A method and device for selecting batteries with consistency

Abstract

The present application provides a method and device for selecting the consistency of a battery. The method includes: controlling a preset battery to be charged or discharged according to a preset current to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; constructing a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each acquisition time, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; constructing a second fitting curve of the preset battery based on the preset current, the battery charge state corresponding to each battery capacity, and the first fitting curve, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the battery charge state; determining a target charge state interval of the preset battery in the second fitting curve, and the target charge state interval is the charge state interval for improving the consistency of the preset battery.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and particularly to a method and device for selecting battery consistency. Background Art

[0002] In the prior art, multiple batteries are assembled into a battery module or a battery pack in series or parallel, and then the battery module or the battery pack is assembled in a new energy vehicle or other usage environments to supply power externally. The quality of the consistency of the batteries in the battery module or the battery pack has a great influence on the subsequent use of the batteries.

[0003] And during the actual production process of the battery module or the battery pack, after each battery is produced, it needs to be assembled into a battery module or a battery pack, and the assembled battery module or battery pack will not be sold immediately. It may need to be placed in a warehouse for a period of time before being sold externally. Therefore, it is possible that the consistency between the batteries just after production is good, but due to the self-discharge of the batteries during storage, the consistency between the batteries after being stored for a period of time becomes poor, which affects the result of the consistency detection of the battery module or the battery pack after the customer purchases it, and affects the yield rate. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide at least a method and device for selecting battery consistency. By detecting the battery voltage and the corresponding battery capacity during the charging or discharging process of a preset battery under a preset current, a first fitting curve representing the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity is fitted, and through the first fitting curve, the preset current and the state of charge of the battery, a second fitting curve representing the relationship between the voltage drop per unit time of the preset battery and the state of charge of the battery is determined. Thus, by determining that the change of the battery K value (voltage drop per unit time) of the preset battery in the target state of charge interval is small through the second fitting curve, it is determined that the consistency of the preset battery in the target state of charge interval is good. Therefore, during the production process, the factory state of charge of the preset battery can be set in the target state of charge interval, solving the technical problem in the prior art that the consistency of the batteries cannot be measured under various states of charge of the batteries, resulting in the gradual deterioration of the consistency during the storage process of the batteries, and achieving the technical effect of improving the consistency of the batteries leaving the factory.

[0005] The present application mainly includes the following aspects:

[0006] In a first aspect, an embodiment of the present application provides a method for selecting the consistency of batteries. The method for selecting the consistency of batteries includes: controlling a preset battery to be charged or discharged according to a preset current, so as to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; constructing a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each acquisition time, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; constructing a second fitting curve of the preset battery based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge; determining a target state of charge interval of the preset battery in the second fitting curve, and the target state of charge interval is the state of charge interval for improving the consistency of the preset battery.

[0007] Optionally, the first fitting curve is obtained by performing data fitting on the ratio of the battery voltage change amount to the battery capacity change amount at each acquisition time and the battery capacity at each acquisition time, or the first fitting curve is obtained by differentiating a fitting curve representing the relationship between the battery voltage and the battery capacity of the preset battery.

[0008] Optionally, the first fitting curve of the preset battery is constructed by the following method: calculating the difference in battery voltage between each acquisition time and the previous acquisition time, and the difference in battery capacity between each acquisition time and the previous acquisition time; using the battery capacity at each acquisition time as the abscissa and the ratio of the difference in battery voltage to the difference in battery capacity corresponding to each acquisition time as the ordinate for data fitting, to obtain the first fitting curve of the preset battery.

[0009] Optionally, the first fitting curve of the preset battery is constructed by the following method: using the battery capacity at each acquisition time as the abscissa and the battery voltage at each acquisition time as the ordinate for data fitting, to obtain a third fitting curve of the preset battery; differentiating the third fitting curve to obtain the first fitting curve of the preset battery.

[0010] Optionally, constructing the second fitting curve of the preset battery based on the preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve includes: calculating the state of charge of the preset battery corresponding to each battery capacity according to the total capacity of the preset battery and the battery capacity at each acquisition time; obtaining the voltage drop per unit time corresponding to each battery capacity according to the preset current and the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve; replacing each battery capacity of the first fitting curve with the corresponding state of charge of the battery, and replacing the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve with the corresponding voltage drop per unit time, so as to obtain the second fitting curve of the preset battery.

[0011] Optionally, the state of charge of the preset battery corresponding to each battery capacity is calculated by the following formula:

[0012]

[0013] where SOC i refers to the state of charge of the battery at the i-th acquisition time, Q i refers to the battery capacity at the i-th acquisition time, and Q0 refers to the total capacity of the preset battery.

[0014] Optionally, determining the target state of charge interval of the preset battery in the second fitting curve includes: calculating the slope of each point of the second fitting curve; determining the target state of charge interval of the preset battery according to the target points whose slopes belong to the preset slope interval.

[0015] In a second aspect, an embodiment of the present application further provides a device for selecting the consistency of batteries. The device includes: an acquisition module, configured to control a preset battery to charge or discharge according to a preset current, so as to acquire the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; a first construction module, configured to construct a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each acquisition time, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; a second construction module, configured to construct a second fitting curve of the preset battery based on the preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge of the battery; a determination module, configured to determine the target state of charge interval of the preset battery in the second fitting curve, where the target state of charge interval is the state of charge interval for improving the consistency of the preset battery.

[0016] In a third aspect, an embodiment of the present application further provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus. When the machine-readable instructions are run by the processor, the steps of the battery consistency selection method described in the first aspect or any possible implementation manner of the first aspect are executed.

[0017] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is run by a processor, the steps of the battery consistency selection method described in the first aspect or any possible implementation manner of the first aspect are executed.

[0018] An embodiment of the present application provides a battery consistency selection method and device. The method includes: controlling a preset battery to charge or discharge according to a preset current to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; constructing a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each acquisition time, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; constructing a second fitting curve of the preset battery based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge; determining a target state of charge interval of the preset battery in the second fitting curve, where the target state of charge interval is the state of charge interval for improving the consistency of the preset battery. By detecting the battery voltage and the corresponding battery capacity during the charging or discharging process of the preset battery at the preset current, a first fitting curve characterizing the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity is fitted, and a second fitting curve characterizing the relationship between the voltage drop per unit time of the preset battery and the state of charge is determined through the first fitting curve, the preset current, and the state of charge. Therefore, it is determined that the change in the battery K value of the preset battery is small in the target state of charge interval through the second fitting curve, and it is determined that the consistency of the preset battery is good in the target state of charge interval. Thus, the factory state of charge of the preset battery can be set in the target state of charge interval during the production process, solving the technical problem in the prior art that the consistency of the battery gradually deteriorates during the storage process because the consistency of the battery cannot be measured at each state of charge, and achieving the technical effect of improving the consistency of the factory battery.

[0019] To make the above objects, features, and advantages of the present application more obvious and understandable, the following provides preferred embodiments in conjunction with the accompanying drawings and describes them in detail as follows. Brief Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can be obtained based on these drawings.

[0021] Figure 1 The flowchart showing a method for selecting the consistency of a battery provided by an embodiment of the present application is shown.

[0022] Figure 2 The flowchart showing the steps of constructing a second fitting curve of a preset battery based on a preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve provided by an embodiment of the present application is shown.

[0023] Figure 3 The schematic diagram showing the relationship curve used to characterize the state of charge of each battery and the ratio of the change in battery voltage to the change in battery capacity is shown.

[0024] Figure 4 The functional block diagram of a device for selecting the consistency of a battery provided by an embodiment of the present application is shown.

[0025] Figure 5 The structural schematic diagram of an electronic device provided by an embodiment of the present application is shown. Detailed Description of the Embodiments

[0026] To make the objects, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of illustration and description and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to actual scale. The flowcharts used in the present application show the operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context relationships may be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0027] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. The components of the embodiments of the present application generally described and illustrated in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0028] In the prior art, if the consistency difference between batteries is large, during the charging and discharging process, some batteries will be fully charged or discharged to the lower limit cut-off condition first, resulting in other batteries being unable to be fully charged or discharged, and thus the output energy of the whole vehicle will be low, and the performance of the whole vehicle cannot be fully exerted, affecting the user experience. In addition, when an abnormality occurs in a certain battery in a battery module or battery pack, it is basically manifested as an abnormality in voltage, which will cause a large voltage difference between the batteries in the battery module or battery pack. When the battery consistency in the battery module or battery pack is not good, the voltage difference between the batteries will also be relatively large, so it is impossible to accurately judge whether the battery is abnormal based on the voltage difference, which easily leads to misjudgment or missed judgment, affecting the safety assessment of the battery module or battery pack.

[0029] Based on this, the embodiments of the present application provide a method and device for selecting battery consistency. By detecting the battery voltage and the corresponding battery capacity during the charging or discharging process of a preset battery at a preset current, a first fitting curve representing the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity is fitted, and through the first fitting curve, the preset current, and the state of charge of the battery, a second fitting curve representing the relationship between the voltage drop per unit time of the preset battery and the state of charge of the battery is determined. Thus, if it is determined that the change in the battery K value of the preset battery in the target state of charge interval is small through the second fitting curve, it is determined that the consistency of the preset battery in the target state of charge interval is good. Therefore, during the production process, the factory state of charge of the preset battery can be set in the target state of charge interval, solving the technical problem in the prior art that the consistency of the battery cannot be measured at each state of charge of the battery, resulting in the gradual deterioration of the consistency during the storage process of the battery, and achieving the technical effect of improving the consistency of the factory-produced batteries. Specifically as follows:

[0030] Please refer to Figure 1 , Figure 1 which is a flowchart of a method for selecting battery consistency provided by an embodiment of the present application. As Figure 1 shown, the method for selecting battery consistency provided by the embodiment of the present application includes the following steps:

[0031] S101: Control the preset battery to charge or discharge at a preset current, so as to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time.

[0032] That is to say, control the preset battery to charge at a preset current, or control the preset battery to discharge at a preset current, and collect the battery voltage and the battery capacity of the preset battery at each acquisition time during the charging or discharging process.

[0033] The battery voltage is the voltage across the preset battery at each acquisition time, and the battery capacity is the capacity of the preset battery at each acquisition time.

[0034] Exemplarily, if the preset battery is controlled to discharge at a preset current, the preset current is generally selected as a small current. For a small battery, 0.05C is selected. The small current can reduce the polarization during the discharging process.

[0035] Among them, each acquisition time is an acquisition time obtained by spacing a preset time interval, or the difference in battery voltage between adjacent acquisition times is the same. That is to say, the battery voltage and the corresponding battery capacity of the preset battery are collected at intervals of a preset time interval, or the battery voltage and the corresponding battery capacity of the preset battery are collected at intervals of a preset battery voltage difference. Each acquisition time corresponds to a battery voltage and a battery capacity.

[0036] S102: Construct a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each acquisition time.

[0037] The first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity. That is to say, the abscissa of the first fitting curve is the battery capacity, and the ordinate is the ratio of the battery voltage change amount to the battery capacity change amount.

[0038] The first fitting curve is obtained by performing data fitting on the ratio of the battery voltage change amount to the battery capacity change amount at each acquisition time and the battery capacity at each acquisition time, or the first fitting curve is obtained by differentiating the fitting curve representing the relationship between the battery voltage and the battery capacity of the preset battery.

[0039] The first fitting curve of the preset battery is constructed in the following way: Calculate the difference in battery voltage between each acquisition time and the previous acquisition time, and the difference in battery capacity between each acquisition time and the previous acquisition time; Use the battery capacity at each acquisition time as the abscissa, and use the ratio of the battery voltage difference to the battery capacity difference corresponding to each acquisition time as the ordinate to perform data fitting, and obtain the first fitting curve of the preset battery.

[0040] That is to say, for each acquisition time, the difference between the battery voltage at this acquisition time and the battery voltage at the previous acquisition time corresponding to this acquisition time is used as the battery voltage difference at this acquisition time, and the difference between the battery capacity at this acquisition time and the battery capacity at the previous acquisition time corresponding to this acquisition time is used as the battery capacity difference at this acquisition time; the battery capacity at each acquisition time is used as the abscissa, and the ratio of the battery voltage difference to the battery capacity difference corresponding to each acquisition time is used as the ordinate to fit the first fitting curve.

[0041] The first fitting curve of the preset battery is constructed in the following manner: The battery capacity at each acquisition time is used as the abscissa, and the battery voltage at each acquisition time is used as the ordinate for data fitting to obtain the third fitting curve of the preset battery; the third fitting curve is differentiated to obtain the first fitting curve of the preset battery.

[0042] That is to say, the battery capacity at each acquisition time is used as the abscissa and the battery voltage at this acquisition time is used as the corresponding ordinate for data fitting to obtain the third fitting curve, and the third fitting curve is used to characterize the relationship between the battery capacity and the battery voltage of the preset battery at each acquisition time. That is, the third fitting curve is the V-Q curve, and after differentiating the V-Q curve, the dV / dQ-Q curve is obtained, that is, the first fitting curve is obtained. The specific method for data fitting in this application is not limited.

[0043] Among them, the physical meaning of dV / dQ is the capacity contained in the battery material within the unit voltage range, and the peaks in the dV / dQ-Q curve mainly reflect the phase changes of the active material during the process of lithium intercalation and deintercalation. Each battery capacity in the text refers to the battery capacity at each acquisition time, and each battery voltage refers to the battery voltage at each acquisition time.

[0044] S103: Based on the preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve, construct the second fitting curve of the preset battery.

[0045] The second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge of the battery.

[0046] Please refer to Figure 2 , Figure 2 is the flowchart of the steps for constructing the second fitting curve of the preset battery based on the preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve provided by the embodiments of this application. As Figure 2 shown, the construction of the second fitting curve of the preset battery based on the preset current, the state of charge of the battery corresponding to each battery capacity, and the first fitting curve provided by the embodiments of this application includes:

[0047] S1031: Calculate the state of charge (SOC) of the preset battery corresponding to each battery capacity based on the total capacity of the preset battery and the battery capacity at each acquisition time.

[0048] The SOC of the preset battery corresponding to each battery capacity is calculated by the following formula:

[0049]

[0050] In formula (1), SOC i refers to the state of charge of the battery at the i-th acquisition time, Q i refers to the battery capacity at the i-th acquisition time, and Q0 refers to the total capacity of the preset battery.

[0051] S1032: Obtain the voltage drop per unit time corresponding to each battery capacity based on the preset current and the ratio of the change in battery voltage to the change in battery capacity at each battery capacity of the first fitting curve.

[0052] Among them, if we let Among them, t represents time, I refers to the preset current, dV refers to the change in battery voltage, and dQ refers to the change in battery capacity. The battery K value is the voltage drop per unit time, that is So Furthermore, K = F(V) × I.

[0053] That is to say, multiply the ratio of the change in battery voltage to the change in battery capacity at each battery capacity of the first fitting curve by the preset current to obtain the voltage drop per unit time corresponding to each battery capacity. Or, multiply the ordinate corresponding to each battery capacity of the first fitting curve by the preset current to obtain the battery K value corresponding to each battery capacity.

[0054] S1033: Replace each battery capacity of the first fitting curve with the corresponding state of charge of the battery, and replace the ratio of the change in battery voltage to the change in battery capacity at each battery capacity of the first fitting curve with the corresponding voltage drop per unit time, to obtain the second fitting curve of the preset battery.

[0055] That is to say, replace each battery charge on the abscissa of the first fitting curve with the state of charge of the battery at this battery capacity, and replace the ordinate of each battery capacity of the first fitting curve with the corresponding voltage drop per unit time, to obtain the second fitting curve.

[0056] That is, the abscissa of the second fitting curve is the state of charge of the battery at each battery capacity, and the ordinate is the voltage drop per unit time (battery K value) at each battery capacity.

[0057] Alternatively, since the ratio of the change in battery voltage to the change in battery capacity at each battery capacity of the first fitting curve is multiplied by a preset current, and the preset current is a fixed value. Furthermore, it is also possible to only replace the battery power at each abscissa of the first fitting curve with the state of charge of the battery at this battery capacity, and keep the ordinate of each battery capacity of the first fitting curve unchanged, that is, the ratio of the change in battery voltage to the change in battery capacity at each battery capacity, to obtain a fourth fitting curve, and the fourth fitting curve is a dV / dQ-SOC curve. That is to say, the fourth fitting curve is used to characterize the relationship between each state of charge of the battery and the ratio of the change in battery voltage to the change in battery capacity. The trend of the fourth fitting curve can also reflect the change of the battery K value with the state of charge of the battery, so as to determine the target state of charge interval.

[0058] Return Figure 1 , S104: Determine the target state of charge interval of the preset battery in the second fitting curve.

[0059] The target state of charge interval is the state of charge interval for improving the consistency of the preset battery.

[0060] The determining the target state of charge interval of the preset battery in the second fitting curve includes: calculating the slope of each point of the second fitting curve; determining the target state of charge interval of the preset battery according to the target points whose slope belongs to the preset slope interval.

[0061] Specifically, calculate the slope of the second fitting curve, that is, take the derivative of the second fitting curve; find the target points in the second fitting curve whose slope belongs to the preset slope interval, and the target points should be continuous points, and take the interval between the minimum state of charge and the maximum state of charge in the target points as the target state of charge interval. That is to say, the second fitting curve is relatively flat in the target state of charge interval.

[0062] That is to say, through the slope of the second fitting curve, it can be seen in which state of charge interval the battery K value changes greatly. If the battery K value changes greatly, it is considered that in this state of charge interval of the preset battery, the voltage drop of the preset battery per unit time is large. Since there will be slight differences between the battery K values of each preset battery in the actual process, after a period of time, the voltage differences between each preset battery will be large, and the consistency of the preset battery is poor; through the slope of the second fitting curve, it can be seen in which state of charge interval the battery K value changes little. If the battery K value changes little, it is considered that in this state of charge interval of the preset battery, the voltage drop of the preset battery per unit time is small, then after a period of time when multiple preset batteries are placed, the voltage differences between each preset battery are small, and the consistency of the preset battery is good.

[0063] The embodiment is as follows: a square aluminum shell battery of graphite system with model NCM622 is taken as a preset battery, and the total capacity of the battery is 185Ah. After the preset battery is fully charged, it is discharged with a small current of I=0.05C=9.25A, and the battery voltage and battery capacity of the discharge process are recorded at a time interval of 0.01s to obtain the battery discharge data shown in Table 1. Specifically, after the preset battery is fully charged with a small current, it is left for 30 minutes, and then the power is discharged with a small current, and the total capacity of the preset battery can be obtained.

[0064] Table 1:

[0065]

[0066]

[0067] For example, with respect to Table 1, if only the battery power of each battery on the abscissa of the first fitting curve is replaced with the battery state of charge under the battery capacity, and the ordinate of each battery capacity of the first fitting curve remains unchanged, a fourth fitting curve dV / dQ-SOC curve is obtained. Figure 3 , Figure 3 This is a schematic diagram of a relationship curve for characterizing the state of charge of each battery and the ratio of the battery voltage change to the battery capacity change provided in the embodiment of the present application. Figure 3 As shown, the vertical coordinates in areas 1 to 5 vary greatly, while the trend of the fourth fitting curve in the target state of charge interval is relatively gentle, which means that in the overload production of preset batteries, the factory state of charge of the preset batteries can be set within the target state of charge interval, so that after being placed for a period of time, the voltage changes of each preset battery are small, and the consistency of the preset batteries is better.

[0068] Moreover, it can be clearly seen from the method of the present application the influence of the state of charge of the battery on the K value of the battery. If it is necessary to strictly control the consistency of the preset battery, then in the second fitting curve, select the area with a larger slope and a larger change in the ordinate of the curve. That is to say, in this area, the state of charge of the battery will cause a large voltage change over time. Therefore, if the manufacturer needs to strictly control the consistency, the factory power of the preset battery is set in this area. Furthermore, if the consistency of the preset battery is good after being placed for a period of time, it means that the consistency design of this type of battery is good. If the control of the consistency of the preset battery is appropriately relaxed, then in the second fitting curve, select the area with a smaller slope and a smaller change in the ordinate of the curve. That is to say, in this area, the state of charge of the battery will cause a small voltage change over time. Therefore, after being placed for a period of time, the voltage change of the battery is small. The present application can intuitively reflect the influence of the state of charge SOC of the battery on the K value of the battery, and can also more accurately and conveniently select the SOC value of the preset battery at the time of leaving the factory according to the consistency requirements of the battery, with higher accuracy.

[0069] Based on the same inventive concept, an embodiment of the present application also provides a device for selecting the consistency of a battery corresponding to the method for selecting the consistency of a battery provided in the above embodiment. Since the principle of solving problems by the device in the embodiment of the present application is similar to the method for selecting the consistency of a battery in the above embodiment of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.

[0070] As Figure 4 shown, Figure 4 FIG. is a functional module diagram of a device for selecting the consistency of a battery provided by an embodiment of the present application. The device 10 for selecting the consistency of a battery includes: a collection module 101, a first construction module 102, a second construction module 103, and a determination module 104.

[0071] The collection module 101 is configured to control the preset battery to be charged or discharged according to a preset current, so as to collect the battery voltage and the corresponding battery capacity of the preset battery at each collection time; the first construction module 102 is configured to construct a first fitting curve of the preset battery based on the battery voltage and the battery capacity at each collection time, and the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; the second construction module 103 is configured to construct a second fitting curve of the preset battery based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve, and the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge; the determination module 104 is configured to determine a target state of charge interval of the preset battery in the second fitting curve, and the target state of charge interval is the state of charge interval for improving the consistency of the preset battery.

[0072] Based on the same application concept, refer to Figure 5 As shown, it is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The electronic device 20 includes: a processor 201, a memory 202, and a bus 203. The memory 202 stores machine-readable instructions executable by the processor 201. When the electronic device 20 runs, communication is carried out between the processor 201 and the memory 202 through the bus 203. When the machine-readable instructions are run by the processor 201, the steps of the battery consistency selection method described in any one of the above embodiments are executed.

[0073] Specifically, when the machine-readable instructions are executed by the processor 201, the following processing can be performed: controlling a preset battery to charge or discharge according to a preset current to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; based on the battery voltage and the battery capacity at each acquisition time, constructing a first fitting curve of the preset battery, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; based on the preset current, the battery charge state corresponding to each battery capacity, and the first fitting curve, constructing a second fitting curve of the preset battery, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the battery charge state; determining a target charge state interval of the preset battery in the second fitting curve, and the target charge state interval is the charge state interval for improving the consistency of the preset battery.

[0074] Based on the same application concept, an embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is run by a processor, the steps of the battery consistency selection method provided in the above embodiment are executed.

[0075] Specifically, the storage medium can be a general storage medium, such as a removable disk, a hard disk, etc. When the computer program on the storage medium runs, it can execute the above-mentioned method for selecting the consistency of the battery. By detecting the battery voltage and the corresponding battery capacity during the charging or discharging process of the preset battery under the preset current, a first fitting curve is fitted to represent the relationship between the ratio of the change in battery voltage to the change in battery capacity and the battery capacity. And through the first fitting curve, the preset current, and the state of charge of the battery, a second fitting curve is determined to represent the relationship between the voltage drop per unit time of the preset battery and the state of charge of the battery. Thus, by determining that the change in the battery K value of the preset battery is small in the target state of charge interval through the second fitting curve, it is determined that the consistency of the preset battery is good in the target state of charge interval. Therefore, in the production process, the factory state of charge of the preset battery can be set in the target state of charge interval, which solves the technical problem in the prior art that the consistency of the battery cannot be measured in each state of charge of the battery, resulting in the gradual deterioration of the consistency during the storage process of the battery, and achieves the technical effect of improving the consistency of the factory-produced battery.

[0076] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described system and device can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein. In the several embodiments provided in the present application, it should be understood that the disclosed system, device, and method can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces. The indirect coupling or communication connection of the device or unit may be in an electrical, mechanical, or other form.

[0077] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0078] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0079] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0080] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection 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 method for selecting battery consistency, characterized in that The method includes: Controlling a preset battery to be charged or discharged according to a preset current, so as to collect the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; Constructing a first fitting curve of the preset battery according to the battery voltage and the battery capacity at each acquisition time, where the first fitting curve is used to characterize the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; Based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve, constructing a second fitting curve of the preset battery, where the second fitting curve is used to characterize the relationship between the voltage drop per unit time of the preset battery and the state of charge; or, replacing the battery capacity of each abscissa of the first fitting curve with the state of charge at this battery capacity, and keeping the ordinate of each battery capacity of the first fitting curve unchanged to obtain a fourth fitting curve, where the fourth fitting curve is used to characterize the relationship between each state of charge and the ratio of the battery voltage change amount to the battery capacity change amount, and the trend of the fourth fitting curve is used to reflect the change of the voltage drop per unit time of the battery with the state of charge, so as to determine the target state of charge interval; Determining the target state of charge interval of the preset battery in the second fitting curve, where the target state of charge interval is the state of charge interval for improving the consistency of the preset battery; wherein, the target state of charge interval is used to indicate restricting the change of the voltage drop per unit time, so as to restrict the voltage change of the preset battery by setting the state of charge of the preset battery at the time of leaving the factory within the target state of charge interval during the production of the preset battery; Wherein, the constructing the second fitting curve of the preset battery based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve includes: Calculating the state of charge corresponding to each battery capacity of the preset battery according to the total capacity of the preset battery and the battery capacity at each acquisition time; Obtaining the voltage drop per unit time corresponding to each battery capacity according to the preset current and the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve; Replacing the battery capacity of each of the first fitting curve with the corresponding state of charge, and replacing the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve with the corresponding voltage drop per unit time, to obtain the second fitting curve of the preset battery.

2. The method according to claim 1, characterized in that The first fitting curve is obtained by performing data fitting on the ratio of the battery voltage change amount to the battery capacity change amount at each acquisition time and the battery capacity at each acquisition time, or the first fitting curve is obtained by differentiating the fitting curve characterizing the relationship between the battery voltage and the battery capacity of the preset battery.

3. The method according to claim 2, wherein The first fitting curve of the preset battery is constructed by the following method: Calculating the battery voltage difference between each acquisition time and the previous acquisition time, and the battery capacity difference between each acquisition time and the previous acquisition time; Taking the battery capacity at each acquisition time as the abscissa and the ratio of the battery voltage difference to the battery capacity difference corresponding to each acquisition time as the ordinate for data fitting, a first fitting curve of the preset battery is obtained.

4. The method according to claim 2, wherein The first fitting curve of the preset battery is constructed in the following manner: Taking the battery capacity at each acquisition time as the abscissa and the battery voltage at each acquisition time as the ordinate for data fitting, a third fitting curve of the preset battery is obtained; Differentiating the third fitting curve to obtain the first fitting curve of the preset battery.

5. The method according to claim 1, wherein The state of charge of the preset battery corresponding to each battery capacity is calculated by the following formula: Among them, refers to the state of charge of the battery at the i-th acquisition time, refers to the battery capacity at the i-th acquisition time, refers to the total capacity of the preset battery.

6. The method according to claim 1, wherein Determining the target state of charge interval of the preset battery in the second fitting curve includes: Calculating the slope of each point on the second fitting curve; Based on the target points whose slope belongs to the preset slope interval, determining the target state of charge interval of the preset battery.

7. A device for selecting batteries with consistency, characterized in that, The device includes: An acquisition module, configured to control the preset battery to be charged or discharged according to a preset current, so as to acquire the battery voltage and the corresponding battery capacity of the preset battery at each acquisition time; A first construction module, configured to construct a first fitting curve of the preset battery according to the battery voltage and battery capacity at each acquisition time, where the first fitting curve is used to represent the relationship between the ratio of the battery voltage change amount to the battery capacity change amount and the battery capacity; A second construction module, configured to construct a second fitting curve of the preset battery based on the preset current, the state of charge corresponding to each battery capacity, and the first fitting curve, where the second fitting curve is used to represent the relationship between the voltage drop per unit time of the preset battery and the state of charge; A determination module, configured to determine the target state of charge interval of the preset battery in the second fitting curve, where the target state of charge interval is the state of charge interval for improving the consistency of the preset battery; The second construction module is further configured to: Calculate the state of charge of the preset battery corresponding to each battery capacity according to the total capacity of the preset battery and the battery capacity at each acquisition time; Obtain the voltage drop per unit time corresponding to each battery capacity according to the preset current and the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve; Replacing each battery capacity of the first fitting curve with the corresponding state of charge, and replacing the ratio of the battery voltage change amount to the battery capacity change amount at each battery capacity of the first fitting curve with the corresponding voltage drop per unit time, to obtain the second fitting curve of the preset battery; Alternatively, the second construction module is further configured to: Replace each battery capacity on the abscissa of the first fitting curve with the state of charge of the battery at that battery capacity, and keep the ordinates of each battery capacity of the first fitting curve unchanged to obtain a fourth fitting curve. The fourth fitting curve is used to characterize the relationship between each state of charge of the battery and the ratio of the change in battery voltage to the change in battery capacity. The change in the voltage drop per unit time with respect to the state of charge of the battery is reflected by the trend of the fourth fitting curve to determine the target state of charge interval; Among them, the target state of charge interval is used to indicate the change in restricting the voltage drop per unit time. By setting the state of charge of the preset battery at the time of leaving the factory within the target state of charge interval during the process of producing the preset battery, the voltage change of the preset battery is restricted.

8. An electronic device, characterized in that, Including: A processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus. When the machine-readable instructions are run by the processor, the steps of the method for selecting the consistency of the battery according to any one of claims 1 to 6 are executed.

9. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium. When the computer program is run by the processor, the steps of the method for selecting the consistency of the battery according to any one of claims 1 to 6 are executed.

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