Standby battery control system, energy storage device and vehicle

Abstract

The utility model relates to a standby battery control system, an energy storage device and a vehicle, and relates to the technical field of power management. The backup battery control system includes a controller, a charging circuit, and a discharging circuit. Wherein the charging circuit is connected with the controller and the automobile storage battery and is used for controlling the automobile storage battery to charge the standby battery; the discharging circuit is connected with the standby battery and used for controlling the standby battery to discharge according to the output voltage of the automobile storage battery; the discharge circuit comprises a comparison sub-circuit, a boost chip and a reference sub-circuit. The comparison sub-circuit is used for comparing the reference voltage with the output voltage of the automobile storage battery and generating a discharge enable signal; the boost chip controls the standby battery to discharge in response to the discharge enable signal. Thus, through the charging circuit and the discharging circuit which are separately designed, compared with the mode that a finished product chip is directly used for standby battery management, the cost is reduced, the flexibility and expandability of vehicle standby battery management are improved, and a user can conveniently expand or customize functions according to actual requirements.

Description

Technical Field

[0001] The present application relates to the field of power management technology, and in particular to a backup battery control system, an energy storage device, and a vehicle. Background Art

[0002] A car battery is a rechargeable power supply device used to provide power to the vehicle's various electrical systems (such as audio, lighting, navigation, etc.) when the engine is not running. It plays a vital role in the vehicle. In order to be able to drive the vehicle's electrical system normally when the car battery is abnormal, it is usually necessary to equip the vehicle with a backup battery.

[0003] Currently, finished chips are usually used to manage vehicle backup batteries. However, these chips have a single function and cannot be expanded according to actual needs, resulting in poor flexibility in backup battery management.

[0004] Therefore, how to improve the flexibility of vehicle backup battery management so as to expand the functions of vehicle backup batteries is an urgent problem to be solved. Summary of the Invention

[0005] An embodiment of the present application provides a backup battery control system that improves the flexibility of vehicle backup battery management so as to expand the functions of the vehicle backup battery and at least partially solve the above-mentioned technical problems.

[0006] In order to achieve the above objectives, according to a first aspect of the present application, a backup battery control system is provided, comprising:

[0007] Controller;

[0008] a charging circuit connected to the controller and the car battery, for controlling the charging of the backup battery from the car battery;

[0009] A discharge circuit is connected to the backup battery and is used to control the discharge of the backup battery according to the output voltage of the car battery.

[0010] Optionally, the discharge circuit includes a comparison subcircuit, a boost chip, and a reference subcircuit for outputting a reference voltage;

[0011] The comparison subcircuit is connected to the reference subcircuit and the vehicle battery, and is used to compare the reference voltage with the output voltage of the vehicle battery, and generate a discharge enable signal according to the comparison result;

[0012] The boost chip is connected to the backup battery and the comparison sub-circuit, and controls the discharge of the backup battery in response to the discharge enable signal;

[0013] Wherein, the comparison subcircuit includes a first resistor, a first comparator, a second comparator and a voltage dividing unit;

[0014] The first comparator has a first input connected to the car battery and the voltage divider, a second input connected to the voltage divider and the first input of the second comparator, and an output connected to one end of the first resistor and the output of the second comparator;

[0015] The second input terminal of the second comparator is connected to the reference sub-circuit; the other end of the first resistor is connected to a voltage source.

[0016] Optionally, the reference subcircuit includes a reference source;

[0017] The output end of the reference source is connected to the comparison sub-circuit, and is used to provide the reference voltage to the comparison sub-circuit.

[0018] Optionally, the reference subcircuit includes a second resistor and a third resistor;

[0019] One end of the second resistor is connected to a voltage source, and the other end is connected to one end of the third resistor and the comparison sub-circuit;

[0020] The other end of the third resistor is grounded.

[0021] Optionally, the discharge circuit further includes a driving subcircuit provided between the comparison subcircuit and the boost chip;

[0022] The driving sub-circuit drives the boost chip in response to the discharge enable signal.

[0023] Optionally, the driving sub-circuit includes a first switching tube and a fourth resistor;

[0024] The first switch tube includes a first electrode connected to the backup battery and one end of the fourth resistor, a second electrode connected to the boost chip, and a control electrode connected to the other end of the fourth resistor and the comparison subcircuit.

[0025] Optionally, the charging circuit includes a charging chip and a fifth resistor;

[0026] The charging chip includes an input terminal connected to the car battery, an output terminal connected to the backup battery, and a reference terminal connected to one end of the fifth resistor;

[0027] The other end of the fifth resistor is grounded;

[0028] The reference terminal is used to set the charging current output by the charging chip.

[0029] Optionally, the charging circuit further includes a sixth resistor and a second switch tube;

[0030] One end of the sixth resistor is connected to one end of the fifth resistor and the reference end of the charging chip, and the other end is connected to the first electrode of the second switching tube;

[0031] The second electrode of the second switch tube is grounded, and the control electrode is connected to the controller.

[0032] Optionally, the backup battery control system further includes a health detection circuit;

[0033] The health detection circuit is connected to the backup battery and the controller, and is used to measure the internal resistance of the backup battery to detect the health condition of the backup battery according to the internal resistance.

[0034] Optionally, the health detection circuit includes a third switch tube and a seventh resistor;

[0035] The third switch tube includes a first electrode connected to the backup battery, a second electrode connected to one end of the seventh resistor, and a control electrode connected to the controller;

[0036] The other end of the seventh resistor is grounded.

[0037] According to a second aspect of the present application, there is provided an energy storage device comprising a backup battery, a car battery and the above-mentioned backup battery control system.

[0038] According to a third aspect of the present application, a vehicle includes the above-mentioned energy storage device.

[0039] In summary, the backup battery control system provided in the embodiments of the present application controls the charging of the backup battery from the vehicle battery through a controller and charging circuit. The discharge circuit outputs a discharge enable signal to control the discharge of the backup battery when the vehicle battery output voltage drops, thereby achieving charge and discharge control of the backup battery. The separate design of the charging and discharging circuits reduces costs compared to directly using off-the-shelf chips for backup battery management, improving the flexibility and scalability of vehicle backup battery management and facilitating user-defined functionality expansion or customization.

[0040] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0042] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0043] Figure 1 is a block diagram of a backup battery control system provided in an exemplary embodiment of the present disclosure.

[0044] Figure 2 FIG. 1 is a circuit connection diagram of a backup battery control system provided in an exemplary embodiment of the present disclosure.

[0045] Figure 3 FIG. 4 is a circuit connection diagram of a discharge circuit provided in an exemplary embodiment of the present disclosure.

[0046] Figure 4 FIG. 4 is a circuit connection diagram of a reference sub-circuit provided in an exemplary embodiment of the present disclosure.

[0047] Figure 5 is a block diagram of an energy storage device provided in an exemplary embodiment of the present disclosure.

[0048] Explanation of the accompanying symbols: 1. Controller; 2. Charging circuit; 3. Discharging circuit; 31. Comparison subcircuit; 32. Reference subcircuit; 33. Driving subcircuit; 4. Health detection circuit; 5. Output circuit. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0050] According to the first aspect of this application, referring to Figures 1 to 4 The present disclosure provides a backup battery control system, including a controller 1, a charging circuit 2 and a discharging circuit 3.

[0051] The charging circuit 2 is connected to the controller 1 and the vehicle battery to control the charging process of the backup battery from the vehicle battery. The discharging circuit 3 is connected to the backup battery to control the discharge of the backup battery based on the output voltage of the vehicle battery. For example, the discharging circuit 3 may first detect the output voltage of the vehicle battery, then generate a discharge enable signal based on the detected output voltage, and then control the discharge of the backup battery based on the discharge enable signal.

[0052] Among them, the discharge circuit 3 does not need to be connected to the controller 1, and the output voltage detection of the car battery is realized by hardware, which has a faster response speed. As an example of a backup battery usage scenario, in an emergency such as a serious collision of the vehicle, the car battery may not be able to supply power normally due to physical damage (such as a broken connection line) or power outage. At this time, the emergency call system (ECALL) needs to be started immediately to send an emergency signal to the rescue center automatically or manually and may make a voice call. At this time, a backup battery is needed as an independent power supply for the emergency call system to ensure that when the car battery fails, enough power can still be obtained to complete the emergency call process. As another example of a backup battery usage scenario, when the vehicle encounters an abnormal situation that causes the car battery to be unable to continue to supply power, and the important information of the vehicle (such as vehicle location, fault code, driving data, etc.) needs to be transmitted to the remote server in a timely manner. At this time, the backup battery can provide power support for the key data transmission system to ensure that the key data transmission system can continue to work within a period of time after the vehicle car battery fails, thereby ensuring the security and timeliness of the information.

[0053] In the above embodiment, controller 1 and charging circuit 2 control the charging of the backup battery from the vehicle battery. Discharge circuit 3 outputs a discharge enable signal to control the discharge of the backup battery when the vehicle battery output voltage drops, thereby achieving charge and discharge control of the backup battery. This separate design of charging circuit 2 and discharging circuit 3 reduces costs compared to directly using off-the-shelf chips for backup battery management, improves the flexibility and scalability of vehicle backup battery management, and facilitates user-defined functionality expansion or customization.

[0054] Reference Figure 2 and Figure 3 In some embodiments, the discharge circuit 3 includes a comparison sub-circuit 31 , a boost chip U1 , and a reference sub-circuit 32 for outputting a reference voltage.

[0055] Comparison sub-circuit 31 is connected to reference sub-circuit 32 and the vehicle battery, and is used to compare the reference voltage with the vehicle battery's output voltage and generate a discharge enable signal based on the comparison result. Boost chip U1 is connected to the backup battery and comparison sub-circuit 31, and responds to the discharge enable signal to control the discharge of the backup battery.

[0056] In some embodiments, the comparison sub-circuit 31 includes a first resistor R1, a first comparator A1, a second comparator A2, and a voltage divider 311. The first comparator A1 has a first input connected to the vehicle battery and the voltage divider 311, a second input connected to the voltage divider 311 and the first input of the second comparator A2, and an output connected to one end of the first resistor R1 and the output of the second comparator A2. The second input of the second comparator A2 is connected to the reference sub-circuit 32. The other end of the first resistor R1 is connected to the voltage source VCC.

[0057] As an example, the voltage dividing unit 311 includes at least two resistors connected in series. For example, the voltage dividing unit 311 may include an eighth resistor R8 and a ninth resistor R9. One end of the eighth resistor R8 is connected to the first input terminal of the first comparator A1 and the car battery, and the other end is connected to one end of the ninth resistor R9, the second input terminal of the first comparator A1, and the first input terminal of the second comparator A2. The other end of the ninth resistor R9 is grounded.

[0058] Combine Figure 3 The first input of the first comparator A1 and the first input of the second comparator A2 can be positive inputs, while the second input of the first comparator A1 and the second input of the second comparator A2 can be negative inputs. The second input of the first comparator A1 and the first input of the second comparator A2 are connected to node A. The potential of node A is obtained by dividing the output voltage of the car battery by the voltage divider unit 311. The higher the output voltage of the car battery, the higher the potential of node A. Furthermore, because the first input of the first comparator A1 is connected to the car battery, the potential of the first input of the first comparator A1 is always higher than the potential of its second input, causing the first comparator A1 to always output a high level. When the output voltage of the car battery is within the normal range, the potential of node A is higher than the reference voltage output by the reference subcircuit 32, causing the second comparator A2 to output a high level. As the output voltage of the car battery gradually decreases, the potential of node A also decreases until the potential of node A falls below the reference voltage, indicating that the car battery has lost power. At this point, the second comparator A2 outputs a low level.

[0059] As an example, the comparison sub-circuit 31 conforms to the wired-AND logic, that is, the comparison sub-circuit 31 can maintain a high level state only when the first comparator A1 and the second comparator A2 are both in a high impedance state. If at least one of the first comparator A1 and the second comparator A2 is in a low impedance state, the comparison sub-circuit 31 outputs a discharge enable signal in a low level state. Figure 3One end of the first resistor R1, the output of the first comparator A1, and the output of the second comparator A2 are connected to node B. The potential of node B serves as the output of the comparison sub-circuit 31. The first resistor R1 is a pull-up resistor. When both the first comparator A1 and the second comparator A2 are in a high-impedance state, the voltage source discharges to node B through the first resistor R1, maintaining a high level in the comparison sub-circuit 31. When the second comparator A2 is in a low-impedance state, the voltage source, the first resistor R1, and the second comparator A2 form a discharge path, pulling down the potential of node B and causing the comparison sub-circuit 31 to output a low-level discharge enable signal.

[0060] As an example, the reference sub-circuit 32 includes a reference source. An output terminal of the reference source is connected to the comparison sub-circuit 31 for providing a reference voltage to the comparison sub-circuit 31.

[0061] As another example, the reference subcircuit 32 includes a second resistor R2 and a third resistor R3, wherein one end of the second resistor R2 is connected to the voltage source VCC, and the other end is connected to one end of the third resistor R3 and the comparison subcircuit 31; the other end of the third resistor R3 is grounded.

[0062] In the above embodiment, the reference subcircuit 32 uses a reference source to make the output reference voltage more accurate. The reference subcircuit 32 uses a voltage divider structure formed by the second resistor R2 and the third resistor R3 to reduce the cost of outputting the reference voltage.

[0063] Further reading Figure 2 As shown, in some embodiments, the discharge circuit 3 further includes a driving subcircuit 33 provided between the comparison subcircuit 31 and the boost chip U1 , and the driving subcircuit 33 is configured to drive the boost chip U1 based on the discharge enable signal.

[0064] As an example, the driver sub-circuit 33 includes a first switch transistor Q1 and a fourth resistor R4. The first switch transistor Q1 includes a first electrode connected to the backup battery and one end of the fourth resistor R4, a second electrode connected to the boost chip U1, and a control electrode connected to the other end of the fourth resistor R4 and the comparison sub-circuit 31 to receive a discharge enable signal.

[0065] As an example, the boost chip U1 can be a high-level triggered chip. When the first switch Q1 receives the discharge enable signal from the comparison sub-circuit 31, the first switch Q1 is turned on due to the voltage difference between its first electrode and the control electrode under the voltage division of the fourth resistor R4. This connects the backup battery to the boost chip U1, triggering the boost chip U1 to start boosting the output voltage of the backup battery for output.

[0066] Reference Figure 2In some embodiments, the charging circuit 2 includes a charging chip U2 and a fifth resistor R5. The charging chip U2 includes an input terminal connected to the vehicle battery, an output terminal connected to the backup battery, and a reference terminal connected to one end of the fifth resistor R5; the other end of the fifth resistor R5 is grounded, and the reference terminal is used to set the charging current output by the charging chip U2.

[0067] As an example, the charging current output by the charging chip U2 is related to the resistance of the ground resistor connected to its reference terminal. For example, the smaller the resistance of the ground resistor connected to the reference terminal, the greater the charging current output by the charging chip U2.

[0068] In some embodiments, the charging circuit 2 further includes a sixth resistor R6 and a second switch Q2. One end of the sixth resistor R6 is connected to one end of the fifth resistor R5 and the reference terminal of the charging chip U2, and the other end is connected to the first electrode of the second switch Q2. The second electrode of the second switch Q2 is grounded, and the control electrode is connected to the controller 1 for receiving a fast charge enable signal output by the controller 1.

[0069] As an example, when the second switch tube Q2 is in the off state, the sixth resistor R6 is in the open circuit state, and the fifth resistor R5 is grounded. At this time, the charging current output by the charging chip U2 can be expressed as I CHG1 =(K ISET / R SET5 ); where K ISET is the preset value of the charging chip U2, which is related to the model of the charging chip U2; R SET5 is the resistance of the fifth resistor R5. When the second switch tube Q2 is turned on, the sixth resistor R6 and the fifth resistor R5 are connected in parallel and then grounded. At this time, the resistance to ground connected to the reference terminal of the charging chip U2 can be expressed as R SET =(R SET5 ·R SET6 ) / (R SET5 +R SET6 ); where R SET5 is the resistance of the fifth resistor R5; R SET6 is the resistance of the fifth and sixth resistors. When the second switch tube Q2 is in the on state, the charging current of the charging chip U2 can be expressed as: I CHG2 =(K ISET / R SET ). Therefore, the charging current of the charging chip U2 when the second switch tube Q2 is in the off state is smaller than the charging current of the charging chip U2 when the second switch tube Q2 is in the on state.

[0070] Among them, the fast charge enable signal is generated by the controller 1 based on the battery voltage of the backup battery. As an example, when the controller 1 detects that the battery voltage of the backup battery is greater than or equal to the first preset value, it means that the backup battery has sufficient power. At this time, the controller 1 outputs a low-level charge enable signal to the charging chip U2 to control the car battery to stop charging the backup battery. When the controller 1 detects that the battery voltage of the backup battery is greater than the second preset value and less than the first preset value, it means that the backup battery has sufficient power. At this time, the controller 1 can output a high-level charge enable signal to trigger the charging of the backup battery. At the same time, the controller 1 outputs a low-level fast charge enable signal to disconnect the second switch tube Q2 to charge the backup battery with a smaller charging current, thereby extending the service life of the backup battery. When the controller 1 detects that the battery voltage of the backup battery is less than or equal to the second preset value, it means that the backup battery has low power. At this time, the controller 1 can output a high-level charge enable signal to trigger the charging of the backup battery. At the same time, the controller 1 outputs a high-level fast charge enable signal to turn on the second switch tube Q2 to charge the backup battery with a larger charging current, thereby improving the charging efficiency of the backup battery. In this way, the controller 1 can dynamically adjust the start and stop of charging to the backup battery by controlling the state of the charging enable signal based on the acquired battery voltage of the backup battery, and can further adjust the charging current by controlling the state of the fast charging enable signal, thereby realizing dynamic adjustment of the charging efficiency according to the power of the backup battery and automatic control of the start and stop of charging of the backup battery, avoiding overcharging of the backup battery.

[0071] In the above embodiment, controller 1 controls the second switch Q2 to conduct, connecting the sixth resistor R6 and the fifth resistor R5 in parallel to the reference terminal, forming a smaller equivalent resistance to ground, thereby triggering the charging chip U2 to output a higher charging current and achieve a fast charging mode. Conversely, controller 1 controls the second switch Q2 to disconnect, connecting only the fifth resistor R5 to the reference terminal, providing a larger resistance to ground. The charging chip U2 then outputs a lower charging current for conventional charging needs, enhancing the flexibility and controllability of the charging process and meeting charging needs in different scenarios.

[0072] In some embodiments, the backup battery control system further includes a health detection circuit 4. The health detection circuit 4 is connected to the backup battery and the controller 1 and is configured to measure the internal resistance of the backup battery to detect the health of the backup battery based on the measured internal resistance.

[0073] As an example, the health detection circuit 4 includes a third switch tube Q3 and a seventh resistor R7. The third switch tube Q3 has a first electrode connected to the backup battery, a second electrode connected to one end of the seventh resistor R7, and a control electrode connected to the controller 1. The other end of the seventh resistor R7 is grounded.

[0074] As an example, since the internal resistance of the backup resistor may change with the state of the backup battery, such as the charge level, temperature, etc., the internal resistance of the backup resistor is not a constant value. In order to more accurately generate the internal resistance of the backup battery under different conditions, a differential resistor can be used to calculate the internal resistance of the backup battery. The internal resistance of the backup battery can be expressed as: R i =-dU / dI=-(U OCV -U CCV ) / (I OCV -I CCV )=(U OCV -U CCV ) / I CCV Among them, U OCV is the open circuit voltage of the backup battery when fully charged, U CCV is the discharge voltage of the backup battery when the third switch tube Q3 is on, I CCV is the discharge current of the backup battery when the third switch tube Q3 is on, I OCV is the open circuit discharge current of the backup battery when it is fully charged. In this embodiment, I OCV =0.

[0075] Furthermore, the discharge voltage of the backup battery when the third switch tube Q3 is on can be obtained by sampling the output voltage of the backup battery by the controller 1 at the moment when the third switch tube Q3 is off. The discharge current of the backup battery when the third switch tube Q3 is on can be expressed as: I CCV =U CCV / (R7+R Q3 ), where R7 is the resistance of the seventh resistor R7, R Q3 It is the internal resistance of the third switch tube Q3, thereby realizing the acquisition of the discharge current of the backup battery when the third switch tube Q3 is in the on state. Therefore, the internal resistance of the backup battery can be calculated, so as to analyze the health status of the backup battery through the internal resistance of the backup battery.

[0076] In the above embodiment, the controller 1 controls the on and off of the third switch tube Q3, and records the discharge voltage of the backup battery when the third switch tube Q3 is on, thereby generating the discharge current of the backup battery when the third switch tube Q3 is on. Combined with the open-circuit discharge voltage and discharge current of the backup battery in a fully charged state sampled by the controller 1, the internal resistance of the backup battery is calculated.

[0077] In some embodiments, the backup battery control system further includes an output circuit 5. The output circuit 5 is connected to the vehicle battery and the discharge circuit 3, and is used to output energy from the vehicle battery or the backup battery.

[0078] As an example, the output circuit 5 includes a DC converter chip U3 and an inductor L. The input end of the DC converter chip is connected to the car battery and the boost chip U1, and the output end is connected to one end of the inductor L. The other end of the inductor L is used to output energy from the car battery or backup battery.

[0079] In some embodiments, the backup battery control system further includes a unidirectional conduction circuit, comprising a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 is connected to the vehicle battery, and the cathode is connected to the input of the charging chip U2; the anode of the second diode D2 is connected to the output of the charging chip U2, and the cathode is connected to the backup battery; the anode of the third diode D3 is connected to the vehicle battery, and the cathode is connected to the output circuit 5; and the anode of the fourth diode D4 is connected to the boost chip U1, and the cathode is connected to the output circuit 5.

[0080] In the above embodiment, the first diode D1, the second diode D2, and the third diode D3 enable unidirectional conduction between the car battery and the charging chip U2, between the charging chip U2 and the backup battery, between the car battery and the output circuit 5, and between the boost chip U1 and the output circuit 5, thereby avoiding current backflow.

[0081] According to a second aspect of the present disclosure, there is provided an energy storage device, referring to Figure 5 The energy storage device 10 includes a backup battery 200, a car battery 100, and the aforementioned backup battery control system 300. The energy storage device has all the beneficial effects of the aforementioned backup battery control system 300, which will not be described in detail in this disclosure.

[0082] According to a third aspect of the present application, a vehicle includes the above-mentioned energy storage device.

[0083] The vehicle may be a fuel vehicle, a plug-in hybrid vehicle, a new energy vehicle, etc., and this disclosure does not make any specific limitations on this.

[0084] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0085] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0087] The above are merely preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A backup battery control system, characterized in that: include: Controller; a charging circuit connected to the controller and the car battery, for controlling the charging of the backup battery from the car battery; a discharge circuit connected to the backup battery and configured to control the discharge of the backup battery according to the output voltage of the car battery; Wherein, the discharge circuit includes a comparison subcircuit, a boost chip and a reference subcircuit for outputting a reference voltage; The comparison subcircuit is connected to the reference subcircuit and the vehicle battery, and is used to compare the reference voltage with the output voltage of the vehicle battery, and generate a discharge enable signal according to the comparison result; The boost chip is connected to the backup battery and the comparison sub-circuit, and controls the discharge of the backup battery in response to the discharge enable signal.

2. The backup battery control system according to claim 1, characterized in that: The comparison subcircuit includes a first resistor, a first comparator, a second comparator and a voltage dividing unit; The first comparator has a first input connected to the car battery and the voltage divider, a second input connected to the voltage divider and the first input of the second comparator, and an output connected to one end of the first resistor and the output of the second comparator; The second input terminal of the second comparator is connected to the reference sub-circuit; the other end of the first resistor is connected to a voltage source.

3. A backup battery control system according to claim 1, characterized in that: The reference subcircuit includes a reference source; The output end of the reference source is connected to the comparison sub-circuit, and is used to provide the reference voltage to the comparison sub-circuit.

4. The backup battery control system according to claim 1, characterized in that: The reference subcircuit includes a second resistor and a third resistor; One end of the second resistor is connected to a voltage source, and the other end is connected to one end of the third resistor and the comparison sub-circuit; The other end of the third resistor is grounded.

5. The backup battery control system according to claim 1, characterized in that: The discharge circuit further includes a driving subcircuit provided between the comparison subcircuit and the boost chip; The driving sub-circuit drives the boost chip in response to the discharge enable signal.

6. The backup battery control system according to claim 5, characterized in that: The driving sub-circuit includes a first switch tube and a fourth resistor; The first switch tube includes a first electrode connected to the backup battery and one end of the fourth resistor, a second electrode connected to the boost chip, and a control electrode connected to the other end of the fourth resistor and the comparison subcircuit.

7. The backup battery control system according to claim 1, characterized in that: The charging circuit includes a charging chip and a fifth resistor; The charging chip includes an input terminal connected to the car battery, an output terminal connected to the backup battery, and a reference terminal connected to one end of the fifth resistor; The other end of the fifth resistor is grounded; The reference terminal is used to set the charging current output by the charging chip.

8. The backup battery control system according to claim 7, characterized in that: The charging circuit further includes a sixth resistor and a second switch tube; One end of the sixth resistor is connected to one end of the fifth resistor and the reference end of the charging chip, and the other end is connected to the first electrode of the second switching tube; The second electrode of the second switch tube is grounded, and the control electrode is connected to the controller.

9. The backup battery control system according to claim 1, characterized in that: The backup battery control system also includes a health detection circuit; The health detection circuit is connected to the backup battery and the controller, and is used to measure the internal resistance of the backup battery to detect the health condition of the backup battery according to the internal resistance.

10. A backup battery control system according to claim 9, characterized in that: The health detection circuit includes a third switch tube and a seventh resistor; The third switch tube includes a first electrode connected to the backup battery, a second electrode connected to one end of the seventh resistor, and a control electrode connected to the controller; The other end of the seventh resistor is grounded.

11. An energy storage device, characterized in that: The device comprises a backup battery, a car battery and a backup battery control system as claimed in any one of claims 1 to 10.

12. A vehicle, characterized in that: Comprising the energy storage device as claimed in claim 11.

Images