Battery management system and battery device

Abstract

This application relates to a battery management system and battery device, comprising: a main control chip, a power module, and a power supply control module. The power supply control module connects the battery pack of the battery device, an external charging device, and the power module. The power module connects the main control chip and a relay of the battery device. The main control chip connects the battery pack and the external charging device. When the first supply voltage of the battery pack is lower than a protection threshold, the power supply control module stops outputting the first supply voltage to the power module, and the main control chip loses power. When the main control chip loses power, it stops outputting a shutdown signal to the external charging device, so that the external charging device outputs a second supply voltage to the power supply control module. The power supply control module outputs the second supply voltage to the power module, so that the main control chip is powered on and the relay switches to the on state, allowing the battery pack to be charged through the external charging device. This effectively solves the problem that the battery cannot be restored by external charging after undervoltage, especially when the battery voltage reaches 0V, which is inconvenient to use.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a battery management system and battery device. Background Technology

[0002] As global oil resources become increasingly scarce, the demand for new energy sources is growing. Lithium-ion batteries, as the most popular alternative to fossil fuels, have rapidly penetrated various industries. When the voltage and capacity of a single lithium-ion battery cannot meet usage requirements, multiple batteries are connected in series and parallel to form a battery pack to increase the operating voltage and capacity. For safer and more controllable operation, a Battery Management System (BMS) is added to intelligently manage and maintain each battery cell.

[0003] However, lithium batteries currently have inherent static power consumption during use. When left unused for extended periods, the cell voltage can drop significantly, even reaching 0V. When an external battery management system (BMS) is used, the combined static power consumption of the lithium battery and the BMS further shortens the storage time. If the battery pack is not fully charged in time, the BMS will actively disconnect its power supply to reduce static power consumption and prevent irreversible damage from overuse. However, because the static power consumption of the individual cells cannot be eliminated, the cell voltage will drop to 0V. In such cases, the battery capacity cannot be restored through external charging; it must be returned to the factory for disassembly and maintenance, which is extremely inconvenient. Summary of the Invention

[0004] Based on this, a battery management system and battery device are provided to address the problem that the battery cannot be restored by external charging after it is undervoltage, especially when the battery voltage reaches 0V, which causes inconvenience in use.

[0005] A battery management system includes: a main control chip, a power module, and a power supply control module. The power supply control module is connected to the battery pack of the battery device, an external charging device, and the power module. The power module is connected to the main control chip and a relay of the battery device. The main control chip is also connected to the battery pack and the external charging device.

[0006] When the first supply voltage of the battery pack is lower than the protection threshold, the power supply control module stops outputting the first supply voltage to the power module, so as to de-energize the main control chip.

[0007] When the main control chip loses power, it stops outputting a shutdown signal to the external charging device, so that the external charging device outputs a second power supply voltage to the power supply control module.

[0008] The power supply control module outputs the second power supply voltage to the power module, so that the main control chip is powered on and the relay is switched to the conducting state, and the battery pack is charged through the external charging device.

[0009] In one embodiment, when the main control chip detects that the first power supply voltage of the battery pack meets the switching conditions, it re-outputs the shutdown signal to the external charging device, so that the external charging device stops outputting the second power supply voltage to the power supply control module, and the power supply control module switches to outputting the first power supply voltage to the power module.

[0010] In one embodiment, the power supply control module includes a voltage output circuit, a low-voltage identification circuit, a power supply control circuit, and a low-voltage charging circuit. The voltage output circuit is connected to the battery pack, the low-voltage identification circuit, and the power supply control circuit. The low-voltage identification circuit is connected to the battery pack, the external charging device, and the power supply control circuit. The power supply control circuit is connected to the battery pack and the power module. The low-voltage charging circuit is connected to the low-voltage identification circuit, the external charging device, and the power module.

[0011] In one embodiment, the voltage output circuit includes a voltage divider unit and a voltage regulator unit, the voltage divider unit being connected to the battery pack and the voltage regulator unit being connected to the low-voltage identification circuit and the power supply control circuit.

[0012] In one embodiment, the low-voltage identification circuit includes a comparator, a first voltage divider unit, and a second voltage divider unit. The comparator is connected to the voltage regulator unit, the first voltage divider unit, the second voltage divider unit, and the power supply control circuit. The first voltage divider unit is connected to the battery pack, and the second voltage divider unit is connected to the voltage regulator unit and the low-voltage charging circuit.

[0013] In one embodiment, the power supply control circuit includes a first switching unit and a second switching unit, wherein the first switching unit is connected to the comparator, the voltage regulator unit and the second switching unit, and the second switching unit is connected to the battery pack and the power module.

[0014] In one embodiment, the low-voltage charging circuit includes a first conducting tube and a second conducting tube. The external charging device is connected to the power module through the first conducting tube, and the external charging device is connected to the second voltage divider unit through the second conducting tube.

[0015] In one embodiment, the power module includes a first power supply, a second power supply, and a linear regulator. The first power supply is connected to the main control chip through the linear regulator. The first power supply is also connected to the power supply control module and the second power supply. The second power supply is connected to the main control chip and the relay.

[0016] In one embodiment, the battery management system further includes a front-end monitoring chip that connects the battery pack to the main control chip.

[0017] In one embodiment, a battery device is provided, including: a battery pack, a relay, and the aforementioned battery management system. The battery management system is connected to the battery pack, the external charging device, and the control terminal of the relay. One contact terminal of the relay is connected to the battery pack, and the other contact terminal of the relay is connected to the external charging device or a load via an external terminal.

[0018] In the aforementioned battery management system and battery device, when the power supply control module determines that the first supply voltage of the battery pack is lower than the protection threshold, it cuts off the power supply to the power module, causing the main control chip and relay to lose power. After the main control chip loses power, it stops outputting a shutdown signal to the external charging device, causing the external charging device to provide a second supply voltage to the power supply control module. The second supply voltage is then output to the power module, causing the relay to resume conduction and connecting the charging circuit between the battery pack and the external charging device. This effectively solves the problem of inconvenience caused by the inability to recover from battery undervoltage, especially when the battery voltage reaches 0V, through external charging. Attached Figure Description

[0019] Figure 1 This is a system block diagram of a battery device in one embodiment;

[0020] Figure 2 This is a system block diagram of the power supply control module in one embodiment;

[0021] Figure 3 This is a circuit diagram of a voltage output circuit in one embodiment;

[0022] Figure 4 This is a circuit diagram of a low-voltage identification circuit, a power supply control circuit, and a low-voltage charging circuit in one embodiment.

[0023] Figure 5 This is a schematic diagram showing the connection between the battery device and an external device in one embodiment. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0026] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0027] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0028] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0029] As described in the background section, lithium batteries have inherent static power consumption during use. When left unused for extended periods, the cell voltage can drop significantly, even reaching 0V. When an external Battery Management System (BMS) is used, the combined static power consumption of the lithium battery and the BMS further shortens the storage time. If the battery pack is not fully charged in time, the BMS will actively disconnect its power supply to reduce static power consumption and prevent irreversible damage from overuse. However, because the static power consumption of the individual cells cannot be eliminated, the cell voltage will drop to 0V. In such cases, the battery capacity cannot be restored through external charging; it must be returned to the factory for disassembly and maintenance, which is extremely inconvenient.

[0030] Based on this, this application provides a battery management system and battery device. When it is determined that the voltage of the battery pack used for power supply is lower than a protection threshold, the power supply to the battery management system is cut off, and the main control chip and relay are also de-energized. After the main control chip loses power, it stops outputting a shutdown signal to the external charging device, causing the external charging device to provide a second power supply voltage to the power supply control module. The second power supply voltage is then output to the power module, causing the relay to resume conduction and connecting the charging circuit between the battery pack and the external charging device. This effectively solves the problem that after the battery is under-voltage, especially when the battery voltage reaches 0V, it cannot be restored by external charging, which is inconvenient to use.

[0031] In one embodiment, such as Figure 1 The diagram illustrates a battery management system, comprising: a main control chip 110, a power module 120, and a power supply control module 130. The power supply control module 130 is connected to the battery pack 200 of the battery device, an external charging device, and the power module 120. The power module 120 is connected to the main control chip 110 and a relay 300 of the battery device. The main control chip 110 is also connected to the battery pack 200 and the external charging device. When the first supply voltage of the battery pack 200 is lower than a protection threshold, the power supply control module 130 stops outputting the first supply voltage to the power module 120, thereby de-energizing the main control chip 110. When de-energized, the main control chip 110 stops outputting a shutdown signal to the external charging device, thereby causing the external charging device to output a second supply voltage to the power supply control module 130. The power supply control module 130 outputs the second supply voltage to the power module 120, thereby energizing the main control chip 110, switching the relay 300 to the on state, and charging the battery pack 200 through the external charging device.

[0032] The battery pack 200 of the battery device can be composed of a single cell or multiple cells connected in series. The series connection includes a total positive terminal B+ and a total negative terminal B-. The total positive terminal B+ and the total negative terminal B- of the battery pack 200 are connected to the external positive terminal P+ and the external negative terminal P-, respectively. The external devices connected to these two external terminals are not unique; they can be connected to a load to form a discharge circuit, using the battery pack 200 to supply power to the load; or they can be connected to an external charging device to form a charging circuit, using the external charging device to charge the battery pack 200.

[0033] A relay 300 is also provided on the connection line between the main positive terminal B+ of the battery pack 200 and the external positive terminal P+, or on the connection line between the main negative terminal B- and the external negative terminal P-, to control whether the discharge circuit or charging circuit between the battery pack 200 and the external device is open. When the relay 300 is turned on, the discharge circuit or charging circuit between the battery pack 200 and the external device is connected, which can be used to supply power to the load or charge it using an external charging device; when the relay 300 is turned off, the discharge circuit or charging circuit between the battery pack 200 and the external device is disconnected, and it is not possible to supply power to the load or charge it using an external charging device.

[0034] The battery management system (BMS) can be used to monitor and manage the operating status of the battery pack 200, that is, to control and monitor the operating status of the discharge circuit and charging circuit of the battery pack 200. Specifically, the power module 120 is connected to the total positive terminal B+ and the total negative terminal B- of the battery pack 200 through the power supply control module 130 to obtain a first supply voltage, and supplies power to the main control chip 110 according to the obtained first supply voltage to ensure the normal operation of the battery management system. The power module 120 is also connected to the control terminal of the relay 300. The main control chip 110 can output an enable signal to the power module 120 to control the power module 120 to supply power to the control terminal of the relay 300, so that the relay 300 is turned on, thereby turning on the discharge circuit or charging circuit of the battery pack 200. Correspondingly, when the main control chip 110 stops outputting the enable signal to the power module 120, the power module 120 stops supplying power to the control terminal of the relay 300, so that the relay 300 is turned off, thereby turning off the discharge circuit or charging circuit of the battery pack 200.

[0035] The main control chip 110 can connect to the battery pack 200 to obtain its operating parameters and determine whether to output an enable signal to the power module 120 based on these parameters. For example, the operating parameter could be the voltage of the battery pack 200. When the main control chip 110 detects that the voltage of the battery pack 200 is lower than a preset low voltage threshold, it stops outputting the enable signal to the power module 120, controlling the power module 120 to stop supplying power to the control terminal of the relay 300, causing the relay 300 to disconnect and thus disconnecting the discharge circuit of the battery pack 200. Subsequently, when the battery pack 200 is connected to an external charging device to form a charging circuit, the main control chip 110 can correspondingly re-output the enable signal to the power module 120, controlling the power module 120 to supply power to the control terminal of the relay 300, causing the relay 300 to conduct. The specific setting value of the preset low voltage threshold is not unique and can be set according to the actual power supply parameters of the battery pack 200. It can be understood as the voltage value when the battery pack 200 does not have enough energy to supply power to the load.

[0036] When the main control chip 110 detects that the voltage of the battery pack 200 is lower than the preset low voltage threshold and cuts off the discharge circuit of the battery pack 200, it will also issue a reminder message to remind the user to charge the battery pack 200 in time. If the user still does not charge it in time, the first supply voltage of the battery pack 200 will continue to decrease due to the power consumption of the main control chip and its own static self-discharge. When it continues to decrease to the protection threshold, the power supply control module 130 stops outputting the first supply voltage to the power module 120, so that the main control chip 110 cannot obtain the energy of the battery device itself for normal power supply through the power module 120, but instead obtains the second supply voltage through the power supply control module 130 connected to the external charging device. The power supply control module 130 connects the positive terminal C+ and the negative terminal C- of the external charging device to obtain the second supply voltage. The protection threshold is lower than the preset low voltage threshold, and the specific setting value is not unique. It can be set according to the actual power supply parameters of the battery pack 200. It can be understood as the voltage value when the battery pack 200 does not have enough energy to supply power to the battery management system.

[0037] The main control chip 110 is connected to an external charging device via a communication line. When the battery device is powered normally by the power module 120, it continuously outputs a shutdown signal to the external charging device to prevent the external charging device from outputting a second supply voltage to the power supply control module 130. When the main control chip loses power and stops outputting the shutdown signal to the external charging device, the external charging device outputs a second supply voltage to the power supply control module 130. The power supply control module 130 outputs the second supply voltage to the power module 120 to restore power supply to the main control chip 110. Simultaneously, the main control chip 110 outputs an enable signal to the power module 120, controlling the power module 120 to supply power to the control terminal of the relay 300, causing the relay 300 to conduct, thereby activating the charging circuit of the battery pack 200, allowing the battery pack 200 to be charged using an external charging device or other external power source.

[0038] In the aforementioned battery management system, when the power supply control module determines that the first supply voltage is lower than the protection threshold, it cuts off the power supply to the power module, causing the main control chip and relays to lose power. After the main control chip loses power, it stops outputting a shutdown signal to the external charging device, causing the external charging device to provide a second supply voltage to the power supply control module. The second supply voltage is then output to the power module, causing the relays to resume conduction and connecting the charging circuit between the battery pack and the external charging device. This effectively solves the problem of inconvenience caused by the inability to recover from battery undervoltage, especially when the battery voltage reaches 0V, through external charging.

[0039] In one embodiment, such as Figure 1As shown, when the main control chip 110 detects that the first power supply voltage of the battery pack 200 meets the switching conditions, it re-outputs the shutdown signal to the external charging device, so that the external charging device stops outputting the second power supply voltage to the power supply control module 130, and the power supply control module 130 switches to outputting the first power supply voltage to the power module 120.

[0040] The switching condition can be understood as ensuring that switching to the first supply voltage to power the main control chip 110 does not cause the first supply voltage to drop back to the protection threshold in a short period of time. The switching condition that the first supply voltage must meet can be that the first supply voltage is greater than a preset switching threshold. Obviously, the preset switching threshold is greater than both the protection threshold and the preset low-battery threshold; the specific setting value is not limited and can be set according to the actual power supply parameters of the battery pack 200 and the main control chip 110. For example, in this embodiment, to ensure system reliability and stability, the preset switching threshold is set to the voltage value when the battery pack 200 is fully charged. During the charging process of the battery pack 200, the battery management system does not consume the battery pack 200's power but obtains power from an external charging device, which also reduces the capacity consumption of the battery pack 200 itself.

[0041] The main control chip 110 obtains the operating parameters of the battery pack 110 in various ways. In one embodiment, the battery management system further includes a front-end monitoring chip 140, which is connected to the battery pack 200 and the main control chip 110. Specifically, the front-end monitoring chip 140 can be connected to each cell in the battery pack 200 to obtain its cell voltage, temperature, and current parameters. Alternatively, it can be directly connected to the total positive terminal B+ and the total negative terminal B- of the battery pack 200 to collect the overall voltage, current, and temperature parameters of the battery pack 200. When the main control chip 110 is powered on, the front-end monitoring chip 140 can communicate with the main control chip 110 via I / O. 2 The C-communication enables bidirectional data communication, sending the real-time collected operating parameters to the main control chip 110. This provides the main control chip 110 with the data foundation for monitoring and controlling the operating status of the battery pack 200, thus better enabling the management of the battery pack 200.

[0042] In one embodiment, such as Figure 2 As shown, the power supply control module 130 includes a voltage output circuit 131, a low-voltage identification circuit 132, a power supply control circuit 133, and a low-voltage charging circuit 134. The voltage output circuit 131 is connected to the battery pack 200, the low-voltage identification circuit 132, and the power supply control circuit 133. The low-voltage identification circuit 132 is connected to the battery pack 200, the external charging device, and the power supply control circuit 133. The power supply control circuit 133 is connected to the battery pack 200 and the power module 120. The low-voltage charging circuit 134 is connected to the low-voltage identification circuit 132, the external charging device, and the power module 120.

[0043] The voltage output circuit 131 connects the positive terminal B+ and the negative terminal B- of the battery pack 200 to obtain a first supply voltage, converts it into an internal supply voltage of 3.3V, and then outputs it to the low-voltage identification circuit 132 and the power supply control circuit 133 through the VCC_EN terminal. The low-voltage identification circuit 132 compares the first supply voltage of the battery pack 200 with the internal supply voltage output by the voltage output circuit 131 and outputs the comparison result to the power supply control circuit 133. The power supply control circuit 133 controls whether to output the first supply voltage of the battery pack 200 to the power module 120 based on the comparison result output by the low-voltage identification circuit 132. When the first supply voltage continuously decreases to a protection threshold and the power supply control circuit 133 stops outputting the first supply voltage to the power module 120, the low-voltage charging circuit 134 connects to an external charging device to obtain a second supply voltage for power supply.

[0044] like Figure 3 As shown, in one embodiment, the voltage output circuit includes a voltage divider unit and a voltage regulator unit. The voltage divider unit is connected to the battery pack and the voltage regulator unit, and the voltage regulator unit is connected to the low-voltage identification circuit and the power supply control circuit.

[0045] The voltage divider unit includes resistors R1 and R2, a Zener diode D1, and transistors Q1 and Q2. Resistors R1 and R2 are connected in series. The other end of resistor R1 is connected to the positive terminal B+ of the battery pack, and the other end of resistor R2 is connected to the negative terminal B- of the battery pack via the reverse-connected Zener diode D1, thus obtaining the first supply voltage for voltage division. The common terminal of the series resistors R1 and R2 is connected to the collectors of both transistors Q1 and Q2. The other end of resistor R2 is also connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the base of transistor Q2, and the emitter of transistor Q2 is connected to the voltage regulator unit. After the first supply voltage is divided and turned on by transistors Q1 and Q2, the divided first supply voltage is output to the voltage regulator unit.

[0046] The voltage regulator unit includes resistors R3 and R4, Zener diodes D2 and D3, capacitors C1 and C2, and a linear regulator U1. Zener diode D2 is connected in parallel with capacitor C1. The anode of Zener diode D2 is connected to the negative terminal B- of the battery pack. The cathode of Zener diode D2 is connected to the emitter of transistor Q2 through resistor R3. The cathode of Zener diode D2 is connected to the IN terminal of linear regulator U1 through resistor R4. The GND terminal of linear regulator U1 is connected to the negative terminal B- of the battery pack. Zener diode D3 is connected in parallel with capacitor C2. The anode of Zener diode D3 is connected to the negative terminal B- of the battery pack. The cathode of Zener diode D3 is connected to the OUT terminal of linear regulator U1. The OUT terminal of linear regulator U1 is connected to the low-voltage identification circuit and the power supply control circuit through the VCC_EN terminal.

[0047] In one embodiment, such as Figure 4 As shown, the low-voltage identification circuit includes a comparator U2, a first voltage divider unit, and a second voltage divider unit. The comparator U2 is connected to the voltage regulator unit, the first voltage divider unit, the second voltage divider unit, and the power supply control circuit. The first voltage divider unit is connected to the battery pack, and the second voltage divider unit is connected to the voltage regulator unit and the low-voltage charging circuit.

[0048] The first voltage divider unit includes resistors R5, R6, and R7, and capacitor C3. The second voltage divider unit includes resistors R8 and R9, diode D4, and capacitor C4. Resistors R5, R6, and R7 are connected in series. The other end of resistor R5 is connected to the positive terminal B+ of the battery pack. The common terminal of resistors R6 and R7 is connected to the IN+ terminal of comparator U2. The other end of resistor R7 is connected to the negative terminal B- of the battery pack. Capacitor C3 is connected in parallel with resistor R7. Resistors R8 and R9 are connected in series. The other end of resistor R8 is connected to the cathode of diode D4 and the low-voltage charging circuit. The anode of diode D4 is connected to the VCC_EN terminal. The other end of resistor R9 is connected to the negative terminal B- of the battery pack. The common terminal of resistors R8 and R9 is connected to the IN- terminal of comparator U2. Capacitor C4 is connected in parallel with resistor R9. The VCC terminal of comparator U2 is connected to the VCC_EN terminal, the VSS terminal of comparator U2 is connected to the total negative terminal B- of the battery pack, and the OUT terminal of comparator U2 is used to output the comparison result to the first switching unit of the power supply control circuit.

[0049] Comparator U2 compares the voltage division result of the first supply voltage of the battery pack connected to its IN+ terminal through the first voltage divider unit with the voltage division result of the internal supply voltage output by the voltage output circuit connected to its IN- terminal through the second voltage divider unit. When the input at the IN+ terminal is greater than the input at the IN- terminal, that is, when the voltage division result of the first supply voltage through the first voltage divider unit is greater than the voltage division result of the internal supply voltage through the second voltage divider unit, the output of the OUT terminal of comparator U2 is high. When the input at the IN+ terminal is less than the input at the IN- terminal, that is, when the voltage division result of the first supply voltage through the first voltage divider unit is less than the voltage division result of the internal supply voltage through the second voltage divider unit, the output of the OUT terminal of comparator U2 is low.

[0050] In one embodiment, such as Figure 4 As shown, the power supply control circuit includes a first switching unit and a second switching unit. The first switching unit is connected to the comparator U2, the voltage regulator unit and the second switching unit, and the second switching unit is connected to the battery pack and the power module.

[0051] The first switching unit includes resistors R12, R13, and R14, and transistors Q3 and Q5. The second switching unit includes resistors R15, R16, R17, R18, and R19, a Zener diode D6, a diode D7, a diode D9, transistor Q6, a MOSFET Q7 (P-channel type), and a capacitor C5. The base of transistor Q3 is connected to the OUT terminal of comparator U2 through resistor R12. The emitter of transistor Q3 is connected to the negative terminal B- of the battery pack. The collector of transistor Q3 is connected to the base of transistor Q5 through resistor R13. The base of transistor Q5 is also connected to the VCC_EN terminal through resistor R14. The emitter of transistor Q5 is connected to the VCC_EN terminal. The collector of transistor Q5 is connected to the base of transistor Q6 in sequence through resistor R15, diode D7, and resistor R16. The base is connected to the battery pack's negative terminal B- via resistor R19 and capacitor C5. The emitter of transistor Q6 is connected to the battery pack's negative terminal B-. The collector of transistor Q6 is connected to the gate of MOSFET Q7 via resistor R17. The gate of MOSFET Q7 is connected to the battery pack's positive terminal B+ via resistor R18 and Zener diode D6. The source of MOSFET Q7 is connected to the battery pack's positive terminal B+. The drain of MOSFET Q7 is connected to the power module's BAT+ terminal via diode D9.

[0052] The base of transistor Q3 is connected to the OUT terminal of comparator U2 via resistor R12 to obtain the comparison result. When the comparison result is high, transistors Q3 and Q5 conduct in sequence, outputting the internal supply voltage from the voltage output circuit to transistor Q6. After transistor Q6 conducts, the gate of MOSFET Q7 is switched to a low level, and MOSFET Q7 conducts, connecting the battery pack's positive terminal B+ to the power module's BAT+ terminal, outputting the first supply voltage to the power module. Conversely, when the comparison result is low, transistors Q3 and Q5 are switched off in sequence. The internal supply voltage from the voltage output circuit is not output to transistor Q6, and transistor Q6 is off. The gate of MOSFET Q7 is switched to the high level connected to the battery pack's positive terminal B+, and MOSFET Q7 is off. The first supply voltage from the battery pack's positive terminal B+ stops being output to the power module.

[0053] In addition, the power supply control circuit includes resistors R10 and R11 and a MOSFET Q4 (N-channel). The gate of MOSFET Q4 is connected to the OUT terminal of comparator U2 through resistor R11, the source of MOSFET Q4 is connected to the negative terminal B- of the battery pack, and the drain of MOSFET Q4 is connected to the IN- terminal of comparator U2 through resistor R10. The positive terminal B+ of the battery pack is connected to the low-voltage identification circuit power supply control circuit through a ferrite bead FB1 to suppress high-frequency noise and spike interference on the signal and power lines.

[0054] In one embodiment, such as Figure 4 As shown, the low-voltage charging circuit includes a first conducting diode and a second conducting diode. The external charging device is connected to the power module through the first conducting diode, and to the second voltage divider unit through the second conducting diode. The first conducting diode is diode D8, and the second conducting diode is diode D5. The positive terminal C+ of the external charging device is connected to the BAT+ terminal of the power module through diode D8, supplying the second supply voltage to the power module for power. Additionally, the positive terminal C+ of the external charging device is also connected to the other end of the resistor R8 in the second voltage divider unit through diode D5. This allows the second supply voltage to be divided and input to the IN- terminal of comparator U2 while simultaneously supplying power to the power module. Since the second supply voltage is greater than the internal supply voltage output by the voltage output circuit, diode D4 will not conduct. Furthermore, the design of the voltage division value in the first voltage divider unit ensures that during continuous charging of the battery pack, the power module will not be powered by the first supply voltage automatically switched to by the power supply control module. This ensures that when the second supply voltage is available, it is continuously used to power the power module.

[0055] In one embodiment, such as Figure 1 As shown, the power module 120 includes a first power supply DC-DC1, a second power supply DC-DC2, and a linear regulator LDO. The first power supply DC-DC1 is connected to the main control chip 110 through the linear regulator LDO. The first power supply DC-DC1 is also connected to the power supply control module 130 and the second power supply DC-DC2. The second power supply DC-DC2 is connected to the main control chip 110 and the relay 300.

[0056] The first power supply DC-DC1 is used to step down either the first or second power supply voltage output by the power supply control module 130 and output it to the linear regulator LDO and the second power supply DC-DC2, respectively. The linear regulator LDO is used to linearly regulate the voltage after stepping down the first power supply DC-DC1, outputting a voltage that meets the power supply requirements of the main control chip 110. The second power supply DC-DC2 is used to boost the voltage after stepping down the first power supply DC-DC1 to the power supply voltage required by the relay 300, providing power to the excitation coil of the relay 300. In addition, the second power supply DC-DC2 is also used to connect to the main control chip 110 to receive an enable signal; power is only provided to the excitation coil of the relay 300 when an enable signal is present.

[0057] In one embodiment, such as Figure 1 and Figure 5As shown, a battery device is provided, including: a battery pack 200, a relay 300 and the aforementioned battery management system 100. The battery management system 100 connects the battery pack 200, an external charging device and the control terminal of the relay 300. One contact terminal of the relay 300 is connected to the battery pack 200, and the other contact terminal of the relay 300 is connected to an external charging device or a load through an external terminal.

[0058] The battery pack 200 can be composed of a single cell or multiple cells (C1~Cx) connected in series. After series connection, it includes a total positive terminal B+ and a total negative terminal B-. The total positive terminal B+ and the total negative terminal B- of the battery pack 200 are respectively connected to the external positive terminal P+ and the external negative terminal P-. The external devices connected to these two external terminals are not unique; they can be connected to a load to form a discharge circuit, using the battery pack 200 to power the load; or they can be connected to an external charging device to form a charging circuit, using the external charging device to charge the battery pack 200. A relay 300 is also provided on the connection line between the total positive terminal B+ and the external positive terminal P+ or the connection line between the total negative terminal B- and the external negative terminal P- of the battery pack 200. For example, in this embodiment, the control terminal of the relay 300 is connected to the power management system, one contact terminal of the relay 300 is connected to the total negative terminal B- of the battery pack 200, and the other contact terminal of the relay 300 is connected to an external charging device or a load through the external negative terminal P-.

[0059] The battery management system can be used to monitor and manage the operating status of the battery pack 200, that is, to control and monitor the operating status of the discharge circuit and charging circuit of the battery pack 200. When the first supply voltage of the battery pack 200 is detected to be lower than the preset low voltage threshold, the power supply to the control terminal of the relay 300 will be stopped, causing the relay 300 to open, thereby disconnecting the discharge circuit of the battery pack 200. At the same time, a reminder message will be issued to remind the user to charge the battery pack 200 in time. If the user still does not charge in time, the first supply voltage of the battery pack 200 will continue to decrease due to the power consumption of the main control chip and its own static self-discharge. When it continues to decrease to the protection threshold, the power management system will automatically cut off the acquisition of the first supply voltage and switch to obtaining the second supply voltage by connecting the positive terminal C+ and the negative terminal C- of the external charging device, supplying power to the control terminal of the relay 300, causing the relay 300 to conduct, thereby opening the charging circuit of the battery pack 200, and charging the battery pack 200 using the external charging device or other external power source.

[0060] For specific limitations in one or more of the battery device embodiments provided above, please refer to the limitations of the power management system above, which will not be repeated here.

[0061] In this embodiment, when the battery pack is severely depleted, a second power supply voltage can be provided to the power management system through an external charging device to enable the relay to resume conduction, thereby connecting the charging circuit between the battery pack and the external charging device. This effectively solves the problem that the battery cannot be restored by external charging after it is undervoltage, especially when the battery voltage reaches 0V, which is inconvenient to use.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery management system, characterized in that, It includes: a main control chip, a power module and a power supply control module. The power supply control module is connected to the battery pack of the battery device, an external charging device and the power module. The power module is connected to the main control chip and the relay of the battery device. The main control chip is also connected to the battery pack and the external charging device. When the first supply voltage of the battery pack is lower than the protection threshold, the power supply control module stops outputting the first supply voltage to the power module, so as to de-energize the main control chip. When the main control chip loses power, it stops outputting a shutdown signal to the external charging device, so that the external charging device outputs a second power supply voltage to the power supply control module. The power supply control module outputs the second power supply voltage to the power module, so that the main control chip is powered on and the relay is switched to the on state, and the battery pack is charged through the external charging device. The power supply control module includes a voltage output circuit, a low-voltage identification circuit, a power supply control circuit, and a low-voltage charging circuit. The voltage output circuit includes a voltage divider unit and a voltage regulator unit. The low-voltage identification circuit includes a comparator, a first voltage divider unit, and a second voltage divider unit. The low-voltage charging circuit includes a first conducting diode and a second conducting diode. The voltage divider unit is connected to the battery pack and the voltage regulator unit. The voltage regulator unit is connected to the comparator, the second voltage divider unit, and the power supply control circuit. The comparator is connected to the first voltage divider unit, the second voltage divider unit, and the power supply control circuit. The first voltage divider unit is connected to the battery pack. The external charging device is connected to the power module through the first conducting diode. The external charging device is connected to the second voltage divider unit through the second conducting diode. The power supply control circuit is connected to the battery pack and the power module.

2. The battery management system according to claim 1, characterized in that, When the main control chip detects that the first power supply voltage of the battery pack meets the switching conditions, it re-outputs the shutdown signal to the external charging device, so that the external charging device stops outputting the second power supply voltage to the power supply control module, and the power supply control module switches to outputting the first power supply voltage to the power module.

3. The battery management system according to claim 1, characterized in that, The power supply control circuit includes a first switching unit and a second switching unit. The first switching unit is connected to the comparator, the voltage regulator unit and the second switching unit, and the second switching unit is connected to the battery pack and the power module.

4. The battery management system according to claim 3, characterized in that, The voltage divider unit includes resistor R1, resistor R2, Zener diode D1, transistor Q1, and transistor Q2; After resistors R1 and R2 are connected in series, the other end of resistor R1 is connected to the positive terminal B+ of the battery pack, and the other end of resistor R2 is connected to the negative terminal B- of the battery pack through the Zener diode D1 connected in reverse. The common terminal of resistors R1 and R2 connected in series is connected to the collectors of transistors Q1 and Q2. The other end of resistor R2 is also connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the base of transistor Q2. The emitter of transistor Q2 is connected to the voltage regulator unit.

5. The battery management system according to claim 4, characterized in that, The voltage regulator unit includes resistor R3, resistor R4, Zener diode D2, Zener diode D3, capacitor C1, capacitor C2, and linear regulator U1; The Zener diode D2 is connected in parallel with the capacitor C1. The anode of the Zener diode D2 is connected to the negative terminal B- of the battery pack. The cathode of the Zener diode D2 is connected to the emitter of the transistor Q2 through the resistor R3. The cathode of the Zener diode D2 is connected to the IN terminal of the linear regulator U1 through the resistor R4. The GND terminal of the linear regulator U1 is connected to the negative terminal B- of the battery pack. The Zener diode D3 is connected in parallel with the capacitor C2. The anode of the Zener diode D3 is connected to the negative terminal B- of the battery pack. The cathode of the Zener diode D3 is connected to the OUT terminal of the linear regulator U1. The OUT terminal of the linear regulator U1 is connected to the low-voltage identification circuit and the power supply control circuit through the VCC_EN terminal.

6. The battery management system according to claim 5, characterized in that, The first voltage divider unit includes resistors R5, R6, and R7 and capacitor C3; the second voltage divider unit includes resistors R8 and R9, diode D4 and capacitor C4. Resistors R5, R6, and R7 are connected in series. The other end of resistor R5 is connected to the positive terminal B+ of the battery pack. The common terminal of resistors R6 and R7 is connected to the IN+ terminal of comparator U2. The other end of resistor R7 is connected to the negative terminal B- of the battery pack. Capacitor C3 is connected in parallel with resistor R7. Resistors R8 and R9 are connected in series. The other end of resistor R8 is connected to the cathode of diode D4 and the low-voltage charging circuit. The anode of diode D4 is connected to the VCC_EN terminal. The other end of resistor R9 is connected to the negative terminal B- of the battery pack. The common terminal of resistors R8 and R9 is connected to the IN- terminal of comparator U2. Capacitor C4 is connected in parallel with resistor R9. The VCC terminal of comparator U2 is connected to the VCC_EN terminal. The VSS terminal of comparator U2 is connected to the negative terminal B- of the battery pack. The OUT terminal of comparator U2 is used to output the comparison result to the first switching unit of the power supply control circuit.

7. The battery management system according to claim 6, characterized in that, The first switching unit includes resistors R12, R13, and R14, transistors Q3 and Q5, and the second switching unit includes resistors R15, R16, R17, R18, and R19, Zener diodes D6, D7, and D9, transistor Q6, MOSFET Q7, and capacitor C5. The base of transistor Q3 is connected to the OUT terminal of comparator U2 through resistor R12. The emitter of transistor Q3 is connected to the negative terminal B- of the battery pack. The collector of transistor Q3 is connected to the base of transistor Q5 through resistor R13. The base of transistor Q5 is also connected to the VCC_EN terminal through resistor R14. The emitter of transistor Q5 is connected to the VCC_EN terminal. The collector of transistor Q5 is connected to the base of transistor Q6 in sequence through resistor R15, diode D7, and resistor R16. The base is connected to the negative terminal B- of the battery pack via resistor R19 and capacitor C5. The emitter of transistor Q6 is connected to the negative terminal B- of the battery pack. The collector of transistor Q6 is connected to the gate of MOSFET Q7 via resistor R17. The gate of MOSFET Q7 is connected to the positive terminal B+ of the battery pack via resistor R18 and Zener diode D6. The source of MOSFET Q7 is connected to the positive terminal B+ of the battery pack. The drain of MOSFET Q7 is connected to the BAT+ terminal of the power module via diode D9.

8. The battery management system according to claim 1, characterized in that, The power module includes a first power supply, a second power supply, and a linear regulator. The first power supply is connected to the main control chip through the linear regulator. The first power supply is also connected to the power supply control module and the second power supply. The second power supply is connected to the main control chip and the relay.

9. The battery management system according to any one of claims 1-8, characterized in that, It also includes a front-end monitoring chip, which connects the battery pack to the main control chip.

10. A battery device, characterized in that, include: The battery pack, the relay, and the battery management system according to any one of claims 1-9, wherein the battery management system connects the battery pack, the external charging device, and the control terminal of the relay, one contact terminal of the relay is connected to the battery pack, and the other contact terminal of the relay is connected to the external charging device or load through an external terminal.

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