 are connected to the input terminal of the drive circuit. The anode of diode D2 is connected to the positive terminal of the auxiliary battery cell BAT1; wherein, the first voltage output from the first output terminal causes diode D2 to be reverse-biased and cut off.

3. The BMS self-power-off control circuit as described in claim 1, characterized in that, It also includes a BAT1 charging circuit connected to the auxiliary battery cell BAT1 for charging the auxiliary battery cell BAT1. The BAT1 charging circuit includes: a battery cell charging chip U1, the output of which is connected to the auxiliary battery cell BAT1; and a switch Q4 for turning on or off the power supply circuit of the battery cell charging chip U1. The control terminal of the switch Q4 is connected to the controller, the input terminal of the switch Q4 is connected to the first output terminal of the DC-DC power module, and the output terminal of the switch Q4 is connected to the power supply terminal of the battery cell charging chip U1.

4. The BMS self-power-off control circuit as described in claim 1, characterized in that, It also includes a voltage detection circuit connected to the controller for detecting the voltage of the auxiliary battery cell BAT1.

5. The BMS self-power-off control circuit as described in claim 4, characterized in that, The voltage detection circuit includes: voltage divider resistors R2 and R3, connected in series with the negative terminal of the auxiliary battery cell BAT1, for dividing the voltage of BAT1; operational amplifier U4, the non-inverting input of which is connected to the middle node of the voltage divider resistors R2 and R3, and the inverting input and output of operational amplifier U4 are connected to the AD sampling port of the controller; operational amplifier U3, the non-inverting input of which is connected to the positive terminal of the auxiliary battery cell BAT1, and the inverting input and output of operational amplifier U3 are connected to the end of the voltage divider resistor R2 furthest from the middle node.

6. The BMS self-power-off control circuit as described in claim 1, characterized in that, It also includes a protection circuit, which comprises: a cell protection chip U2, electrically connected to the auxiliary cell BAT1; a switch Q2, the control terminal of which is connected to the cell protection chip U2, for turning on or off the discharge circuit of the auxiliary cell BAT1; and a switch Q3, the control terminal of which is connected to the cell protection chip U2, for turning on or off the charging circuit of the auxiliary cell BAT1; wherein, the switch Q3 and the switch Q2 are connected in series to form a first branch, the input terminal of the first branch is connected to the negative terminal of the auxiliary cell BAT1, and the output terminal of the first branch is connected to the ground signal.

7. The BMS self-power-off control circuit as described in claim 1, characterized in that, The isolating switch is an optical MOS relay, the driving circuit is a light-emitting diode, and the main circuit includes a MOSFET.

8. The BMS self-power-off control circuit as described in claim 1, characterized in that, The DC-DC power module includes an isolation unit DC-DC1 and a power supply unit DC-DC2. The input terminal of the isolation unit DC-DC1 is connected to the main battery BAT2 through the main circuit. The input terminal of the power supply unit DC-DC2 is connected to the first output terminal of the isolation unit DC-DC1 to convert its output first voltage into a second voltage. The output terminal of the power supply unit DC-DC2 is connected to the power supply terminal of the controller.

9. The BMS self-power-off control circuit as described in claim 8, characterized in that, It also includes a button state detection circuit connected to the controller for monitoring the state of the external button SW. The button state detection circuit includes: a resistor R4, one end of which is connected to the first output terminal of the isolation unit DC-DC1; a resistor R5, which is connected between the resistor R4 and the I / O input port of the controller, with one end of the external button SW connected to ground and the other end connected between the resistor R4 and the resistor R5; a diode D4, whose anode is connected between the resistor R4 and the resistor R5, and whose cathode is connected to one end of the external button SW; and a diode D3, which is connected to the discharge circuit of the auxiliary battery cell BAT1, with the cathode of the diode D3 connected to the external button SW and the cathode of the diode D4, and the anode of the diode D3 connected to the input terminal of the switching transistor Q1.

10. An energy storage battery system, characterized in that, include: External communication power supply; battery PACK, including battery management system BMS and main battery BAT2, the main battery BAT2 is electrically connected to the external communication power supply through the main circuit so that the external communication power supply can charge and discharge it, the battery management system BMS includes: a communication module, which is communicatively connected to the external communication power supply; The controller is connected to the communication module; the DC-DC power module is connected to the main battery BAT2 and the controller to supply power to the controller; the battery PACK further includes the BMS self-power-off control circuit according to any one of claims 1 to 9, the self-power-off control circuit is connected to the controller, and the main circuit of the disconnect switch is connected in series in the power supply circuit between the DC-DC power module and the main battery BAT2.

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