Battery protection circuit, vehicle-mounted battery and vehicle
Patent Information
- Application Number
- CN202522581017.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-03
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-12-03
AI Technical Summary
Existing vehicle lithium batteries are prone to excessive charging current due to a lack of current limiting control during charging, which can lead to battery damage or incomplete charging. Furthermore, they lack an effective and reliable charging management mechanism.
Design a battery protection circuit, including first and second charging protection circuits, detection circuit and control module, to monitor the status of energy storage module through current limiting device and control module, and realize current limiting charging and safety protection.
It effectively avoids overheating, damage, and incomplete charging of the energy storage module, improves battery life, and ensures the safety and reliability of the charging process and the efficient energy storage of the battery.
Smart Images
Figure CN224935380U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle power management technology, and in particular to a battery protection circuit, a vehicle battery, and a vehicle. Background Technology
[0002] Currently, mainstream 12V or 24V automotive lithium batteries typically use the car's alternator to directly charge the battery.
[0003] In the case of using a car alternator for direct charging, the applicant discovered that when the battery is recharged after the over-discharge protection has been lifted, if no current limit is set, excessive charging current can easily occur, causing damage to the battery. When the battery is close to full charge, the lack of current limiting control can prematurely trigger the overcharge protection mechanism, causing the charging process to be interrupted, thereby reducing the actual full-charge capacity of the battery. Utility Model Content
[0004] This application provides a battery protection circuit, an on-board battery, and a vehicle to achieve intelligent current-limited charging of the energy storage module, ensuring a safe and reliable charging process, and achieving efficient energy storage in a fully charged state, thereby improving the range of the energy storage module.
[0005] The first aspect of this application provides a battery protection circuit for protecting an energy storage module from charging and discharging. The battery protection circuit includes a first charging protection circuit, a second charging protection circuit, a detection circuit, and a control module. The first charging protection circuit connects an external power source and the energy storage module to transfer electrical energy from the external power source to the energy storage module. The first charging protection circuit includes an overcharge protection switch and a first drive circuit, which is electrically connected to the overcharge protection switch and receives a drive signal to control the on / off state of the overcharge protection switch. The second charging protection circuit includes a current-limiting device. The second charging protection circuit is connected in parallel with the overcharge protection switch. The detection circuit collects state parameters of the energy storage module. The state parameters include at least the charging parameters of the energy storage module. The control module is connected to the first charging protection circuit, the second charging protection circuit, and the detection circuit. Based on the detection signal from the detection circuit, when the state parameters meet preset conditions, the control module disconnects the first charging protection circuit and connects the second charging protection circuit to charge the energy storage module and limit the charging current of the energy storage module.
[0006] A second aspect of this application provides a vehicle battery, the vehicle battery including an energy storage module and the battery protection circuit described in the first aspect. The battery protection circuit is electrically connected to the energy storage module, and the battery protection circuit is used to transfer electrical energy from an external power source to the energy storage module for charging, and to transfer electrical energy from the energy storage module to an external load for power supply.
[0007] A third aspect of this application provides a vehicle comprising an automotive engine, on-board electrical equipment, and the on-board battery described in the second aspect above. The automotive engine provides charging power to the energy storage module of the on-board battery, and the on-board battery supplies power to the on-board electrical equipment.
[0008] The battery protection circuit provided in this application, by adding a second charging protection circuit, can effectively control the charging current in the charging circuit of the energy storage module, enabling current-limited charging of the energy storage module by the vehicle's alternator. This effectively avoids safety hazards such as overheating, damage, or even explosion of the energy storage module caused by excessive current, thereby ensuring the safety and reliability of the energy storage module during charging. Simultaneously, it can effectively prevent capacity decay of the energy storage module, ensuring efficient energy storage at full charge and improving the module's range. Furthermore, the second charging protection circuit is composed of discrete components, resulting in a simple circuit structure and low material cost. Attached Figure Description
[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0010] Figure 1 A functional module diagram of a battery protection circuit provided for an embodiment of this application.
[0011] Figure 2 for Figure 1 The diagram shows a specific circuit structure of a battery protection circuit.
[0012] Figure 3 for Figure 1 The diagram shows a specific circuit structure of the first driving circuit.
[0013] Figure 4 for Figure 1 The diagram shows a specific circuit structure of the second driving circuit.
[0014] Figure 5 This is a schematic diagram of a specific circuit structure for a power conversion circuit provided for an embodiment of this application.
[0015] Figure 6 A schematic diagram of the functional modules of a vehicle battery provided for an embodiment of this application.
[0016] Figure 7 A schematic diagram of the functional modules of a vehicle provided for an embodiment of this application.
[0017] Reference numerals: 100, Battery protection circuit; 10, Connection terminal; 11, Positive terminal; 12, Negative terminal; 21, First charging protection circuit; Q21, Overcharge protection switch; 211, First drive circuit; 22, Over-discharge protection circuit; Q22, Over-discharge protection switch; 221, Second drive circuit; 30, Control module; 31, BMS; 32, Control unit; 40, Second charging protection circuit; Q23, Current limiting switch; R21, Current limiting resistor; 50, Detection circuit; 51, Current detection circuit; R22, current sampling resistor; 52, voltage detection circuit; 53, temperature detection circuit; 60, heating module; 70, power conversion circuit; 200, energy storage module; 300, housing; 1000, vehicle battery; 2000, vehicle engine; 3000, vehicle electrical equipment; 1, vehicle; BAT+, positive terminal; BAT-, negative terminal; GND, signal ground connection point; PGND, power ground connection point; TVS1, high-power absorption device; V1, bias voltage. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are schematic diagrams, and should not be construed as limiting the scope of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.
[0020] Current vehicle power supply systems typically employ a battery-engine collaborative architecture: the car engine directly charges the energy storage module of the onboard battery, while onboard electrical equipment (such as parking air conditioning and lighting systems) is directly powered by the onboard battery. During operation of these onboard electrical devices, the over-discharge protection mechanism of the energy storage module is easily triggered, causing the module to be in a low-voltage state. With the widespread use of lithium batteries, their low internal resistance (only 1 / 10 that of lead-acid batteries) means that when charging begins after the over-discharge protection of a lithium battery has been released, the initial charging surge current can reach thousands of amperes, posing a potential risk of burnout to power components in the circuit. When the battery is close to full charge, the lack of current limiting control can prematurely trigger overcharge protection, causing charging interruption, resulting in incomplete charging and a reduction in actual capacity. Furthermore, dynamic current fluctuations during charging also pose a potential risk of exceeding safety thresholds.
[0021] In related technologies, 12V or 24V automotive lithium batteries can be directly charged by the car's alternator, with a Battery Management System (BMS) used for overcharge and over-discharge protection. However, an effective current-limiting charging management mechanism is lacking. Configuring a DC-DC constant current control circuit presents problems such as high cost, insufficient control precision, and poor flexibility. Therefore, a safe and reliable charging management architecture is urgently needed to address critical operating conditions such as low-voltage charging, overcurrent charging, and near-full charge.
[0022] Please see Figure 1 and Figure 2 This application provides a battery protection circuit 100, which can be applied to vehicle batteries (e.g., 12V / 24V lithium batteries). For example, the battery protection circuit 100 can receive power input from an external power source (e.g., a car engine) to charge the energy storage module of the vehicle battery, and enable the energy storage module to discharge to external loads (e.g., parking air conditioners, lighting systems, audio systems, and other vehicle electrical equipment). The battery protection circuit 100 also provides charge and discharge protection for the energy storage module of the vehicle battery.
[0023] In this embodiment, the battery protection circuit 100 includes a first charging protection circuit 21, which is used to connect an external power source / external load and an energy storage module 200 to transfer the electrical energy from the external power source to the energy storage module 200 for charging, and to transfer the electrical energy from the energy storage module 200 to the external load for power supply.
[0024] Specifically, the battery protection circuit 100 further includes a connection terminal 10, which includes a positive terminal 11 and a negative terminal 12. The positive terminal 11 and the negative terminal 12 are electrically connected to the positive terminal BAT+ and the negative terminal BAT- of the energy storage module 200, respectively. The positive terminal 11 and the negative terminal 12 are also used to electrically connect to the positive and negative terminals of an external power source / load, respectively. A first charging protection circuit 21 is electrically connected between one of the terminals of the energy storage module 200 and the corresponding terminal of the connection terminal 10. For example, the first charging protection circuit 21 can be electrically connected between the positive terminal BAT+ and the positive terminal 11 of the energy storage module 200, or it can be electrically connected between the negative terminal BAT- and the negative terminal 12 of the energy storage module 200. In this application, the structure of the battery protection circuit 100 is described using the example of the first charging protection circuit 21 being electrically connected between the negative terminal BAT- and the negative terminal 12 of the energy storage module 200.
[0025] The external power source, such as a car engine, can be electrically connected to the first charging protection circuit 21 via the connection terminal 10, thereby providing charging power to the energy storage module 200 through the first charging protection circuit 21. External loads, such as parking air conditioners, lighting systems, audio systems, and other vehicle electrical equipment, can be electrically connected to the first charging protection circuit 21 via the connection terminal 10, thereby obtaining the discharge output of the energy storage module 200 through the first charging protection circuit 21.
[0026] In this embodiment, the battery protection circuit 100 further includes a second charging protection circuit 40, a control module 30, and a detection circuit 50. The second charging protection circuit 40 is connected in parallel with the first charging protection circuit 21. The detection circuit 50 is used to collect state parameters of the energy storage module 200, wherein the state parameters include at least the charging electrical parameters of the energy storage module 200. These charging electrical parameters include the voltage and / or charging current of the energy storage module 200. The control module 30 is connected to the first charging protection circuit 21, the second charging protection circuit 40, and the detection circuit 50. The control module 30 is used to acquire the state parameters collected by the detection circuit 50 to monitor the charging state of the energy storage module 200. The control module 30 can also control the on / off state (hereinafter referred to as "on / off state") of the first charging protection circuit 21 and the second charging protection circuit 40 according to the state parameters.
[0027] In this embodiment, the second charging protection circuit 40 includes a current-limiting device. Specifically, the current-limiting device includes a current-limiting resistor R21. The impedance of the second charging protection circuit 40 is greater than the impedance of the first charging protection circuit 21. Thus, compared to the charging circuit of the energy storage module 200 constructed by the first charging protection circuit 21, when the second charging protection circuit 40 is turned on as the charging circuit of the energy storage module 200, due to the connection of the current-limiting resistor R21, based on the physical characteristics of Ohm's law, under a constant charging voltage, the charging current in the charging circuit of the energy storage module 200 will decrease, thereby achieving the purpose of current-limiting charging of the energy storage module 200.
[0028] During charging, if the control module 30 determines that the state parameters of the energy storage module 200 do not meet the preset conditions, the control module 30 outputs a drive signal to turn on the first charging protection circuit 21 and turn off the second charging protection circuit 40, so that the energy storage module 200 is charged with a large current through the first charging protection circuit 21. If the control module 30 determines that the state parameters of the energy storage module 200 meet the preset conditions, the control module 30 outputs a drive signal to turn off the first charging protection circuit 21 and turn on the second charging protection circuit 40, so that the energy storage module 200 is charged through the second charging protection circuit 40 and the charging current of the energy storage module 200 is limited, that is, the energy storage module 200 is charged with a small current. The battery protection circuit 100 provided in this application is particularly suitable for applications requiring high reliability and safety, such as vehicle battery systems, and can effectively improve the stability and safety of the entire system.
[0029] In one embodiment, the detection circuit 50 transmits specific values of state parameters to the control module 30, such as the voltage value of the energy storage module 200 or the charging current value of the energy storage module 200. The control module 30 determines whether a preset condition is met by judging whether the specific value falls within a preset range. In another embodiment, the detection circuit 50 may also transmit a level signal indicating whether the state parameter falls within a preset range to the control module 30. For example, a level signal of 1 indicates that it falls within the preset range, and a level signal of 0 indicates that it is outside the preset range. The control module 30 determines whether the preset condition is met based on the level signal. If the detection circuit 50 detects multiple state parameters, one of the above embodiments can be used, or a combination of the above two embodiments can be used.
[0030] In this embodiment, the preset conditions include at least one of the following: a) the voltage of the energy storage module 200 drops to a first threshold; b) the charging current of the energy storage module 200 reaches a second threshold; c) the voltage of the energy storage module 200 reaches a third threshold, wherein the first threshold is less than the third threshold.
[0031] Understandably, during the discharge process of energy storage module 200, an over-discharge protection mechanism will be triggered when the voltage of energy storage module 200 drops to the first threshold. When energy storage module 200 begins charging after the over-discharge protection is released, its initial inrush current may reach thousands of amperes, far exceeding the second threshold, thus posing a potential threat of burnout to power components in the circuit. When energy storage module 200 approaches full charge, its voltage reaches the third threshold, triggering overcharge protection. By setting the above preset conditions to energy storage module 200 voltage dropping to the first threshold, charging current reaching the second threshold, and voltage reaching the third threshold, the energy storage module 200 can be effectively protected from damage caused by large current surges and to avoid premature triggering of overcharge protection, which would result in incomplete charging and actual capacity loss, thereby improving the safety and battery life of energy storage module 200.
[0032] It should be noted that the specific values of the first threshold, the second threshold, and the third threshold can be flexibly configured according to actual design requirements. Taking a lithium iron phosphate battery as an example, when the charging voltage of a single cell reaches 3.9V and triggers the overcharge protection mechanism, the other cells may still be in an undervoltage state. At this time, by disconnecting the first charging protection circuit 21 and simultaneously turning on the second charging protection circuit 40, overcharge protection can be provided for the single cell that has reached the threshold voltage, while other cells can be continuously charged to the target voltage value with a controlled small current, thereby effectively avoiding overall battery capacity decay and ensuring energy storage efficiency at full charge. Thus, the third threshold can be set to 3.9V. As another example, when the discharge of a single cell reaches a voltage drop of 2.5V, the over-discharge protection mechanism will be triggered. Thus, the first threshold can be set to 2.5V.
[0033] In this embodiment, the first charging protection circuit 21 includes an overcharge protection switch Q21, wherein the overcharge protection switch Q21 and the second charging protection circuit 40 are connected in parallel and electrically between one pole of the energy storage module 200 and the corresponding polarity terminal of the connection terminal 10. In this embodiment, the overcharge protection switch Q21 includes a MOSFET. Correspondingly, the first charging protection circuit 21 also includes a first driving circuit 211, wherein the first driving circuit 211 is electrically connected to the control module 30 and the overcharge protection switch Q21, and the first driving circuit 211 is used to receive the driving signal output by the control module 30 to control the on / off state of the overcharge protection switch Q21. For example, the first driving circuit 211 may respond to the driving signal CHG_SW output by the control module 30 and output an enable signal CHG_EN to the gate of the overcharge protection switch Q21 to conduct the overcharge protection switch Q21. The first driving circuit 211 may employ Figure 3 The circuit structure shown is used to implement this.
[0034] The current limiting device also includes a current limiting switch Q23, which is connected in series with a current limiting resistor R21. The control module 30 is also electrically connected to the current limiting switch Q23 to control the on / off state of the second charging protection circuit 40 by controlling the on / off state of the current limiting switch Q23. In this embodiment, the current limiting switch Q23 includes a MOSFET. Correspondingly, the second charging protection circuit 40 may also include a third driving circuit (not shown), wherein the current limiting switch Q23 is electrically connected to the control module 30 through the third driving circuit, which receives a driving signal output by the control module 30 to control the on / off state of the current limiting switch Q23. For example, the third driving circuit may output an enable signal SW to the gate of the current limiting switch Q23 in response to the driving signal output by the control module 30, thereby turning on the current limiting switch Q23. The third driving circuit may be implemented using the same or similar circuit structure as the first driving circuit 211.
[0035] In this embodiment, the battery protection circuit 100 further includes an over-discharge protection circuit 22, wherein the over-discharge protection circuit 22 is electrically connected between one pole of the energy storage module 200 and the corresponding polarity terminal of the connection terminal 10. The control module 30 is also electrically connected to the over-discharge protection circuit 22 to control the on / off state of the over-discharge protection circuit 22.
[0036] Specifically, the over-discharge protection circuit 22 includes an over-discharge protection switch Q22. When the first charging protection circuit 21 is in the off state and the second charging protection circuit 40 is in the on state, the second charging protection circuit 40 and the over-discharge protection switch Q22 are connected in series. When the first charging protection circuit 21 is in the on state and the second charging protection circuit 40 is in the off state, the overcharge protection switch Q22 and the over-discharge protection switch Q21 are connected in series between the energy storage module 200 and the connection terminal 10.
[0037] In this embodiment, the over-discharge protection switch Q22 includes a MOSFET. Correspondingly, the over-discharge protection circuit 22 also includes a second driving circuit 221, which is electrically connected to both the control module 30 and the over-discharge protection switch Q22. The second driving circuit 221 receives a driving signal output from the control module 30 to control the on / off state of the over-discharge protection switch Q22. For example, the second driving circuit 221 may output an enable signal DSG_EN to the gate of the over-discharge protection switch Q22 in response to the driving signal DSG_SW output from the control module 30, thereby turning on the over-discharge protection switch Q22. The second driving circuit 221 may employ... Figure 4 The circuit structure shown is used to implement this.
[0038] Please see Figure 2In this embodiment, the battery protection circuit 100 may further include a high-power absorption device (TVS1), which is connected in parallel with the over-discharge protection switch Q22. The high-power absorption device TVS1 clamps the voltage of the over-discharge protection switch Q22, ensuring that the voltage difference between the source and drain of the over-discharge protection switch Q22 is less than a preset voltage, thereby preventing the reverse voltage spike generated when the over-discharge protection switch Q22 is disconnected from damaging the over-discharge protection switch Q22. In some embodiments, the high-power absorption device TVS1 may be a transient voltage suppressor (TVS).
[0039] In one specific implementation, such as Figure 1 and Figure 2 As shown, the overcharge protection switch Q21 and the second charging protection circuit 40 are connected in parallel between the negative terminal BAT- of the energy storage module 200 and the negative terminal 12 of the connection terminal 10. The over-discharge protection switch Q22 is connected between the negative terminal BAT- of the energy storage module 200 and the overcharge protection switch Q21. The negative terminal BAT- of the energy storage module 200 is also electrically connected to the signal ground connection point GND.
[0040] The overcharge protection switch Q21, over-discharge protection switch Q22, and current limiting switch Q23 are all implemented using NMOS transistors. The gate of the overcharge protection switch Q21 is used to receive the enable signal CHG_EN output by the first driving circuit 211, the gate of the over-discharge protection switch Q22 is used to receive the enable signal DSG_EN output by the second driving circuit 221, and the gate of the current limiting switch Q23 is used to receive the enable signal SW output by the third driving circuit.
[0041] The source of over-discharge protection switch Q22 is electrically connected to the negative terminal BAT- of energy storage module 200, i.e., the source of over-discharge protection switch Q22 is electrically connected to signal ground connection point GND. The drain of over-discharge protection switch Q22 and the drain of overcharge protection switch Q21 are electrically connected, and the common connection point between them is electrically connected to power ground connection point PGND. The drain of current limiting switch Q23 is electrically connected to the common connection point via current limiting resistor R21. The source of current limiting switch Q23 and the source of overcharge protection switch Q21 are both connected to the negative terminal 12.
[0042] It is understandable that connecting the source of the over-discharge protection switch Q22 to the signal ground connection point GND provides a stable reference potential for the enable signal DSG_EN, ensuring that the gate-source drive voltage of the over-discharge protection switch Q22 can conduct through the over-discharge protection switch Q22. Connecting the drain of the over-discharge protection switch Q22 to the power ground connection point PGND satisfies the control requirements of electrical isolation and noise isolation in the circuit structure.
[0043] Please continue reading. Figure 2When the overcharge protection switch Q21 is in the open state, its source terminal remains electrically connected to the negative terminal 12. When the overcharge protection switch Q21 is in the closed state, the negative terminal 12 is electrically connected to the power ground connection point PGND through the closed overcharge protection switch Q21. Thus, when the overcharge protection switch Q21 switches between open and closed states, the voltage at the source of the overcharge protection switch Q21 will dynamically change. To avoid the fluctuation of the source voltage of the overcharge protection switch Q21 affecting the effective control of the open and closed states of the overcharge protection switch Q21, in this embodiment, please refer to... Figure 5 The battery protection circuit 100 also includes a power conversion circuit 70, which is electrically connected to the positive terminal BAT+ of the energy storage module 200 to receive the voltage of the energy storage module 200 and convert the voltage into a bias voltage V1 that maintains a constant voltage difference with the voltage CAR- of the negative terminal 12. For example, when the negative terminal 12 is electrically connected to the power ground connection point PGND via the on overcharge protection switch Q21, or when the negative terminal 12 is disconnected from the power ground connection point PGND and electrically connected to the negative terminal of an external power supply or external load, the voltage difference between the bias voltage V1 and the voltage CAR- of the negative terminal 12 remains constant. In this embodiment, the value of the constant voltage difference is equal to the gate-source conduction threshold of the overcharge protection switch Q21, for example, 12.1V.
[0044] Please see Figure 3 The first driving circuit 211 includes an NMOS transistor Q31 and a PMOS transistor Q32. The gate of the NMOS transistor Q31 is electrically connected to the control module 30 via resistor R31 to receive the driving signal CHG_SW. Its source is electrically connected to the signal ground connection point GND, and its gate is also electrically connected to the source via resistor R32. Its drain is electrically connected to the gate of the PMOS transistor Q32 via resistor R33. The source of the PMOS transistor Q32 is used to receive the bias voltage V1 output by the power conversion circuit 70, and its source is also electrically connected to its gate via resistor R34. The drain of the PMOS transistor Q32 is electrically connected to the output terminal of the first driving circuit 211 to output the enable signal CHG_EN. The output terminal of the first driving circuit 211 is also electrically connected to the negative terminal 12 via resistor R35 to establish an output potential reference.
[0045] Please combine Figure 2 and Figure 3 In this embodiment, the output terminal of the first driving circuit 211 is also electrically connected to the gate of the overcharge protection switch Q21 to output the enable signal CHG_EN to the overcharge protection switch Q21. In this embodiment, the drain of the PMOS transistor Q32 is electrically connected to the output terminal of the first driving circuit 211 via diodes D31 and D32 to achieve isolation between power ground (PGND) and signal ground (GND), thereby meeting the circuit's electrical and noise isolation control requirements.
[0046] Since the voltage difference between the bias voltage V1 and the voltage of the negative terminal 12 is equal to the voltage difference between the gate and source of the overcharge protection switch Q21, and the voltage difference remains constant, equal to the gate-source conduction threshold of the overcharge protection switch Q21, the bias voltage V1 can provide a reliable control reference for the overcharge protection switch Q21, ensuring that the gate-source drive voltage of the overcharge protection switch Q21 is not affected by the circuit state, thereby ensuring that the system can achieve accurate and effective control of the overcharge protection switch Q21 under all operating conditions.
[0047] Specifically, the drive signal CHG_SW includes high and low levels. When the drive signal CHG_SW output by the control module 30 is high, the NMOS transistor Q31 is turned on, and the gate of the PMOS transistor Q32 is electrically connected to the signal ground connection point GND through the turned-on NMOS transistor Q31, causing the gate potential of the PMOS transistor Q32 to be pulled down, thereby turning on the PMOS transistor Q32. In this way, the bias voltage V1 can be transmitted to the output terminal of the first drive circuit 211 through the turned-on PMOS transistor Q32. At this time, the enable signal CHG_EN is the bias voltage V1, so the overcharge protection switch Q21 is turned on. Conversely, when the drive signal CHG_SW output by the control module 30 is low, the NMOS transistor Q31 is turned off, and the gate voltage of the PMOS transistor Q32 is equal to the source voltage, causing the PMOS transistor Q32 to be turned off. Thus, the enable signal CHG_EN output by the output terminal of the first drive circuit 211 is the voltage CAR- of the negative terminal 12, and therefore, the overcharge protection switch Q21 is turned off.
[0048] In this embodiment, since the source of the current limiting switch Q23 and the source of the overcharge protection switch Q21 are both connected to the negative terminal 12, the voltage at the source of the current limiting switch Q23 will also dynamically change according to the on / off state of the overcharge protection switch Q21. As mentioned above, the third driving circuit corresponding to the current limiting switch Q23 can be implemented using the same or similar circuit structure as the first driving circuit 211. Therefore, the technical solution provided in this application can also ensure that the system can achieve precise and effective control of the current limiting switch Q23 under all operating conditions.
[0049] Please refer to it again. Figure 1 The detection circuit 50 includes at least a current detection circuit 51 and a voltage detection circuit 52. Specifically, when the first charging protection circuit 21 is in the off state and the second charging protection circuit 40 is in the on state, the second charging protection circuit 40 is connected in series with the current detection circuit 51. When the first charging protection circuit 21 is in the on state and the second charging protection circuit 40 is in the off state, the overcharge protection switch Q21 is connected in series with the current detection circuit 51.
[0050] The current detection circuit 51 detects the charging current of the energy storage module 200 and feeds the detected charging current back to the control module 30. The voltage detection circuit 52 is electrically connected to both the energy storage module 200 and the control module 30. The voltage detection circuit 52 detects the voltage of the energy storage module 200 and feeds the detected voltage back to the control module 30. Thus, the control module 30 can monitor the charging and discharging state of the energy storage module 200 in real time based on the charging current parameters fed back by the current detection circuit 51 and the voltage parameters fed back by the voltage detection circuit 52.
[0051] Please refer to it again. Figure 2 In this embodiment, the current detection circuit 51 may include a current sampling resistor R22 connected in series in the charging circuit of the energy storage module 200, and current sampling points CAR-H and CAR-L disposed across the current sampling resistor R22. The current detection circuit 51 detects the charging current of the energy storage module 200 through the current sampling resistor R22. The current sampling points CAR-H and CAR-L are electrically connected to the control module 30 via an amplifier circuit (not shown), thereby feeding back the charging current detected by the current detection circuit 51 to the control module 30.
[0052] In this embodiment, as Figure 1 and Figure 2 As shown, when both overcharge protection switch Q21 and over-discharge protection switch Q22 are in the ON state and current limiting switch Q21 is in the OFF state, the current sampling resistor R22 is connected in series with the overcharge protection switch Q21. When the overcharge protection switch Q21 is in the OFF state and both current limiting switch Q23 and over-discharge protection switch Q22 are in the ON state, the current sampling resistor R22 is connected in series with the second charging protection circuit 40.
[0053] In low-temperature environments, the electrochemical reaction rate inside the energy storage module 200 (especially the battery) decreases significantly, leading to increased internal resistance, a sharp reduction in effective capacity, decreased charging and discharging efficiency, and even malfunction. This not only severely affects the device's battery life and instantaneous power output, but forced charging under these conditions may also cause irreversible damage to the battery, shortening its lifespan.
[0054] To address the above problems, in one implementation method, please refer to [link / reference]. Figure 1 The battery protection circuit 100 also includes a heating module 60, which is used to heat the energy storage module 200. The heating module 60 may include a heating film.
[0055] The detection circuit 50 also includes a temperature detection circuit 53. The temperature detection circuit 53 is used to detect the temperature of the energy storage module 200 and send the detected temperature of the energy storage module 200 to the control module 30.
[0056] The control module 30 is also electrically connected to the heating module 60 to acquire the temperature detected by the temperature detection circuit 53 and to implement corresponding control based on the temperature of the energy storage module 200. For example, when the temperature of the energy storage module 200 is lower than a preset temperature, the control module 60 is used to heat the energy storage module 200. Thus, under low-temperature conditions, by controlling the heating module 60 to heat the energy storage module 200, the energy storage module 200 can be kept within a suitable operating temperature range, thereby effectively improving its performance in low-temperature environments, ensuring charging safety, and extending the overall lifespan of the energy storage module 200.
[0057] Please continue reading. Figure 1 In this embodiment, the control module 30 includes a battery management system (BMS) 31 and a control unit 32 that are communicatively connected to each other. The BMS 31 and the control unit 32 jointly implement the control function of the battery protection circuit 100. The current detection circuit 51 and the voltage detection circuit 52 can feed back the detected electrical parameters to the BMS 31 and / or the control unit 32.
[0058] The BMS 31 can be used to implement overcharge and over-discharge protection control of the energy storage module 200. Specifically, the BMS 31 can be electrically connected to the first charging protection circuit 21 and the over-discharge protection circuit 22 respectively. The BMS 31 can be used to control the on / off states of the first charging protection circuit 21 and the over-discharge protection circuit 22 respectively to ensure the safe operation of the energy storage module 200. For example, the BMS 31 can be used to output drive signals CHG_SW and DSG_SW.
[0059] The control unit 32 can be a microcontroller, a central processing unit (CPU), a microcontroller unit (MCU), other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices. The control unit 32 can be used to implement current-limited charging control of the energy storage module 200. Specifically, the control unit 32 can be electrically connected to the current-limiting switch Q23 to control the on / off state of the current-limiting switch Q23, thereby effectively preventing potential damage caused by excessive charging current and avoiding premature triggering of overcharge protection, ensuring the stability and safety of the entire system. The control unit 32 can also be used to control the operating state of the heating module 60 to heat the energy storage module 200.
[0060] In other embodiments, BMS 31 can also be used to implement current-limited charging control or heating control of the energy storage module 200. Similarly, control module 32 can also be used to implement overcharge and over-discharge protection control of the energy storage module 200.
[0061] In other embodiments, the control functions of the battery protection circuit 100 may also be performed separately by the BMS 31 or the control unit 32.
[0062] The battery protection circuit 100 provided in this application, by adding a second charging protection circuit 40, can effectively control the charging current in the charging circuit of the energy storage module 200, realizing current-limited charging of the energy storage module 200 by the vehicle alternator. This effectively avoids safety hazards such as overheating, damage, or even explosion of the energy storage module 200 caused by excessive current, thereby ensuring the safety and reliability of the energy storage module 200 during the charging process. Simultaneously, it can also effectively prevent capacity decay of the energy storage module 200, ensuring efficient energy storage in a fully charged state and improving the driving range of the energy storage module 200. Furthermore, the second charging protection circuit 40 is composed of discrete components, resulting in a simple circuit structure and low material cost.
[0063] Please see Figure 6 Embodiments of this application also provide a vehicle battery 1000, which includes an energy storage module 200 and the aforementioned battery protection circuit 100. The battery protection circuit 100 is electrically connected to the energy storage module 200. The battery protection circuit 100 receives power input from an external power source (e.g., a car alternator) and charges the energy storage module 200, and also enables the energy storage module 200 to discharge power to external loads (e.g., parking air conditioners, lighting systems, audio systems, and other vehicle electrical equipment), thereby supplying power to the external loads.
[0064] The vehicle battery 1000 can be a 12V or 24V vehicle battery, such as a lithium-ion battery. The energy storage module 200 includes a rechargeable battery or a supercapacitor. The rechargeable battery includes sodium-ion batteries, lithium-ion batteries, or lead-acid batteries, etc. For example, in a 24V vehicle battery 1000, the energy storage module 200 can use a 25.6V 230AH lithium iron phosphate cell. The type of energy storage module 200 is not specifically limited in the embodiments of this application.
[0065] The vehicle battery 1000 is equipped with a battery interface, which has a positive terminal and a negative terminal. In one embodiment, please refer to... Figure 1 The positive terminal of the battery and the positive terminal 11 of the battery protection circuit 100 can be integrated into a common positive terminal contact, while the negative terminal of the battery and the negative terminal 12 can be integrated into a common negative terminal contact, thereby forming a compact electrical connection structure.
[0066] The vehicle battery 1000 also includes a housing 300, an energy storage module 200 and a battery protection circuit 100, which are located inside the housing 300.
[0067] Optionally, the vehicle battery 1000 further includes a first terminal and a second terminal disposed on the housing 300, at least one of the first terminal and the second terminal being connected to the connection terminal of the battery protection circuit 100, and the first terminal and the second terminal being used to connect to the vehicle engine and / or vehicle electrical equipment.
[0068] Understandable Figure 1 This is merely an example of a battery protection circuit 100 used in this application to implement battery charge / discharge protection functions, and does not constitute a limitation on the battery protection circuit 100. The battery protection circuit 100 may include more components than shown. Similarly, Figure 6 This is merely an example of a vehicle battery 1000 used in this application to implement battery charge and discharge protection functions, and does not constitute a limitation on the vehicle battery 1000. The vehicle battery 1000 may include more components than shown in the figure. For example, the vehicle battery 1000 may also include wireless communication interface circuitry, etc.
[0069] Please see Figure 7 This application also provides a vehicle 1, which includes an automotive engine 2000, on-board electrical equipment 3000, and the aforementioned on-board battery 1000. The automotive engine 2000 provides charging power to the energy storage module 200 of the on-board battery 1000, and the on-board battery 1000 supplies power to the on-board electrical equipment 3000, thereby ensuring the normal operation of the on-board electrical equipment 3000 and the normal operation of the vehicle 1. The on-board electrical equipment 3000 may include, but is not limited to, a parking air conditioner, a lighting system, and an audio system.
[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.
Claims
1. A battery protection circuit for charging and discharging protection of an energy storage module, characterized in that, The battery protection circuit includes: A first charging protection circuit is used to connect an external power source and the energy storage module to transfer electrical energy from the external power source to the energy storage module. The first charging protection circuit includes an overcharge protection switch and a first driving circuit. The first driving circuit is electrically connected to the overcharge protection switch and is used to receive a driving signal to control the on / off state of the overcharge protection switch. The second charging protection circuit includes a current limiting device, and the second charging protection circuit is connected in parallel with the overcharge protection switch; A detection circuit is used to collect the status parameters of the energy storage module; wherein, the status parameters include at least the charging parameters of the energy storage module; The control module is connected to the first charging protection circuit, the second charging protection circuit, and the detection circuit, respectively. The control module is used to disconnect the first charging protection circuit and turn on the second charging protection circuit when the state parameters meet the preset conditions based on the detection signal of the detection circuit, so as to charge the energy storage module and limit the charging current of the energy storage module through the second charging protection circuit.
2. The battery protection circuit as described in claim 1, characterized in that, The current limiting device includes a current limiting switch and a current limiting resistor, which are connected in series.
3. The battery protection circuit as described in claim 1, characterized in that, The charging parameters include the voltage and / or charging current of the energy storage module.
4. The battery protection circuit as described in claim 1 or 3, characterized in that, The preset conditions include at least one of the following: The voltage of the energy storage module drops to a first threshold. The charging current of the energy storage module reaches the second threshold. The voltage of the energy storage module reaches a third threshold, wherein the first threshold is less than the third threshold.
5. The battery protection circuit as described in claim 1, characterized in that, The battery protection circuit also includes an over-discharge protection circuit, which includes an over-discharge protection switch. The control module is also electrically connected to the over-discharge protection circuit, and the control module is also used to control the on / off state of the over-discharge protection circuit; wherein, when the first charging protection circuit is in the off state and the second charging protection circuit is in the on state, the second charging protection circuit is connected in series with the over-discharge protection switch; when the first charging protection circuit is in the on state and the second charging protection circuit is in the off state, the overcharge protection switch is connected in series with the over-discharge protection switch.
6. The battery protection circuit as described in claim 1 or 3, characterized in that, The detection circuit includes a current detection circuit, wherein when the first charging protection circuit is in the off state and the second charging protection circuit is in the on state, the second charging protection circuit is connected in series with the current detection circuit; when the first charging protection circuit is in the on state and the second charging protection circuit is in the off state, the overcharge protection switch is connected in series with the current detection circuit. The current detection circuit is used to detect the charging current of the energy storage module and feed the detected charging current back to the control module.
7. The battery protection circuit as described in claim 1, characterized in that, The battery protection circuit also includes connection terminals, which include a positive terminal and a negative terminal. The positive terminal and the negative terminal are electrically connected to the positive and negative terminals of the energy storage module in a one-to-one correspondence. The positive terminal and the negative terminal are also used to electrically connect to the positive and negative terminals of an external power source or an external load in a one-to-one correspondence. The overcharge protection switch and the second charging protection circuit are electrically connected between one pole of the energy storage module and the corresponding polarity terminal of the connection terminal.
8. The battery protection circuit as described in claim 7, characterized in that, The battery protection circuit also includes an over-discharge protection circuit, which includes an over-discharge protection switch; the over-discharge protection switch and the overcharge protection switch are connected in series between the energy storage module and the connection terminal. The over-discharge protection switch includes a MOSFET, and / or the overcharge protection switch includes a MOSFET.
9. The battery protection circuit as described in claim 8, characterized in that, The overcharge protection switch and the second charging protection circuit are connected in parallel between the negative terminal of the energy storage module and the negative terminal. The battery protection circuit further includes an over-discharge protection circuit, which includes an over-discharge protection switch; wherein the over-discharge protection switch is electrically connected between the negative terminal of the energy storage module and the overcharge protection switch; the negative terminal of the energy storage module is also electrically connected to the signal ground connection point. The current limiting device includes a current limiting switch and a current limiting resistor, wherein the current limiting switch and the current limiting resistor are connected in series; The overcharge protection switch, the over-discharge protection switch, and the current limiting switch are all implemented using NMOS transistors; The drain of the over-discharge protection switch and the drain of the overcharge protection switch are electrically connected, and the common connection point between them is electrically connected to the power ground connection point. The drain of the current limiting switch is electrically connected to the common connection node via the current limiting resistor, and the source of the current limiting switch and the source of the overcharge protection switch are both connected to the negative terminal.
10. The battery protection circuit as described in claim 1 or 3, characterized in that, The detection circuit includes a voltage detection circuit, which is electrically connected to both the energy storage module and the control module. The voltage detection circuit is used to detect the voltage of the energy storage module and feed the detected voltage back to the control module.
11. The battery protection circuit as described in claim 1 or 3, characterized in that, The detection circuit includes a temperature detection circuit, which is used to detect the temperature of the energy storage module. The battery protection circuit also includes a heating module, which is used to heat the energy storage module. The control module is also electrically connected to the heating module. The control module is also used to acquire the temperature detected by the temperature detection circuit, and when the temperature is lower than the preset temperature, control the heating module to heat the energy storage module.
12. The battery protection circuit as described in claim 5 or 8, characterized in that, It also includes a high-power absorption device, which is connected in parallel with the over-discharge protection switch to clamp the voltage of the over-discharge protection switch.
13. A vehicle battery, characterized in that, include: Energy storage modules are used to store electrical energy; as well as The battery protection circuit as described in any one of claims 1-12, wherein the battery protection circuit is electrically connected to the energy storage module, and the battery protection circuit is used to transfer electrical energy from an external power source to the energy storage module for charging, and to transfer electrical energy from the energy storage module to an external load for power supply.
14. The vehicle battery as described in claim 13, characterized in that, The energy storage module includes a rechargeable battery or a supercapacitor, wherein the rechargeable battery includes a sodium battery, a lithium battery, or a lead-acid battery. The vehicle battery also includes: A housing for housing the energy storage module and the battery protection circuit; A first terminal and a second terminal are disposed on the housing. At least one of the first terminal and the second terminal is connected to the battery protection circuit. The first terminal and the second terminal are used to connect to the vehicle engine and / or on-board electrical equipment.
15. A vehicle, characterized in that, include: Car engine; Vehicle-mounted electrical equipment; as well as The vehicle battery as described in claim 13 or 14, wherein the vehicle engine is used to provide charging power to the energy storage module of the vehicle battery, and the vehicle battery is used to supply power to the vehicle electrical equipment.