Practical 8.4 V lithium battery voltage detection method
By obtaining the relationship between the lithium battery voltage and the reference voltage, generating a breakdown signal and calculating the sampling voltage, combining analog-to-digital conversion and dynamic compensation models, the problem of low voltage detection accuracy and susceptibility to interference in the prior art is solved, and a more accurate and safe lithium battery voltage detection is achieved.
Patent Information
- Application Number
- CN202510253458.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-05-13
AI Technical Summary
The existing 8.4V lithium battery voltage detection method has problems such as narrow range, low calculation accuracy, easy to be disturbed, complex circuit and high cost, and it is difficult to replace complex operational amplifier sampling circuits when the accuracy is met.
By obtaining the voltage drops in series between the voltage regulator and diode, the reference voltage is obtained, the lithium battery voltage is compared with the reference voltage, the breakdown signal is generated, the sampling voltage is calculated and analog-to-digital conversion is performed, the lithium battery voltage status is analyzed, and the detection results are optimized through the dynamic compensation model.
It realizes more accurate lithium battery voltage detection, avoids safety hazards caused by overvoltage, can accurately judge the full and empty state of lithium battery, and reduces detection errors, providing more detailed and accurate lithium battery power information.
Smart Images
Figure CN119986433A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lithium battery management, and in particular to a practical 8.4V lithium battery voltage detection method. Background Art
[0002] In the prior art, the existing 8.4V lithium battery voltage detection method usually uses resistor voltage division, and calculates the battery voltage by reading the corresponding value through A / D sampling, or uses a complex operational amplifier to sample the voltage value and calculate the battery voltage. When the voltage is sampled by the voltage divider resistor, the range from low power 6VDC to full power 8.4VDC is narrow, which affects the calculation accuracy and is prone to inaccurate sampling when interfered; the method of sampling the voltage value by the operational amplifier is complex in circuit and high in cost, and affects the PCB layout when the space is limited; there is a lack of methods to improve the problem of narrow range, and it is difficult to eliminate the situation of being susceptible to interference. The layout of the detection voltage circuit is cumbersome, and it cannot replace the complex operational amplifier sampling circuit when the accuracy is met, and it cannot reduce the cost; To this end, the present invention provides a practical 8.4V lithium battery voltage detection method. Summary of the invention
[0003] The object of the present invention is to provide a practical 8.4V lithium battery voltage detection method to solve at least one of the above-mentioned prior art problems.
[0004] In a first aspect, the present invention provides a practical 8.4V lithium battery voltage detection method, comprising the following steps: Obtain the measured voltage drop of the voltage regulator tube and the diode in series to obtain a reference voltage, compare the lithium battery voltage with the reference voltage, and generate a breakdown signal; Based on the breakdown signal, a sampling voltage is calculated, and the sampling voltage is converted into an analog value by analog-to-digital conversion; Based on the analog value analysis, the voltage state of the lithium battery is judged and the measured voltage of the lithium battery is obtained. Based on the influence of temperature on the voltage of the lithium battery, the influence of the temperature drift effect of the battery itself and the temperature sensitivity of the detection circuit are analyzed and optimized; Based on the designed lithium battery voltage detection circuit, the internal ground voltage and reference voltage are periodically measured, the reference voltage of the lithium battery is dynamically compensated, and a dynamic compensation model is established.
[0005] In a second aspect, the present invention provides a practical 8.4V lithium battery voltage detection system, comprising the following modules: Data acquisition module: obtains the detection data required by the detection system and passes it to the data analysis module; Data analysis module: Analyze and determine the voltage status of the battery based on the obtained detection data, and generate corresponding feedback signals according to the data; Model analysis module: analyze the detection circuit, establish a model for optimization and correction to improve detection accuracy and efficiency; Measurement output module: output the optimized and analyzed lithium battery test data accordingly.
[0006] Beneficial effects of the present invention: 1. In the analog-to-digital conversion calculation, the digital-to-analog AD value is calculated by combining the accurate sampling voltage and reference voltage, so that the test result accurately reflects the actual voltage of the lithium battery; the breakdown signal is generated by analyzing the relationship between the lithium battery voltage and the reference voltage, the circuit conduction condition is judged and the sampling voltage is calculated; when the sampling voltage is detected to be greater than the reference voltage, an alarm can be given in time to effectively avoid the safety hazards and equipment damage risks caused by lithium battery overvoltage; based on the digital-to-analog AD value, the full and empty states of the lithium battery are judged, and the measured voltage of the lithium battery at the intermediate power level is accurately calculated, which fully covers various possible voltage states of the lithium battery, and provides users with more detailed and accurate lithium battery power information; 2. Establish a mathematical model of voltage and temperature, and use this model to compensate for the measured voltage, so as to reduce the measurement error caused by the increase of battery internal resistance at low temperature and abnormal voltage fluctuation at high temperature; in view of the problem that the electrical performance of components in the detection circuit changes with temperature, the corresponding relationship of compensation parameters is analyzed through the voltage divider ratio temperature drift compensation formula to realize dynamic adjustment of the detection circuit and ensure the accuracy of sampling voltage calculation; according to the preset algorithm and model, the measured voltage and detection circuit parameters are automatically compensated and adjusted; the dynamic correction model of the reference voltage takes into account the influence of temperature and aging factors, and can update and optimize the model parameters in real time according to the actual measurement data. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0008] Figure 1 This is a flow chart of a practical 8.4V lithium battery voltage detection method provided in Example 1 of the present invention; Figure 2 This is a flow chart of the steps of a practical 8.4V lithium battery voltage detection system provided by Example 2 of the present invention; Figure 3 The present invention provides a practical circuit diagram of a 8.4V lithium battery voltage detection method. DETAILED DESCRIPTION
[0009] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0010] Example 1 like Figure 1 As shown, a practical 8.4V lithium battery voltage detection method provided by an embodiment of the present invention specifically includes the following steps: Step 1: Obtain the measured voltage drop of the voltage regulator tube and the diode in series to obtain a reference voltage, compare the lithium battery voltage with the reference voltage, and generate a breakdown signal. Based on the breakdown signal, calculate the sampling voltage, perform analog-to-digital conversion on the sampling voltage to obtain a digital-to-analog A / D value, and determine the voltage state of the lithium battery based on the analog-to-digital value analysis and obtain the measured voltage of the lithium battery; In some specific embodiments, Figure 3 As shown, a lithium battery voltage detection circuit is designed, and the voltage regulator tube Z1 and the diode D5 are actually measured by a precision multimeter, and the sum of the voltage drops of the voltage regulator tube Z1 and the diode D5 after being connected in series is marked as the reference voltage; It should be noted that in the actual circuit, the series voltage drop of the voltage regulator Z1 and the diode D5 plays a key role in the relevant judgment of the lithium battery voltage. Accurately obtaining the series voltage drop is the basis for subsequent detection; Compare the lithium battery voltage with the obtained reference voltage and analyze to obtain a breakdown signal; Specifically, if the lithium battery voltage is less than or equal to the reference voltage, it indicates that the voltage regulator Z1 and the diode D5 do not meet the conduction conditions, and a non-breakdown signal is generated; If the lithium battery voltage is greater than the reference voltage, it indicates that the voltage regulator Z1 and the diode D5 are in conduction condition, generating a breakdown signal; Based on the obtained non-breakdown signal, no leakage current flows through the resistor R20, and the voltage read by VBAT is 0V, which is the sampling voltage input to the chip. 0V, the internal voltage of the lithium battery is lower than the reference voltage, indicating that the lithium battery has been fully discharged and marked as no power; For example, when the lithium battery voltage is 6V, the lithium battery has been fully discharged and is considered to be in a state of no power. In the actual circuit, when the lithium battery voltage is 6V, the voltage regulator Z1 and the diode D5 are not conductive, and no leakage current flows through the resistor R20. At this time, the voltage read by VBAT is 0V, and the sampling voltage input to the chip is 0V. Compared with the A / D reference voltage inside the chip, it is calculated that the lithium battery is lower than 6V and the reading is 0; The sampled voltage obtained based on the breakdown signal , compare the sampling voltage with the chip's internal A / D reference voltage Compare, if the sampled voltage is less than or equal to the reference voltage , a low-level signal is generated to calculate the digital-to-analog A / D value of the lithium battery; It should be noted that the reference voltage It is preset by the technicians in the professional field of the present invention and can be adjusted according to the specific situation; If the sample voltage is greater than the reference voltage , a high-level signal is generated, indicating that the internal voltage of the lithium battery is too high, and an alarm is issued through a high-level signal; For example, when the lithium battery voltage When the voltage drop of the voltage regulator Z1 is 8.5V, The voltage drop of diode D5 is 5.6V. The reference voltage is 0.45V 2.35V; The voltage read is the sampling voltage By formula , and the sampling voltage at this time is obtained The sampling voltage is 2.45V. Greater than the reference voltage =2.35V, generate a high level signal, and use the high level signal to alarm; The sampling voltage range of the A / D inside the chip is obtained by calculation and analysis. The internal reference voltage is , the total scale of 10-bit A / D is 1024; based on the obtained sampling voltage and the reference voltage is , through the formula Get the digital-to-analog A / D value; The voltage state of the lithium battery is determined based on the analog value analysis, and the calculated analog value is compared with the corresponding relationship based on the corresponding formula between the lithium battery voltage and the digital-analog A / D value; If the A / D value is equal to 0, the lithium battery is judged to be in an empty state, and the voltage is equal to the reference voltage of 6V; If the A / D value is equal to the maximum value preset by the system, the lithium battery is judged to be fully charged and the voltage is equal to 8.4V; If the A / D value is between 0 and the maximum value, then according to the formula Calculate the actual voltage of the lithium battery , determine the voltage state of the lithium battery, and calculate the measured voltage of the lithium battery through the digital-to-analog A / D value; For example, when the lithium battery voltage is 8.3V, the lithium battery voltage is greater than the sum of the voltage drops of the voltage regulator tube Z1 and the diode D5, and the conduction condition is met, that is, the current flowing through R20 is 2.25V / 20K=112.5uA. Read the sample voltage 8.3V-(5.6V+0.45V)=2.25V, by sampling voltage The internal reference voltage of the chip The comparison and calculation result shows that the A / D value is 2.25 / 3.3*1024=710.45. The measured voltage of the lithium battery is 8.25V. The technical solution of the present invention is as follows: a precision multimeter is used to measure the voltage drop of a voltage regulator tube and a diode in series to obtain a reference voltage, and a voltage judgment threshold is accurately determined, laying a foundation for subsequent accurate judgment of the voltage state of a lithium battery; in the analog-to-digital conversion calculation, the digital-to-analog AD value is calculated in combination with the accurate sampling voltage and the reference voltage, so that the detection result accurately reflects the actual voltage of the lithium battery; a breakdown signal is generated by analyzing the relationship between the lithium battery voltage and the reference voltage, the circuit conduction condition is judged and the sampling voltage is calculated; when it is detected that the sampling voltage is greater than the reference voltage, an alarm can be given in time, effectively avoiding the safety hazards and equipment damage risks caused by overvoltage of the lithium battery; based on the digital-to-analog AD value, the full charge and empty charge states of the lithium battery are judged, and the measured voltage of the lithium battery with an intermediate charge is accurately calculated, which comprehensively covers various possible voltage states of the lithium battery, and provides users with more detailed and accurate lithium battery charge information.
[0011] Example 2 like Figure 1 As shown, a practical 8.4V lithium battery voltage detection method provided by an embodiment of the present invention specifically includes the following steps: Step 2: Based on the impact of temperature on lithium battery voltage, analyze and optimize the impact of the temperature drift effect of the battery itself and the temperature sensitivity of the detection circuit; In some specific embodiments, based on the fact that the voltage of a lithium battery changes with temperature, in a low temperature environment, the chemical reaction rate inside the battery decreases, the internal resistance of the battery increases, and the output voltage of the battery decreases; In a high temperature environment, the chemical reaction rate accelerates, causing abnormal fluctuations in the battery voltage, affecting the safety and life of the battery; resulting in deviations in the voltage detection threshold judgment based on the setting at normal temperature, affecting the accuracy of the measured voltage; Based on the influence of temperature on lithium batteries, a mathematical model of lithium battery voltage and temperature is established. By obtaining the voltage characteristic curves of lithium batteries at different temperatures, the functional relationship between voltage and temperature is obtained. During the detection process, the battery temperature T is measured in real time, and the measured voltage is compensated according to the functional relationship. Get compensation voltage ,in is the measured voltage, k is the preset compensation coefficient, T is the measured temperature of the lithium battery, is the reference temperature; It should be noted that the reference temperature The ideal temperature for measuring the voltage of lithium batteries; Based on the temperature sensitivity of the detection circuit, the electrical properties of the components in the circuit are affected by temperature changes, and the resistance of the components changes with temperature, which affects the calculation of the sampling voltage; Integrate a temperature sensor in the detection circuit to monitor the circuit's operating temperature in real time , the temperature signal collected by the temperature sensor is fed back to the microcontroller, and the microcontroller adjusts the parameters of the detection circuit according to the temperature change; Specifically, through the formula Get the detection circuit voltage divider ratio temperature drift compensation, where is the output voltage of the lithium battery, is the internal voltage of the lithium battery, and is the resistance value of the component, , the corresponding relationship of compensation parameters is obtained by analysis ; Dynamically adjusting the detection circuit based on the calculated dynamic compensation parameters; Step 3: Based on the designed lithium battery voltage detection circuit, periodically measure the internal ground voltage and reference voltage, dynamically compensate the reference voltage of the lithium battery, and establish a dynamic compensation model; In some specific embodiments, based on the designed lithium battery voltage detection circuit, a preset compensation time period is set, and a high-precision digital multimeter is used to measure the internal ground voltage. and reference voltage Take measurements; Build a dual-channel differential measurement architecture to obtain internal ground voltage in real time and reference voltage , through the formula ,in is the voltage division coefficient, and , and is the circuit resistance; is the ground voltage temperature drift model, and ,in ; By formula ] to obtain the dynamic correction model of the reference voltage, where is the compensation voltage, is the calibration voltage, is the temperature coefficient, and , is the material characteristic constant, Temperature not measured, is the aging compensation coefficient, and ; The reference voltage and ground voltage are automatically updated and corrected through a dynamic correction model of the reference voltage through a calibration cycle; The technical solution of the embodiment of the present invention is as follows: considering the characteristics of lithium battery voltage changing with temperature, a mathematical model of voltage and temperature is established, and the measured voltage is compensated and calculated by the model to reduce the measurement error caused by the increase of battery internal resistance at low temperature and abnormal voltage fluctuation at high temperature; so that the measurement result can more accurately reflect the real voltage of the lithium battery, and avoid the judgment deviation caused by the detection threshold set at normal temperature under different temperature environments; in view of the problem that the electrical performance of components in the detection circuit changes with temperature, a temperature sensor is integrated in the circuit, the working temperature is monitored in real time, the parameters of the detection circuit are adjusted according to the temperature change, and the corresponding relationship of the compensation parameters is analyzed by the voltage divider ratio temperature drift compensation formula to realize dynamic adjustment of the detection circuit and ensure the accuracy of the sampling voltage calculation; by integrating the temperature sensor, the temperature change of the battery and the detection circuit is monitored in real time, and the temperature signal is fed back to the microcontroller, and the measured voltage and the detection circuit parameters are automatically compensated and adjusted according to the preset algorithm and model; the dynamic correction model of the reference voltage takes into account the influence of temperature and aging factors, and can update and optimize the model parameters in real time according to the actual measurement data.
[0012] Example 3 like Figure 2 As shown, a practical 8.4V lithium battery voltage detection system provided by an embodiment of the present invention specifically includes the following modules: Data acquisition module: obtains the detection data required by the detection system and passes it to the data analysis module; Data analysis module: Analyze and determine the voltage status of the battery based on the obtained detection data, and generate corresponding feedback signals according to the data; Model analysis module: analyze the detection circuit, establish a model for optimization and correction to improve detection accuracy and efficiency; Measurement output module: output the optimized and analyzed lithium battery test data accordingly.
[0013] An embodiment of the present invention is described in detail above, but the content described is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention; all equivalent changes and improvements made within the scope of application of the present invention should still fall within the scope of the patent coverage of the present invention.
Claims
1. A practical 8.4V lithium battery voltage detection method, characterized in that: The following steps are involved: Obtain the measured voltage drop of the voltage regulator tube and the diode in series to obtain a reference voltage, compare the lithium battery voltage with the reference voltage, and generate a breakdown signal; Based on the breakdown signal, a sampling voltage is calculated, the sampling voltage is converted into a digital-to-analog value to obtain a digital-to-analog A / D value, and the actual voltage of the lithium battery is calculated; Based on the analog value analysis, the voltage state of the lithium battery is judged and the measured voltage of the lithium battery is obtained. Based on the influence of temperature on the voltage of the lithium battery, the influence of the temperature drift effect of the battery itself and the temperature sensitivity of the detection circuit are analyzed and optimized; Based on the designed lithium battery voltage detection circuit, the internal ground voltage and reference voltage are periodically measured, the reference voltage of the lithium battery is dynamically compensated, a dual-channel differential measurement architecture is constructed, and a dynamic compensation model is established.
2. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The method for obtaining the breakdown signal is: Design a lithium battery voltage detection circuit, use a precision multimeter to measure the voltage regulator Z1 and the diode D5, and mark the sum of the voltage drops of the voltage regulator Z1 and the diode D5 in series as the reference voltage; Compare the lithium battery voltage with the obtained reference voltage and analyze to obtain a breakdown signal; If the lithium battery voltage is less than or equal to the reference voltage, it indicates that the voltage regulator Z1 and the diode D5 do not meet the conduction conditions, and a non-breakdown signal is generated; If the lithium battery voltage is greater than the reference voltage, it indicates that the voltage regulator Z1 and the diode D5 are in conduction condition, generating a breakdown signal.
3. A practical 8.4V lithium battery voltage detection method according to claim 2, characterized in that: The analysis method of the non-breakdown signal is: Based on the obtained non-breakdown signal, no leakage current flows through the resistor R20, and the voltage read by VBAT is 0V, which is the sampling voltage input to the chip. The internal voltage of the lithium battery is lower than the reference voltage, indicating that the lithium battery has been fully discharged and marked as having no power.
4. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The method for obtaining the digital-analog A / D value is: The sampled voltage obtained based on the breakdown signal , compare the sampling voltage with the chip's internal A / D reference voltage Compare, if the sampled voltage is less than or equal to the reference voltage , a low-level signal is generated to calculate the digital-to-analog A / D value of the lithium battery; The sampling voltage range of the A / D inside the chip is obtained by calculation and analysis. The internal reference voltage is , the total scale of 10-bit A / D is 1024; based on the obtained sampling voltage and the reference voltage is , through the formula Get the digital-to-analog A / D value.
5. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The method for obtaining the actual voltage is: The voltage state of the lithium battery is determined based on the analog value analysis, and the calculated analog value is compared with the corresponding relationship based on the corresponding formula between the lithium battery voltage and the digital-analog A / D value; If the A / D value is equal to 0, the lithium battery is judged to be in an empty state, and the voltage is equal to the reference voltage of 6V; If the A / D value is equal to the maximum value preset by the system, the lithium battery is judged to be fully charged and the voltage is equal to 8.4V; If the A / D value is between 0 and the maximum value, then according to the formula Calculate the actual voltage of the lithium battery , judge the voltage state of the lithium battery, and calculate the measured voltage of the lithium battery through the digital-to-analog A / D value.
6. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The method for obtaining the dynamic compensation parameters is: The voltage of lithium batteries changes with temperature. In low temperature environments, the chemical reaction rate inside the battery decreases, the internal resistance of the battery increases, and the battery output voltage decreases. Based on the influence of temperature on lithium batteries, a mathematical model of lithium battery voltage and temperature is established. By obtaining the voltage characteristic curves of lithium batteries at different temperatures, the functional relationship between voltage and temperature is obtained. During the detection process, the battery temperature T is measured in real time, and the measured voltage is compensated according to the functional relationship. Get compensation voltage ,in is the measured voltage, k is the preset compensation coefficient, T is the measured temperature of the lithium battery, is the base temperature.
7. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: Integrate a temperature sensor in the detection circuit to monitor the circuit's operating temperature in real time , the temperature signal collected by the temperature sensor is fed back to the microcontroller, and the microcontroller adjusts the parameters of the detection circuit according to the temperature change. Get the detection circuit voltage divider ratio temperature drift compensation, where is the output voltage of the lithium battery, is the internal voltage of the lithium battery, and is the resistance value of the component, , the corresponding relationship of compensation parameters is obtained by analysis ; Based on the calculated dynamic compensation parameters, the detection circuit is dynamically adjusted.
8. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The dual-channel differential measurement architecture is obtained by: Based on the designed lithium battery voltage detection circuit, a preset compensation time period is set, and a high-precision digital multimeter is used to measure the internal ground voltage. and reference voltage Take measurements; Build a dual-channel differential measurement architecture to obtain internal ground voltage in real time and reference voltage , through the formula ,in is the voltage division coefficient, and , and is the circuit resistance; is the ground voltage temperature drift model, and ,in .
9. A practical 8.4V lithium battery voltage detection method according to claim 1, characterized in that: The acquisition process of the dynamic correction model of the reference voltage is as follows: By formula The dynamic correction model of the reference voltage is obtained, where is the compensation voltage, is the calibration voltage, is the temperature coefficient, and , is the material characteristic constant, Temperature not measured, is the aging compensation coefficient, and .
10. A practical 8.4V lithium battery voltage detection method according to claim 9, characterized in that: The application method of the dynamic correction model of the reference voltage is: The reference voltage and ground voltage are automatically updated and corrected through a dynamic correction model of the reference voltage in a calibration cycle.