Lithium battery residual capacity calculation method and lithium battery capacity acquisition and display device

Abstract

The application provides a lithium battery residual capacity calculation method and a lithium battery capacity acquisition and display device. The method comprises the following steps: acquiring the voltage across a target battery at a regular time interval; calculating the difference between the current acquired voltage value and the last acquired voltage value of the target battery, and judging whether the target battery is in a charging state or a discharging state according to the difference and preset charging voltage variation threshold and discharging voltage variation threshold; if the target battery is in a charging state, determining the residual capacity of the target battery according to a preset charging voltage capacity curve; if the target battery is in a discharging state, determining the residual capacity of the target battery according to a preset discharging voltage capacity curve; and displaying the residual capacity of the target battery in the form of a capacity percentage, wherein the granularity of the capacity percentage is 5%. The application can improve the real-time performance and accuracy of battery capacity calculation, and improve the stability and accuracy of capacity display, thereby optimizing the user experience.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a method for calculating the remaining power of a lithium battery and a lithium battery power acquisition and display device. Background Technology

[0002] Battery power monitoring and display has become an indispensable part of smart wearable devices, providing users with intuitive power information to help them plan their usage and charging schedules. However, existing methods for calculating and displaying remaining lithium battery power have certain limitations and inaccuracies, affecting the user experience.

[0003] Currently, most smart wearable products use battery voltage-based measurement methods when designing their battery power acquisition and display functions. Specifically, this method collects the battery voltage and compares it with a battery voltage-power curve provided by the battery manufacturer to determine the current battery level, which is then displayed to the user as a percentage. While this method can reflect changes in battery power to some extent, it has several problems in practical applications: 1) False readings due to voltage fluctuations: During battery discharge, current fluctuations cause voltage fluctuations. These fluctuations result in different voltage values ​​measured at different times for the same battery, leading to a higher current value than the previous measurement when converting to a percentage of battery power. This contradicts the logic that battery power gradually decreases with use; 2) Abnormal voltage during charging: When the battery is charging, the voltage suddenly increases. If the same battery voltage-power curve as during discharge is used, the voltage value collected during charging will be too high, causing abnormal power display.

[0004] In view of the limitations of the prior art, the present invention aims to provide a method for calculating the remaining power of a lithium battery and a lithium battery power acquisition and display device, so as to avoid abnormal power display caused by the voltage being too high during charging, improve real-time performance and accuracy, and solve the impact of voltage fluctuations on the accuracy of power display, thereby improving the stability and accuracy of power display and optimizing user experience. Summary of the Invention

[0005] The purpose of this invention is to provide a method for calculating the remaining power of a lithium battery and a lithium battery power acquisition and display device, so as to avoid abnormal power display caused by excessively high voltage during charging, improve real-time performance and accuracy, solve the impact of voltage fluctuations on the accuracy of power display, improve the stability and accuracy of power display, and thus optimize the user experience.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for calculating the remaining capacity of a lithium battery, comprising the following steps:

[0007] Step S1: Periodically collect the voltage across the target battery terminals;

[0008] Step S2: Calculate the difference between the current voltage value and the previous voltage value of the target battery, and determine whether the target battery is in a charging state or a discharging state based on the difference and the preset charging voltage change threshold and discharging voltage change threshold.

[0009] Step S3: If the target battery is in a charging state, determine the remaining capacity of the target battery according to a preset charging voltage-capacity curve; if the target battery is in a discharging state, determine the remaining capacity of the target battery according to a preset discharging voltage-capacity curve.

[0010] Step S4: Display the remaining power of the target battery as a percentage, with a granularity of 5%.

[0011] In the lithium battery remaining capacity calculation method of the present invention, the specific method for periodically collecting the voltage across the target battery in step S1 is as follows:

[0012] The voltage acquisition unit acquires the voltage value across the target battery once per second.

[0013] In the lithium battery remaining capacity calculation method of the present invention, the specific method for determining whether the target battery is in a charging state or a discharging state based on the difference and the preset charging voltage change threshold and discharging voltage change threshold in step S2 is as follows:

[0014] The target battery is initially in a discharging state by default. If the difference is greater than the charging voltage change threshold, the target battery enters the charging state; if the difference is less than the discharging voltage change threshold, the target battery enters the discharging state; otherwise, the target battery remains in the previous state.

[0015] In the lithium battery remaining power calculation method of the present invention, before step S1, the method further includes: measuring the voltage change of the target battery during the charging and discharging process; setting a charging voltage change threshold and a discharging voltage change threshold according to the change, wherein the charging voltage change threshold should be less than the minimum value in the positive domain of the measured instantaneous voltage change during charging, and the discharging voltage threshold should be greater than the maximum value in the negative domain of the measured instantaneous voltage change during discharging.

[0016] In the lithium battery remaining capacity calculation method of the present invention, the charging voltage-capacity curve in step S3 is a pre-acquired mapping relationship data between the charging voltage and capacity percentage of the target battery; the discharging voltage-capacity curve is a pre-acquired mapping relationship data between the discharging voltage and capacity percentage of the target battery.

[0017] This invention also provides a battery power acquisition and display device, comprising: a voltage acquisition unit, a power supply, a microcontroller, and a power display unit. The power supply is the operating power supply for the microcontroller. The microcontroller calls a computer program to execute the above-mentioned lithium battery remaining power calculation method to determine the lithium battery power, and displays the power through the power display unit.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention provides a method for calculating the remaining capacity of a lithium battery. By detecting the voltage difference at the moment of charging and discharging, the charging and discharging state is determined, and the charging and discharging voltage-capacity curve is immediately switched to determine the corresponding battery capacity value. This method can avoid abnormal capacity display caused by the voltage being too high at the moment of charging, and has good real-time performance and accuracy.

[0020] 2. This invention displays the remaining power of the target battery as a percentage, with a granularity of 5%. This addresses the impact of voltage fluctuations on the accuracy of power display, improving the stability and accuracy of power display and thus optimizing the user experience. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the method for calculating the remaining capacity of a lithium battery provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the discharge voltage-to-charge curve provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the charging voltage-to-power curve provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram illustrating the mapping relationship between charging and discharging test time and battery capacity percentage provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram illustrating the mapping relationship between time and battery voltage difference during charge / discharge testing provided in an embodiment of the present invention.

[0026] Figure 6 This is a schematic block diagram of the lithium battery power acquisition and display device provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0028] like Figure 1 As shown in the figure, this embodiment of the invention provides a method for calculating the remaining capacity of a lithium battery, the method comprising the following steps:

[0029] Step S1: Periodically acquire the voltage across the target battery. In this step, the voltage value across the target battery is acquired once per second by the voltage acquisition unit, and the previous voltage value and the current voltage value are recorded. The voltage acquisition unit can be a microcontroller ADC.

[0030] Step S2: Calculate the difference between the current voltage value and the previous voltage value of the target battery. Based on the difference and preset charging voltage change thresholds and discharging voltage change thresholds, determine whether the target battery is in a charging or discharging state. The voltage difference can be calculated based on the voltage value collected and recorded in step S1. In this step, a software algorithm detects the voltage difference at the moment of charging and discharging to determine whether the battery is in a charging or discharging state. The target battery is initially in a discharging state. If the difference is greater than the charging voltage change threshold, the target battery enters a charging state; if the difference is less than the discharging voltage change threshold, the target battery enters a discharging state; otherwise, the target battery remains in the previous state.

[0031] Figure 2 , Figure 3 These are schematic diagrams of the charging voltage-to-capacity curve and the discharging voltage-to-capacity curve of the lithium battery provided in the embodiments of the present invention. Taking a 3.7V / 45mAh lithium battery as an example, from... Figure 2 , Figure 3 It is known that the relationship between battery voltage and battery capacity percentage is non-linear during charging and discharging, and the capacity percentage at the same voltage is different from the voltage at the same capacity percentage. Therefore, to improve the accuracy of battery level display, it is necessary to distinguish whether the battery is currently charging or discharging, and then use the corresponding charging voltage-capacity curve or discharging voltage-capacity curve to determine the current battery level.

[0032] In this embodiment of the invention, the instantaneous charging and discharging is captured by detecting the real-time voltage difference of the target battery and comparing it with a set threshold. This allows for timely detection of changes in the battery's charging and discharging state, and the corresponding charging and discharging voltage-to-power curve is immediately switched based on the changed state to determine the corresponding battery capacity. Therefore, the solution of this invention avoids abnormal capacity display caused by excessively high voltage during charging and errors in capacity due to the use of incorrect voltage-to-power change curves, resulting in better accuracy of the remaining battery capacity. Furthermore, by periodically collecting battery voltage and determining the charging and discharging state, changes in battery state can be detected promptly, and the voltage-to-power change curve can be switched accordingly, leading to better real-time performance in calculating and displaying the remaining battery capacity. The higher the collection frequency, the better the real-time performance.

[0033] Step S3: If the target battery is in a charging state, determine the remaining capacity of the target battery according to a preset charging voltage-capacity curve; if the target battery is in a discharging state, determine the remaining capacity of the target battery according to a preset discharging voltage-capacity curve.

[0034] In this embodiment of the invention, the charging voltage-capacity curve in step S3 is a pre-acquired mapping relationship data between the charging voltage and capacity percentage of the target battery; the discharging voltage-capacity curve is a pre-acquired mapping relationship data between the discharging voltage and capacity percentage of the target battery. Specifically, in this embodiment of the invention, the charging voltage-capacity curve and the discharging voltage-capacity curve are provided by the battery manufacturer and stored in the microcontroller in tabular form.

[0035] Step S4: Display the remaining battery power of the target battery as a percentage, with a granularity of 5%. For example, when the battery is charging, if the current power level is 80%, the display will still show 80% when charging to 81% to 84%, and will only change to 85% when charging to 85%. Displaying the power level in 5% granularity can also mitigate the problem of sudden increases and decreases in power level during charging. During battery discharge, voltage fluctuations may cause the voltage value measured at different times to differ, resulting in a higher current value than the previous measurement when converted to a power percentage. This contradicts the logic that battery power gradually decreases with use. In this embodiment of the invention, displaying the remaining battery power in 5% granularity as a percentage can effectively improve this logically contradictory problem of sudden increases in power level during battery discharge. In summary, this display method can solve the impact of voltage fluctuations on the accuracy of power level display, improve the stability and accuracy of power level display, and thus optimize the user experience.

[0036] The aforementioned method for calculating the remaining capacity of a lithium battery determines the charging and discharging state by detecting the voltage difference at the moment of charging and discharging, and immediately switches the charging and discharging voltage-capacity curve to determine the corresponding battery capacity value. This avoids abnormal capacity display caused by excessively high voltage collected at the moment of charging, and has good real-time performance and accuracy. The remaining capacity of the target battery is displayed in the form of a capacity percentage with a granularity of 5%, which can solve the impact of voltage fluctuations on the accuracy of capacity display, improve the stability and accuracy of capacity display, and thus optimize the user experience.

[0037] In this embodiment of the invention, before step S1, the setting of the charging voltage change threshold and the discharging voltage change threshold can be achieved in the following ways:

[0038] The voltage change of the target battery during the charging and discharging process is measured, and charging voltage change threshold and discharging voltage change threshold are set according to the change. The charging voltage change threshold should be less than the minimum value in the positive domain of the measured instantaneous voltage change during charging, and the discharging voltage threshold should be greater than the maximum value in the negative domain of the measured instantaneous voltage change during discharging.

[0039] Figure 4 , Figure 5 These are schematic diagrams illustrating the mapping relationship between time and battery capacity percentage during charge / discharge testing, and the mapping relationship between time and battery voltage difference, provided in embodiments of the present invention. Figure 4-5 In the middle, three sets of charge-discharge tests were conducted sequentially for 5 minutes, 10 minutes, and 20 minutes. Figure 5 It is known that battery voltage jumps during charging or discharging; the target battery voltage increases during charging and decreases during discharging. The voltage jump during charging and discharging is within a certain range, therefore, the voltage change during charging and discharging can be used to capture the instantaneous changes and promptly detect changes in the charging and discharging state. Figure 5 For example, set a charging voltage change threshold VT1 and a discharging voltage change threshold VT2, where VT1 should be less than VT2. Figure 5 The minimum value of the instantaneous voltage change during charging obtained by measurement, VT2, should be greater than [the value of VT2 in the positive domain]. Figure 5 The maximum value within the negative domain of the instantaneous voltage change during charging, obtained through measurement, is used as the charging voltage change threshold VT1, which is positive, while the discharging voltage change threshold VT2 is negative. In practical applications, the range of voltage changes during charging and discharging is obtained through multiple measurements, and the charging and discharging voltage change thresholds are set based on these ranges.

[0040] like Figure 6 As shown in the figure, this embodiment of the invention provides a lithium battery power acquisition and display device. The device includes a voltage acquisition unit, a power supply, a microcontroller, and a power display unit. The power supply is the operating power supply for the microcontroller. The microcontroller calls a computer program to implement the above-mentioned method for calculating the remaining power of the lithium battery.

[0041] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for calculating the remaining capacity of a lithium battery, characterized in that, Includes the following steps: Step S1: Periodically collect the voltage across the target battery terminals; Step S2: Calculate the difference between the current voltage value and the previous voltage value of the target battery, and determine whether the target battery is in a charging state or a discharging state based on the difference and the preset charging voltage change threshold and discharging voltage change threshold. Step S3: If the target battery is in a charging state, determine the remaining capacity of the target battery according to a preset charging voltage-capacity curve; if the target battery is in a discharging state, determine the remaining capacity of the target battery according to a preset discharging voltage-capacity curve. Step S4: Display the remaining power of the target battery as a percentage, with a granularity of 5%.

2. The method for calculating the remaining capacity of a lithium battery according to claim 1, characterized in that, In step S1, the specific method for periodically collecting the voltage across the target battery is as follows: The voltage acquisition unit acquires the voltage value across the target battery once per second.

3. The method for calculating the remaining capacity of a lithium battery according to claim 1, characterized in that, In step S2, the specific method for determining whether the target battery is in a charging or discharging state based on the difference and preset charging voltage change thresholds and discharging voltage change thresholds is as follows: The target battery is initially in a discharging state by default. If the difference is greater than the charging voltage change threshold, the target battery enters the charging state; if the difference is less than the discharging voltage change threshold, the target battery enters the discharging state; otherwise, the target battery remains in the previous state.

4. The method for calculating the remaining capacity of a lithium battery according to claim 1, characterized in that, Before step S1, the method further includes: measuring the voltage change of the target battery during the charging and discharging process; setting a charging voltage change threshold and a discharging voltage change threshold based on the change, wherein the charging voltage change threshold should be less than the minimum value in the positive domain of the measured instantaneous voltage change during charging, and the discharging voltage threshold should be greater than the maximum value in the negative domain of the measured instantaneous voltage change during discharging.

5. The method for calculating the remaining capacity of a lithium battery according to claim 1, characterized in that, The charging voltage-capacity curve in step S3 is a pre-acquired mapping relationship data between the charging voltage and capacity percentage of the target battery; the discharging voltage-capacity curve is a pre-acquired mapping relationship data between the discharging voltage and capacity percentage of the target battery.

6. A battery power acquisition and display device, characterized in that, include: The system includes a voltage acquisition unit, a power supply, a microcontroller, and a power display unit. The power supply is the operating power source for the microcontroller. The microcontroller calls a computer program to execute the lithium battery remaining power calculation method according to any one of claims 1 to 5 to determine the lithium battery power, and displays the power through the power display unit.

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