WO2018126901A1 - Method and device for testing health status of battery - Google Patents

Abstract

A method and device for testing the health status of a battery. The method for testing the health status of a battery comprises: according to a set sampling period, continuously measuring voltage values and capacity values at the same moments of a battery to be tested (S101); calculating the capacity difference and voltage difference respectively according to the voltage values and capacity values measured twice (S102); determining the ratio of the capacity difference to the voltage difference (S103); and obtaining an aging coefficient corresponding to the determined ratio according to preset correspondences between ratios and aging coefficients (S104).

Description

Battery health state detecting method and device Technical field

Embodiments of the present invention relate to, but are not limited to, the field of battery testing, and in particular, to a battery health state detecting method and apparatus.

Background technique

The degree of battery aging, also known as State of Health (SOH), refers to the ratio of the amount of electricity discharged by a fully charged battery to the nominal amount of electricity, representing the ability of the battery to store electricity. As the battery is used and aged, SOH will gradually decrease. It is clearly stated in IEEE Standard 1188-1996 that the battery needs to be replaced when the capacity of the battery drops to 80%, that is, when the SOH value is less than 0.8.

Summary of the invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

For battery SOH measurements, the degree of battery aging is typically estimated by detecting changes in internal resistance, or by full discharge.

Usually, the battery aging and the internal resistance of the battery have a direct relationship, but the internal resistance of the battery is very small, and has a great relationship with the current power, temperature and charge and discharge conditions, which will cause the detection of internal resistance is very difficult. It is only possible to estimate a relatively accurate internal resistance if the environment is stable. Therefore, based on the accuracy of the measurement results, the full discharge method is generally used for measurement. However, the full discharge method can only be tested offline and requires a long test time.

The embodiment of the invention provides a battery health state detecting method and device for realizing online detection of battery health.

An embodiment of the present invention provides a battery health state detecting method, including:

Collecting the voltage value and capacity value of the battery to be tested at the same time;

Calculating the capacity difference and the voltage difference according to the voltage value and the capacity value collected twice;

Determining a ratio of the capacity difference to the voltage difference;

Obtain an aging coefficient corresponding to the determined ratio according to a preset relationship between the ratio and the aging coefficient.

In an exemplary embodiment, the step of separately calculating a capacity difference value and a voltage difference value according to the two collected voltage values and capacity values, including:

When the difference between the voltage value collected in the nth time and the voltage value collected in the first time reaches the preset pressure difference threshold, the capacity difference is calculated according to the voltage value and the capacity value collected at the nth and the first time respectively. And the voltage difference; wherein the acquisition is performed every time the battery health state detection is performed, and n is a natural number greater than 1.

In an exemplary embodiment, before the step of collecting the voltage value and the capacity value of the battery to be tested, the battery health state detecting method further includes:

When the battery to be tested is in a charging state, stop collecting the voltage value and the capacity value at the same time, and discard the collected voltage value and capacity value;

When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.

In an exemplary embodiment, the manner of presetting the correspondence between the ratio and the aging coefficient includes:

Performing an aging test on a set number of batteries of the same type as the battery to be tested;

Obtaining a typical aging curve according to the aging test; the aging curve is a curve corresponding to the aging coefficient of the charge change cycle accumulated value;

Determining, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

Corresponding relationship between the ratio and the aging coefficient is set according to the slope and the aging curve.

In an exemplary embodiment, the step of obtaining a typical aging curve according to the aging test comprises:

Recording the cumulative value of each power change cycle of each battery and the corresponding aging coefficient information;

Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

Selecting the same electric quantity change cycle accumulating value corresponding to each of the corresponding aging coefficient ranges Typical aging factor;

A typical aging curve is determined according to the typical aging coefficients corresponding to the respective cumulative values of the respective power change cycles.

In an exemplary embodiment, before the step of collecting the voltage value and the capacity value of the battery to be tested, the battery health state detecting method further includes:

Periodically collecting the power value of the battery to be tested;

Determining, according to the collected electric quantity value, the current electric quantity change cycle of the battery to be tested;

Obtaining an aging coefficient range corresponding to a current accumulated value of the current battery change of the battery to be tested;

And the step of obtaining an aging coefficient corresponding to the determined ratio according to the preset relationship between the ratio and the aging coefficient, including:

And obtaining, according to a preset relationship between the ratio and the aging coefficient, an aging coefficient corresponding to the determined ratio within the range of aging coefficients corresponding to the current accumulated value of the power change cycle.

In an exemplary embodiment, the determining, according to the collected electric quantity value, the step of calculating the current electric quantity change cycle of the battery to be tested includes:

Loading the cumulative value of the corresponding power change cycle when the aging coefficient range of the battery to be tested is acquired last time;

Determining the accumulated value of the power change cycle according to the collected power value;

When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.

Embodiments of the present invention provide a computer readable storage medium storing computer executable instructions, which are implemented by a processor to implement the battery health state detecting method described above.

Embodiments of the present invention provide a battery health state detecting apparatus, including:

The sampling module is configured to collect the voltage value and the capacity value of the battery to be tested at the same time;

The parameter calculation module is configured to calculate the capacity difference and the voltage difference respectively according to the two collected voltage values and capacity values;

a slope determining module configured to determine a ratio of the capacity difference value to the voltage difference value;

The aging determination module is configured to acquire and match according to a preset ratio of the ratio and the aging coefficient The aging factor corresponding to the determined ratio.

In an exemplary embodiment, the parameter calculation module is configured to set the difference between the voltage value acquired in the nth time and the voltage value collected in the first time to reach the preset pressure difference threshold, according to the nth and the first The collected voltage value and the capacity value respectively calculate the capacity difference value and the voltage difference value; wherein each time the battery health state detection is performed, the acquisition is the first acquisition, and n is a natural number greater than 1.

In an exemplary embodiment, the sampling module is configured to stop collecting the simultaneously recorded voltage value and capacity value when the battery to be tested is in a charging state, and discard the collected voltage value and capacity value;

When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.

In an exemplary embodiment, the apparatus further includes a cyclic accumulation module, the cyclic accumulation module comprising:

a typical curve acquisition module is configured to obtain a typical aging curve according to the aging test; the aging curve is a curve corresponding to a aging coefficient of a charge change cycle cumulative value;

a slope detecting module, configured to determine, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

And a setting module configured to set a correspondence between the ratio and the aging coefficient according to the slope and the aging curve.

In an exemplary embodiment, the typical curve acquisition module is configured to record each power change cycle cumulative value of each battery and corresponding corresponding aging coefficient information;

Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

Selecting a typical aging coefficient corresponding to each of the same power change cycle cumulative values from the corresponding aging coefficient ranges;

A typical aging curve is determined according to the typical aging coefficients corresponding to the respective cumulative values of the respective power change cycles.

In an exemplary embodiment, the sampling module is further configured to periodically collect the power value of the battery to be tested;

The aging determination module is configured to: determine, according to the collected electric quantity value, a current electric quantity change cycle of the battery to be tested; and obtain an aging coefficient range corresponding to a current accumulated electric energy change cycle cumulative value of the battery to be tested; The corresponding relationship between the ratio and the aging coefficient is obtained within the range of the aging coefficient corresponding to the current accumulated value of the electric quantity change cycle, and the aging coefficient corresponding to the determined ratio is obtained.

In an exemplary embodiment, the aging determination module is configured to load a corresponding power change cycle cumulative value when the aging coefficient range of the battery to be tested is acquired last time;

Determining the accumulated value of the power change cycle according to the collected power value;

When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.

The beneficial effects of the embodiments of the present invention are as follows:

The method and the device provided by the embodiments of the present invention determine the ratio of the capacity difference and the voltage difference; according to the correspondence between the preset ratio and the aging coefficient, obtain an aging coefficient corresponding to the determined ratio, thereby realizing the battery health degree online. Detection, and relative to the full discharge method, effectively reduces the detection time.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a flowchart of a battery health state detecting method according to an embodiment of the present invention;

2 is a schematic diagram showing a series of N _soc and λ corresponding to an embodiment of the present invention;

3 is a schematic view showing curves α, β, and γ of different ages after the same battery undergoes different charge and discharge cycles in the embodiment of the present invention;

4 is a schematic flow chart of suspension detection in an embodiment of the present invention;

5 is a schematic diagram showing an aging curve after 1000 cycles of charge and discharge in a new state of the same battery in the embodiment of the present invention;

6 is a specific flowchart of a loop accumulation method in an embodiment of the present invention;

7 is a specific flow chart of a slope method in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a battery health state detecting apparatus according to an embodiment of the present invention.

Embodiments of the invention

The embodiments of the present invention provide a method and an apparatus for detecting a health state of a battery. The embodiments of the present invention are further described in detail below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , a first embodiment of the present invention provides a battery health state detecting method, including steps S101 to S104.

Step S101, continuously collecting the voltage value and the capacity value of the battery to be tested at the same time according to the set sampling period; wherein the size of the sampling period can be set according to actual conditions.

Step S102, calculating a capacity difference value and a voltage difference value according to the two collected voltage values and capacity values.

Step S103, determining a ratio of the capacity difference value to the voltage difference value.

Step S104: Acquire an aging coefficient corresponding to the determined ratio according to a correspondence between the preset ratio and the aging coefficient.

In the embodiment of the present invention, the ratio of the capacity difference to the voltage difference is determined; according to the correspondence between the preset ratio and the aging coefficient, an aging coefficient corresponding to the determined ratio is obtained, thereby realizing online detection of battery health.

Based on the accuracy of the measurement results, the full discharge method is generally used for measurement. However, the full discharge method can only be tested offline, and requires a long test time. Compared with the complete discharge method, the embodiment of the invention effectively reduces the detection time and realizes real-time online detection.

That is, the embodiment of the present invention pre-tests a series of battery voltage-availability (V _bat -Capacity) data when the recorded point of N _soc -λ is obtained; then the slope is determined by the measured ΔV-ΔC slope. The pre-tested voltage-availability (V _bat -Capacity) data is used as a benchmark, and the recording point of N _soc -λ closest to the slope can be obtained, thereby obtaining a corresponding aging coefficient. Among them, N _soc refers to the cumulative value of the power change cycle, λ is the battery aging coefficient, ΔV is the voltage difference, and ΔC is the capacitance difference.

On the basis of the above-described embodiments, a modified embodiment of the above-described embodiment is proposed. It is to be noted that, in order to simplify the description, only the differences from the above embodiment will be described in the respective modified embodiments.

In one embodiment of the present invention, the correspondence between the ratio and the aging coefficient is preset according to the ΔV-ΔC slope method. That is to say, the manner in which the preset ratio and the aging coefficient correspond to each other includes:

Performing an aging test on a set number of batteries of the same type as the battery to be tested;

According to the aging test, a typical aging curve is obtained; the aging curve reflects the relationship between the accumulated value of the power change cycle and the aging coefficient; that is, the aging curve is specifically the cumulative value of each power change cycle and the power change cycle. The curve of the aging coefficient corresponding to the accumulated value.

Determining, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

Corresponding relationship between the ratio and the aging coefficient is set according to the slope and the aging curve.

In an exemplary embodiment, the embodiment of the present invention performs an aging test on the battery according to the method of accumulating the amount of the electric quantity, that is, the step of obtaining a typical aging curve according to the aging test, including:

Stepping according to the set accumulated value change, recording the cumulative value of each power change cycle of each battery and the corresponding aging coefficient information;

Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

Selecting, from the corresponding range of aging coefficients, a typical aging coefficient value corresponding to each of the same power change cycle cumulative values;

A typical aging curve is determined based on the typical aging coefficient values corresponding to each of the same charge change cycle accumulated values.

In another embodiment of the present invention, before the step of collecting the voltage value and the capacity value of the battery to be tested at the same time, the method further includes:

Periodically collecting the power value of the battery to be tested;

Determining, according to the collected electric quantity value, the current electric quantity change cycle of the battery to be tested;

Obtaining an aging coefficient range corresponding to a current accumulated value of the current battery change cycle of the battery to be tested according to a preset relationship between a cyclical accumulated value and a aging coefficient range;

Obtaining, according to a correspondence between a preset ratio and an aging coefficient, obtaining a ratio corresponding to the determined ratio The steps of the aging factor include:

And obtaining, according to a preset relationship between the ratio and the aging coefficient, an aging coefficient corresponding to the determined ratio within the range of aging coefficients corresponding to the current accumulated value of the power change cycle.

In an exemplary embodiment, the determining, according to the collected electric quantity value, the step of calculating the current electric quantity change cycle of the battery to be tested includes:

Loading the cumulative value of the corresponding power change cycle when the aging coefficient range of the battery to be tested is acquired last time;

According to the collected electric quantity value, the cumulative value of the electric quantity change cycle is determined; specifically, when the collected electric quantity value reaches the set accumulating threshold value, the accumulated value of the electric quantity change cycle is incremented by one.

When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.

Briefly describe the implementation principle of the embodiment of the present invention:

According to the influence of SOC (State of Capacity) changes on aging, aging detection is performed by the method of accumulating electric quantity changes. The effects of changes in SOC at different voltage or power stages on battery aging are different, so it is necessary to increase the aging factor for voltage or SOC changes at different stages. According to the cyclic accumulation theory, the following algorithm can be derived:

λ=1-a*N _soc

Where λ is the battery aging coefficient; N _soc refers to the cumulative value of the charge change cycle, where N _soc is incremented by 1% for each change in charge; a is the ratio of aging for every 1% change in charge. For example, when the battery in the terminal is shipped from the factory, the N _soc value is 0. After the factory starts to accumulate, it is assumed that the factory power is 50%, the user continuously uses 10%, the value is 40; if the user charges to 100%, the value is added to 140 (ie 100+40).

As can be seen from Fig. 2, a series of N _{soc -} λ coordinates can be obtained. Since the aging speed is not linear, the aging under different accumulated amounts is calculated according to the charge and discharge SOC accumulation amount. That is, the accumulated aging coefficient is continuously updated according to the accumulated amount. At the same time, a batch of batteries (set number) is used for the aging test, and the obtained aging coefficient is high or low. According to the change of the charge and discharge SOC accumulation amount, a series of aging coefficient ranges [λ _low , λ _high ] are recorded. At the same time, a typical discharge curve is also found to calculate the specific aging coefficient, so that the aging coefficient range of the battery and the typical aging value can be obtained by the cyclic accumulation method. This will prepare you for the accurate calculation of SOH in the next step.

Specifically, the intermediate value of the aging coefficient range [λ _low , λ _high ] is taken as a typical aging coefficient, or the coefficient in the interval which is close to the user's charge electric law is taken as a typical aging coefficient. For example, the aging interval of 0.6 to 0.65 as shown in FIG. 2, by calculating the intermediate value of 0.625, can find a typical curve corresponding to the current N _soc and the aging coefficient of 0.625, and even the aging value. However, in order to further verify the aging coefficient by another method, based on the typical curve, the typical aging coefficient is discarded, and in the aging interval, the specific value of the corresponding aging coefficient on the typical aging curve is found according to the slope method. It is worth noting that this value must also be within the aging range and may be the same as the typical aging factor.

From the above method, a more accurate aging range of SOH can be obtained. Next, the exact value is further confirmed based on the ΔV-ΔC slope method. That is to say, using a series of battery voltage-available capacity V _bat -Capacity data at a series of N _soc -λ recording points of the typical curve above, the measured ΔV-ΔC slope is measured and calculated by the cyclic accumulation method. The V _bat -Capacity data of the typical curve in the aging range is benchmarked, and the closest N _soc -λ recording point can be obtained, then the aging coefficient λ coefficient is the calculated aging coefficient.

The principle of the ΔV-△C slope method is as follows:

According to different degrees of aging, the capacity that the battery can release is also different. As shown in Fig. 3, the same battery has different battery aging curves α, β, γ after different charging and discharging cycles.

The capacity corresponding to different voltage values is also different. In a certain voltage segment, the capacity change value can be detected by using a coulomb counter or other BMS (Battery Monitor System) technology. For the three curves in the figure, the change in capacity from the X voltage to the Y voltage is different. which is:

Therefore, an important conclusion can be drawn that the voltage change amount ΔC of the several curves is different from the voltage change amount ΔV from the voltage X to the voltage Y. Based on this slope, the SOH value can be further confirmed. And the larger the voltage change amount ΔV taken, the more accurate the SOH value will be.

As far as Figure 3 is concerned, it can be seen that the ΔV-ΔC slope of the same battery after aging at different degrees:

The cyclic accumulation method can obtain the SOH range, on the basis of which a more specific and accurate SOH value can be calculated from the difference in slope.

In still another embodiment of the present invention, the step of separately calculating a capacity difference value and a voltage difference value according to the two collected voltage values and capacity values, including:

When the difference between the voltage value collected in the nth time and the voltage value collected in the first time reaches the preset pressure difference threshold, the capacity difference is calculated according to the voltage value and the capacity value collected at the nth and the first time respectively. And the voltage difference; wherein n is a natural number greater than 1, and the acquisition performed when performing battery health detection is the first acquisition.

Embodiments of the present invention increase the detection accuracy of the embodiments of the present invention.

In still another embodiment of the present invention, before the step of collecting the voltage value and the capacity value of the battery to be tested, the method further includes:

When the battery to be tested is in a charging state, stop collecting the voltage value and the capacity value at the same time, and discard the collected voltage value and capacity value;

When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.

As shown in FIG. 4, in the calculation process of the ΔV-ΔC slope method, if the device is in the charging state, the calculation process is stopped, and the previous sampling data is discarded, because the battery voltage will rise in different amplitudes due to the state of charge. This has a large impact on the slope calculation.

Step S401, connecting a charging device to perform charging;

Step S402, stopping the ΔV-ΔC slope method calculation process, and discarding the data in the calculation process;

Step S403, disconnecting the charging device and stopping charging;

In step S404, the recalculation process is started.

The implementation flow of the present invention will be described with reference to a specific application example.

As shown in FIG. 5, the process of aging detection and ΔV-ΔC slope calculation is performed in advance: the aging coefficient range [λ _low , λ is calculated after 1000 charge and discharge cycles in several new states of the same battery in this example. _High ] is [0.6, 0.7], that is, the aging coefficient is between 0.6 and 0.7, including 0.6 and 0.7, and the typical value is 0.65.

Taking a series of coordinates (such as the number of integer charge and discharge cycles) from the discharge curve of Figure 5 above, the aging coefficient after different charge and discharge cycles can be obtained, so that the range of aging coefficients corresponding to the cumulative value of the charge change cycle can be obtained. value.

As shown in FIG. 6, the cyclic accumulation method of specific aging detection includes:

Step S601, the battery monitoring system BMS provides the power change information, and the variation range is generally 1%;

In step S602, when the power is changed, the process jumps to S603. Otherwise, the process goes to step S604.

Step S603, based on step S602, the power accumulation value N _{soc is} correspondingly increased, and the timer is reset.

Step S604, when the timer is triggered, the power is automatically queried, then the timer is reset, and the timer is continued. In this example, the timer is set to 10 minutes;

Step S605, when a new battery accumulated value of the last N _soc SOH value calculated using the amount accumulated value N _soc increased when compared to a predetermined value, for example 100 mAh, aging coefficient calculation starts;

Step S606, loading the accumulated value of the power used in the last calculation of the SOH value, and querying the required data from the basic data of the power aging;

Step S607, calculation of the SOH (ie, λ) value interval. According to the new electric charge accumulating value N _soc and the battery aging coefficient and the electric energy accumulating value data N _{soc -} λ _low table, N _{soc -} λ _high table, and N _soc - typical λ table stored in advance, we can look up the table to obtain [λ _Low , λ _high ] and typical λ.

In this example, the electric charge accumulated value N _soc is 200100, that is, the number of charge and discharge cycles is 1000.5 times. Since the electric charge accumulating value N _{soc -} λ table in this example only stores the battery aging coefficient under the integer number of charge and discharge times, the N _{soc is} obtained by looking up the table at 1000 and 1001 times, and we select the number of charge and discharge cycles. The low value, ie [λ _low , λ _high ] is [0.6, 0.7], and the typical aging coefficient is 0.65.

Step S608, the new aging coefficient range and the typical aging coefficient and the last calculated value If the ratio is less than the last value, it is valid, skip to step S610; if it is greater than the last value, it is invalid, skip to step S609;

Step S609, if the calculated value is invalid, the electric quantity accumulated value N _{soc is} updated and stored, and the aging coefficient range and the typical aging coefficient are not updated;

In step S610, the electric quantity accumulated value N _{soc is} updated and stored, and the aging coefficient range and the typical aging coefficient are updated and stored.

As shown in Figure 7, the ΔV-ΔC slope method for specific aging detection includes:

The battery aging SOH interval value obtained based on the cyclic accumulation method. In this embodiment, the slope is calculated according to the capacity change of the battery from 4.1V to 3.6V, and the slope table of the target storage is obtained to obtain the final battery aging coefficient, as shown in FIG. 7, including:

In step S701, the battery monitoring system BMS can provide battery data such as battery voltage and real-time capacity.

In step S702, after the battery is in the sleep state for a period of time (for example, ten minutes), the battery voltage tends to be stable. After the voltage has stabilized, the sampling voltage is started and recorded. In this example, the sampled battery voltage is 4.1V;

Step S703, based on step S702, simultaneously recording the available capacity value of the battery while sampling the voltage. In this example, the available usable capacity value is 1500 mAh.

Step S704, as in step S702, after the battery voltage tends to be stable, the voltage is sampled, if compared with the voltage obtained in step S702. In this example, after 50 minutes of use and 10 minutes of dormancy, a new battery voltage of 3.6V was obtained.

Step S705, based on step S704, if the pressure difference is greater than 0.4V, the process goes to step S706, otherwise the process goes to step S704 to continue the detection. In this example, the differential pressure reached (4.1-3.6) V, or 0.5 V, compounding requirements.

Step S706, based on step S705, obtaining an available capacity value of 500 mAh, and the two sampling available capacity change amount is (1500-500) mAh, that is, 1000 mAh.

Step S707, based on the previous steps, calculate the ΔV-ΔC slope k:

In step S708, a plurality of slope values corresponding to the same voltage change in the range can be calculated from the voltage-capacity table of different typical degrees of aging and the range of the battery aging coefficient calculated by the cyclic accumulation method. In this example, the battery aging factor range is [0.6, 0.7]. Within this interval, there are several voltage-capacity tables with typical curves with different degrees of aging, as shown in Table 1:

Aging coefficient	Voltage change	Capacity change	Slope
0.6	4.1V reduced to 3.6V	900mAh	1.8
0.61	4.1V reduced to 3.6V	920mAh	1.84
0.62	4.1V reduced to 3.6V	940mAh	1.88
0.63	4.1V reduced to 3.6V	960mAh	1.92
0.64	4.1V reduced to 3.6V	980mAh	1.96
0.65	4.1V reduced to 3.6V	1000mAh	2
0.66	4.1V reduced to 3.6V	1020mAh	2.04
0.67	4.1V reduced to 3.6V	1040mAh	2.08
0.68	4.1V reduced to 3.6V	1060mAh	2.12
0.69	4.1V reduced to 3.6V	1080mAh	2.16
0.7	4.1V reduced to 3.6V	1100mAh	2.2

Step S709, in this example, the battery aging coefficient interval range is [0.6, 0.7]. This interval is obtained by the cyclic accumulation method;

In step S710, in step S707, the slope k is obtained by the ΔV-ΔC slope method. For the slope of the marked table, the aging coefficient corresponding to the calibration curve is 0.65;

Step S711, based on step S710, the SOH aging coefficient obtained is 0.65;

In step S712, the currently stored SOH value is obtained. If the newly calculated SOH value is less than the value, it is determined to be valid, and the process goes to step S714. If it is invalid, skip to step S713, and the SOH value currently stored in this example is also 0.65, so skip to S714;

Step S713, if the new SOH value is invalid, the current calculation is ended;

Step S714, updating the aging coefficient and storing;

In step S715, the calculation is completed.

Embodiments of the present invention provide a computer readable storage medium storing computer executable instructions, which are implemented by a processor to implement the battery health state detecting method described above. Based on the battery health state detecting method of the above embodiments, the embodiment of the present invention further provides a battery health state detecting device.

As shown in FIG. 8, a battery health state detecting apparatus according to an embodiment of the present invention includes:

The sampling module 810 is configured to collect the voltage value and the capacity value of the battery to be tested at the same time;

The parameter calculation module 811 is configured to calculate a capacity difference value and a voltage difference value respectively according to the two collected voltage values and capacity values;

a slope determination module 812 configured to determine a ratio of the capacity difference value to the voltage difference value;

The aging determination module 813 is configured to obtain an aging coefficient corresponding to the determined ratio according to a correspondence between the preset ratio and the aging coefficient.

In the embodiment of the present invention, the ratio of the capacity difference to the voltage difference is determined; according to the correspondence between the preset ratio and the aging coefficient, an aging coefficient corresponding to the determined ratio is obtained, thereby realizing online detection of battery health.

Based on the accuracy of the measurement results, the full discharge method is generally used for measurement. However, the full discharge method can only be tested offline, and requires a long test time. Compared with the complete discharge method, the embodiment of the present invention effectively reduces the detection time and realizes real-time online detection.

In an embodiment of the present invention, the parameter calculation module 811 is configured to: when the difference between the voltage value acquired in the nth time and the voltage value collected in the first time reaches a preset pressure difference threshold, according to the nth The voltage value and the capacity value collected in the first and the first time respectively calculate the capacity difference value and the voltage difference value; wherein the acquisition is performed for each time the battery health state detection is performed, and n is a natural number greater than 1. .

In another embodiment of the present invention, the sampling module is configured to stop collecting the simultaneously recorded voltage value and capacity value when the battery to be tested is in a charging state, and discard the collected voltage value and capacity value. ;

When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.

In still another embodiment of the present invention, the apparatus further includes a cyclic accumulation module, and the cyclic accumulation module includes:

The typical curve acquisition module is configured to: obtain a typical aging curve according to the aging test; the aging curve is a curve corresponding to the aging coefficient of the power change cycle cumulative value;

a slope detecting module, configured to determine, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

And a setting module configured to set a correspondence between the ratio and the aging coefficient according to the slope and the aging curve.

In an exemplary embodiment, the typical curve acquisition module is configured to record each power change cycle cumulative value of each battery and corresponding corresponding aging coefficient information;

Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

Selecting a typical aging coefficient corresponding to each of the same power change cycle cumulative values from the corresponding aging coefficient ranges;

A typical aging curve is determined according to the typical aging coefficients corresponding to the respective cumulative values of the respective power change cycles.

In still another embodiment of the present invention, the sampling module is further configured to periodically collect the power value of the battery to be tested;

The aging determination module is configured to: determine, according to the collected electric quantity value, a current electric quantity change cycle of the battery to be tested; and obtain an aging coefficient range corresponding to a current accumulated electric energy change cycle cumulative value of the battery to be tested; The corresponding relationship between the ratio and the aging coefficient is obtained within the range of the aging coefficient corresponding to the current accumulated value of the electric quantity change cycle, and the aging coefficient corresponding to the determined ratio is obtained.

In an exemplary embodiment, the aging determination module is configured to: load a corresponding power change cycle cumulative value when the aging coefficient range of the battery to be tested is acquired last time;

Determining the accumulated value of the power change cycle according to the collected power value;

When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.

Those of ordinary skill in the art will appreciate that all or some of the steps, systems, and functional blocks/units of the methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be composed of several physical The components work together. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer readable medium, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and nonvolatile, implemented in any method or technology for storing information, such as computer readable instructions, data structures, program modules or other data. Sex, removable and non-removable media. Computer storage media include, but are not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), and Electrically Erasable Programmable Read-only Memory (EEPROM). Flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cassette, magnetic tape, disk storage or other magnetic storage device, or Any other medium used to store the desired information and that can be accessed by the computer. Moreover, it is well known to those skilled in the art that communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and can include any information delivery media. .

A person skilled in the art can understand that the technical solutions of the present disclosure may be modified or equivalent, without departing from the spirit and scope of the present disclosure, and should be included in the scope of the claims of the present disclosure.

Industrial applicability

The embodiment of the invention provides a battery health state detecting method and device, which realizes online detection of battery health and effectively reduces the detection time.

Claims (15)

1. A battery health detection method includes:

   Collecting the voltage value and capacity value of the battery to be tested at the same time;

   Calculating the capacity difference and the voltage difference according to the voltage value and the capacity value collected twice;

   Determining a ratio of the capacity difference to the voltage difference;

   Obtain an aging coefficient corresponding to the determined ratio according to a preset relationship between the ratio and the aging coefficient.
2. The method of claim 1 wherein said step of calculating a capacity difference and a voltage difference based on the two acquired voltage values and capacity values comprises:

   When the difference between the voltage value collected in the nth time and the voltage value collected in the first time reaches the preset pressure difference threshold, the capacity difference is calculated according to the voltage value and the capacity value collected at the nth and the first time respectively. And the voltage difference; wherein the acquisition is performed every time the battery health state detection is performed, and n is a natural number greater than 1.
3. The method of claim 1, before the step of collecting the voltage value and the capacity value of the battery to be tested at the same time, the method further comprising:

   When the battery to be tested is in a charging state, stop collecting the voltage value and the capacity value at the same time, and discard the collected voltage value and capacity value;

   When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.
4. The method according to any one of claims 1 to 3, wherein the manner of presetting the correspondence between the ratio and the aging coefficient comprises:

   Performing an aging test on a set number of batteries of the same type as the battery to be tested;

   Obtaining a typical aging curve according to the aging test; the aging curve is a curve corresponding to the aging coefficient of the charge change cycle accumulated value;

   Determining, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

   Corresponding relationship between the ratio and the aging coefficient is set according to the slope and the aging curve.
5. The method of claim 4, wherein said step of obtaining a typical aging curve according to said aging test comprises:

   Recording the cumulative value of each power change cycle of each battery and the corresponding aging coefficient information;

   Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

   Selecting a typical aging coefficient corresponding to each of the same power change cycle cumulative values from the corresponding aging coefficient ranges;

   A typical aging curve is determined according to the typical aging coefficients corresponding to the respective cumulative values of the respective power change cycles.
6. The method according to any one of claims 1 to 3, before the step of collecting the voltage value and the capacity value of the battery to be tested at the same time, the method further comprises:

   Periodically collecting the power value of the battery to be tested;

   Determining, according to the collected electric quantity value, the current electric quantity change cycle of the battery to be tested;

   Obtaining an aging coefficient range corresponding to a current accumulated value of the current battery change of the battery to be tested;

   And the step of obtaining an aging coefficient corresponding to the determined ratio according to the preset relationship between the ratio and the aging coefficient, including:

   And obtaining, according to a preset relationship between the ratio and the aging coefficient, an aging coefficient corresponding to the determined ratio within the range of aging coefficients corresponding to the current accumulated value of the power change cycle.
7. The method of claim 6, wherein the step of determining the current battery change cycle of the battery to be tested according to the collected power value comprises:

   Loading the cumulative value of the corresponding power change cycle when the aging coefficient range of the battery to be tested is acquired last time;

   Determining the accumulated value of the power change cycle according to the collected power value;

   When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.
8. A battery health detecting device includes:

   The sampling module is configured to collect the voltage value and the capacity value of the battery to be tested at the same time;

   The parameter calculation module is configured to calculate the capacity separately according to the voltage value and the capacity value collected twice Difference and voltage difference;

   a slope determining module configured to determine a ratio of the capacity difference value to the voltage difference value;

   The aging determination module is configured to obtain an aging coefficient corresponding to the determined ratio according to a preset relationship between the ratio and the aging coefficient.
9. The device according to claim 8, wherein the parameter calculation module is configured to set the difference between the voltage value acquired at the nth time and the voltage value collected at the first time to reach a preset pressure difference threshold, according to the nth time And the voltage value and the capacity value collected for the first time, respectively calculating the capacity difference value and the voltage difference value; wherein each time the battery health state detection is performed, the acquisition is the first acquisition, and n is a natural number greater than 1.
10. The apparatus according to claim 8, wherein said sampling module is configured to stop collecting the simultaneously recorded voltage value and capacity value when said battery to be tested is in a charging state, and discarding the collected voltage value and capacity value;

    When the battery to be tested is in a non-charging state, and the voltage of the battery to be tested is in a preset steady state, the simultaneously recorded voltage value and capacity value are collected.
11. The apparatus of any of claims 8-10, further comprising a cyclic accumulation module, the cyclic accumulation module comprising:

    a typical curve acquisition module is configured to obtain a typical aging curve according to the aging test; the aging curve is a curve corresponding to a aging coefficient of a charge change cycle cumulative value;

    a slope detecting module, configured to determine, according to the aging curve, a slope corresponding to each of the charge change cycle accumulated values, wherein the slope is a ratio of the capacity difference value to the voltage difference value;

    And a setting module configured to set a correspondence between the ratio and the aging coefficient according to the slope and the aging curve.
12. The apparatus of claim 11 wherein said typical curve acquisition module is configured to:

    Recording the cumulative value of each power change cycle of each battery and the corresponding aging coefficient information;

    Determining, according to the recorded information, a range of aging coefficients corresponding to all of the batteries at each of the same charge change cycle accumulation values;

    Selecting the same electric quantity change cycle accumulating value corresponding to each of the corresponding aging coefficient ranges Typical aging factor;

    A typical aging curve is determined according to the typical aging coefficients corresponding to the respective cumulative values of the respective power change cycles.
13. The apparatus according to any one of claims 8 to 10, wherein the sampling module is further configured to periodically collect the power value of the battery to be tested;

    The aging determination module is configured to: determine, according to the collected electric quantity value, a current electric quantity change cycle of the battery to be tested; and obtain an aging coefficient range corresponding to a current accumulated electric energy change cycle cumulative value of the battery to be tested; The corresponding relationship between the ratio and the aging coefficient is obtained within the range of the aging coefficient corresponding to the current accumulated value of the electric quantity change cycle, and the aging coefficient corresponding to the determined ratio is obtained.
14. The device according to claim 13, wherein the aging determination module is configured to: load a corresponding power change cycle cumulative value when the aging coefficient range of the battery to be tested is acquired last time;

    Determining the accumulated value of the power change cycle according to the collected power value;

    When the determined power change cycle cumulative value is increased relative to the loaded power change cycle cumulative value increase setting calculation threshold value, the determined power change cycle cumulative value is determined as the current power change cycle tired.
15. A computer readable storage medium storing computer executable instructions that, when executed by a processor, implement the battery health state detection method of claim 1.

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