Method, apparatus and machine-readable program product for determining state of charge of battery

Abstract

The present disclosure provides a method, device and machine readable program product for determining a state of charge of a battery, the method comprising: obtaining a corrected FCC based on a battery full charge capacity FCC correction parameter and an FCC initial estimated value corresponding to an initial battery parameter of the battery; the current state of charge (SOC) of the battery is determined at least partially according to the corrected FCC, the FCC initial estimation value is obtained by inquiring an FCC database at least storing battery parameters and the FCC which are associated with each other according to the initial battery parameters, the FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, and the current SOC of the battery is determined at least partially according to the corrected FCC. The estimated SOC is obtained by querying an SOC database storing battery parameters and SOC values associated with each other using assembled battery parameters including initial battery parameters.

Description

Technical Field

[0001] The present disclosure relates to the field of new energy technology, and in particular to battery management technology. More particularly, the present disclosure relates to a method, device, and machine-readable program product for determining the state of charge (SOC) of a battery. Background Art

[0002] With the widespread popularity of various electronic products, various types of batteries are widely used in the industry. Among them, lithium batteries are particularly valued in various fields for their high specific energy, light weight, low self-charging rate, and good cycle life. Due to the need to be applicable to a variety of application scenarios, batteries often require a variety of different charging strategies.

[0003] For different charging strategies, how to intelligently and accurately and reliably judge the charge state of batteries, especially lithium batteries, during the charging process has important practical application significance for improving the battery charging process, improving the use and utilization efficiency of batteries, improving user convenience and further promoting the development of the battery market.

[0004] The methods for estimating the state of charge (SOC) of a battery in the prior art mainly include the coulomb integration method, the open circuit voltage method, the coulomb integration and open circuit voltage combination method, the dynamic voltage method, and the like.

[0005] The Coulomb integration method dynamically estimates the battery's SOC by accumulating the change in charge during the charging process. This method is simple to calculate, easy to implement, and has low requirements for the microprocessor. However, the Coulomb integration method requires obtaining the initial SOC value of the battery in advance, and is prone to accumulated errors. When the operating conditions of the lithium battery change, the total rechargeable capacity of the battery changes, especially at low temperatures (temperatures below 0°C), the total rechargeable capacity of the battery is greatly reduced, and coupled with the accumulated errors of the Coulomb integration, it is difficult to accurately estimate the remaining capacity.

[0006] The open circuit voltage method indirectly estimates the SOC by measuring the relationship between the open circuit voltage (OCV) of the battery and the lithium ion concentration inside the battery. The target battery needs to be left to stand for more than 1 hour, and at different temperatures or life periods, the SOC estimated by the open circuit voltage method may be significantly different from the actual SOC.

[0007] The method combining Coulomb integration with open circuit voltage can eliminate the cumulative error problem of Coulomb integration, but it still cannot solve the problem of changes in the total rechargeable capacity of the battery due to changes in operating conditions such as changes in ambient temperature.

[0008] The dynamic voltage method has a simple structure and requires very low microprocessor computing power. However, due to the battery voltage acquisition error and the nonlinear relationship between voltage and SOC, its accuracy is poor. Therefore, it can only be used in mobile devices that require low cost and low precision.

[0009] In view of the importance of SOC estimation during battery charging, the present invention provides a method, device and machine-readable program product for determining the state of charge of a battery. The method can accurately estimate the SOC of the battery and improve the user experience.

[0010] The present invention also provides an apparatus for determining the state of charge of a battery and a machine-readable program product. Summary of the invention

[0011] A brief overview of the disclosure is provided below in order to provide a basic understanding of certain aspects of the disclosure. It should be understood that this overview is not an exhaustive overview of the disclosure. It is not intended to identify key or important parts of the disclosure, nor is it intended to limit the scope of the disclosure. Its purpose is simply to provide certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0012] According to one aspect of the present disclosure, a method for determining the state of charge of a battery is provided, the method comprising: obtaining a corrected FCC based on a battery full charge capacity FCC correction parameter and an FCC initial estimate corresponding to an initial battery parameter of the battery; determining a current state of charge SOC of the battery at least in part based on the corrected FCC, wherein the FCC initial estimate is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other based on the initial battery parameters, and wherein the FCC correction parameter is obtained based on a deviation between an estimated SOC and an actual SOC of the battery, wherein the estimated SOC is obtained by querying an SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameters.

[0013] According to one aspect of the present disclosure, there is provided a device for determining the state of charge of a battery, comprising: a processing circuit configured to perform the following steps: obtaining a corrected FCC based on a battery full charge capacity FCC correction parameter and an FCC initial estimate corresponding to an initial battery parameter of the battery; determining the current state of charge SOC of the battery at least in part based on the corrected FCC, wherein the FCC initial estimate is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other based on the initial battery parameters, and wherein the FCC correction parameter is obtained based on a deviation between an estimated SOC and an actual SOC of the battery, wherein the estimated SOC is obtained by querying an SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameters.

[0014] According to other aspects of the present disclosure, a machine-readable code and a machine-readable program product for implementing the above method are also provided. In addition, a non-transitory computer-readable storage medium storing executable instructions is also provided, and when the executable instructions are executed by a processor, the processor executes the above method or each function of the above device.

[0015] According to the method, device and machine-readable program product of the embodiments of the present disclosure, in the process of calculating the SOC of the battery, the FCC initial estimation value in the FCC database storing the battery parameters and FCC associated with each other and the FCC correction parameter obtained based on the deviation between the estimated SOC and the actual SOC of the battery are used. In this way, the deviation between the historical SOC estimation data and the real SOC data can be used to appropriately correct the FCC, thereby improving the accuracy of determining the SOC.

[0016] By using the embodiments of the present disclosure, the state of charge of the battery can be accurately determined, thereby improving the user experience.

[0017] These and other advantages of the present disclosure will become more apparent through the following detailed description of preferred embodiments of the present disclosure in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to further illustrate the above and other advantages and features of the present disclosure, the specific embodiments of the present disclosure are further described in detail below in conjunction with the accompanying drawings. The drawings together with the following detailed description are included in this specification and form a part of this specification. Elements with the same function and structure are represented by the same reference numerals. It should be understood that these drawings only describe typical examples of the present disclosure and should not be regarded as limiting the scope of the present disclosure. In the drawings:

[0019] Figure 1 Schematically shows a flow chart of a method for determining a state of charge of a battery according to one embodiment;

[0020] Figure 2A A schematic diagram schematically illustrates a method of querying an FCC database to obtain an initial FCC estimate according to one embodiment;

[0021] Figure 2B A schematic diagram schematically shows a method of querying an SOC database to obtain FCC correction parameters according to one embodiment;

[0022] Figure 3 Schematically illustrates a schematic diagram of determining the current SOC according to a revised FCC according to one embodiment;

[0023] Figure 4Schematically shows a flow chart of a method for determining a state of charge of a battery according to one embodiment;

[0024] Figure 5 Schematically illustrates a flow chart of updating an FCC database according to one embodiment;

[0025] Figure 6 A schematic diagram of the structure of a device for determining the state of charge of a battery according to one embodiment is schematically shown;

[0026] Fig. 7A The test results and deviations of determining SOC under low current conditions according to one embodiment of the present invention are shown;

[0027] Figure 7B The experimental results and deviations of determining SOC under high current conditions according to one embodiment of the present invention are shown;

[0028] Figure 7C The test results and deviations of determining SOC in a fast charging situation according to one embodiment of the present invention are shown;

[0029] Figure 8 A comparison result diagram of the SOC value determined according to one embodiment of the present invention and the actual SOC of a lithium battery in 19 charge and discharge cycles is shown.

[0030] The blocks indicated by dashed lines in the above figures correspond to optional steps or optional components. DETAILED DESCRIPTION

[0031] Exemplary implementations of the present disclosure are described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the present disclosure.

[0032] It is also necessary to explain here that, in order to avoid obscuring the contents of the present disclosure due to unnecessary details, only the device structures and / or processing steps closely related to the solutions according to the contents of the present disclosure are shown in the accompanying drawings, while other details that are not closely related to the contents of the present disclosure are omitted.

[0033] <First Embodiment>

[0034] The present embodiment provides a method for determining the state of charge of a battery.

[0035] Figure 1 FIG. 4 shows a flow chart of a method for determining the state of charge of a battery according to a first embodiment. Figure 1 As shown, method 10 includes: step S101, obtaining a corrected FCC based on a battery full charge capacity FCC correction parameter and an FCC initial estimate corresponding to an initial battery parameter of the battery; and step S103, determining a current state of charge SOC of the battery at least partially based on the corrected FCC.

[0036] Here, the FCC initial estimation value may be obtained by querying an FCC database storing at least battery parameters and FCC associated with each other according to the initial battery parameters. For example, the initial battery parameters may be battery parameters at the initial stage of battery charging.

[0037] In addition, the FCC correction parameter may be obtained based on a deviation between an estimated SOC of the battery and an actual SOC, wherein the estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including initial battery parameters.

[0038] Preferably, the initial battery parameters may include current and temperature.

[0039] As an example, in step S101, the corrected FCC can be obtained based on the following formula (1):

[0040] Corrected FCC = FCC initial estimate * (1 + FCC comp )……Formula (1)

[0041] The initial FCC estimate in the above formula is obtained using the FCC database. comp is an FCC correction parameter, which is the capacity deviation caused by the incomplete discharge or over-discharge of the lithium battery due to factors such as temperature change and battery aging. In one embodiment of the present invention, it is obtained based on the deviation between the estimated SOC and the actual SOC of the battery according to the following formula:

[0042] FCC comp =(SOC 实际 -SOC 估计 )*FCC initial estimate...Formula (2)

[0043] The estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including initial battery parameters. The actual SOC can be obtained by measuring, for example, a cycler.

[0044] As an example, in step S103, the current state of charge SOC of the battery can be obtained based on the following formula (2):

[0045] Current SOC = RCA / revised FCC ... Formula (3)

[0046] Wherein, RCA is the current power of the battery, that is, the current remaining capacity, which can be obtained, for example, based on the previous power of the battery and the power change of the battery (such as the charging power), and wherein the corrected FCC comes from the calculation result of the above formula (1).

[0047] Note that, although not shown in the figure, in or before steps S101 and S103, it is preferred to also include a process of obtaining required battery parameters (current battery parameters and / or battery parameters in the initial charging stage). Battery parameters may include, but are not limited to, battery voltage (voltage across the battery), battery current (current flowing through the battery), battery temperature, battery state, SOC, coulomb charge, cut-off current, charge limit voltage, rated capacity and / or health value, etc.

[0048] In this way, the SOC can be calculated using the FCC corrected by the deviation between the SOC estimation data and the SOC real data, thereby improving the accuracy of determining the SOC.

[0049] Next, details of the FCC database and the preferred processing performed using the FCC database will be further described.

[0050] In a method for determining the state of charge of a battery in one embodiment, the FCC database may be two-dimensional, but is not limited thereto. For example, the FCC database may include a current dimension and a temperature dimension, and the FCC data of each temperature point and current point at least includes an initial estimated value of the FCC.

[0051] As an example, the FCC database may describe the FCC estimated value under the conditions of a specific temperature T and a specific current I. The FCC database includes two parameters or dimensions of the data space, namely temperature and current, and the data in the corresponding data space includes at least the FCC estimated value during the charging process under the corresponding scenario. Optionally, the data in the corresponding data space may also include the initial capacity of the battery, which at the initial moment is the product of the previously measured battery health value and the rated capacity of the battery. The initial moment here can be considered as the time when the SOC at the start of charging and the SOC at the end of charging of the charging data are both 0 or the data in the charging process has not been updated.

[0052] like Figure 2AAs shown, step S101 of querying the FCC database according to the initial battery parameters includes: step S1011, using the initial battery parameters to query the relevant data items in the FCC database; and step S1012, based on the difference between the battery parameters in the relevant data items and the initial battery parameters, obtaining the FCC initial estimation value according to the FCC in the relevant data items.

[0053] As an example, in step S1011 , an initial FCC estimation value is obtained by querying relevant data items in an FCC database using the battery current and temperature (curr, temp) at the initial stage of charging.

[0054] The query of the FCC database can be implemented, for example, by using a two-dimensional linear interpolation algorithm. The example execution flow of the two-dimensional linear interpolation algorithm is as follows:

[0055] Step I-1: Use the battery parameters (curr, temp) to find the current point curr closest to the current curr in the FCC database 0 and curr 1 , the temperature point temp closest to temperature T 0 and temp 1 In particular, when the current curr is greater than or equal to the maximum value of 10A among the current points or less than the minimum value of 2A among the current points, curr 0 and curr 1 For the same value of 10A or 2A, when the temperature temp is greater than or equal to the maximum value of 65℃ or less than the minimum value of 5℃, temp 0 and temp 1 The same value is 65° C. or 5° C. Those skilled in the art clearly know that the above specific temperature values ​​and current values ​​are used only for the convenience of description, and those skilled in the art can set the same or different specific values ​​according to actual needs.

[0056] Step I-2:

[0057] (1) Search the corresponding current curr in the FCC database 0 , temperature point temp 0 FCC estimated value fcc_est curr0,temp0 , corresponding to the current curr 0 , temperature point temp 1 FCC estimated value fcc_est cuur0,temp1 , corresponding to the current curr 1 , temperature point temp 0 FCC estimated value fcc_est curr1,temp0 , corresponding to the current curr 1, temperature point temp 1 FCC estimated value fcc_est curr1,temp1 ;

[0058] (2) Calculate the temperature weight and current weight of each data point, where the corresponding temperature 0 and temp 1 The temperature weights are

[0059]

[0060] temp_weight 1 =1000-temp_weight 0 ;

[0061] Corresponding to curr 0 and curr 1 The current weights are

[0062]

[0063] curr_weight 1 =1000-curr_weight 0

[0064] Among them, 1000 in the formula is a coefficient used to facilitate the calculation of the weight. Those skilled in the art clearly know that the coefficient can be freely omitted or set according to specific application requirements, and it only needs to be processed accordingly with other steps in the same implementation.

[0065] Step I-3: Substitute the temperature weight, current weight and FCC estimate at the corresponding point obtained in step I-1 and step I-2 into the following formula to obtain the initial FCC estimate corresponding to (curr, temp).

[0066]

[0067] Among them, the coefficient It is a coefficient cited for the convenience of calculation, which corresponds to the coefficient 1000 in step I-2, so it can be omitted or specifically set.

[0068] Preferably, the battery parameter curr used to query the FCC database can select the maximum current curr during the charging process. max , temp can select the average temperature during charging avg , but not limited to this.

[0069] Next, details of the SOC database and preferred processing using the SOC database will be further described.

[0070] The SOC database may also be referred to as an RC table. In one embodiment of the method for determining the state of charge of a battery, the SOC database may be three-dimensional, but is not limited thereto. As an example, the SOC database may include a voltage dimension, a current dimension, and a temperature dimension (i.e., battery parameters involving three dimensions), and the lithium battery capacity at each voltage point, temperature point, and current point includes the SOC value of the battery at the corresponding voltage, temperature, and current.

[0071] In this case, the SOC database can describe the SOC value under the conditions of a specific voltage V, a specific temperature T, and a specific current I. The SOC database includes three data space dimensions: voltage, temperature, and current. The data in the corresponding data space includes at least the SOC value of the battery under the corresponding scenario.

[0072] As mentioned above, in step S101, the FCC correction parameter is also used to correct the FCC deviation caused by the incomplete discharge or over-discharge of the lithium battery due to factors such as temperature change and battery aging. Figure 2B As shown, in step S101, the step of determining the FCC correction parameter includes: step S1016, querying the SOC database using the combined battery parameters to obtain an estimated SOC; and step S1017, obtaining the FCC correction coefficient based on the deviation between the estimated SOC and the actual SOC.

[0073] As an example, the estimated SOC may be obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including an initial battery parameter. Here, the combined battery parameter may include a first and a second equivalent voltage of the battery, which respectively represent the idle voltage of the battery and the sum of the charge cutoff voltage and the charge impedance voltage. Specifically, querying the SOC database using the combined battery parameter includes: querying the SOC database using the first equivalent voltage of the battery with the initial current and the initial temperature to obtain the first SOC; querying the SOC database using the second equivalent voltage of the battery with the initial current and the initial temperature to obtain the second SOC; and determining the difference between the first SOC and the second SOC as the estimated SOC, wherein the first equivalent voltage is the sum of the idle voltage of the battery and the charge impedance voltage, and the second equivalent voltage is the sum of the charge cutoff voltage of the battery and the charge impedance voltage.

[0074] As an example, the specific process of querying the SOC database to determine the first SOC and the second SOC and then obtaining the estimated SOC is as follows:

[0075] According to the combined battery parameters, a SOC database storing battery parameters and SOC values ​​associated with each other is queried, and the combined battery parameters at least include current, temperature, charging impedance voltage, idle voltage idle_volt representing the battery without load, and discharge cut-off voltage eod_volt of the battery. Preferably, the SOC database is an RC table with three data dimensions of voltage volt, current curr, and temperature temp. The query can be performed by three-dimensional linear interpolation.

[0076] As an example, taking the query of the SOC used to determine the estimated SOC as an example, the first SOC, that is, the SOC now and the second SOC, namely SOC end It can be obtained by querying the SOC database as shown in the following formula:

[0077] SOC now =RC(idle_volt+curr*(sysim+chgir),curr,temp)

[0078] SOC end =RC(eod_volt+curr*(sysim+chgir),curr,temp)

[0079] Among them, idle_volt is the idle voltage, eod_volt is the cut-off voltage, curr is the current used for query, temp is the temperature used for query, sysim is the line resistance representing the line impedance, and chgir is the battery internal resistance.

[0080] According to the above table lookup operation, the SOC corresponding to the idle voltage idle_volt of the battery without load can be obtained respectively. now and the SOC at the time of charging stop corresponding to the discharge cut-off voltage eod_volt of the battery end Based on this, the estimated SOC can be obtained, that is, estimated SOC = SOC now -SOC end .

[0081] Accordingly, the FCC correction parameter fcc in formula (2) can be obtained: comp =(estimated SOC-actual SOC)*FCC estimated value, where the FCC estimated value is the FCC estimated value obtained in step I-3 of the above FCC database query, and the actual SOC can be measured by a cycler, for example. Therefore, the above process of determining the estimated SOC can prevent the estimated battery SOC from being falsely high or falsely low due to battery aging or temperature changes.

[0082] Preferably, the battery temperature is sampled in real time throughout the charging process, and the above charging battery temperature used to retrieve the SOC database is calculated based on the current sampling value of the battery temperature. Note that the present disclosure does not place any particular restrictions on the "current sampling value" of the battery temperature and the method of calculating the "charging battery temperature" based on it. By way of example only, in one example, the "current sampling value" of the battery temperature may be the sampling value sampled when charging is terminated, and the sampling value may simply be used as the "charging battery temperature". Also by way of example only, in an alternative example, the battery temperature sampling value may select another sampling value of the battery temperature during the charging process or statistics of these sampling values ​​for various considerations, which will not be elaborated here.

[0083] Based on the FCC estimation value and FCC correction parameter fcc obtained in the above steps comp , the revised FCC can be obtained.

[0084] As described above, in step S103, the current state of charge SOC of the battery is determined at least in part based on the corrected FCC. Figure 3 A preferred embodiment of determining the current SOC of a battery based at least in part on a revised FCC is described. Specifically, Figure 3 As shown, in step S103, determining the current SOC of the battery according to the corrected FCC includes: step S1031, judging the charging mode of the battery according to the current battery parameters; and step S1032, determining the current SOC under the judged charging mode.

[0085] Preferably, the charging mode of the battery may include constant current charging and constant voltage charging.

[0086] As an example, when the battery meets the constraints of constant voltage charging, the lithium battery is charged in constant voltage charging mode, otherwise it is charged in constant current mode. Among them, the constraints of constant voltage charging include, for example, the average voltage is greater than or equal to the charging limit voltage, the average current is greater than 0, the long-term average current (the average current within 45 seconds) is greater than the short-term average current (the average current within 15 seconds), and the voltage fluctuation is less than 1 / 100 compared to the average voltage.

[0087] Preferably, when the determined charging mode is constant current charging, the current SOC is determined using the current charge of the battery and the corrected FCC.

[0088] As an example, the battery's charging capacity deltauah is used to update the battery's current capacity, i.e., the remaining capacity RCA. The updated RCA and the corrected FCC obtained in the previous step are used to determine the current SOC. As an example, the current SOC can be determined using the following two formulas:

[0089] RCA=RCA+deltauaah,

[0090] The coefficient 10000 in the above formula is only added to facilitate calculation by eliminating the decimal point of the SOC. Those skilled in the art clearly know that this parameter can be cancelled or changed according to actual application requirements as long as it matches other steps.

[0091] Preferably, when the determined charging mode is constant voltage charging, the current SOC is determined according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

[0092] Preferably, determining the current SOC according to the relationship between the current charging current and the current reference current includes: when the difference between the current charging current and the current reference current is 0, determining the current SOC as the sum of the previous SOC and a predetermined SOC increment. Here, equal also includes the case of "substantially" equal, which means the case where the current charging current or its statistics have only a small difference with the reference current due to factors such as measurement resolution and measurement error. Preferably, whenever the difference between the current charging current and the current reference current is 0, the current SOC is determined as the sum of the previous SOC and a predetermined SOC increment. For example, in the constant voltage charging mode during the charging process of the battery, the SOC can be updated whenever the difference between the current charging current and the current reference current is 0, along with the change of the current charging current.

[0093] Preferably, the difference is determined based on i) a first difference between the current charging current and the previous charging current, and ii) a second difference between the previous charging current and the charging cut-off current adjusted based on the previous SOC and a predetermined adjustment factor. Alternatively, the difference between the current charging current and the current reference current can also be determined based on the difference between the first difference and the second difference, wherein the second difference is used to measure whether the first difference (i.e., the change in the charging current) satisfies the condition for increasing the SOC. It can be understood that the above-mentioned representation of the sum / difference of the first difference and the second difference can be used basically equivalently, the only difference being that the value of the adjustment factor is a positive number or a negative number.

[0094] As an example, the average value of the charging current within a certain period of time (for example, 15 seconds) can be selected as the representation of the previous charging current. At this time, the current reference current can be expressed as:

[0095]

[0096] Among them, eoc is the cut-off current, SOC is the previous state of charge, and ratio is an empirical value that can be adjusted according to actual needs. The size of the ratio can be adjusted to control the step size of the current charging current to "catch up" with the current reference current, in other words, the frequency.

[0097] According to the above formula, the difference between the current charging current and the current reference current is (current curr avg -Previous curr avg )and When the difference between the current charging current and the current reference current is 0, the current SOC is determined as the sum of the previous SOC and the predetermined SOC increment.

[0098] As an example, the ratio may be set to an integer such as 5 or 10, but is not limited thereto. Only one ratio may be selected during the charging process. Alternatively, multiple different ratios may be selected during the entire charging process to flexibly adjust the step size of the current current "catching up" with the reference current according to actual needs.

[0099] As an example, only one fixed SOC increment, such as 10 or 100, may be selected in the constant voltage charging mode of the entire charging process, but is not limited thereto. Alternatively, multiple different SOC increments may be selected throughout the charging process to flexibly adjust the smoothness of the determined SOC change according to actual needs.

[0100] The following uses a specific embodiment to illustrate an example of determining the SOC according to the "catch-up" method during constant voltage charging, in which multiple different ratios are used and a fixed SOC increment is selected.

[0101] Step S10321_1: If eoc is 250mA, the predetermined SOC increment is 10 (i.e. 10 / 10,000), the average current at the start of the "catch-up" operation is 801mA, the SOC is 9716 (i.e. 9716 / 10,000), and ratio1 is 10, then based on the above data, the first reference current can be obtained as

[0102]

[0103] Step S10321_2: Because the charging current will gradually decrease as the SOC increases during constant voltage charging, when the average current drops to the first reference current of 781.6mA, the SOC is updated to include the predetermined increment of 10, then the SOC is 9726, and in order to catch up more frequently in a smaller interval, ratio2 is selected as 5, so the second reference current is

[0104]

[0105] Step S10321_3: When the average current drops to the second reference current of 771.9 mA, the SOC is updated to include the predetermined increment. At this time, the SOC is 9736, and the ratio is still selected as ratio2=5. Therefore, the third reference current is

[0106]

[0107] And so on, until the average current is equal to the charge cut-off current. Those skilled in the art can set a suitable way to stop such superposition, for example, stop such superposition when the measured current charging current is less than or equal to a set value (less than the charge cut-off current).

[0108] The above specific embodiment of determining SOC by the "catch-up" method between the charging current and the reference current is for illustration only. Those skilled in the art can flexibly adjust the values ​​of ratio and SOC increment according to actual needs, so that one ratio value can be used throughout the entire charging process, or multiple different ratio values ​​can be used according to the development of the charging process, and one SOC increment can be used throughout the charging process, or multiple different SOC increments can be used according to the development of the charging process. The above "catch-up" method for determining SOC can effectively improve the situation where the SOC is not updated accurately and timely during the battery charging process, especially when the charging current is small.

[0109] The above steps S1031 and S1032 are not limited to being executed only once, but are judged in real time based on whether the battery parameters meet the constraints of the aforementioned constant voltage charging. In other words, during one charging process, step S1031 can be continuously executed multiple times based on the battery parameters (measured in real time and / or counted by real-time measurement values) to determine whether the battery charging process is in a constant current charging state or a constant voltage charging state. After each state is determined, the SOC is updated according to the state until the next judgment.

[0110] Preferably, the charging tail power chg_tail_cc in the battery charging process is also defined. The charging tail power is initially chg_tail_cc=ratioe*facc, wherein ratioe is an empirical value, and facc is the rated capacity of the battery. Whenever the battery charging process enters a constant voltage charging state, the charging tail power is updated to chg_tail_cc=chg_tail_cc-deltauah using the charging power deltauah of the battery. Until the charging tail power chg_tail_cc is updated to be less than or equal to 0, the current SOC is determined as the sum of the previous SOC and the predetermined SOC increment. The specific content is not repeated here.

[0111] For the above steps, those skilled in the art are well aware that the cut-off voltage can be used to constrain in a similar manner as the cut-off current. Therefore, the above steps use the cut-off current and / or cut-off voltage to make full charge judgments, which can effectively prevent the battery from being overcharged or undercharged. The entire charging process can accurately estimate the battery SOC without jumps, thereby extending the use time of the device.

[0112] Next, we will refer to Figure 4 and Figure 5 , further embodiments related to the updating of the FCC database are described. Those skilled in the art can understand that the updating of the FCC database and the original acquisition method of the data items in the database can correspond to each other. Therefore, based on the updating of the FCC data described below, a method for constructing the initially used FCC database can be obtained, which will not be described in detail here.

[0113] like Figure 4 As shown, in a method 10B for determining the state of charge of a battery in one embodiment, the method further includes: an optional step S105, when a preset update condition is met, using an FCC error value to update relevant data items in the FCC database, wherein the FCC error value is a calculated deviation between a current FCC estimate value obtained by querying the FCC database based on statistical battery parameters (also referred to as statistical values ​​of battery parameters) and a true FCC.

[0114] As an example, the preset update condition may include that the temperature change of the battery during charging does not exceed a predetermined range.

[0115] Preferably, the update weights at the relevant data items are calculated based on the differences of the plurality of statistical battery parameters. As an example, the statistical battery parameters may include at least the maximum current curr max and the average temperature temp avg .

[0116] As an example, updating the FCC database may include determining relevant data items to be updated in the FCC database based at least on the statistical battery parameters.

[0117] As an example, updating relevant data items in the FCC database may include: calculating update weights at the relevant data items based on the difference between the battery parameters in the relevant data items and the statistical battery parameters; and updating the FCC at the relevant data items in the FCC database based on the FCC error value and the update weights at the relevant data items.

[0118] Preferably, the real FCC is the sum of the accumulated charging capacity of the battery during the charging process, the remaining capacity before charging and a capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the time of charging cutoff and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charging cutoff current.

[0119] First refer to Figure 5 A specific example of updating the FCC database is described below. Specifically, Figure 5 As shown, Figure 4 An example of step S105 for updating the FCC database in the embodiment of the present invention, the updating S105 includes: step S1051, determining the relevant data items to be updated based on at least the statistical battery parameters; step S1052, calculating the update weights at the relevant data items according to the differences between the battery parameters in the relevant data items and the statistical battery parameters, which may include update weights corresponding to each battery parameter respectively; step S1053, multiplying and accumulating the update weights at the relevant data items and the FCC estimated values ​​to obtain the capacity values, and subtracting the FCC true value of the battery charging data from the accumulated capacity value to obtain the FCC error value; step S1054, updating the FCC at the relevant data items in the FCC database according to the FCC error value and the update weights at the relevant data items.

[0120] In step S1051, the relevant data items to be updated may be determined based on statistical battery parameters, which may include, for example, the maximum current curr max and the average temperature temp avg As an example, you can look up the FCC database for the distance from the average temperature temp avg The nearest temperature point temp 0 and temp 1 ; and find the maximum value of the current curr max The nearest current point curr 0 and curr 1 , thereby determining four adjacent related data items. The above method of determining related data items is only an example, and those skilled in the art clearly know that there are other methods of determining related data items to be updated based on statistical battery parameters.

[0121] In step S1052, the update weights corresponding to each relevant data item and each battery parameter, namely, the temperature weight and the current weight, may be calculated. The calculation formulas for the temperature weight and the current weight are as follows:

[0122]

[0123] temp_weight 1=1000-temp_weight 0

[0124]

[0125] curr_weight 1 =1000-curr_weight 0

[0126] The constant 1000 in the formula is only set to reduce the number of decimal places in the weight to facilitate calculation. Those skilled in the art clearly know that the constant 1000 can also be canceled or set to other values ​​corresponding to the next step and / or other steps.

[0127] In particular, when the average temperature temp avg When the temperature is greater than the maximum value of 65℃ or less than the minimum value of 5℃, the temp 0 and temp 1 is the same value 65℃ or 5℃; when the maximum current curr max When the current is greater than the maximum value of 10A or less than the minimum value of 2A, curr 0 and curr 1 The same value is 10A or 2A; at temp 0 =temp 1 When temp_weight 0 =temp_weight 1 =500, in curr 0 =curr 1 curr_weight 0 =curr_weight 1 =500.

[0128] In step S1053, the temperature weights, current weights, and FCC estimated values ​​from the FCC database of four adjacent related data items are multiplied and added together to obtain an accumulated capacity value, and then the estimated charge value from the battery charging data is subtracted from the accumulated capacity value to obtain a capacity error value fcc_error:

[0129]

[0130] Among them, the estimated charge value fcc_est from the battery charging data c, which can also be considered as the "real FCC", is equal to the sum of the accumulated charge power of the battery during the charging process, the remaining capacity before charging and the capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the end of charging and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charge cut-off current, and wherein i and j are 0 or 1. When fcc_error≤0, the following steps are no longer performed and the update is stopped.

[0131] In step S1054, the FCC at the relevant data item in the FCC database is updated according to the FCC error value obtained in the above steps and the update weight at the relevant data item.

[0132] As an example, the following formula is used to update the FCC:

[0133]

[0134] Preferably, in the above-mentioned updating, in the FCC database, the relevant data items to be updated are determined based on at least the battery parameters used in the process of calculating the SOC (battery parameters used for calculating the SOC).

[0135] In addition, as mentioned above, those skilled in the art can understand that the update of the FCC database and the original acquisition method of the data items in the database can correspond to each other. Therefore, based on the FCC data update described above, a method for constructing the FCC database for initial use can be obtained, which will not be repeated here.

[0136] Optionally, the method for determining the battery state of charge may further include the following optional step S107: judging whether full charge is reached according to the SOC determined in the above steps, taking the SOC limited to an integer range of 1 to 10000 as an example, when SOC<9900, only the time identification value is updated to the current time value; conversely, when the duration for which the battery SOC remains unchanged before and after the update is greater than a full charge timeout threshold (for example, 30 seconds), the battery SOC value is updated to 10000, the remaining capacity RCA value is updated to a corrected FCC, and the status value is updated to a fully charged state.

[0137] <Second Embodiment>

[0138] The present embodiment provides a device for determining the state of charge of a battery.

[0139] Figure 6 A functional module block diagram of a device for determining a state of charge of a battery according to a second embodiment is shown.

[0140] like Figure 6As shown, the device 60 includes a processing circuit 610, which is configured to: obtain a corrected FCC based on the battery full charge capacity FCC correction parameter and the FCC initial estimation value corresponding to the initial battery parameter of the battery; determine the current state of charge SOC of the battery at least in part based on the corrected FCC, wherein the FCC initial estimation value is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other based on the initial battery parameters, and wherein the FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, wherein the estimated SOC is obtained by querying an SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameter. Optionally, the device 60 may also include an acquisition circuit 620 for obtaining various parameters required in the processing of the processing circuit. Preferably, the acquisition circuit 620 may include a sensor for measuring battery parameters.

[0141] In the above description of the method for determining the state of charge of a battery, it has actually been disclosed as follows: Figure 6 The processing and functions implemented by each functional module of the device for determining the state of charge of a battery shown in FIG. Figures 1 to 5 The various method steps described and the processing therein can be Figure 6 The processing circuit 610 is combined with the acquisition circuit 620 to realize the above-mentioned functions, wherein the acquisition circuit 620 is used to obtain various battery parameters, and the processing circuit 610 is used to realize various processing, calculation and control. Therefore, in the following, the functions of these processing circuits are summarized without repeating some details discussed above.

[0142] Here, the processing circuit 610 can be implemented as a chip, a processor, various microcontrollers, etc., and can be implemented by one or more application-specific integrated circuits and / or corresponding software programs. The acquisition circuit can, for example, have at least one sensor, and collect the state parameters (battery parameters) of the battery through at least one sensor. As mentioned above, the battery parameters can include, for example, at least one of the battery voltage, the battery current and the temperature, but are not limited thereto. For example, optionally, the battery parameters can include (charging) power. The temperature is obtained, for example, by a temperature sensor, the battery current is obtained by a current sensing circuit, the battery voltage is obtained, for example, by a voltage sensing circuit, and the power can be measured using a coulomb meter.

[0143] In one example, the initial battery parameters include at least current and temperature.

[0144] In one example, the processing circuit can be further configured to: use the initial battery parameters to query relevant data items in the FCC database; based on the difference between the battery parameters in the relevant data items and the initial battery parameters, obtain the FCC initial estimate value according to the FCC in the relevant data items.

[0145] In one example, the processing circuit can be further configured to: query the SOC database using the first equivalent voltage, initial current and initial temperature of the battery to obtain a first SOC; and query the SOC database using the second equivalent voltage, initial current and initial temperature of the battery to obtain a second SOC; and determine the difference between the first SOC and the second SOC as the estimated SOC, wherein the first equivalent voltage is the sum of the idle voltage and the charging impedance voltage of the battery, and the second equivalent voltage is the sum of the charging cut-off voltage and the charging impedance voltage of the battery.

[0146] In one example, the processing circuit may be further configured to: determine a charging mode of the battery according to current battery parameters; and determine a current SOC under the determined charging mode.

[0147] In one example, the processing circuit may be further configured to: when the determined charging mode is constant current charging, determine the current SOC using the current power of the battery and the corrected FCC.

[0148] In one example, the processing circuit can be further configured to: when the determined charging mode is constant voltage charging, determine the current SOC according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

[0149] In one example, the processing circuit may be further configured to: when the difference between the current charging current and the current reference current is zero, determine the current SOC as the sum of the previous SOC and a predetermined SOC increment.

[0150] In one example, the processing circuit can be further configured to determine the difference based on i) a first difference between the current charging current and the previous charging current, and ii) a second difference between the previous charging current and the charging cut-off current adjusted based on the previous SOC and a predetermined adjustment factor.

[0151] In one example, the processing circuit can be further configured to: when a preset update condition is met, use an FCC error value to update relevant data items in the FCC database, wherein the FCC error value is a calculated deviation between a current FCC estimate value obtained by querying the FCC database based on statistical battery parameters and a true FCC.

[0152] In one example, the processing circuit may be further configured to determine, in an FCC database, relevant data items to be updated based at least on the statistical battery parameters.

[0153] In one example, the processing circuit can be further configured to: calculate an update weight at the relevant data item based on the difference between the battery parameter in the relevant data item and the statistical battery parameter; and update the FCC at the relevant data item in the FCC database based on the FCC error value and the update weight at the relevant data item.

[0154] In one example, the processing circuit may be further configured to calculate update weights at relevant data items based on the differences of the plurality of statistical battery parameters.

[0155] Here, the statistical battery parameters include at least maximum current and average temperature.

[0156] Here, the real FCC is the sum of the accumulated charging capacity of the battery during the charging process, the remaining capacity before charging and the capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the time of charging cutoff and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charging cutoff current.

[0157] <Effect>

[0158] According to the above embodiments of the present disclosure, significant technical effects can be achieved. FIG. 7A to FIG. 8 , the technical effect is described with respect to the data obtained in an example scenario by using the device of the second embodiment to implement the method of the first embodiment during the charging process or charge-discharge cycle of the battery.

[0159] Specifically, Fig. 7A A SOC test curve of a group of lithium batteries according to one embodiment of the present disclosure undergoing a small current charge at a temperature of 25°C is provided, wherein the charging capacity of the lithium battery is 4900mAh, the charging cut-off voltage is 4.45V, the charging cut-off current is 200mA, the charging current is 0.98A, and the working process is divided into standing for 1min, constant current and constant voltage charging, and standing for 30min.

[0160] Figure 7BA SOC test curve of a group of lithium batteries according to one embodiment of the present disclosure undergoing a large current charge at a temperature of 25°C is provided, wherein the charging capacity of the lithium battery is 4900mAh, the charging cut-off voltage is 4.45V, the charging cut-off current is 200mA, the charging current is 5.88A, and the working process is divided into standing for 1min, constant current and constant voltage charging, and standing for 30min.

[0161] Figure 7C A set of SOC test curves of a lithium battery according to one embodiment of the present disclosure undergoing a rapid charge at a temperature of 25° C. The specific steps of charging are as follows:

[0162] (1) Use a constant current of 12.4A to charge the battery until the voltage reaches 4.2V, and then maintain a constant voltage of 4.2V to charge the battery until the battery reaches 1.8C (the current is 8.882A at this time);

[0163] (2) Charge at 1.8C (current is 8.882A) until the battery voltage reaches 4.3V, then charge at 4.3V until the battery capacity reaches 1.5C (current is

[0164] 7.35A);

[0165] (3) Charge at 1.5C (current is 7.35A) until the battery voltage reaches 4.4V, then charge at 4.4V until the battery capacity reaches 1.2C (current is 5.88A).

[0166] (4) Charge at a constant current of 1.2C (current is 5.88A) until the battery voltage reaches 4.48V.

[0167] Constant voltage charging until the battery capacity reaches 0.17C (the current is 0.833A at this time).

[0168] In the above FIG. 7A to FIG. 7C In the figure, the red line represents the SOC result measured using a calibrated cycler, the blue line represents the SOC result determined using the above-mentioned embodiment of the present disclosure, the black line represents the deviation between the two methods, the horizontal axis is the charging time in seconds, the vertical axis corresponding to the measurement / determination result is the SOC in percentage, and the vertical axis corresponding to the deviation between the two methods is the deviation size in percentage.

[0169] from Fig. 7A Small current charging, Figure 7B High current charging and Figure 7CIt can be seen from the three examples of fast charging that during the entire charging process, there is no jump in the SOC of the lithium battery determined by the implementation method in the present disclosure, and the difference with the actual SOC value recorded by the cycler is within 3%. The maximum error value of low-current charging is 1.37%, the maximum error value of high-current charging is 2.04%, and the maximum error of fast charging is 1.83%.

[0170] also, Figure 8 A comparison result diagram of the SOC value determined according to one embodiment of the present disclosure and the actual SOC in 19 charge and discharge cycles of the lithium battery is also shown. Figure 8 In the figure, the horizontal axis is the number of charge and discharge cycles, and the vertical axis is the maximum error between the SOC value determined during the charging process and the actual SOC, in percentage. In the test, at 25°C, the rated capacity of the lithium battery is 4900mAh, and the charging is carried out using the above-mentioned fast charging mode, the discharge cut-off voltage is 3V, and the discharge current is 0.98A. The working process of one charge and discharge cycle is divided into constant current discharge, rest for 30 minutes, fast charging, and rest for 30 minutes, and this cycle is repeated 19 times.

[0171] It can be seen that during the entire charge and discharge process, the SOC determined according to the above implementation does not jump. In 19 charge and discharge cycles, the maximum difference between the SOC determined according to the above implementation and the actual SOC recorded by the cycler gradually decreases from the initial 7.5% to 2.56%, and finally stabilizes at the 13th cycle.

[0172] The implementation mode of the present invention jointly estimates the state of charge SOC of the lithium battery by using the health value, temperature, current and FCC database of the lithium battery. Therefore, even if there is an error in the initial capacity estimation of the lithium battery (for example, the initial health value estimation is inaccurate), the state of charge SOC of the lithium battery can be accurately estimated in an adaptive manner to prevent the occurrence of falsely high or falsely low SOC of the lithium battery due to aging of the lithium battery or temperature changes.

[0173] In summary, according to the method and device of the implementation method in the present disclosure, the actual capacity value of the lithium battery is estimated by jointly estimating the health value, temperature, current and two-dimensional lithium battery FCC database of the lithium battery. The lithium battery can not only be fully charged in high current charging, low current charging and fast charging, but also accurately estimate the actual capacity of the lithium battery under high and low temperature conditions, preventing the occurrence of false high and false low SOC of the lithium battery due to aging of the lithium battery or temperature changes. At the same time, the Coulomb integral is used to estimate the SOC in the constant current charging stage, and the relationship between the charging cut-off current and the charging current is used to approximate the SOC in the constant voltage charging stage, effectively preventing the lithium battery from being overcharged and undercharged, extending the use time of the equipment, and improving the user experience.

[0174] The basic principles of the present disclosure are described above in conjunction with specific implementation methods. However, it should be pointed out that for those skilled in the art, it is understandable that all or any steps or components of the methods and devices of the present disclosure can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in the form of hardware, firmware, software, or a combination thereof. This can be achieved by those skilled in the art using their basic circuit design knowledge or basic programming skills after reading the description of the present disclosure.

[0175] Furthermore, the present disclosure also proposes a program product storing machine-readable instruction codes. When the instruction codes are read and executed by a machine, the method according to the implementation mode of the present disclosure can be executed.

[0176] Accordingly, the storage medium for carrying the program product storing the machine-readable instruction code is also included in the disclosure of the present disclosure. The storage medium includes but is not limited to a floppy disk, an optical disk, a magneto-optical disk, a memory card, a memory stick, etc. In the case of implementing the present disclosure through software or firmware, the program constituting the software is installed from the storage medium or the network to a computer with a dedicated hardware structure, and the computer can perform various functions when various programs are installed.

[0177] It should also be noted that in the method, device and system of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present disclosure. In addition, the steps of performing the above-mentioned series of processes can naturally be performed in chronological order according to the order of description, but do not necessarily need to be performed in chronological order. Some steps can be performed in parallel or independently of each other.

[0178] Finally, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In addition, in the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or device that includes the elements.

[0179] The present invention also provides the following configuration:

[0180] 1. A method for determining a state of charge of a battery, comprising:

[0181] Obtaining a corrected FCC based on the FCC correction parameter of the full charge capacity of the battery and the FCC initial estimation value corresponding to the initial battery parameter of the battery;

[0182] determining a current state of charge (SOC) of the battery based at least in part on the corrected FCC,

[0183] The FCC initial estimation value is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other according to the initial battery parameters, and

[0184] The FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, wherein the estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameter.

[0185] 2. The method according to configuration 1, wherein the initial battery parameters include at least current and temperature.

[0186] 3. The method according to configuration 1, wherein querying the FCC database according to the initial battery parameters comprises:

[0187] Using the initial battery parameters to query relevant data items in the FCC database;

[0188] The FCC initial estimation value is obtained according to the FCC in the relevant data item based on the difference between the battery parameter in the relevant data item and the initial battery parameter.

[0189] 4. The method according to configuration 2, wherein querying the SOC database using the combined battery parameters comprises:

[0190] Querying a SOC database using a first equivalent voltage, an initial current, and an initial temperature of the battery to obtain a first SOC; and

[0191] Querying the SOC database to obtain a second SOC using the second equivalent voltage, the initial current, and the initial temperature of the battery; and

[0192] determining a difference between the first SOC and the second SOC as the estimated SOC,

[0193] The first equivalent voltage is the sum of the idle voltage of the battery and the charging impedance voltage, and the second equivalent voltage is the sum of the charging cut-off voltage of the battery and the charging impedance voltage.

[0194] 5. The method of configuration 1, wherein determining a current SOC of the battery based at least in part on the corrected FCC comprises:

[0195] Determine the battery charging mode based on the current battery parameters;

[0196] In the determined charging mode, the current SOC is determined.

[0197] 6. The method according to configuration 5, wherein:

[0198] When the determined charging mode is constant current charging, the current SOC is determined using the current charge of the battery and the corrected FCC.

[0199] 7. The method according to configuration 5, wherein:

[0200] When the determined charging mode is constant voltage charging, the current SOC is determined according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

[0201] 8. The method according to configuration 7, wherein determining the current SOC according to the relationship between the current charging current and the current reference current comprises:

[0202] In the case where the difference between the current charging current and the current reference current is 0, the current SOC is determined as the sum of the previous SOC and a predetermined SOC increment.

[0203] 9. The method according to configuration 8, wherein:

[0204] The difference is determined based on a sum of i) a first difference between a present charging current and a previous charging current, and ii) a second difference between the previous charging current and the charge cutoff current adjusted based on a previous SOC and a predetermined adjustment factor.

[0205] 10. The method according to configuration 1 further comprises: when a preset update condition is met, using an FCC error value to update relevant data items in the FCC database, wherein the FCC error value is a calculated deviation between a current FCC estimate value obtained by querying the FCC database based on statistical battery parameters and a true FCC.

[0206] 11. The method according to configuration 10, wherein, in the FCC database, the relevant data items to be updated are determined based at least on the statistical battery parameters.

[0207] 12. The method of configuration 11, wherein updating the relevant data items in the FCC database comprises:

[0208] Calculating an update weight at the relevant data item according to a difference between the battery parameter in the relevant data item and the statistical battery parameter;

[0209] The FCC at the relevant data item in the FCC database is updated according to the FCC error value and the update weight at the relevant data item.

[0210] 13. The method according to configuration 12, wherein:

[0211] Update weights at relevant data items are calculated based on the differences in the plurality of statistical battery parameters.

[0212] 14. The method according to configuration 12, wherein:

[0213] The statistical battery parameters include at least maximum current and average temperature.

[0214] 15. The method according to configuration 10, wherein:

[0215] The real FCC is the sum of the accumulated charging capacity of the battery during the charging process, the remaining capacity before charging and the capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the time of charging cutoff and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charging cutoff current.

[0216] 16. An apparatus for determining the state of charge of a battery, comprising:

[0217] A processing circuit configured to:

[0218] Obtaining a corrected FCC based on the FCC correction parameter of the full charge capacity of the battery and the FCC initial estimation value corresponding to the initial battery parameter of the battery;

[0219] determining a current state of charge (SOC) of the battery based at least in part on the corrected FCC,

[0220] The FCC initial estimation value is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other according to the initial battery parameters, and

[0221] The FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, wherein the estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameter.

[0222] 17. The device according to configuration 16, wherein the initial battery parameters include at least current and temperature.

[0223] 18. The device according to configuration 16, wherein the processing circuit is further configured to:

[0224] Using the initial battery parameters to query relevant data items in the FCC database;

[0225] The FCC initial estimation value is obtained according to the FCC in the relevant data item based on the difference between the battery parameter in the relevant data item and the initial battery parameter.

[0226] 19. The device according to configuration 17, the processing circuit is further configured to:

[0227] Querying a SOC database using a first equivalent voltage, an initial current, and an initial temperature of the battery to obtain a first SOC; and

[0228] Querying the SOC database to obtain a second SOC using the second equivalent voltage, the initial current, and the initial temperature of the battery; and

[0229] determining a difference between the first SOC and the second SOC as the estimated SOC,

[0230] The first equivalent voltage is the sum of the idle voltage of the battery and the charging impedance voltage, and the second equivalent voltage is the sum of the charging cut-off voltage of the battery and the charging impedance voltage.

[0231] 20. The device of configuration 16, wherein the processing circuit is further configured to:

[0232] Determine the battery charging mode based on the current battery parameters;

[0233] In the determined charging mode, the current SOC is determined.

[0234] 21. The apparatus according to configuration 20, wherein:

[0235] When the determined charging mode is constant current charging, the current SOC is determined using the current charge of the battery and the corrected FCC.

[0236] 22. The apparatus according to configuration 20, wherein:

[0237] When the determined charging mode is constant voltage charging, the current SOC is determined according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

[0238] 23. The device according to configuration 22, wherein the processing circuit is further configured to:

[0239] In the case where the difference between the current charging current and the current reference current is 0, the current SOC is determined as the sum of the previous SOC and a predetermined SOC increment.

[0240] 24. The apparatus according to configuration 23, wherein:

[0241] The difference is determined based on a sum of i) a first difference between a present charging current and a previous charging current, and ii) a second difference between the previous charging current and the charge cutoff current adjusted based on a previous SOC and a predetermined adjustment factor.

[0242] 25. The device of configuration 16, wherein the processing circuit is further configured to:

[0243] When the preset update condition is met, the relevant data items in the FCC database are updated using the FCC error value, wherein the FCC error value is a calculated deviation between the current FCC estimate value obtained by querying the FCC database based on statistical battery parameters and the actual FCC.

[0244] 26. The device of configuration 25, the processing circuit further configured to: determine, in an FCC database, relevant data items to be updated based at least on the statistical battery parameters.

[0245] 27. The device according to configuration 26, the processing circuit is further configured to:

[0246] Calculating an update weight at the relevant data item according to a difference between the battery parameter in the relevant data item and the statistical battery parameter;

[0247] The FCC at the relevant data item in the FCC database is updated according to the FCC error value and the update weight at the relevant data item.

[0248] 28. The apparatus of configuration 27, wherein the processing circuit is further configured to:

[0249] Update weights at relevant data items are calculated based on the differences in the plurality of statistical battery parameters.

[0250] 29. The apparatus according to configuration 27, wherein:

[0251] The statistical battery parameters include at least maximum current and average temperature.

[0252] 30. The apparatus according to configuration 25, wherein:

[0253] The real FCC is the sum of the accumulated charging capacity of the battery during the charging process, the remaining capacity before charging and the capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the time of charging cutoff and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charging cutoff current.

[0254] 31. A machine-readable program product having a machine-readable program recorded thereon, wherein when the machine-readable program is executed by a processor, the method for determining the state of charge of a battery as described in any one of configurations 1 to 15 is implemented.

[0255] Although the embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings, it should be understood that the embodiments described above are only used to illustrate the present disclosure and do not constitute a limitation of the present disclosure. For those skilled in the art, various modifications and changes can be made to the above embodiments without departing from the essence and scope of the present disclosure. Therefore, the scope of the present disclosure is limited only by the attached claims and their equivalents.

Claims

1. A method for determining a state of charge of a battery, comprising: Obtaining a corrected FCC based on the FCC correction parameter of the full charge capacity of the battery and the FCC initial estimation value corresponding to the initial battery parameter of the battery; determining a current state of charge (SOC) of the battery based at least in part on the corrected FCC, The FCC initial estimation value is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other according to the initial battery parameters, and The FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, wherein the estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameter.

2. The method according to claim 1, wherein: The initial battery parameters include at least current and temperature.

3. The method according to claim 1, wherein: Querying the FCC database based on initial battery parameters includes: Using the initial battery parameters to query relevant data items in the FCC database; The FCC initial estimation value is obtained according to the FCC in the relevant data item based on the difference between the battery parameter in the relevant data item and the initial battery parameter.

4. The method according to claim 2, wherein: Querying the SOC database using combined battery parameters includes: Querying a SOC database using a first equivalent voltage, an initial current, and an initial temperature of the battery to obtain a first SOC; and Querying the SOC database to obtain a second SOC using the second equivalent voltage, the initial current, and the initial temperature of the battery; and determining a difference between the first SOC and the second SOC as the estimated SOC, The first equivalent voltage is the sum of the idle voltage of the battery and the charging impedance voltage, and the second equivalent voltage is the sum of the charging cut-off voltage of the battery and the charging impedance voltage.

5. The method according to claim 1, wherein: Determining a current SOC of the battery based at least in part on the revised FCC includes: Determine the battery charging mode based on the current battery parameters; In the determined charging mode, the current SOC is determined.

6. The method according to claim 5, wherein: When the determined charging mode is constant current charging, the current SOC is determined using the current charge of the battery and the corrected FCC.

7. The method according to claim 5, wherein: When the determined charging mode is constant voltage charging, the current SOC is determined according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

8. The method according to claim 7, wherein: Determining the current SOC according to the relationship between the current charging current and the current reference current includes: In the case where the difference between the current charging current and the current reference current is 0, the current SOC is determined as the sum of the previous SOC and a predetermined SOC increment.

9. The method according to claim 8, wherein: The difference is determined based on a sum of i) a first difference between a present charging current and a previous charging current, and ii) a second difference between the previous charging current and the charge cutoff current adjusted based on a previous SOC and a predetermined adjustment factor.

10. The method according to claim 1, further comprising: When the preset update condition is met, the relevant data items in the FCC database are updated using the FCC error value, wherein the FCC error value is a calculated deviation between the current FCC estimate value obtained by querying the FCC database based on statistical battery parameters and the actual FCC.

11. The method according to claim 10, wherein: In the FCC database, relevant data items to be updated are determined based at least on the statistical battery parameters.

12. The method according to claim 11, wherein: Updates to relevant data items in the FCC database include: Calculating an update weight at the relevant data item according to a difference between the battery parameter in the relevant data item and the statistical battery parameter; The FCC at the relevant data item in the FCC database is updated according to the FCC error value and the update weight at the relevant data item.

13. The method according to claim 12, wherein: Update weights at relevant data items are calculated based on the differences in the plurality of statistical battery parameters.

14. The method according to claim 12, wherein: The statistical battery parameters include at least maximum current and average temperature.

15. The method according to claim 10, wherein: The real FCC is the sum of the accumulated charging capacity of the battery during the charging process, the remaining capacity before charging and the capacity correction value, wherein the capacity correction value is obtained based on the deviation between the actual SOC at the time of charging cutoff and the estimated SOC obtained by querying the SOC database using the combined battery parameters including the charging cutoff current.

16. An apparatus for determining the state of charge of a battery, comprising: A processing circuit configured to: Obtaining a corrected FCC based on the FCC correction parameter of the full charge capacity of the battery and the FCC initial estimation value corresponding to the initial battery parameter of the battery; determining a current state of charge (SOC) of the battery based at least in part on the corrected FCC, The FCC initial estimation value is obtained by querying an FCC database storing at least battery parameters and FCC associated with each other according to the initial battery parameters, and The FCC correction parameter is obtained based on the deviation between the estimated SOC and the actual SOC of the battery, wherein the estimated SOC is obtained by querying a SOC database storing battery parameters and SOC values ​​associated with each other using a combined battery parameter including the initial battery parameter.

17. The device according to claim 16, wherein: The processing circuit is further configured to: Using the initial battery parameters to query relevant data items in the FCC database; The FCC initial estimation value is obtained according to the FCC in the relevant data item based on the difference between the battery parameter in the relevant data item and the initial battery parameter.

18. The apparatus according to claim 16, wherein: The processing circuit is further configured to: Determine the battery charging mode based on the current battery parameters; In the determined charging mode, the current SOC is determined.

19. The apparatus according to claim 18, wherein: The processing circuit is further configured to: When the determined charging mode is constant voltage charging, the current SOC is determined according to the relationship between the current charging current of the battery and the current reference current, wherein the current reference current is determined based on at least the previous SOC of the battery, the previous charging current and the charging cut-off current.

20. A machine-readable program product having a machine-readable program recorded thereon, characterized in that: When the machine-readable program is executed by a processor, the method for determining the state of charge of a battery according to any one of claims 1 to 15 is implemented.

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