Self-adaptive cut-off voltage adjusting system and adjusting method of parking battery

Abstract

The invention provides a self-adaptive cut-off voltage adjusting system and method of a parking battery. The self-adaptive cut-off voltage adjusting system of the parking battery comprises an acquisition module, a processing module and a control execution module. The acquisition module is used for acquiring temperature, discharge current and terminal voltage data of the parking battery in real time; the processing module is in communication connection with the acquisition module and calculates a dynamic cut-off voltage; and the control execution module is electrically connected with the processing module and is also electrically connected with the discharge MOS, and when the terminal voltage reaches the dynamic cut-off voltage, the control execution module turns off the discharge MOS to stop discharging. According to the adaptive cut-off voltage regulation system of the parking battery, the characteristics of voltage sag and SOC-OCV relation offset of the lithium iron phosphate battery at low temperature are dynamically adapted through the temperature-current two-parameter associated two-dimensional curve model, the misjudgment rate of the residual electric quantity is greatly reduced, and the problem that the parking battery cannot be started when the residual electric quantity exists is avoided.

Description

Technical Field

[0001] This application belongs to the field of battery management technology, specifically relating to an adaptive cutoff voltage regulation system and method for a parking battery. Background Technology

[0002] Lithium iron phosphate (LFP) batteries are lithium-ion batteries that use lithium iron phosphate as the cathode material. They possess core advantages such as high safety, long cycle life, and controllable cost, making them the mainstream choice for parking batteries in commercial vehicles. With the rapid popularization of new energy commercial vehicles, the existing stock of commercial parking batteries has exceeded 20 million units and continues to grow.

[0003] However, traditional battery management systems (BMS) rely on SOC (State of Charge) estimation and employ a fixed cutoff voltage strategy, which has significant drawbacks in low-temperature environments: low temperatures cause a sudden drop in battery voltage, resulting in a shift in the SOC-OCV (open-circuit voltage) relationship, increased coulombic measurement errors, and consequently, misjudgments of remaining charge; the fixed cutoff voltage easily triggers protection mechanisms prematurely, potentially preventing the vehicle from starting even if the battery actually retains 20% charge; existing temperature compensation methods are mostly static adjustments, failing to consider the impact of current load, making it difficult to balance battery protection and available charge. These problems severely impact the operational reliability of commercial vehicles in low-temperature environments and may even pose driving safety hazards, hindering the further promotion and application of lithium iron phosphate batteries in the commercial vehicle sector. Summary of the Invention

[0004] This application provides an adaptive cutoff voltage regulation system and method for parking batteries, aiming to solve the technical problems existing in the prior art, such as misjudgment of remaining power in low-temperature environments, premature triggering of protection mechanisms, and unreliable operation of battery management systems.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, an adaptive cutoff voltage regulation system for a parking battery is provided, comprising: The data acquisition module is used to collect real-time data on the temperature, discharge current, and terminal voltage of the parking battery. The processing module, communicatively connected to the acquisition module, combines the received data from the acquisition module to obtain a two-dimensional curve model by fitting the cutoff voltage corresponding to the remaining 20% ​​state of charge of the battery under different temperatures and currents. The processing module then calculates the dynamic cutoff voltage based on the acquired two-dimensional curve model. The control execution module is electrically connected to the processing module and also electrically connected to the discharge MOS. When the terminal voltage reaches the dynamic cutoff voltage, the control execution module turns off the discharge MOS to stop the discharge.

[0006] In conjunction with the first aspect, in one possible implementation, the acquisition module includes: Temperature sensor used to detect the temperature around the parking battery; A current sensor, connected in series in the circuit containing the parking battery, is used to detect the discharge current of the parking battery; and The data acquisition chip is used to detect the terminal voltage of the parking battery.

[0007] In conjunction with the first aspect, in one possible implementation, the temperature sensor has a temperature acquisition range of -35℃ to 25℃, and when the detected temperature is below -35℃ or above 25℃, it is processed according to the corresponding boundary value.

[0008] In conjunction with the first aspect, in one possible implementation, the adaptive cutoff voltage regulation system for the parking battery further includes: A hysteresis comparator is used to compare the terminal voltage data acquired by the acquisition module with the dynamic cutoff voltage, and output a switching signal to the control execution module; and A reference voltage module is electrically connected to the hysteresis comparator and provides a stable reference voltage for the hysteresis comparator.

[0009] In conjunction with the first aspect, in one possible implementation, the processing module includes: The MCU body is electrically connected to the acquisition module and the discharge MOS, respectively. The storage unit is communicatively connected to the MCU main body and stores the data transmitted by the acquisition module; A control logic unit, communicatively connected to the storage unit, calculates the dynamic cutoff voltage using a preset formula; and The judgment unit is communicatively connected to the control logic unit and electrically connected to the control execution module. The judgment unit compares the dynamic cutoff voltage with the charging cutoff voltage threshold and transmits the corresponding information to the control execution module.

[0010] In conjunction with the first aspect, in one possible implementation, the processing module is further configured with a charging cut-off voltage adjustment unit, which is communicatively connected to the judgment unit and is used to dynamically adjust the threshold of the charging cut-off voltage based on battery impedance and open-circuit voltage data.

[0011] In conjunction with the first aspect, in one possible implementation, the control execution module includes: A control logic unit is electrically connected to the processing module and connected to the discharge MOS to control the turn-off of the discharge MOS.

[0012] The adaptive cutoff voltage regulation system for parking batteries provided in this application, compared with existing technologies, continuously captures the temperature, discharge current, and terminal voltage data of the parking battery through an acquisition module, providing real-time and complete raw parameters for subsequent calculations; the processing module calls a pre-stored two-dimensional curve model; the processing module substitutes the real-time acquired temperature and discharge current data into the two-dimensional curve model to accurately calculate the dynamic cutoff voltage under the current operating conditions; the control execution module compares the terminal voltage with the dynamic cutoff voltage in real time, and when the terminal voltage reaches the threshold, it immediately turns off the discharge MOSFET to terminate the discharge process and avoid over-discharge of the battery. Through a two-dimensional curve model that correlates temperature and current parameters, it dynamically adapts to the characteristics of sudden voltage drops and SOC-OCV relationship shifts in lithium iron phosphate batteries at low temperatures, effectively correcting coulomb measurement errors, significantly reducing the misjudgment rate of remaining charge, and avoiding the problem of being unable to start despite remaining charge. This system is suitable for commercial vehicle operation in cold regions. The dynamic cutoff voltage is calculated based on a remaining 20% ​​SOC, ensuring that the battery retains sufficient starting charge while maximizing the utilization of effective charge, balancing battery protection and energy utilization efficiency. The system requires no additional hardware compensation circuitry and can be directly integrated into existing BMS systems, offering strong compatibility. It can be implemented with just a software upgrade, significantly reducing the cost and time required to retrofit existing commercial vehicle battery systems.

[0013] Secondly, an adaptive cutoff voltage regulation method for a parking battery is provided, implemented based on an adaptive cutoff voltage regulation system for a parking battery as described in any of the possible implementations above, characterized by comprising the following steps: S1: Real-time data acquisition of parking battery temperature, discharge current and terminal voltage data via acquisition module; S2: The processing module receives the temperature and discharge current data. If the temperature exceeds the range of -35℃ to 25℃, it corrects the temperature according to the boundary value. S3: Based on the preset temperature-current two-dimensional curve model, substitute the corrected temperature and discharge current data to calculate the dynamic cutoff voltage; S4: When the terminal voltage is detected to reach the dynamic cutoff voltage, the control execution module turns off the discharge MOS transistor and stops the discharge; S5: Update the collected data in real time, repeat steps S2~S4, and realize dynamic iterative optimization of the cutoff voltage.

[0014] In conjunction with the second aspect, in one possible implementation, the construction process of the two-dimensional curve model described in step S3 includes: Under different temperature and current conditions, the cutoff voltage of the battery with 20% SOC was measured. The slope and intercept of the corresponding temperature and current ranges were obtained by linear fitting, and a two-parameter correlation model was established.

[0015] In conjunction with the second aspect, in one possible implementation, step S4 is followed by: The impedance and open-circuit voltage data during battery charging are collected, and the charging cutoff voltage and cutoff current thresholds are dynamically adjusted based on the number of battery cycles.

[0016] The adaptive cutoff voltage adjustment method for parking batteries provided in this application, compared with existing technologies, dynamically adapts to the characteristics of sudden voltage drop and SOC-OCV relationship shift of lithium iron phosphate batteries at low temperatures through a two-dimensional curve model with temperature-current dual-parameter correlation. This effectively corrects coulomb measurement errors, significantly reduces the misjudgment rate of remaining charge, and avoids the problem of failure to start despite remaining charge. It is suitable for commercial vehicle operation in cold regions. The dynamic cutoff voltage is calculated based on a remaining 20% ​​SOC, ensuring that the battery retains sufficient starting charge while maximizing the utilization of effective charge, balancing battery protection and energy utilization efficiency. The system does not require additional hardware compensation circuits and can be directly integrated into existing BMS systems, exhibiting strong compatibility and requiring only software upgrades, significantly reducing the cost and time required to retrofit existing commercial vehicle battery systems. Comprehensive acquisition of core parameters provides a data foundation for subsequent adjustments; temperature boundary value correction avoids data distortion under extreme temperatures, ensuring the stability of adjustments; and the dynamic cutoff voltage calculation based on the two-dimensional curve model achieves precise adaptation of dual parameters. By continuously repeating steps S2 to S4, the cutoff voltage can respond in real time to minute changes in temperature and current, forming a linear and continuous adjustment effect, avoiding the impact on the battery caused by traditional step-like adjustments. No complex operating procedures are required; it can be fully automated without human intervention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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 based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of an adaptive cutoff voltage regulation system for a parking battery provided in an embodiment of this application; Figure 2 This is a flowchart illustrating the calculation of the cutoff voltage by the processing module used in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of an adaptive cutoff voltage regulation system for a parking battery provided in another embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Data Acquisition Module; 11. Temperature Sensor; 12. Current Sensor; 13. Data Acquisition Chip; 2. Processing module; 21. MCU main body; 22. Storage unit; 23. Control logic unit; 24. Judgment unit; 25. Charging cut-off voltage adjustment unit; 3. Control and execution module; 4. Discharge MOS; 5. Hysteresis comparator; 6. Reference voltage module. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is actually illustrative only and is in no way intended to limit this application or its application or use. 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.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0024] It should be noted that the terms "length," "width," "height," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the application. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0025] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Additionally, "multiple" and "several" mean two or more, unless otherwise explicitly specified.

[0028] Please refer to the following: Figures 1 to 3The adaptive cutoff voltage regulation system for parking batteries provided in this application is described below. The adaptive cutoff voltage regulation system for parking batteries includes a data acquisition module 1, a processing module 2, and a control execution module 3. The data acquisition module 1 is used to acquire real-time data on the temperature, discharge current, and terminal voltage of the parking battery. The processing module 2 is communicatively connected to the data acquisition module 1 and, based on the received data, obtains a two-dimensional curve model by fitting the cutoff voltage corresponding to the remaining 20% ​​state of charge of the battery under different temperatures and currents. The processing module 2 calculates the dynamic cutoff voltage based on the acquired two-dimensional curve model. The control execution module 3 is electrically connected to the processing module 2 and also electrically connected to the discharge MOS 4. When the terminal voltage reaches the dynamic cutoff voltage, the control execution module 3 turns off the discharge MOS 4 to stop the discharge.

[0029] It should be noted that the discharge MOS4 is an electronic switching element used in the battery management system (BMS) to control the on / off state of the discharge current.

[0030] It should be noted that this embodiment links the two core variables that affect the cutoff voltage: battery temperature and discharge current. With the remaining 20% ​​SOC (state of charge) of the battery as the key node, a two-dimensional temperature-current curve model is formed by fitting measured data, so that the cutoff voltage changes dynamically with real-time operating conditions, replacing the traditional fixed threshold strategy.

[0031] In practice, the acquisition module 1 continuously captures the temperature, discharge current, and terminal voltage data of the parking battery, providing real-time and complete raw parameters for subsequent calculations; the processing module 2 calls the pre-stored two-dimensional curve model; the processing module 2 substitutes the real-time acquired temperature and discharge current data into the two-dimensional curve model to accurately calculate the dynamic cutoff voltage under the current operating conditions; the control execution module 3 compares the terminal voltage with the dynamic cutoff voltage in real time, and when the terminal voltage reaches the threshold, it immediately turns off the discharge MOSFET to terminate the discharge process and avoid over-discharge of the battery.

[0032] The adaptive cutoff voltage regulation system for parking batteries provided in this embodiment, compared with existing technologies, dynamically adapts to the characteristics of sudden voltage drop and SOC-OCV relationship shift of lithium iron phosphate batteries at low temperatures through a two-dimensional curve model with temperature-current dual-parameter correlation. This effectively corrects coulomb measurement errors, significantly reduces the false judgment rate of remaining charge, and avoids the problem of vehicles failing to start despite having remaining charge. It is suitable for commercial vehicle operation in cold regions. The dynamic cutoff voltage is calculated based on a remaining 20% ​​SOC, ensuring that the battery retains sufficient starting charge while maximizing the utilization of effective charge, balancing battery protection and energy utilization efficiency. The system requires no additional hardware compensation circuitry and can be directly integrated into existing BMS systems, exhibiting strong compatibility. It only requires a software upgrade, significantly reducing the cost and time required to retrofit existing commercial vehicle battery systems.

[0033] In some embodiments, see Figure 1 The acquisition module 1 includes a temperature sensor 11, a current sensor 12, and an acquisition chip 13. The temperature sensor 11 is used to detect the temperature around the parking battery; the current sensor 12 is connected in series in the circuit where the parking battery is located and is used to detect the discharge current of the parking battery; the acquisition chip 13 is used to detect the terminal voltage of the parking battery.

[0034] In practice, the temperature sensor 11 can be either a TMP275-Q1 or an EVS 101 sensor. The current sensor 12 can be either an ACP 3000 / 24 ​​or a CSNV500 sensor.

[0035] This embodiment clearly defines the specific composition and division of labor of the acquisition module 1. The temperature sensor 11 directly detects the temperature around the battery, which can more accurately reflect the actual operating temperature of the battery and avoid adjustment deviations caused by the temperature difference between the environment and the battery itself. The current sensor 12 is connected in series in the circuit and can capture the dynamic changes of the discharge current in real time, ensuring that the current parameters are highly consistent with the actual operating conditions. The acquisition chip 13 is specifically used to detect the terminal voltage, which can accurately capture the subtle changes in the terminal voltage of the lithium iron phosphate cell and avoid voltage signal distortion. The three work together to effectively overcome the shortcomings of the traditional acquisition module 1, such as single parameters and insufficient accuracy, making the raw data acquired by the processing module 2 more valuable for reference. The dynamic cutoff voltage calculated based on this accurate acquisition data can better match the real-time operating state of the battery.

[0036] In some embodiments, the temperature sensor 11 has a temperature acquisition range of -35℃ to 25℃. When the detected temperature is below -35℃ or above 25℃, it is processed according to the corresponding boundary value. The acquisition range of -35℃ to 25℃ accurately covers the low winter temperatures and daily ambient temperatures in most regions, effectively capturing the characteristic changes of the battery at low temperatures, providing reliable temperature parameters for dynamic cutoff voltage calculation, and solving the problems of traditional systems not having a clear temperature adaptation range and acquisition failure at low temperatures.

[0037] When the temperature is below -35℃ or above 25℃, the boundary value processing rules prevent abnormal fluctuations in sensor data collected under extreme temperatures. This ensures stable input parameters for the processing module 2 when calculating the dynamic cutoff voltage, preventing deviations in cutoff voltage calculations due to extreme temperatures, and thus avoiding over-discharge protection failure or premature shutdown. This design ensures the system's accuracy under core operating conditions while improving stability and reliability in extreme environments. It allows the parking battery to function normally under cold, hot, and other special climatic conditions, effectively protecting the battery from damage and ensuring the starting reliability of commercial vehicles.

[0038] In some embodiments, see Figure 3The adaptive cutoff voltage regulation system for the parking battery also includes a hysteresis comparator 5 and a reference voltage module 6. The hysteresis comparator 5 is used to compare the terminal voltage data acquired by the acquisition module 1 with the dynamic cutoff voltage and output a switching signal to the control execution module 3; the reference voltage module 6 is electrically connected to the hysteresis comparator 5 and provides a stable reference voltage for the hysteresis comparator 5.

[0039] This embodiment improves the accuracy and stability of the dynamic cutoff voltage-triggered shutdown action by adding a hysteresis comparator 5 and a reference voltage module 6. The reference voltage module 6 provides a stable and constant reference voltage for the hysteresis comparator 5, avoiding comparison reference offset caused by power fluctuations and electromagnetic interference, and ensuring the accuracy of voltage comparison. The hysteresis comparator 5 can effectively suppress false triggering caused by terminal voltage fluctuations by setting upper and lower threshold voltages. When the terminal voltage reaches the dynamic cutoff voltage, it stably outputs a flip signal to the control execution module 3, ensuring the consistency of the shutdown action, avoiding frequent shutdown and startup caused by instantaneous voltage fluctuations, and reducing the impact on the battery and discharge MOSFET.

[0040] The hysteresis comparator 5 and the reference voltage module 6 in this embodiment make up for the shortcomings of slow response and weak anti-interference ability of traditional software comparison, making the shutdown command of the control execution module 3 more accurate and reliable, ensuring that the battery stops discharging in time at the dynamic cutoff voltage threshold, avoiding over-discharge damage to the battery, and preventing premature shutdown that would waste power.

[0041] In some embodiments, the reference voltage module 6 includes a reference voltage source, a filter circuit, a buffer amplifier circuit, and a voltage fine-tuning circuit. The reference voltage source sets an initial reference voltage via an external resistor, which is unaffected by fluctuations in the input power supply voltage. The filter circuit removes high-frequency noise from the reference voltage, ensuring that the reference voltage ripple is ≤5mV, thus preventing noise-induced reference offset. The buffer amplifier circuit amplifies the reference voltage before outputting it, enhancing its load-carrying capacity and ensuring stability even with frequent switching of the hysteresis comparator 5. The voltage fine-tuning circuit adjusts the reference voltage according to actual calibration requirements, ensuring comparison accuracy.

[0042] In some embodiments, the hysteresis comparator 5 module includes a comparator chip, a positive feedback resistor network, an input voltage divider circuit, and an output drive circuit. The hysteresis voltage is calculated through the positive feedback resistor network, and the upper threshold voltage of the hysteresis comparator 5 is equal to the dynamic cutoff voltage plus 0.25V, and the lower threshold voltage is equal to the dynamic cutoff voltage minus 0.25V.

[0043] When the acquired terminal voltage is less than the lower threshold voltage, the comparator outputs a high level, controlling the execution module 3 to keep the discharge MOSFET on, and the battery discharges normally. When the terminal voltage rises to the upper threshold voltage, the comparator outputs a low level (flip signal), controlling the execution module 3 to turn off the discharge MOSFET and stop discharging. After the discharge stops, if the terminal voltage rises slightly due to the battery recovery, as long as it does not fall below the lower threshold voltage, the comparator remains at a low level to avoid false triggering and ensure stable shutdown.

[0044] If the parking battery terminal voltage is high, the input voltage divider circuit will proportionally reduce the terminal voltage to the range that the comparator can handle, and then compare it with the voltage divider signal of the dynamic cutoff voltage to ensure that the comparison logic remains unchanged.

[0045] In some embodiments, see Figure 1 The processing module 2 includes an MCU body 21, a storage unit 22, a control logic unit 23, and a judgment unit 24. The MCU body 21 is electrically connected to the acquisition module 1 and the discharge MOS4 respectively; the storage unit 22 is communicatively connected to the MCU body 21 and stores the data transmitted by the acquisition module 1; the control logic unit 23 is communicatively connected to the storage unit 22 and calculates the dynamic cutoff voltage using a preset formula; the judgment unit 24 is communicatively connected to the control logic unit 23 and electrically connected to the control execution module 3. The judgment unit 24 compares the dynamic cutoff voltage with the charging cutoff voltage threshold and transmits the corresponding information to the control execution module 3.

[0046] In practical implementation, the MCU main body 21 serves as the core control hub, responsible for coordinating the work of each unit and ensuring the timeliness of data transmission and command issuance; the storage unit 22 can store the temperature, current, and voltage data transmitted by the acquisition module 1 in real time, providing historical data reference for the control logic unit 23 and facilitating subsequent traceability and fault diagnosis; the control logic unit 23 calculates the dynamic cutoff voltage through a preset formula, and can quickly substitute real-time data to complete the calculation, improving the real-time performance of cutoff voltage adjustment; the judgment unit 24 can achieve coordinated adaptation of charging and discharging thresholds by comparing the dynamic cutoff voltage with the charging cutoff voltage threshold, avoiding mutual conflicts in charging and discharging adjustments.

[0047] In this embodiment, the processing module 2 has clearly defined functions and works efficiently together, enabling it to respond quickly to changes in operating conditions and complete data processing and threshold calculations within milliseconds, ensuring that the dynamic cutoff voltage keeps pace with changes in battery status. Simultaneously, the modular design provides the system with excellent scalability and maintainability. The preset formulas of the control logic unit 23 can be adjusted according to the characteristics of different commercial vehicle batteries, adapting to various models of lithium iron phosphate parking batteries and further enhancing the system's compatibility and applicability.

[0048] In some embodiments, see Figure 3The processing module 2 is also equipped with a charging cut-off voltage adjustment unit 25, which is communicatively connected to the judgment unit 24 and is used to dynamically adjust the threshold of the charging cut-off voltage based on the battery impedance and open circuit voltage data.

[0049] During cyclic use, the impedance of a high-cycle battery will increase significantly, and a fixed charging threshold can easily lead to undercharging or overcharging.

[0050] The charging cut-off voltage adjustment unit 25 can adjust the charging cut-off voltage in a targeted manner by monitoring impedance and OCV data in real time, ensuring that the battery reaches its optimal capacity with each charge, while avoiding overcharging and damage to the battery. The charging and discharging adjustments are mutually adapted and form a closed loop. On the discharging side, 20% of the starting capacity is maintained, and on the charging side, energy is precisely replenished based on the battery's degradation state. This not only improves the battery's energy utilization efficiency but also effectively extends the battery's cycle life.

[0051] In some embodiments, the charging cut-off voltage adjustment unit 25 includes a data receiving unit, a parameter calculation unit, a threshold processing unit, and a diagnostic unit. The data receiving unit is communicatively connected to the acquisition module 1 and the storage unit 22, and is used to receive battery impedance data, OCV data, and the cumulative number of battery cycles. The parameter calculation unit has built-in algorithm logic, inputs three types of data, and calculates the impedance correction coefficient, OCV correction coefficient, and cycle count correction coefficient. The threshold storage unit 22 pre-stores the standard threshold for new batteries and a threshold mapping table for different attenuation levels; the pre-stored threshold table enables fast retrieval and improves response speed. The threshold output unit is communicatively connected to the judgment unit 24, outputs the final charging cut-off voltage threshold and cut-off current threshold, and simultaneously feeds it back to the control execution module 3 for real-time control of the charging process. The fault diagnosis unit monitors the validity of data acquisition, and outputs a default safety threshold if a fault occurs.

[0052] It should be noted that the battery impedance data is acquired by the acquisition module 1 through the impedance detection circuit; the OCV (open circuit voltage) data is acquired when there is no load after the discharge is turned off; the cumulative number of battery cycles is recorded by the storage unit 22, and the count is incremented by 1 for each completed charge and discharge operation.

[0053] In practice, the greater the impedance, the greater the impedance correction coefficient, and the charging cut-off voltage needs to be appropriately increased to offset the voltage loss caused by the impedance; when the OCV is lower than the standard value of a new battery, the charging cut-off current is reduced; when the number of cycles exceeds the preset threshold, the threshold adaptation attenuation is further optimized.

[0054] In some embodiments, the control execution module 3 includes a control logic unit, which is electrically connected to the processing module 2 and connected to the discharge MOS4 to control the turn-off of the discharge MOS4.

[0055] In this embodiment, the control logic unit can quickly receive the judgment signal from the processing module 2 and convert it into precise control commands to drive the discharge MOS transistor to turn off. This unit has high response speed and anti-interference capability. After receiving the flip signal, it can complete the command output within microseconds, avoiding battery over-discharge due to response delay. The direct connection between the control logic unit and the discharge MOS 4 reduces signal loss and interference in the intermediate transmission links, further improving the reliability of the turn-off action.

[0056] Based on the same inventive concept, this application also provides an adaptive cutoff voltage regulation method for a parking battery, implemented based on the adaptive cutoff voltage regulation system for a parking battery as described in any of the above embodiments, including the following steps: S1: The temperature, discharge current, and terminal voltage data of the parking battery are collected in real time by the acquisition module 1; S2: The processing module 2 receives the temperature and discharge current data, and if the temperature exceeds the range of -35℃ to 25℃, it is corrected according to the boundary value; S3: Based on the preset temperature-current two-dimensional curve model, the corrected temperature and discharge current data are substituted to calculate the dynamic cutoff voltage; S4: When the terminal voltage is detected to reach the dynamic cutoff voltage, the control execution module 3 turns off the discharge MOS transistor and stops the discharge; S5: The collected data is updated in real time, and steps S2 to S4 are repeated to achieve dynamic iterative optimization of the cutoff voltage.

[0057] The adaptive cutoff voltage adjustment method for parking batteries provided in this embodiment, compared with existing technologies, achieves comprehensive acquisition of core parameters, providing a data foundation for subsequent adjustments; temperature boundary value correction avoids data distortion under extreme temperatures, ensuring adjustment stability; and dynamic cutoff voltage is calculated based on a two-dimensional curve model, achieving precise adaptation of dual parameters. By continuously repeating steps S2~S4, the cutoff voltage can respond in real time to subtle changes in temperature and current, forming a linear and continuous adjustment effect, avoiding the impact on the battery caused by traditional step adjustments. It requires no complex operating procedures, can be fully automated, requires no manual intervention, and is suitable for unattended parking scenarios in commercial vehicles.

[0058] In some embodiments, the process of constructing the two-dimensional curve model in step S3 includes: measuring the cutoff voltage of the battery when it has 20% SOC under different temperature and current conditions, obtaining the slope and intercept of the corresponding temperature range and current range through linear fitting, and establishing a two-parameter correlation model.

[0059] In practical implementation, the dynamic cutoff voltage calculated based on this measured model can accurately match the battery's voltage requirements under different operating conditions. Under low temperature and low current conditions, the cutoff voltage can be appropriately reduced to retain sufficient starting power; under normal temperature and high current conditions, the cutoff voltage can be reasonably increased to improve energy utilization efficiency.

[0060] This embodiment constructs the system within a temperature range of -35℃ to 25℃, selecting multiple key temperature points and measuring the cutoff voltage at 20% SOC of the battery under different discharge current levels to ensure data coverage of the main operating conditions of commercial vehicles. A two-parameter correlation model between temperature, current, and cutoff voltage is established through linear fitting to obtain the slope and intercept, enabling the model to accurately reflect the actual characteristics of the battery and avoid deviations caused by theoretical derivations. The model based on measured data exhibits high stability and reliability, effectively resisting the influence of individual battery differences and ensuring consistent adjustment effects for batteries from the same or different batches. This facilitates unified management and maintenance of commercial vehicle fleets, further enhancing the system's promotional value.

[0061] In some embodiments, after step S4, the method further includes: collecting impedance and open-circuit voltage data during battery charging, and dynamically adjusting the charging cut-off voltage and cut-off current thresholds based on the battery cycle count. This embodiment adds a dynamic adjustment step for charging parameters after discharge shutdown, achieving seamless connection and full-cycle adaptation of the charging and discharging process. After discharge shutdown is completed in step S4, the battery is in a no-load state. At this time, the collected impedance and open-circuit voltage data are not affected by the discharge current and can more accurately reflect the current performance state of the battery. Combined with the battery cycle count, the degree of battery degradation can be accurately determined. The more cycles and the greater the impedance, the more severe the battery degradation. Adjusting the charging cut-off voltage and cut-off current thresholds at this time can avoid undercharging or overcharging caused by battery degradation.

[0062] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An adaptive cutoff voltage regulation system for a parking battery, characterized in that, include: The data acquisition module (1) is used to collect the temperature, discharge current and terminal voltage data of the parking battery in real time; The processing module (2) is connected to the acquisition module (1) in communication. It combines the data received from the acquisition module (1) to obtain a two-dimensional curve model by fitting the cutoff voltage corresponding to the remaining 20% ​​state of charge of the battery under different temperatures and currents. The processing module (2) calculates the dynamic cutoff voltage based on the obtained two-dimensional curve model. as well as The control execution module (3) is electrically connected to the processing module (2) and also electrically connected to the discharge MOS (4). When the terminal voltage reaches the dynamic cutoff voltage, the control execution module (3) turns off the discharge MOS (4) to stop the discharge.

2. The adaptive cutoff voltage regulation system for parking batteries as described in claim 1, characterized in that, The acquisition module (1) includes: Temperature sensor (11) is used to detect the temperature around the parking battery; A current sensor (12) is connected in series in the circuit containing the parking battery and is used to detect the discharge current of the parking battery; and The acquisition chip (13) is used to detect the terminal voltage of the parking battery.

3. The adaptive cutoff voltage regulation system for parking batteries as described in claim 2, characterized in that, The temperature sensor (11) has a temperature acquisition range of -35℃ to 25℃. When the detected temperature is below -35℃ or above 25℃, it is processed according to the corresponding boundary value.

4. The adaptive cutoff voltage regulation system for parking batteries as described in claim 1, characterized in that, The adaptive cutoff voltage regulation system for the parking battery also includes: A hysteresis comparator (5) is used to compare the terminal voltage data acquired by the acquisition module (1) with the dynamic cutoff voltage, and output a switching signal to the control execution module (3); and The reference voltage module (6) is electrically connected to the hysteresis comparator (5) and provides a stable reference voltage for the hysteresis comparator (5).

5. The adaptive cutoff voltage regulation system for parking batteries as described in claim 1, characterized in that, The processing module (2) includes: The MCU body (21) is electrically connected to the acquisition module (1) and the discharge MOS (4) respectively; The storage unit (22) is communicatively connected to the MCU main body (21) and stores the data transmitted by the acquisition module (1); A control logic unit (23) is communicatively connected to the storage unit (22), and the control logic unit (23) calculates the dynamic cutoff voltage using a preset formula; and The judgment unit (24) is communicatively connected to the control logic unit (23) and electrically connected to the control execution module (3). The judgment unit (24) compares the dynamic cutoff voltage with the charging cutoff voltage threshold and transmits the corresponding information to the control execution module (3).

6. The adaptive cutoff voltage regulation system for parking batteries as described in claim 5, characterized in that, The processing module (2) is also equipped with a charging cut-off voltage adjustment unit (25), which is communicatively connected to the judgment unit (24) and is used to dynamically adjust the threshold of the charging cut-off voltage based on battery impedance and open circuit voltage data.

7. The adaptive cutoff voltage regulation system for parking batteries as described in claim 1, characterized in that, The control execution module (3) includes: A control logic unit is electrically connected to the processing module (2) and connected to the discharge MOS (4) to control the turn-off of the discharge MOS (4).

8. An adaptive cutoff voltage regulation method for a parking battery, implemented based on the adaptive cutoff voltage regulation system for a parking battery as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: The temperature, discharge current and terminal voltage data of the parking battery are collected in real time through the acquisition module (1); S2: The processing module (2) receives the temperature and discharge current data. If the temperature exceeds the range of -35℃ to 25℃, it is corrected according to the boundary value. S3: Based on the preset temperature-current two-dimensional curve model, substitute the corrected temperature and discharge current data to calculate the dynamic cutoff voltage; S4: When the terminal voltage is detected to reach the dynamic cutoff voltage, the control execution module (3) turns off the discharge MOS (4) transistor and stops the discharge; S5: Update the collected data in real time, repeat steps S2~S4, and realize dynamic iterative optimization of the cutoff voltage.

9. The adaptive cutoff voltage regulation method for a parking battery as described in claim 8, characterized in that, The construction process of the two-dimensional curve model in step S3 includes: Under different temperature and current conditions, the cutoff voltage of the battery with 20% SOC was measured. The slope and intercept of the corresponding temperature and current ranges were obtained by linear fitting, and a two-parameter correlation model was established.

10. The adaptive cutoff voltage regulation method for a parking battery as described in claim 8, characterized in that, Step S4 is followed by: The impedance and open-circuit voltage data during battery charging are collected, and the charging cutoff voltage and cutoff current thresholds are dynamically adjusted based on the number of battery cycles.

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