CN113125961B

CN113125961B - Battery detection method and device

Info

Publication number: CN113125961B
Application number: CN201911424783.5A
Authority: CN
Inventors: 蒋越星; 范团宝; 胡章荣
Original assignee: HiSilicon Technologies Co Ltd
Current assignee: HiSilicon Technologies Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2024-05-03
Anticipated expiration: 2039-12-31
Also published as: CN113125961A

Abstract

The application provides a battery detection method and device. The method comprises the following steps: collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state; determining a second voltage sequence from the first voltage sequence; constructing a third voltage sequence according to the second voltage sequence; and calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, the first current and the second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state. The application greatly simplifies the acquisition condition of the first voltage sequence (response voltage), thereby greatly relaxing the calculation condition of the impedance value of the battery to be tested under the frequency to be tested and leading the calculation of the impedance of the battery to be tested under the frequency to be tested to be more flexible and convenient.

Description

Battery detection method and device

Technical Field

The application relates to the technical field of detection, in particular to a battery detection method and device.

Background

With the continuous development of the fast-charging technology of terminal equipment, the safety state and service life of the battery under high current are increasingly serious. In order to accurately determine the use state of a battery, battery detection technology has been developed to prevent battery safety accidents under deteriorated conditions such as high-current charging. In the battery detection technology, the electrochemical impedance spectrum of the battery can provide important references for the charge current limit, attenuation mode diagnosis and life state estimation in the use process of the battery, so that safety accidents in the quick charge process are reduced according to the reference information, and the dynamic adjustment of a charge strategy is realized to prolong the service life of the battery. It is clear that the detection of the electrochemical impedance spectrum of the battery is particularly important for the application of battery detection.

The electrochemical impedance spectrum of a commonly used battery is detected by the following modes: and in the state that the battery charger is in place, the battery is fully charged and the terminal equipment is in a screen-off state, pulling square wave current with specific frequency through a current source, detecting response voltage of the battery end to the pulled square wave current with specific frequency through an amplifying/sampling circuit, carrying out Fourier transformation on the pulled square wave current with specific frequency and the collected response voltage to obtain response voltage and square wave current of the battery under specific frequency based on frequency domains, calculating impedance values of the battery under specific frequency according to the response voltage and the square wave current based on the frequency domains, finally, obtaining the impedance values of the battery under different specific frequencies by changing the size of the specific frequency and repeating the processes, and forming an electrochemical impedance spectrum of the battery according to the impedance values of the battery under different specific frequencies.

However, in the above detection manner, on one hand, because the current drawn by the battery is irregular by the system during the use of the battery, and it is difficult to implement loading of the periodic square wave current, as described above, loading of the periodic square wave current can only be implemented in a state that the battery is fully charged, the terminal device is turned off, and the charger is in a state of supplying power to the system of the terminal device, so as to implement calculation of the impedance value of the battery at a specific frequency, obviously, the calculation condition of the impedance value of the battery at the specific frequency is severe, so that the detection condition of the electrochemical impedance spectrum of the battery is severe, and the detection flexibility of the electrochemical impedance spectrum of the battery is poor; on the other hand, the test of the impedance value of the battery under different specific frequencies requires loading square wave current with corresponding frequencies, so that the test time of the impedance value of the battery under a plurality of frequencies is longer, and the detection period of the electrochemical impedance spectrum of the battery under a complete period is greatly prolonged.

Disclosure of Invention

The application provides a battery detection method and device, which are used for solving the problems of harsh impedance value calculation conditions and poor flexibility of a battery, harsh detection conditions and poor detection flexibility of an electrochemical impedance spectrum of the battery, and long detection period of the electrochemical impedance spectrum of the battery under a complete period caused by longer test time of the impedance values of the battery under a plurality of frequencies.

In a first aspect, a battery detection method is provided, including:

Collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values; determining a second voltage sequence according to the first voltage sequence, wherein the second voltage sequence comprises N second voltage values, and the N second voltage values are first voltage values in the first half period of a period to be tested corresponding to the frequency to be tested, which is located in the M first voltage values; constructing a third voltage sequence according to the second voltage sequence, wherein the third voltage sequence comprises 2N third voltage values, and the 2N third voltage values are used for indicating the voltage information of the period to be tested; and calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, a first current and a second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state.

Compared with the prior art, the impedance value of the battery to be tested under the frequency to be tested can be calculated by switching the battery to be tested from the first current state to the second current state and keeping the first voltage sequence of the battery to be tested acquired in the process of keeping the second current state, and compared with the prior art, the impedance value of the battery to be tested under the frequency to be tested is calculated without fully charging the battery, the terminal equipment is turned off, and the charger acquires the response voltage under the state that the terminal equipment is powered by a system of the terminal equipment and provides periodic square wave current, so that the impedance value of the battery to be tested under the frequency to be tested is calculated according to the response voltage and the square wave current, the acquisition condition of the first voltage sequence (the response voltage) is greatly simplified, and the calculation condition of the impedance value of the battery to be tested under the frequency to be tested is greatly widened, and the calculation of the impedance of the battery to be tested under the frequency to be tested is more flexible and convenient. In addition, the second voltage sequence is determined only according to the collected first voltage sequence, the third voltage sequence is constructed according to the second voltage sequence, and the impedance value of the battery to be tested under the frequency to be tested can be calculated according to the third voltage sequence, the first current and the second current, so that the steps are simple, the implementation is easy, and the efficiency of calculating the impedance value is improved. In addition, as the third voltage sequence is constructed according to the second voltage sequence, the voltage information in the period to be tested can be obtained, the impedance value is calculated according to the voltage information in the period to be tested, and the accuracy of calculating the impedance value is ensured.

In one possible implementation, the constructing a third voltage sequence from the second voltage sequence includes:

Determining the sum of the voltage value corresponding to the first current state and the Nth second voltage value in the second voltage sequence as a target voltage value; constructing an n+n second voltage value according to the difference between the target voltage value and an N second voltage value in the second voltage sequence, wherein the n+n second voltage value is positioned in the latter half period of the period to be tested, and at the starting moment of the latter half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and keeps the first current state, and N is more than or equal to 1 and less than or equal to N; constructing a fourth voltage sequence according to the constructed (N+1th) to (2N) th second voltage values; and combining the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence, wherein the 2N third voltage values comprise from a1 st second voltage value to an N th voltage value in the second voltage sequence and from an (n+1) th second voltage value to a 2N th second voltage value in the fourth voltage sequence.

In one possible implementation manner, the combining the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence includes:

Determining a fifth voltage sequence according to the first voltage sequence, wherein the fifth voltage sequence comprises S fifth voltage values, and the S fifth voltage values are first voltage values located in the later half period of the period to be tested in the M first voltage values; correcting the fourth voltage sequence according to the fifth voltage sequence; and combining the second voltage sequence and the corrected fourth voltage sequence to obtain the third voltage sequence.

And the fourth voltage sequence is corrected through the fifth voltage sequence, so that the accuracy of the fourth voltage sequence is improved, and the calculation accuracy of the impedance value is improved.

In one possible implementation, the correcting the fourth voltage sequence according to the fifth voltage sequence includes:

Generating a voltage time function according to S fifth voltage values in the fifth voltage sequence and the acquisition time of each fifth voltage value; inputting the correction time of the (n+n) th second voltage value in the fourth voltage sequence into the voltage time function to obtain the correction voltage of the (n+n) th second voltage value, wherein the correction time of the (n+n) th second voltage value is the corresponding time of the (n+n) th second voltage value in the later half period of the period to be tested; correcting the n+n second voltage value according to the difference value between the correction voltage of the n+n second voltage value and the N second voltage value; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

In one possible implementation, the M first voltage values are collected according to a sampling frequency; the S fifth voltage values are from the (n+1) th first voltage value to the (2N) th first voltage value in the first voltage sequence; said modifying said fourth voltage sequence according to said fifth voltage sequence comprises: determining the (n+n) th first voltage value as a correction voltage of the (n+n) th second voltage value; correcting the n+n second voltage values according to the difference value between the correction voltage of the n+n second voltage values and the N second voltage values; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

Under the condition that M first voltage values are acquired according to the sampling frequency, a voltage time function is not required to be constructed, the N+n second voltage values can be corrected according to the difference value between the N+n first voltage values and the N second voltage values, the correction steps are greatly simplified, and the method is high in efficiency and easy to execute.

In one possible implementation manner, the calculating the impedance value of the battery to be tested at the frequency to be tested according to the third voltage sequence, the first current and the second current includes:

Constructing a first current sequence according to the first current and the second current, wherein the first current sequence comprises 2N third current values, and the third current values in the 2N third current values are in one-to-one correspondence with the third voltage values in the third voltage sequence; and calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

In one possible implementation manner, the calculating, according to the third voltage sequence and the first current sequence, an impedance value of the battery to be tested at the frequency to be tested includes:

Performing Fourier transform on each third current value in the first current sequence to obtain 2N fourth current values; constructing a second current sequence according to the 2N fourth current values; performing Fourier transform on each third voltage value in the third voltage sequence to obtain 2N sixth voltage values; constructing a sixth voltage sequence according to the 2N sixth voltage values; and calculating the impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence.

In one possible implementation, the fourier transforming each third current value in the first current sequence includes: performing Fourier transform on each third current value in the first current sequence according to a first formula, wherein the first formula is as follows:

wherein I ₄ (j) is the j fourth current value, I ₃ (j) is the j third current value, I represents the imaginary part, and 1.ltoreq.j.ltoreq.2N.

In one possible implementation, the fourier transforming each third voltage value in the third voltage sequence includes: performing fourier transform on each third voltage value in the third voltage sequence according to a second formula, wherein the second formula is:

Wherein V ₆ (j) is the jth sixth voltage value, V ₃ (j) is the jth third voltage value, i represents the imaginary part, and 1.ltoreq.j.ltoreq.2N.

In one possible implementation manner, the calculating, according to the second current sequence and the sixth voltage sequence, an impedance value of the battery to be tested at the frequency to be tested includes: calculating an impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence and in combination with a third formula, wherein the third formula is as follows:

Wherein R is an impedance value of the battery to be tested at the frequency to be tested, I ₄ (j) is a j fourth current value, V ₆ (j) is a j sixth voltage value, and I represents an imaginary part.

In one possible implementation manner, the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or the first current state is a state that the battery to be tested discharges with the first current, and the second current state is a state that the battery to be tested stops discharging.

In a second aspect, there is provided a battery detection method including:

Collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values; determining a plurality of second voltage sequences according to the first voltage sequences, wherein each second voltage sequence corresponds to one frequency to be tested in a frequency segment to be tested, the second voltage sequences comprise N second voltage values, and the N second voltage values in the second voltage sequences are first voltage values in the first half period of a period to be tested of the frequency to be tested corresponding to the second voltage sequences in the M first voltage values; constructing a plurality of third voltage sequences according to the plurality of second voltage sequences, wherein each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, the third voltage sequences comprise 2N third voltage values, and the 2N third voltage values are used for indicating voltage information in a period to be tested of the corresponding frequency to be tested; calculating impedance values of the battery to be tested under each frequency to be tested according to the third voltage sequences, a first current and a second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state; and constructing an electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested according to the impedance value of the battery to be tested in each frequency band to be tested.

Compared with the prior art, the impedance value of the battery to be tested under each frequency to be tested in the frequency section to be tested can be calculated through the first voltage sequence of the battery to be tested acquired in the process that the battery to be tested is switched from the first current state to the second current state and the second current state is kept, and compared with the prior art, the terminal equipment is not required to be fully charged, and the screen is turned off and the charger is used for supplying power to a system of the terminal equipment in place, the corresponding square wave current is respectively loaded on the basis of each frequency to be tested in the frequency section to be tested, so that the response voltage corresponding to each frequency to be tested is acquired, the acquisition condition of the first voltage sequence (response voltage) is greatly simplified, the acquisition time is shortened, the time for calculating the impedance value under the plurality of frequencies to be tested is greatly shortened, the calculation condition of the impedance value under the plurality of frequencies to be tested is greatly widened, the calculation of the impedance value under the plurality of frequencies to be tested is more flexible and convenient, the detection condition of the electrochemical impedance spectrum is further widened, and the detection flexibility of the electrochemical impedance spectrum is improved, and the detection time of the electrochemical impedance spectrum is shortened. In addition, the second voltage sequence corresponding to each frequency to be tested is determined only according to the collected first voltage sequence, the third voltage sequence corresponding to each frequency to be tested is built according to the second voltage sequence corresponding to each frequency to be tested, the impedance value of the battery to be tested under each frequency to be tested can be calculated according to the third voltage sequence corresponding to each frequency to be tested, the first current and the second current, and the electrochemical impedance spectrum is built according to the impedance value of the battery to be tested under each frequency to be tested. In addition, as the third voltage sequence corresponding to each frequency to be tested is constructed according to the second voltage sequence corresponding to each frequency to be tested so as to obtain the voltage information in the period to be tested corresponding to each frequency to be tested, the impedance value under each frequency to be tested is calculated according to the voltage information in the period to be tested corresponding to each frequency to be tested, the accuracy of calculating the impedance value is ensured, and the accuracy of electrochemical impedance spectrum is ensured.

In one possible implementation, the constructing a plurality of third voltage sequences from the plurality of second voltage sequences includes: constructing the plurality of third voltage sequences from the plurality of second voltage sequences and using the method of any one of the first aspects.

In one possible implementation manner, the calculating the impedance value of the battery to be tested at each of the frequencies to be tested according to the third voltage sequences, the first current and the second current includes: and respectively calculating the impedance value of the battery to be tested under the frequency to be tested corresponding to each third voltage sequence according to each third voltage sequence, the first current and the second current and combining the method of any one of the first aspect.

In a third aspect, there is provided a battery detection device, comprising:

The first acquisition module is used for acquiring a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values; the first determining module is used for determining a second voltage sequence according to the first voltage sequence, wherein the second voltage sequence comprises N second voltage values, and the N second voltage values are first voltage values in the first half period of a period to be tested, which corresponds to the frequency to be tested, of the M first voltage values; the first construction module is used for constructing a third voltage sequence according to the second voltage sequence, wherein the third voltage sequence comprises 2N third voltage values, and the 2N third voltage values are used for indicating the voltage information of the period to be tested; and the first calculation module is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, the first current and the second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state.

In one possible implementation manner, the first construction module includes:

A determining unit configured to determine, as a target voltage value, a sum of a voltage value corresponding to the first current state and an nth second voltage value in the second voltage sequence; a first construction unit configured to construct an n+n second voltage value according to a difference between the target voltage value and an N-th second voltage value in the second voltage sequence, where the n+n-th second voltage value is located in a second half period of the period to be tested, and at a start time of the second half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and maintains the first current state, where 1N is equal to or less than N; a second construction unit for constructing a fourth voltage sequence according to the constructed (n+1) th to (2N) th second voltage values; the merging unit is configured to merge the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence, where the 2N third voltage values include a1 st second voltage value to an nth voltage value in the second voltage sequence and an n+1th second voltage value to a 2nth second voltage value in the fourth voltage sequence.

In one possible implementation, the merging unit includes:

A determining subunit, configured to determine a fifth voltage sequence according to the first voltage sequence, where the fifth voltage sequence includes S fifth voltage values, where the S fifth voltage values are first voltage values located in a second half period of the period to be tested in the M first voltage values; a correction subunit, configured to correct the fourth voltage sequence according to the fifth voltage sequence; and the merging subunit is used for merging the second voltage sequence and the corrected fourth voltage sequence to obtain the third voltage sequence.

In a possible implementation manner, the correction subunit is specifically configured to generate a voltage time function according to S fifth voltage values in the fifth voltage sequence and the acquisition time of each fifth voltage value; inputting the correction time of the (n+n) th second voltage value in the fourth voltage sequence into the voltage time function to obtain the correction voltage of the (n+n) th second voltage value, wherein the correction time of the (n+n) th second voltage value is the corresponding time of the (n+n) th second voltage value in the later half period of the period to be tested; correcting the n+n second voltage value according to the difference value between the correction voltage of the n+n second voltage value and the N second voltage value; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

In one possible implementation, the M first voltage values are collected according to a sampling frequency; the S fifth voltage values are from the (n+1) th first voltage value to the (2N) th first voltage value in the first voltage sequence; the correction subunit is specifically configured to determine the n+nth first voltage value as a correction voltage of the n+nth second voltage value; correcting the n+n second voltage values according to the difference value between the correction voltage of the n+n second voltage values and the N second voltage values; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

In one possible implementation, the first computing module includes:

A third construction unit, configured to construct a first current sequence according to the first current and the second current, where the first current sequence includes 2N third current values, where a third current value of the 2N third current values corresponds to a third voltage value of the third voltage sequence one to one; and the calculating unit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

In one possible implementation, the computing unit includes:

The first transformation subunit is used for carrying out Fourier transformation on each third current value in the first current sequence to obtain 2N fourth current values; a first construction subunit, configured to construct a second current sequence according to the 2N fourth current values; a second transformation subunit, configured to perform fourier transformation on each third voltage value in the third voltage sequence, so as to obtain 2N sixth voltage values; a second construction subunit, configured to construct a sixth voltage sequence according to the 2N sixth voltage values; and the calculating subunit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence.

In a possible implementation manner, the first transformation subunit is specifically configured to perform fourier transformation on each third current value in the first current sequence according to a first formula, where the first formula is:

In a possible implementation manner, the second transforming subunit is specifically configured to perform fourier transform on each third voltage value in the third voltage sequence according to a second formula, where the second formula is:

In a possible implementation manner, the calculating subunit is specifically configured to calculate, according to the second current sequence and the sixth voltage sequence and in combination with a third formula, an impedance value of the battery to be tested at the frequency to be tested, where the third formula is:

In a fourth aspect, there is provided a battery detection device comprising:

The second acquisition module is used for acquiring a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values; a second determining module, configured to determine a plurality of second voltage sequences according to the first voltage sequences, where each second voltage sequence corresponds to one frequency to be tested in a frequency segment to be tested, where the second voltage sequences include N second voltage values, where the N second voltage values in the second voltage sequences are first voltage values, located in a first half period of a cycle to be tested of the frequency to be tested corresponding to the second voltage sequences, in the M first voltage values; a second construction module, configured to construct a plurality of third voltage sequences according to the plurality of second voltage sequences, where each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, the third voltage sequence includes 2N third voltage values, and the 2N third voltage values are used to indicate voltage information in a corresponding period to be tested of the frequency to be tested; a second calculation module, configured to calculate an impedance value of the battery to be tested at each frequency to be tested according to the plurality of third voltage sequences, a first current and a second current, where the first current corresponds to the first current state, and the second current corresponds to the second current state; and the third construction module is used for constructing an electrochemical impedance spectrum of the battery to be tested in the frequency section to be tested according to the impedance value of the battery to be tested in each frequency section to be tested.

In a possible implementation manner, the second construction module is specifically configured to construct the plurality of third voltage sequences according to the plurality of second voltage sequences and using the apparatus according to any one of the third aspects.

In a possible implementation manner, the second calculating module is specifically configured to calculate, according to each of the third voltage sequences, the first current, and the second current, in combination with the apparatus of any one of the third aspects, an impedance value of the battery to be tested at a frequency to be tested corresponding to each of the third voltage sequences, respectively.

In a fifth aspect, there is provided a computer readable storage medium comprising a computer program which, when executed on a computer, causes the computer to perform the method of any one of the first aspect or the method of any one of the second aspect.

In a sixth aspect, there is provided a computer program for performing the method of any one of the first aspect or the method of any one of the second aspect, when the computer program is executed by a computer.

In a seventh aspect, a chip is provided, comprising a processor and a memory, the memory being for storing a computer program, the processor being for invoking and running the computer program stored in the memory to perform the method of any one of the first aspects or the method of any one of the second aspects.

An eighth aspect provides a terminal device comprising the apparatus of any one of the first aspects or the apparatus of any one of the second aspects.

Drawings

Fig. 1 is a schematic flow chart of a battery detection method according to an embodiment of the present application;

FIG. 2 shows a schematic waveform of current and response voltage during a battery to be tested switching from a state of charge to a stopped state of charge and maintaining the stopped state of charge;

fig. 3 is a waveform diagram showing current and response voltage during the process of switching the battery to be tested from the discharge state to the stop discharge state and maintaining the stop discharge;

FIG. 4 shows a schematic flow chart for constructing a third voltage sequence;

FIG. 5 shows a waveform diagram I corresponding to a third voltage sequence;

FIG. 6 shows a second waveform diagram corresponding to a third voltage sequence;

FIG. 7 is a schematic flow chart of the fourth voltage sequence correction and the third voltage sequence determination according to the corrected fourth voltage sequence;

FIG. 8 shows a waveform diagram I corresponding to the modified fourth voltage sequence;

FIG. 9 shows a second waveform diagram corresponding to the modified fourth voltage sequence;

FIG. 10 is a schematic diagram showing a process of calculating an impedance value of a battery to be tested at a frequency to be tested;

FIG. 11 shows a second flowchart of calculating the impedance value of the battery under test at the frequency under test;

fig. 12 is a second flow chart of a battery detection method according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of a battery detection device according to an embodiment of the present application;

fig. 14 is a schematic diagram of a battery detection device according to a second embodiment of the present application.

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms "first," "second," and the like in the description and in the claims and drawings are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such as a series of steps or elements. The method, system, article, or apparatus is not necessarily limited to those explicitly listed but may include other steps or elements not explicitly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

When the electrochemical impedance spectrum of the battery is detected, a small-amplitude current square wave needs to be applied to the battery, the response voltage of the battery based on the current square wave is collected, and then the impedance value of the battery under the frequency corresponding to the current square wave is calculated according to the response voltage and the current square wave. Because the equivalent circuit symmetry property of the battery, namely, the change trend of the response voltage has consistency under the condition that the change amounts of the currents are the same, based on the principle, under the condition that the current square wave in the first half period of one period and the response voltage based on the current square wave in the first half period are known, the current square wave in the second half period of the period and the response voltage can be constructed based on the equivalent circuit symmetry property of the battery, and further the current square wave in the period and the response voltage are obtained, so that the impedance value of the battery under the frequency corresponding to the period is calculated according to the current square wave in the period and the response voltage.

From the above, it is understood that the impedance value of the battery at the frequency corresponding to the first half cycle of one cycle can be calculated as long as the current square wave in the first half cycle and the response voltage based on the current square wave in the first half cycle are obtained.

Based on the method, the current square wave of the first half period can be simulated by cutting off the charging current and keeping the switching state in the process of charging the battery, and the response voltage of the battery is collected at the starting moment of cutting off the charging current, wherein the collected response voltage at least covers the first half period, and the response voltage in the first half period is determined according to the collection time of the response voltage and the time period corresponding to the first half period, so that the current square wave and the response voltage in the first half period are obtained; or in the discharging process of the battery, cutting off the discharging current of the battery and keeping the cut-off state to simulate the current square wave of the first half period, and starting to collect the response voltage of the battery at the starting moment of cutting off the discharging current, wherein the collected response voltage at least covers the first half period, and the response voltage in the first half period is determined according to the collection time of the response voltage and the time period corresponding to the first half period, so that the current square wave and the response voltage in the first half period are obtained.

It should be noted that, when calculating the impedance value of the battery at a plurality of frequencies, the duration of maintaining the cut-off state may be set according to the period corresponding to the minimum frequency, and the response voltage may be collected multiple times within the set duration, so that the collected response voltage covers at least the period corresponding to the minimum frequency.

Based on the above principle, the present application provides a battery detection method, and fig. 1 is a schematic flow chart of a battery detection method according to an embodiment of the present application. As shown in fig. 1, the method may include:

step 101, collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and maintaining the second current state, wherein the first voltage sequence comprises M first voltage values.

In the embodiment of the application, the battery to be tested can be a battery installed in a terminal device, and the terminal device can be a device requiring battery power, such as a mobile phone, a tablet personal computer, an electronic reader and the like.

The first current state and the second current state may include two cases, wherein:

first kind: the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which the battery to be tested is stopped being charged.

In this case, step 101 may be: in a state in which the battery to be tested is charged by the first current, cutting off the first current and keeping stopping the charging of the battery to be tested, collecting M first voltage values which are response voltages of the battery to be tested, namely cutting off the charging current (i.e., the first current) flowing into the battery to be tested and keeping the cut-off state in the state in which the battery to be tested is charged by the charger, collecting the response voltages of the battery to be tested while cutting off the charging current flowing into the battery to be tested and keeping the cut-off state, and naming the collected response voltages as first voltage values, wherein the collection number of the first voltage values is M. And sequencing the acquired first voltage values according to the sequence of acquisition time from first to last to obtain a first voltage sequence, wherein M first voltage values in the first voltage sequence are V ₁ to V ₁ M in sequence.

The duration of keeping stopped charging the battery to be tested (i.e., the duration of keeping the second current state) may be determined according to the frequency to be tested, i.e., the duration of the period to be tested is calculated according to the frequency to be tested, and the duration of the period to be tested or more is determined as the duration of keeping stopped charging the battery to be tested. For example, if the frequency to be tested is 500Hz, the duration of the period to be tested is 2ms, the duration of stopping charging the battery to be tested is kept to be greater than or equal to 2ms, and if the frequency to be tested is 1Hz, the duration of the period to be tested is 1s, and the duration of stopping charging the battery to be tested is kept to be greater than or equal to 1s. The starting time of the period to be tested is the time when the battery to be tested is switched from the first current state to the second current state.

By setting the duration for which the charging of the battery to be tested is kept stopped, the response voltage (first voltage value) in one complete period can be collected, and therefore the calculation accuracy is ensured.

The second current corresponds to the second current state, which can be understood as a current value of the battery to be tested in the second current state, and since the second current state is a state in which charging of the battery to be tested is stopped, the second current is 0.

Fig. 2 shows a waveform diagram of current and response voltage during the process of switching the battery to be tested from a charged state to a stopped charged state and maintaining the stopped charging. Wherein:

In the charging state (i.e., the first current state), the current I on the battery to be tested is the first current I1 (i.e., the charging current), and the response voltage V on the battery to be tested is the charging voltage V0. In the state of charge stopping (i.e. the second current state), the current I on the battery to be tested is the second current I2, at this time, the second current I2 is 0, and the response voltage V on the battery to be tested is shown as a curve of the response voltage V in the state of charge stopping in the figure. As shown in fig. 2, the first voltage sequence (i.e., V ₁ 1 to V ₁ M) is [ V (1), V (2), V (3), V (4), … …, V (M) ].

The second, the first current state is the state that the battery to be tested discharges with the first current, and the second current state is the state that the battery to be tested stops discharging.

In this case, step 101 may be: in a state that the battery to be tested discharges with the first current, in the process of cutting off the first current and keeping stopping discharging, M first voltage values are collected, wherein the M first voltage values are response voltages of the battery to be tested. That is, in a state where the battery to be tested is not charged and is discharged with the first current, the discharge current (i.e., the first current) of the battery to be tested is cut off and the cut-off state (i.e., the state where the discharge is stopped) is maintained, and the response voltage of the battery to be tested is collected while the discharge current of the battery to be tested is cut off and the cut-off state is maintained, and the collected response voltage is named as a first voltage value, wherein the collection number of the first voltage values is M. And sequencing the acquired first voltage values according to the sequence of acquisition time from first to last to obtain a first voltage sequence, wherein M first voltage values in the first voltage sequence are V ₁ to V ₁ M in sequence.

The duration of the discharge hold (i.e., the duration of the second current state) may be determined according to the frequency to be tested, i.e., the duration of the period to be tested is calculated according to the frequency to be tested, and the duration of the period to be tested is determined to be the duration of the discharge hold. For example, if the frequency to be tested is 500Hz, the duration of the period to be tested is 2ms, the duration of the discharge stopping period is kept to be greater than or equal to 2ms, and if the frequency to be tested is 1Hz, the duration of the period to be tested is 1s, and the duration of the discharge stopping period is kept to be greater than or equal to 1s. The starting time of the period to be tested is the time when the battery to be tested is switched from the first current state to the second current state.

By setting the duration of the discharge hold stop, it is ensured that the response voltage (first voltage value) can be acquired within one complete cycle, thereby ensuring the accuracy of the calculation.

The second current corresponds to the second current state, which can be understood as a current value of the battery to be tested in the second current state, and since the second current state is a state in which discharge is stopped, the second current is 0. In the second mode, the terminal device may be in an off-screen state.

Fig. 3 shows a waveform diagram of current and response voltage during the process of switching the battery to be tested from the discharge state to the stop discharge state and maintaining the stop discharge. Wherein:

in the discharging state (i.e., the first current state), the current I on the battery to be tested is the first current I1 (i.e., the discharging current), and the response voltage V on the battery to be tested is the discharging voltage V0. In the discharge stopping state (i.e., the second current state), the current I on the battery to be tested is the second current I2, at this time, the second current I2 is 0, and the response voltage V on the battery to be tested is shown as a curve of the response voltage V in the discharge stopping state in the figure. As shown in fig. 3, the first voltage sequence (i.e., V ₁ 1 to V ₁ M) is [ V (1), V (2), V (3), V (4), … …, V (M) ].

The manner of acquiring the M first voltage values may include two kinds of the following, in which:

First, M first voltage values are randomly collected, that is, the time interval between any two adjacent first voltage values obtained by collection may be completely different or not completely the same. For example, the first time interval and the second time interval may be set, and the first voltage values are acquired in such a way that the first time interval and the second time interval alternate, i.e. the time interval between two adjacent first voltage values is either the first time interval or the second time interval.

Secondly, setting a sampling frequency, and collecting M first voltage values according to the sampling frequency. I.e. the first voltage value is acquired at fixed time intervals. It should be noted that, in order to collect enough first voltage values in the period to be tested corresponding to the frequency to be tested, so as to meet the calculation requirement, thereby ensuring the accuracy of the test result, when the sampling frequency is set, the sampling frequency is greater than the frequency to be tested. For example, if the frequency to be tested is 500Hz, the sampling frequency may be set to 4000Hz.

In order to further improve accuracy of the test data, a switching duration of the first current state to the second current state may be less than 250us, and a duration of maintaining the second current state may be between 0.5s and 5 s.

Step 102, determining a second voltage sequence according to the first voltage sequence, wherein the second voltage sequence comprises N second voltage values, and the N second voltage values are first voltage values in the first half period of the period to be tested corresponding to the frequency to be tested in the M first voltage values.

In the embodiment of the present application, if the first mode is adopted to collect M first voltage values, the mode of determining the second voltage sequence is as follows: calculating the duration of a period to be tested corresponding to the frequency to be tested according to the frequency to be tested, then taking the moment of switching the first current state into the second current state as the starting moment of the period to be tested, determining the ending moment of the first half period of the period to be tested according to the starting moment of the period to be tested and the duration of the period to be tested, finally comparing the acquisition time of each first voltage value in the first voltage sequence with the starting moment of the period to be tested and the ending moment of the first half period of the period to be tested, if the acquisition time of the first voltage value is between the starting moment of the period to be tested and the ending moment of the first half period of the period to be tested, determining the first voltage value as a second voltage value, and sequencing the determined second voltage values according to the sequence of the acquisition time to obtain a second voltage sequence, wherein the number of the second voltage values is N, and N second voltage values in the second voltage sequence are sequentially from the first second voltage value to the N second voltage value (V ₂ to V ₂ N).

Since the first voltage values in the first voltage sequence are arranged in the order of the acquisition time from the beginning to the end, after the value of N is determined, the first N first voltage values in the first voltage sequence may be directly determined as N second voltage values in the second voltage sequence, as shown in fig. 2 and 3, where the second voltage sequences (i.e., V ₂ 1 to V ₂ N) are [ V (1), V (2), V (3), V (4), … …, V (N) ].

If the second mode is adopted to collect the M first voltage values, the value of N is equal to one half of the ratio of the sampling frequency to the frequency to be tested, i.e., n=f1/2 f, where f1 is the sampling frequency and f is the frequency to be tested, because the first voltage values are collected according to the sampling frequency. After the value of N is obtained, the first N first voltage values in the first voltage sequence are determined to be N second voltage values in the second voltage sequence, and the N second voltage values in the second voltage sequence are sequentially V ₂ to V ₂ N. As shown in fig. 2 and 3, the second voltage sequence (i.e., V ₂ 1 to V ₂ N) is [ V (1), V (2), V (3), V (4), … …, V (N) ].

As can be seen from the above, the voltage value of the battery to be tested in the first half period of the test period can be obtained in step 102, and since the battery to be tested is in the second current state in the first half period of the test period, the second current corresponding to the second current state is determined as the current of the battery to be tested in the first half period of the test period.

Step 103, constructing a third voltage sequence according to the second voltage sequence, wherein the third voltage sequence comprises 2N third voltage values, and the 2N third voltage values are used for indicating voltage information of a period to be tested.

In the embodiment of the present application, since the second voltage sequence is only the voltage information of the first half period of the period to be tested, and the voltage information of the whole period to be tested is required in the calculation, the voltage information of the whole period to be tested, that is, the third voltage sequence, needs to be constructed. Next, a process of constructing the third voltage sequence will be described.

Since the first half period of the period to be tested is a process of switching the battery to be tested from the first current state to the second current state and maintaining the second current state, the second half period of the period to be tested is a process of switching the battery to be tested from the second current state to the first current state and maintaining the first current state. And since the voltage information of the first half period of the period to be tested (i.e. the second voltage sequence) is known, the third voltage sequence is constructed according to the second voltage sequence in combination with the symmetrical nature of the equivalent circuit of the battery to be tested described above.

Fig. 4 shows a schematic flow chart of constructing a third voltage sequence, as shown in fig. 4, comprising the steps of:

step 401, determining the sum of the voltage value corresponding to the first current state and the nth second voltage value in the second voltage sequence as a target voltage value.

In the embodiment of the application, if the first current state is a state in which the battery to be tested is charged by the first current, the voltage value corresponding to the first current state is a charging voltage, and if the first current state is a state in which the battery to be tested is discharged by the first current, the voltage value corresponding to the first current state is a discharging voltage. If V0 represents a voltage value corresponding to the first current state and Vm represents a target voltage value, vm=v0+v ₂N,V₂ N is the nth second voltage value in the second voltage sequence. As shown in fig. 2 and 3, V ₂ n=v (N), vm=v0+v (N).

And step 402, constructing an n+n second voltage value according to the difference between the target voltage value and an N second voltage value in the second voltage sequence, wherein the n+n second voltage value is positioned in the second half period of the period to be tested, and at the starting moment of the second half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and keeps the first current state, and N is more than or equal to 1 and less than or equal to N.

In the embodiment of the present application, the n+n second voltage value may be constructed according to the following formula:

V₂(N+n)＝Vm-V₂n＝V0+V₂N-V₂n

Wherein V ₂ (n+n) is the n+n second voltage value, vm is the target voltage value, V ₂ N is the N second voltage value in the second voltage sequence, V0 is the voltage value corresponding to the first current state, and V ₂ N is the N second voltage value in the second voltage sequence.

The constructed (n+1th) to (2Nth) second voltage values (V ₂ (N+1) to V ₂ (2N)) can be obtained by changing the value of N and combining the formulas.

Step 403, constructing a fourth voltage sequence according to the constructed n+1th to 2nth second voltage values. That is, the fourth voltage sequence includes N second voltage values, sequentially from the (n+1) th to the (2N) th second voltage values (V ₂ (n+1) to V ₂ (2N)).

From the above, the voltage information of the second half period of the period to be tested, i.e., the fourth voltage sequence, is constructed through steps 401 to 403.

Step 404, merging the second voltage sequence and the fourth voltage sequence to obtain a third voltage sequence, wherein the 2N third voltage values (V ₃ to V ₃ N) include the 1 st to nth second voltage values (V ₂ 1 to V ₂ N) in the second voltage sequence and the n+1th to 2nth second voltage values (V ₂ (n+1) to V ₂ (2N)) in the fourth voltage sequence. I.e., V ₂ to V ₂ N in the second voltage sequence are combined with V ₂ (n+1) to V ₂ (2N) in the fourth voltage sequence to obtain a third voltage sequence.

Fig. 5 shows a schematic diagram of waveforms corresponding to the third voltage sequence. In fig. 5, the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which the charging of the battery to be tested is stopped. The waveform diagram of the response voltage corresponding to the first half period is waveforms corresponding to the 1 st to nth first voltage values in fig. 2, and the second voltage sequence (i.e., V ₂ to V ₂ N) is [ V (1), V (2), V (3), V (4), … …, V (N) ]; the second half period corresponds to a fourth voltage sequence, which is constructed from the second voltage sequences [ V (1), V (2), V (3), V (4), … …, V (N) ], the constructed fourth voltage sequences (i.e., V ₂ (n+1) to V ₂ (2N)) being [ v0+v (N) -V (1), v0+v (N) -V (2), v0+v (N) -V (3), v0+v (N) -V (4), … …, v0+v (N) -V (N) ]. To sum up, the third voltage sequence (V ₃ to V ₃ N) can be expressed as: [ V (1), V (2), V (3), V (4), … …, V (N), V0+V (N) -V (1), V0+V (N) -V (2), V0+V (N) -V (3), V0+V (N) -V (4), … …, V0+V (N) -V (N) ].

The sum of the acquisition time of the nth second voltage value and the acquisition time of the nth second voltage value is the time corresponding to the constructed nth (n+n) second voltage value. The waveform corresponding to the period to be tested in fig. 5 is the waveform corresponding to the third voltage sequence.

Fig. 6 shows a second waveform diagram corresponding to the third voltage sequence. In fig. 6, the first current state is a state in which the battery to be tested discharges at the first current, and the second current state is a state in which the battery to be tested stops discharging. The waveform diagram of the response voltage corresponding to the first half period is waveforms corresponding to the 1 st to nth first voltage values in fig. 3, and the second voltage sequence (i.e., V ₂ to V ₂ N) is [ V (1), V (2), V (3), V (4), … …, V (N) ]; the second half period corresponds to a fourth voltage sequence, which is constructed from the second voltage sequences [ V (1), V (2), V (3), V (4), … …, V (N) ], the constructed fourth voltage sequences (i.e., V ₂ (n+1) to V ₂ (2N)) being [ v0+v (N) -V (1), v0+v (N) -V (2), v0+v (N) -V (3), v0+v (N) -V (4), … …, v0+v (N) -V (N) ]. To sum up, the third voltage sequence (V ₃ to V ₃ N) can be expressed as: [ V (1), V (2), V (3), V (4), … …, V (N), V0+V (N) -V (1), V0+V (N) -V (2), V0+V (N) -V (3), V0+V (N) -V (4), … …, V0+V (N) -V (N) ].

The sum of the acquisition time of the nth second voltage value and the acquisition time of the nth second voltage value is the time corresponding to the constructed nth (n+n) second voltage value. The waveform corresponding to the period to be tested in fig. 6 is the waveform corresponding to the third voltage sequence.

Further, in order to further improve the accuracy of constructing the fourth voltage sequence, thereby further improving the accuracy of the third voltage sequence, further improving the calculation accuracy of the impedance value, and further correcting the fourth voltage sequence.

The principle of correcting the fourth voltage sequence is as follows: the fourth voltage sequence is modified according to the difference between each first voltage value and the nth first voltage value in the first voltage sequence (i.e., the distance between the curve corresponding to the second half period in fig. 2 and 3 (shown by the solid line in the figure) and the straight line 201) in the second half period of the period to be tested, so as to improve the accuracy of constructing the fourth voltage sequence. The specific implementation process is as follows:

Fig. 7 shows a schematic flow chart of the correction of the fourth voltage sequence and the determination of the third voltage sequence from the corrected fourth voltage sequence. As shown in fig. 7, the method comprises the following steps:

Step 701, determining a fifth voltage sequence according to the first voltage sequence, wherein the fifth voltage sequence includes S fifth voltage values (V ₅ to V ₅ S), and the S fifth voltage values are first voltage values in the second half period of the period to be tested in the M first voltage values.

In the embodiment of the present application, since the principle of determining the fifth voltage sequence from the first voltage sequence is the same as the principle of determining the second voltage sequence from the first voltage sequence, and the principle of determining the second voltage sequence from the first voltage sequence has been described above, the principle of determining the fifth voltage sequence will not be described here. The first to S fifth voltage values (V ₅ 1 to V ₅ S) in the fifth voltage sequence are the (n+1) th to (n+s) th first voltage values in the first voltage sequence.

Step 702, correcting the fourth voltage sequence according to the fifth voltage sequence.

Next, the above-described correction process will be described in the following two ways. Wherein:

First, a voltage time function is generated according to S fifth voltage values in the fifth voltage sequence and the acquisition time of each fifth voltage value.

And then, inputting the correction time of the (n+n) th second voltage value in the fourth voltage sequence into a voltage time function, and determining the obtained voltage value as the correction voltage of the (n+n) th second voltage value, wherein the correction time of the (n+n) th second voltage value is the corresponding time of the (n+n) th second voltage value in the later half period of the period to be tested. The corresponding time of the n+nth second voltage value in the second half period of the period to be tested has been described above, and thus, a detailed description thereof will not be provided here.

And then, correcting the n+n second voltage value according to the difference value between the correction voltage of the n+n second voltage value and the N second voltage value. Namely, the sum of the difference value between the correction voltage of the n+n second voltage value and the N second voltage value and the n+n second voltage value is determined as the corrected n+n second voltage value.

And finally, constructing a modified fourth voltage sequence according to the modified (N+1th) second voltage value to the modified (2N) second voltage value.

Second, if the M first voltage values are collected according to the sampling frequency, s=n, and S fifth voltage values are the n+1st to 2nth first voltage values in the first voltage sequence. Since the first voltage values are collected according to the sampling frequency, that is, the time intervals between any two adjacent first voltage values are the same, the n+n first voltage values in the first voltage sequence are correction voltages of the n+n second voltage values. From the above, the S fifth voltage values are the n+1st to 2nth first voltage values in the first voltage sequence.

Based on this, the correction process includes: firstly, determining the (n+n) th first voltage value as a correction voltage of the (n+n) th second voltage value; then, the n+n second voltage values are corrected according to the difference between the corrected voltage of the n+n second voltage values and the N second voltage values. The n+n second voltage value=v ₁(N+n)-V₂N+V₂(N+n),V₂ N after correction is the N second voltage value, V ₂ (n+n) is the n+n second voltage value, and V ₁ (n+n) is the n+n first voltage value; and finally, constructing a modified fourth voltage sequence according to the modified (N+1th) second voltage value to the modified (2N) second voltage value.

In the second mode, since the first voltage values are acquired according to the acquisition frequency, that is, the time intervals between any two adjacent first voltage values are the same, the n+nth first voltage value is the correction voltage of the n+nth second voltage value. Based on this, the difference between the n+nth first voltage value and the N-th second voltage value may be calculated first, and then, the sum of the difference between the n+nth first voltage value and the N-th second voltage value and the n+nth second voltage value may be determined as the corrected n+nth second voltage value.

Obviously, in the case of acquiring the M first voltage values according to the sampling frequency, compared with the first mode, when the correction is performed in the second mode, the voltage time function does not need to be constructed, and the correction voltage is determined according to the voltage time function, so that the correction step is greatly simplified, and the correction method is high in efficiency and easy to perform.

In the case where M first voltage values are acquired at the sampling frequency, the correction may be performed by the first method.

Fig. 8 shows a waveform schematic diagram corresponding to the modified fourth voltage sequence, in fig. 8, the first current state is a state of charging the battery to be tested through the first current, the second current state is a state of stopping charging the battery to be tested, and the M first voltage values are collected according to the sampling frequency. Fig. 8 is a waveform corresponding to the modified fourth voltage sequence plotted on the basis of fig. 2 and 5. As shown in FIG. 8, the modified fourth voltage sequence is [ V0+V (N+1) -V (1), V0+V (N+2) -V (2), V0+V (N+3) -V (3), V0+V (N+4) -V (4), … …, V0+V (2N)

-V (N) ]. Wherein the curve shown by the dashed line in the second half period is plotted according to the modified fourth voltage sequence.

Fig. 9 shows a second waveform diagram corresponding to the modified fourth voltage sequence, where in fig. 9, the first current state is a state in which the battery to be tested discharges with the first current, and the second current state is a state in which the battery to be tested stops discharging. The M first voltage values are collected according to the sampling frequency. Fig. 9 is a waveform corresponding to the modified fourth voltage sequence plotted on the basis of fig. 3 and 6. As shown in fig. 9, the modified four voltage sequence is [ v0+v (n+1) -V (1), v0+v (n+2) -V (2), v0+v (n+3) -V (3), v0+v (n+4) -V (4), … …, v0+v (2N) -V (N) ]. Wherein the curve shown by the dashed line in the second half period is plotted according to the modified fourth voltage sequence.

Step 703, combining the second voltage sequence and the modified fourth voltage sequence to obtain a third voltage sequence. As shown in fig. 8 and 9, the third voltage sequence (i.e., V ₃ 1 to V ₃ N) is ：[V(1),V(2),V(3),V(4),……,V(N),V0+V(N+1)-V(1),V0+V(N+2)-V(2),V0+V(N+3)-V(3),V0+V(N+4)-V(4),……,V0+V(2N)-V(N)].

And 104, calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, the first current and the second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state.

In the embodiment of the application, if the first current state is a state of charging the battery to be tested through the first current, and the second current state is a state of stopping charging the battery to be tested, the first current is a charging current of charging the battery to be tested, and the second current is 0; if the first current state is a state that the battery to be tested discharges with the first current, and the second current state is a state that the battery to be tested stops discharging, the first current is a discharging current of the battery to be tested discharging, and the second current is 0.

Fig. 10 shows a schematic flow chart of calculating an impedance value of a battery to be tested at a frequency to be tested, as shown in fig. 10, including the following steps:

Step 110, constructing a first current sequence according to the first current and the second current, wherein the first current sequence comprises 2N third current values, and the third current values in the 2N third current values are in one-to-one correspondence with the third voltage values in the third voltage sequence.

In the embodiment of the present application, since the first N third voltage values in the third voltage sequence belong to the first half period of the period to be tested, and the first half period corresponds to the second current state, the current values corresponding to the first N third voltage values are the second current, and since the second N third voltage values in the third voltage sequence belong to the second half period of the period to be tested, and the second half period corresponds to the first current state, the current values corresponding to the second N third voltage values are the first current. Based on this, the first current sequence includes 3N third current values (I ₃ to I ₃ N), where the first N third current values are the second current and the last N third current values are the first current.

If the first current state is a state of charging the battery to be tested through the first current, the second current state is a state of stopping charging the battery to be tested, the first current is a charging current I1, the second current is 0, the first current sequence (I ₃ 1 to I ₃ N) is [0, … … …,0, I1, … …, I1], wherein the number of 0 and I1 is N.

If the first current state is the state that the battery to be tested discharges with the first current, the second current state is the state that the battery to be tested stops discharging, the first current is the discharging current I1, the second current is 0, the first current sequence (I ₃ 1 to I ₃ N) is [0, … … …,0, I1, … …, I1], wherein the number of 0 and I1 is N.

And 120, calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

In the embodiment of the application, since the third voltage sequence is a voltage based on a time domain, the first current sequence is a current based on the time domain, and the impedance value of the battery under the frequency to be tested is an impedance value based on a frequency domain, the third voltage sequence needs to be transformed from the time domain to the frequency domain, the first current sequence is also transformed from the time domain to the frequency domain, and the impedance value of the battery under the frequency to be tested is calculated according to the transformed third voltage sequence and the first current sequence.

Based on this, fig. 11 shows a second flowchart of calculating the impedance value of the battery to be tested at the frequency to be tested, as shown in fig. 11, including the following steps:

Step 1101, performing fourier transform on each third current value in the first current sequence to obtain 2N fourth current values. For example, each third current value in the first current sequence may be fourier transformed according to a first formula:

Each third current value in the first current sequence is converted from the time domain to the frequency domain in step 1101, and a current value obtained after the third current value is converted from the time domain to the frequency domain is named as a fourth current value, i.e., I ₄ (j) is a current value obtained by performing fourier transform on I ₃ (j).

The above manner of converting the third current value from the time domain to the frequency domain is merely exemplary, and is not intended to limit the present application.

Step 1102, constructing a second current sequence according to the 2N fourth current values. Namely, after the 2N fourth current values are sequenced from the small value to the large value according to the sequence j, the obtained sequence is the second current sequence.

In step 1103, fourier transforming each third voltage value in the third voltage sequence to obtain 2N sixth voltage values. For example, each third voltage value in the third voltage sequence is fourier transformed according to a second formula:

Each third voltage value in the third voltage sequence is converted from the time domain to the frequency domain in step 1103, and a voltage value obtained after the third voltage value is converted from the time domain to the frequency domain is named as a sixth voltage value, that is, V ₆ (j) is a voltage value obtained by performing fourier transform on V ₃ (j).

It should be noted that the above manner of converting the third voltage value from the time domain to the frequency domain is merely exemplary, and is not intended to limit the present application.

Step 1104, constructing a sixth voltage sequence according to the 2N sixth voltage values. Namely, after the 2N sixth voltage values are sequenced from the small value to the large value according to the sequence j, the obtained sequence is a sixth voltage sequence.

Step 1105, calculating an impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence. For example, the impedance value of the battery to be tested at the frequency to be tested may be calculated according to the second current sequence and the sixth voltage sequence in combination with a third formula, where the third formula is:

Wherein, R is the impedance value of the battery to be tested under the frequency to be tested, I ₄ (j) is the j fourth current value, V ₆ (j) is the j sixth voltage value, and I represents the imaginary part.

It should be noted that, when calculating the impedance value of the battery to be tested under the plurality of frequencies to be tested in the above manner, the time for collecting the first voltage sequence may be prolonged, and the collection number of the first voltage values may be increased, so that the collected M first voltage values may cover the period to be tested corresponding to the frequency to be tested with the smallest frequency among the plurality of frequencies to be tested, then, the second voltage sequence corresponding to each frequency to be tested is determined in the first voltage sequence, and then, the impedance value of the battery to be tested under each frequency to be tested is calculated according to the above manner. Obviously, when the impedance value of the battery to be tested under a plurality of frequencies to be tested is calculated, only the first voltage sequence is acquired once, and the first voltage sequence is not required to be acquired based on each frequency to be tested, so that the step of calculating the impedance value of the battery to be tested under the plurality of frequencies to be tested is greatly simplified, and the calculation efficiency is improved.

In summary, through the first voltage sequence of the battery to be tested, which is collected during the process of switching the battery to be tested from the first current state to the second current state and maintaining the second current state, the impedance value of the battery to be tested at the frequency to be tested can be calculated. In addition, the second voltage sequence is determined only according to the collected first voltage sequence, the third voltage sequence is constructed according to the second voltage sequence, and the impedance value of the battery to be tested under the frequency to be tested can be calculated according to the third voltage sequence, the first current and the second current, so that the steps are simple, the implementation is easy, and the efficiency of calculating the impedance value is improved. In addition, as the third voltage sequence is constructed according to the second voltage sequence, the voltage information in the period to be tested can be obtained, the impedance value is calculated according to the voltage information in the period to be tested, and the accuracy of calculating the impedance value is ensured.

Fig. 12 is a second flow chart of a battery detection method according to an embodiment of the present application, as shown in fig. 12, the method includes the following steps:

Step 1201, collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from the first current state to the second current state and maintaining the second current state, wherein the first voltage sequence comprises M first voltage values.

In the embodiment of the application, in order to ensure that a sufficient number of first voltage values can be obtained in the period to be tested corresponding to each frequency to be tested for subsequent calculation, the M first voltage values at least cover a target test period, and the target test period is the period to be tested corresponding to the frequency to be tested with the lowest frequency in the frequency band to be tested. For example, if the frequency band to be tested is 1000Hz to 1Hz, the period to be tested corresponding to 1Hz is 1s, and thus the duration of the target test period is 1s.

The duration of the second current state is greater than or equal to the target test period to ensure that the response voltage value (first voltage value) in the whole target test period can be acquired, thereby ensuring the accuracy of calculation.

Since the manner of collecting the M first voltage values, the first current state, and the second current state have already been described above, a detailed description thereof will be omitted herein.

Step 1202, determining a plurality of second voltage sequences according to the first voltage sequences, wherein each second voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, the second voltage sequences comprise N second voltage values, and the N second voltage values in the second voltage sequences are first voltage values in the first half period of the period to be tested of the frequency to be tested corresponding to the second voltage sequences in the M first voltage values.

In the embodiment of the present application, the second voltage sequence corresponding to each frequency to be tested in the frequency band to be tested is determined in the first voltage sequence according to the principle in the above step 102. The second voltage sequences corresponding to each frequency to be tested comprise N second voltage values, and the number of the voltage values (namely N values) in the second voltage sequences corresponding to each frequency to be tested is not identical.

Step 1203, constructing a plurality of third voltage sequences according to the plurality of second voltage sequences, where each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, and the third voltage sequence includes 2N third voltage values, where the 2N third voltage values are used to indicate voltage information in a period to be tested of the corresponding frequency to be tested.

In the embodiment of the application, a third voltage sequence corresponding to each frequency to be tested is respectively constructed according to the second voltage sequence corresponding to each frequency to be tested. Specifically, the principle of constructing the third voltage sequence corresponding to each frequency to be tested is the same as that of constructing the third voltage sequence in step 103, so that the description thereof is omitted here.

And 1204, calculating the impedance value of the battery to be tested under each frequency to be tested according to a plurality of third voltage sequences, the first current and the second current, wherein the first current corresponds to a first current state, and the second current corresponds to a second current state.

According to the embodiment of the application, the impedance value of the battery to be tested under each frequency to be tested is calculated according to the third voltage sequence, the first current and the second current corresponding to each frequency to be tested. Specifically, the principle of calculating the impedance value of the battery to be tested at each frequency to be tested is the same as that of calculating the impedance value in step 104, so that the description thereof will not be repeated here.

And 1205, constructing an electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested according to the impedance value of the battery to be tested in each frequency band to be tested. For example, a rectangular coordinate system may be established with the frequency as the horizontal axis and the impedance value as the vertical axis, and the impedance value of the battery to be tested at each frequency to be tested may be plotted in the rectangular coordinate system, and the plotted rectangular coordinate system may be determined as the electrochemical impedance spectrum.

It should be noted that after the electrochemical impedance spectrum of the battery to be tested is obtained, the state of the battery to be tested may be estimated by analyzing the electrochemical impedance spectrum, and a corresponding response scheme may be given according to the state of the battery to be tested. For example, if the state of the battery to be tested is that the battery to be tested has a safety risk, the safety risk warning information can be sent to the terminal device for installing the battery to be tested, so that the user can replace the battery according to the safety risk warning information, and the safety accident is avoided. For another example, if the state of the battery to be tested is that the user uses the battery to be tested in an improper use manner, the operation specification may be sent to the terminal device on which the battery to be tested is installed, so that the user uses the battery to be tested according to the operation specification, so as to improve the service life of the battery to be tested, and so on.

In summary, through the first voltage sequence of the battery to be tested collected during the process of switching the battery to be tested from the first current state to the second current state and maintaining the second current state, the impedance value of the battery to be tested at each frequency to be tested in the frequency band to be tested can be calculated. In addition, the second voltage sequence corresponding to each frequency to be tested is determined only according to the collected first voltage sequence, the third voltage sequence corresponding to each frequency to be tested is built according to the second voltage sequence corresponding to each frequency to be tested, the impedance value of the battery to be tested under each frequency to be tested can be calculated according to the third voltage sequence corresponding to each frequency to be tested, the first current and the second current, and the electrochemical impedance spectrum is built according to the impedance value of the battery to be tested under each frequency to be tested. In addition, as the third voltage sequence corresponding to each frequency to be tested is constructed according to the second voltage sequence corresponding to each frequency to be tested so as to obtain the voltage information in the period to be tested corresponding to each frequency to be tested, the impedance value under each frequency to be tested is calculated according to the voltage information in the period to be tested corresponding to each frequency to be tested, the accuracy of calculating the impedance value is ensured, and the accuracy of electrochemical impedance spectrum is ensured.

In the following, a process of constructing an electrochemical impedance spectrum of a battery to be tested in a frequency band to be tested will be described by way of example. If the first current state is a charging state, the second current state is a state of stopping charging, the frequency band to be tested is 1000 Hz-1 Hz, the sampling frequency is 4kHz, the charging voltage is v0, the first current is I1, and the second current is 0, the process of constructing the electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested comprises the following steps:

Since the lowest frequency to be tested in the frequency band to be tested is 1Hz, and the period to be tested corresponding to the lowest frequency to be tested is 1s, the duration of collecting the first voltage sequence can be set to be 1s, that is, the total duration of the battery to be tested in the second current state is 1s. Also, since the sampling frequency is 4kHz, 4000 first voltage values are included in the first voltage sequence, where the first voltage sequence is [ v1, v2, v3, v4, … …, v4000].

For the frequency to be tested of 500Hz in the frequency band to be tested, the process for calculating the impedance value of the battery to be tested at the frequency to be tested of 500Hz comprises the following steps:

The second voltage sequence is determined in the first voltage sequence, and since the frequency to be tested is 500Hz and the sampling frequency is 4kHz, and therefore N is 4, the second voltage sequence is [ v1, v2, v3, v4].

And constructing a fourth voltage sequence according to the second voltage sequence and combining the symmetry property of the equivalent circuit of the battery to be tested, wherein the constructed fourth voltage sequence is [ v0+v4-v1, v0+v4-v2, v0+v4-v3, v0+v4-v4].

And determining a fifth voltage sequence in the first voltage sequence, wherein the fifth voltage sequence is [ v5, v6, v7 and v8], correcting the fourth voltage sequence based on the fifth voltage sequence and v4, and the corrected fourth voltage sequence is [ v0+v5-v1, v0+v6-v2, v0+v7-v3 and v0+v8-v4].

And constructing a third voltage sequence according to the second voltage sequence and the corrected fourth voltage sequence. The third voltage sequence is [ v1, v2, v3, v4, v0+v5-v1, v0+v6-v2, v0+v7-v3, v0+v8-v4]. A first current sequence is constructed and, the first current sequence is [0, 0 ] 0, I1].

According toThe first current sequence is converted into a second current sequence.

According toThe third voltage sequence is converted into a sixth voltage sequence.

According toAnd calculating the impedance value of the battery to be tested at 500Hz by combining the second current sequence and the sixth voltage sequence.

For the frequency to be tested of 1Hz in the frequency band to be tested, the process for calculating the impedance value of the battery to be tested at the frequency to be tested of 500Hz comprises the following steps:

the second voltage sequence is determined in the first voltage sequence, and since the frequency to be tested is 1Hz and the sampling frequency is 4kHz, and therefore N is 2000, the second voltage sequence is [ v1, v2, v3, v4, … …, v2000].

And constructing a fourth voltage sequence according to the second voltage sequence and combining the symmetry property of the equivalent circuit of the battery to be tested, wherein the constructed fourth voltage sequence is [ v0+v2000-v1, v0+v2000-v2, v0+v2000-v3, v0+v2000-v4, … …, v0+v2000-v2000].

And determining a fifth voltage sequence in the first voltage sequence, wherein the fifth voltage sequence is [ v2001, v2002, v2003, … …, v4000], correcting the fourth voltage sequence based on the fifth voltage sequence and v2000, and the corrected fourth voltage sequence is [ v0+v2001-v1, v0+v2002-v2, v0+v2003-v3, v0+v2004-v4, … …, v0+v4000-v2000].

And constructing a third voltage sequence according to the second voltage sequence and the corrected fourth voltage sequence. The third voltage sequence is [ v1, v2, v3, v4, … …, v2000, v0+v2001-v1, v0+v2002-v2, v0+v2003-v3, v0+v2004-v4, … …, v0+v4000-v2000]. And constructing a first current sequence, wherein the constructed first current sequence is [0, …,0, I1, …, I1], and the number of 0 and I1 is 2000.

According toAnd calculating the impedance value of the battery to be tested at 1Hz by combining the second current sequence and the sixth voltage sequence.

And similarly, calculating the impedance value of the battery to be tested at other frequencies to be tested in the frequency band to be tested.

And constructing an electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested according to the impedance value of the battery to be tested in each frequency band to be tested in the frequency band to be tested.

Fig. 13 is a schematic structural diagram of an embodiment of a battery detection device according to the present application, where the battery detection device may be a chip system or an integrated circuit, and the chip system and the integrated circuit may be located in a terminal device to detect a battery in the terminal device. Specifically, as shown in fig. 13, the apparatus 1300 may include: a first acquisition module 1301, a first determination module 1302, a first construction module 1303, a first calculation module 1304, wherein:

The first collecting module 1301 is configured to collect a first voltage sequence of the battery to be tested in a process of switching the battery to be tested from a first current state to a second current state and maintaining the second current state, where the first voltage sequence includes M first voltage values; a first determining module 1302, configured to determine a second voltage sequence according to the first voltage sequence, where the second voltage sequence includes N second voltage values, where the N second voltage values are first voltage values located in a first half period of a period to be tested corresponding to a frequency to be tested in the M first voltage values; a first construction module 1303, configured to construct a third voltage sequence according to the second voltage sequence, where the third voltage sequence includes 2N third voltage values, and the 2N third voltage values are used to indicate voltage information of the period to be tested; a first calculating module 1304, configured to calculate an impedance value of the battery to be tested at the frequency to be tested according to the third voltage sequence, a first current and a second current, where the first current corresponds to the first current state and the second current corresponds to the second current state.

In one possible implementation, the first construction module 1303 includes: a determining unit configured to determine, as a target voltage value, a sum of a voltage value corresponding to the first current state and an nth second voltage value in the second voltage sequence; a first construction unit configured to construct an n+n second voltage value according to a difference between the target voltage value and an N-th second voltage value in the second voltage sequence, where the n+n-th second voltage value is located in a second half period of the period to be tested, and at a start time of the second half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and maintains the first current state, where 1N is equal to or less than N; a second construction unit for constructing a fourth voltage sequence according to the constructed (n+1) th to (2N) th second voltage values; the merging unit is configured to merge the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence, where the 2N third voltage values include a 1 st second voltage value to an nth second voltage value in the second voltage sequence and a (n+1) th second voltage value to a2 nd second voltage value in the fourth voltage sequence.

In one possible implementation, the merging unit includes: a determining subunit, configured to determine a fifth voltage sequence according to the first voltage sequence, where the fifth voltage sequence includes S fifth voltage values, where the S fifth voltage values are first voltage values located in a second half period of the period to be tested in the M first voltage values; a correction subunit, configured to correct the fourth voltage sequence according to the fifth voltage sequence; and the merging subunit is used for merging the second voltage sequence and the corrected fourth voltage sequence to obtain the third voltage sequence.

In one possible implementation, the first computing module 1304 includes: a third construction unit, configured to construct a first current sequence according to the first current and the second current, where the first current sequence includes 2N third current values, where a third current value of the 2N third current values corresponds to a third voltage value of the third voltage sequence one to one; and the calculating unit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

In one possible implementation, the computing unit includes: the first transformation subunit is used for carrying out Fourier transformation on each third current value in the first current sequence to obtain 2N fourth current values; a first construction subunit, configured to construct a second current sequence according to the 2N fourth current values; a second transformation subunit, configured to perform fourier transformation on each third voltage value in the third voltage sequence, so as to obtain 2N sixth voltage values; a second construction subunit, configured to construct a sixth voltage sequence according to the 2N sixth voltage values; and the calculating subunit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence.

In one possible implementation manner, the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or alternatively

The first current state is a state that the battery to be tested discharges with the first current, and the second current state is a state that the battery to be tested stops discharging.

The above device of the present application may be used to implement the technical solution of the method embodiment shown in fig. 1, and its implementation principle and technical effects are similar, and will not be described herein again.

Fig. 14 is a schematic diagram of a second embodiment of a battery detection device according to the present application, where the battery detection device may be a chip system or an integrated circuit, and the chip system and the integrated circuit may be located in a terminal device to detect a battery in the terminal device. Specifically, as shown in fig. 14, the apparatus 1400 may include: a second acquisition module 1401, a second determination module 1402, a second construction module 1403, a second calculation module 1404, a third construction module 1405, wherein:

A second acquisition module 1401, configured to acquire a first voltage sequence of a battery to be tested in a process of switching the battery to be tested from a first current state to a second current state and maintaining the second current state, where the first voltage sequence includes M first voltage values; a second determining module 1402, configured to determine a plurality of second voltage sequences according to the first voltage sequences, where each of the second voltage sequences corresponds to one frequency to be tested in a frequency band to be tested, the second voltage sequences include N second voltage values, where the N second voltage values in the second voltage sequences are first voltage values, of the M first voltage values, located in a first half period of a cycle to be tested of the frequency to be tested corresponding to the second voltage sequences; a second construction module 1403, configured to construct a plurality of third voltage sequences according to the plurality of second voltage sequences, where each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, and the third voltage sequence includes 2N third voltage values, where the 2N third voltage values are used to indicate voltage information in a period to be tested of the corresponding frequency to be tested; a second calculating module 1404, configured to calculate an impedance value of the battery to be tested at each of the frequencies to be tested according to the plurality of third voltage sequences, a first current and a second current, where the first current corresponds to the first current state and the second current corresponds to the second current state; and a third construction module 1405, configured to construct an electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested according to the impedance value of the battery to be tested in each frequency band to be tested.

In a possible implementation manner, the second construction module 1403 is specifically configured to construct the plurality of third voltage sequences according to the plurality of second voltage sequences and using the corresponding apparatus in fig. 13.

In a possible implementation manner, the second calculating module 1404 is specifically configured to calculate, according to each of the third voltage sequences, the first current, and the second current, in combination with the corresponding device in fig. 13, an impedance value of the battery to be tested at the frequency to be tested corresponding to each of the third voltage sequences, respectively.

The above device of the present application may be used to implement the technical solution of the method embodiment shown in fig. 12, and its implementation principle and technical effects are similar, and will not be described herein again.

The application also provides a terminal device comprising the apparatus of any one of fig. 13 or the apparatus of any one of fig. 14, so as to detect a battery in the terminal device. For example, the battery in the terminal device may be detected periodically during use of the terminal device. For example, the battery may be tested in the manner described above at 0 to 3 points per day.

The present application also provides a computer readable storage medium having stored thereon a computer program which, when executed by a computer, causes the computer to perform the steps and/or processes of any of the method embodiments described above.

The application also provides a computer program product comprising computer program code to, when run on a computer, cause the computer to perform the steps and/or processes of any of the method embodiments described above.

The application also provides a chip comprising a processor. The memory for storing the computer program is provided separately from the chip and the processor is adapted to execute the computer program stored in the memory for performing the steps and/or processes of any of the method embodiments described above.

Further, the chip may also include a memory and a communication interface. The communication interface may be an input/output interface, a pin or an input/output circuit, etc.

In implementation, the steps of the above method embodiments may be implemented by integrated logic circuits of hardware in a processor or instructions in software form. The processor may be a general purpose processor, a Digital Signal Processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (field programmable GATE ARRAY, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in the embodiment of the application can be directly embodied in a hardware encoding processor for execution or in a combination of hardware and software modules in the encoding processor for execution. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in a memory, and the processor reads the information in the memory and, in combination with its hardware, performs the steps of the above method.

The memory mentioned in the above embodiments may be volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an erasable programmable ROM (erasable PROM), an electrically erasable programmable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM) which acts as external cache memory. By way of example, and not limitation, many forms of RAM are available, such as static random access memory (STATIC RAM, SRAM), dynamic random access memory (DYNAMIC RAM, DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (double DATA RATE SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (ENHANCED SDRAM, ESDRAM), synchronous link dynamic random access memory (SYNCHLINK DRAM, SLDRAM), and direct memory bus random access memory (direct rambus RAM, DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (personal computer, server, network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery detection method, characterized by comprising:

collecting a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values;

Determining a second voltage sequence according to the first voltage sequence, wherein the second voltage sequence comprises N second voltage values, and the N second voltage values are first voltage values in the first half period of a period to be tested corresponding to the frequency to be tested, which is located in the M first voltage values;

Constructing a third voltage sequence according to the second voltage sequence based on the symmetry of the equivalent circuit of the battery to be tested, wherein the third voltage sequence comprises 2N third voltage values, and the 2N third voltage values are used for indicating the voltage information of the period to be tested;

And calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, a first current and a second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state.

2. The method of claim 1, wherein said constructing a third voltage sequence from said second voltage sequence comprises:

Determining the sum of the voltage value corresponding to the first current state and the Nth second voltage value in the second voltage sequence as a target voltage value;

Constructing an n+n second voltage value according to the difference between the target voltage value and an N second voltage value in the second voltage sequence, wherein the n+n second voltage value is positioned in the latter half period of the period to be tested, and at the starting moment of the latter half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and keeps the first current state, and N is more than or equal to 1 and less than or equal to N;

Constructing a fourth voltage sequence according to the constructed (N+1th) to (2N) th second voltage values;

And combining the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence, wherein the 2N third voltage values comprise 1 st to N second voltage values in the second voltage sequence and (n+1th to 2N second voltage values in the fourth voltage sequence.

3. The method of claim 2, wherein combining the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence comprises:

Determining a fifth voltage sequence according to the first voltage sequence, wherein the fifth voltage sequence comprises S fifth voltage values, and the S fifth voltage values are first voltage values located in the later half period of the period to be tested in the M first voltage values;

correcting the fourth voltage sequence according to the fifth voltage sequence;

and combining the second voltage sequence and the corrected fourth voltage sequence to obtain the third voltage sequence.

4. A method according to claim 3, wherein said modifying said fourth voltage sequence according to said fifth voltage sequence comprises:

Generating a voltage time function according to S fifth voltage values in the fifth voltage sequence and the acquisition time of each fifth voltage value;

Inputting the correction time of the (n+n) th second voltage value in the fourth voltage sequence into the voltage time function to obtain the correction voltage of the (n+n) th second voltage value, wherein the correction time of the (n+n) th second voltage value is the corresponding time of the (n+n) th second voltage value in the later half period of the period to be tested;

Correcting the n+n second voltage value according to the difference value between the correction voltage of the n+n second voltage value and the N second voltage value;

and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

5. A method according to claim 3, wherein the M first voltage values are acquired at a sampling frequency; the S fifth voltage values are from the (n+1) th first voltage value to the (2N) th first voltage value in the first voltage sequence;

said modifying said fourth voltage sequence according to said fifth voltage sequence comprises:

Determining the (n+n) th first voltage value as a correction voltage of the (n+n) th second voltage value;

Correcting the n+n second voltage values according to the difference value between the correction voltage of the n+n second voltage values and the N second voltage values;

6. The method according to any one of claims 1 to 5, wherein calculating the impedance value of the battery to be tested at the frequency to be tested from the third voltage sequence, the first current and the second current comprises:

constructing a first current sequence according to the first current and the second current, wherein the first current sequence comprises 2N third current values, and the third current values in the 2N third current values are in one-to-one correspondence with the third voltage values in the third voltage sequence;

and calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

7. The method of claim 6, wherein calculating an impedance value of the battery under test at the frequency under test from the third voltage sequence and the first current sequence comprises:

Performing Fourier transform on each third current value in the first current sequence to obtain 2N fourth current values;

constructing a second current sequence according to the 2N fourth current values;

performing Fourier transform on each third voltage value in the third voltage sequence to obtain 2N sixth voltage values;

Constructing a sixth voltage sequence according to the 2N sixth voltage values;

and calculating the impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence.

8. The method of claim 7, wherein fourier transforming each third current value in the first sequence of currents comprises:

performing Fourier transform on each third current value in the first current sequence according to a first formula, wherein the first formula is as follows:

Wherein I ₄ ^(j) is the j fourth current value, I ₃ ^(j) is the j third current value, I represents the imaginary part, and 1.ltoreq.j.ltoreq.2N.

9. The method of claim 7, wherein fourier transforming each third voltage value in the third voltage sequence comprises:

performing fourier transform on each third voltage value in the third voltage sequence according to a second formula, wherein the second formula is:

Wherein V ₆ ^(j) is the jth sixth voltage value, V ₃ ^(j) is the jth third voltage value, i represents the imaginary part, and 1.ltoreq.j.ltoreq.2N.

10. The method of claim 7, wherein calculating an impedance value of the battery under test at the frequency under test from the second current sequence and the sixth voltage sequence comprises:

calculating an impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence and in combination with a third formula, wherein the third formula is as follows:

Wherein, R is the impedance value of the battery to be tested at the frequency to be tested, I ₄ ^(j) is the j fourth current value, V ₆ ^(j) is the j sixth voltage value, and I represents the imaginary part.

11. The method according to any one of claims 1 to 10, wherein the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or alternatively

12. A battery detection method, characterized by comprising:

determining a plurality of second voltage sequences according to the first voltage sequences, wherein each second voltage sequence corresponds to one frequency to be tested in a frequency segment to be tested, the second voltage sequences comprise N second voltage values, and the N second voltage values in the second voltage sequences are first voltage values in the first half period of a period to be tested of the frequency to be tested corresponding to the second voltage sequences in the M first voltage values;

constructing a plurality of third voltage sequences according to the second voltage sequences based on symmetry of an equivalent circuit of the battery to be tested, wherein each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, the third voltage sequences comprise 2N third voltage values, and the 2N third voltage values are used for indicating voltage information in a period to be tested of the corresponding frequency to be tested;

calculating impedance values of the battery to be tested under each frequency to be tested according to the third voltage sequences, a first current and a second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state;

And constructing an electrochemical impedance spectrum of the battery to be tested in the frequency band to be tested according to the impedance value of the battery to be tested in each frequency band to be tested.

13. The method of claim 12, wherein constructing a plurality of third voltage sequences from the plurality of second voltage sequences comprises:

Constructing the plurality of third voltage sequences from the plurality of second voltage sequences and using the method of any one of claims 2-5.

14. The method of claim 12, wherein calculating the impedance value of the battery under test at each of the frequencies under test from the plurality of third voltage sequences, the first current, and the second current comprises:

calculating the impedance value of the battery to be tested at the frequency to be tested corresponding to each third voltage sequence according to each third voltage sequence, the first current and the second current and combining the method of any one of claims 6-10.

15. The method according to any one of claims 12 to 14, wherein the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or alternatively

16. A battery detection device, characterized by comprising:

the first acquisition module is used for acquiring a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values;

the first determining module is used for determining a second voltage sequence according to the first voltage sequence, wherein the second voltage sequence comprises N second voltage values, and the N second voltage values are first voltage values in the first half period of a period to be tested, which corresponds to the frequency to be tested, of the M first voltage values;

The first construction module is used for constructing a third voltage sequence according to the second voltage sequence based on the symmetry of the equivalent circuit of the battery to be tested, wherein the third voltage sequence comprises 2N third voltage values, and the 2N third voltage values are used for indicating the voltage information of the period to be tested;

and the first calculation module is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence, the first current and the second current, wherein the first current corresponds to the first current state, and the second current corresponds to the second current state.

17. The apparatus of claim 16, wherein the first build module comprises:

A determining unit configured to determine, as a target voltage value, a sum of a voltage value corresponding to the first current state and an nth second voltage value in the second voltage sequence;

A first construction unit configured to construct an n+n second voltage value according to a difference between the target voltage value and an N-th second voltage value in the second voltage sequence, where the n+n-th second voltage value is located in a second half period of the period to be tested, and at a start time of the second half period of the period to be tested, the battery to be tested is switched from the second current state to the first current state and maintains the first current state, where 1N is equal to or less than N;

A second construction unit for constructing a fourth voltage sequence according to the constructed (n+1) th to (2N) th second voltage values;

The merging unit is configured to merge the second voltage sequence and the fourth voltage sequence to obtain the third voltage sequence, where the 2N third voltage values include a1 st second voltage value to an nth second voltage value in the second voltage sequence and a (n+1) th second voltage value to a2 nd second voltage value in the fourth voltage sequence.

18. The apparatus of claim 17, wherein the merging unit comprises:

A determining subunit, configured to determine a fifth voltage sequence according to the first voltage sequence, where the fifth voltage sequence includes S fifth voltage values, where the S fifth voltage values are first voltage values located in a second half period of the period to be tested in the M first voltage values;

A correction subunit, configured to correct the fourth voltage sequence according to the fifth voltage sequence;

and the merging subunit is used for merging the second voltage sequence and the corrected fourth voltage sequence to obtain the third voltage sequence.

19. The apparatus of claim 18, wherein the correction subunit is configured to generate a voltage-time function according to S fifth voltage values in the fifth voltage sequence and the acquisition time of each of the fifth voltage values; inputting the correction time of the (n+n) th second voltage value in the fourth voltage sequence into the voltage time function to obtain the correction voltage of the (n+n) th second voltage value, wherein the correction time of the (n+n) th second voltage value is the corresponding time of the (n+n) th second voltage value in the later half period of the period to be tested; correcting the n+n second voltage value according to the difference value between the correction voltage of the n+n second voltage value and the N second voltage value; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

20. The apparatus of claim 18, wherein the M first voltage values are collected at a sampling frequency; the S fifth voltage values are from the (n+1) th first voltage value to the (2N) th first voltage value in the first voltage sequence;

the correction subunit is specifically configured to determine the n+nth first voltage value as a correction voltage of the n+nth second voltage value; correcting the n+n second voltage values according to the difference value between the correction voltage of the n+n second voltage values and the N second voltage values; and constructing the fourth voltage sequence after correction according to the (N+1) th second voltage value to the (2N) th second voltage value after correction.

21. The apparatus of any one of claims 16 to 20, wherein the first computing module comprises:

A third construction unit, configured to construct a first current sequence according to the first current and the second current, where the first current sequence includes 2N third current values, where a third current value of the 2N third current values corresponds to a third voltage value of the third voltage sequence one to one;

And the calculating unit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the third voltage sequence and the first current sequence.

22. The apparatus of claim 21, wherein the computing unit comprises:

The first transformation subunit is used for carrying out Fourier transformation on each third current value in the first current sequence to obtain 2N fourth current values;

a first construction subunit, configured to construct a second current sequence according to the 2N fourth current values;

A second transformation subunit, configured to perform fourier transformation on each third voltage value in the third voltage sequence, so as to obtain 2N sixth voltage values;

A second construction subunit, configured to construct a sixth voltage sequence according to the 2N sixth voltage values;

and the calculating subunit is used for calculating the impedance value of the battery to be tested under the frequency to be tested according to the second current sequence and the sixth voltage sequence.

23. The apparatus of claim 22, wherein the first transformation subunit is configured to fourier transform each third current value in the first current sequence according to a first formula, where the first formula is:

24. The apparatus of claim 22, wherein the second transformation subunit is configured to fourier transform each third voltage value in the third voltage sequence according to a second formula, where the second formula is:

25. The apparatus according to claim 22, wherein the calculating subunit is configured to calculate, according to the second current sequence and the sixth voltage sequence, in combination with a third formula, an impedance value of the battery to be tested at the frequency to be tested, wherein the third formula is:

26. The apparatus according to any one of claims 16 to 25, wherein the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or alternatively

27. A battery detection device, characterized by comprising:

The second acquisition module is used for acquiring a first voltage sequence of the battery to be tested in the process of switching the battery to be tested from a first current state to a second current state and keeping the second current state, wherein the first voltage sequence comprises M first voltage values;

A second determining module, configured to determine a plurality of second voltage sequences according to the first voltage sequences, where each second voltage sequence corresponds to one frequency to be tested in a frequency segment to be tested, where the second voltage sequences include N second voltage values, where the N second voltage values in the second voltage sequences are first voltage values, located in a first half period of a cycle to be tested of the frequency to be tested corresponding to the second voltage sequences, in the M first voltage values;

The second construction module is used for constructing a plurality of third voltage sequences according to the second voltage sequences based on symmetry of an equivalent circuit of the battery to be tested, wherein each third voltage sequence corresponds to one frequency to be tested in the frequency band to be tested, the third voltage sequences comprise 2N third voltage values, and the 2N third voltage values are used for indicating voltage information in a period to be tested of the corresponding frequency to be tested;

A second calculation module, configured to calculate an impedance value of the battery to be tested at each frequency to be tested according to the plurality of third voltage sequences, a first current and a second current, where the first current corresponds to the first current state, and the second current corresponds to the second current state;

And the third construction module is used for constructing an electrochemical impedance spectrum of the battery to be tested in the frequency section to be tested according to the impedance value of the battery to be tested in each frequency section to be tested.

28. The apparatus according to claim 27, wherein the second construction module is specifically configured to construct the plurality of third voltage sequences from the plurality of second voltage sequences and using the apparatus according to any one of claims 17 to 20.

29. The apparatus according to claim 27, wherein the second calculating module is specifically configured to calculate, according to each of the third voltage sequences, the first current and the second current, and in combination with the apparatus according to any one of claims 21 to 25, an impedance value of the battery to be tested at a frequency to be tested corresponding to each of the third voltage sequences, respectively.

30. The apparatus according to any one of claims 27 to 29, wherein the first current state is a state in which the battery to be tested is charged by the first current, and the second current state is a state in which charging of the battery to be tested is stopped; or alternatively

31. A computer readable storage medium comprising a computer program which, when executed on a computer, causes the computer to perform the method of any one of claims 1 to 11 or the method of any one of claims 12 to 15.

32. A computer program product, characterized in that the computer program product comprises a computer program which, when executed by a computer, causes the computer to perform the method of any one of claims 1 to 11 or the method of any one of claims 12 to 15.

33. A chip comprising a processor and a memory for storing a computer program, the processor being for invoking and running the computer program stored in the memory to perform the method of any of claims 1-11 or the method of any of claims 12-15.

34. A terminal device comprising the apparatus of any one of claims 16 to 26 or the apparatus of any one of claims 27 to 30.