Method, system and electronic device for testing maximum current of a battery

Abstract

The present invention discloses a method, a system and an electronic device for testing the maximum current of a battery. The method includes: determining state parameters that affect the maximum current, where the state parameters include a first parameter, a second parameter and a third parameter; setting the first parameter as a fixed parameter, and obtaining a relationship curve between the second parameter and the third parameter and the maximum current value as a reference relationship curve; setting the first parameter as a target parameter, and measuring a first maximum current value corresponding to at least one of the second parameter and the third parameter; and obtaining a target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve. The technical solution provided by the present invention saves testing time, improves testing efficiency and reduces testing costs.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of power batteries, and in particular to a maximum current testing method, system, and electronic device for a battery. Background Art

[0002] Compared to traditional fuel vehicles, new energy vehicles produce no exhaust emissions, offering a natural environmental advantage. Electric vehicles are powered by batteries. The greater the battery discharge current, the higher the engine power and greater the power. Battery charging time is closely related to the charge current: a higher charge current shortens the charge time. However, the higher the battery discharge and charge current, the better. Therefore, it's important to understand the battery's maximum charge and discharge current under different conditions to better protect lithium batteries.

[0003] Currently, the maximum current of a battery is usually measured using a dot test method. This method continuously tests different currents and determines whether the current test value is qualified based on the cutoff voltage in the test results. There are usually multiple factors that affect the maximum current. Therefore, each time an influencing factor is changed, the dot test needs to be re-tested, which will increase the test cycle, reduce test efficiency, and consume huge test resources and testing funds. Summary of the invention

[0004] The present invention provides a maximum current testing method, system and electronic equipment for a battery, which saves testing time, improves testing efficiency and reduces testing costs.

[0005] In a first aspect, an embodiment of the present invention provides a method for testing a maximum current of a battery, comprising:

[0006] Determining state parameters that affect the maximum current, wherein the state parameters include a first parameter, a second parameter, and a third parameter;

[0007] Setting the first parameter as a fixed parameter, and obtaining a relationship curve between the second parameter, the third parameter, and the maximum current value as a reference relationship curve;

[0008] Setting the first parameter as a target parameter, and measuring a first maximum current value corresponding to at least one of the second parameter and the third parameter;

[0009] A target relationship curve corresponding to the target parameter is obtained according to the first maximum current value and the reference relationship curve.

[0010] Optionally, obtaining a relationship curve between the second parameter, the third parameter, and the maximum current value as a reference relationship curve includes:

[0011] measuring the maximum current value corresponding to different third parameters under each of the second parameters;

[0012] Establish the relationship between the third parameter and the maximum current under the same second parameter, and form a relationship curve between the third parameter and the maximum current as the reference relationship curve.

[0013] Optionally, measuring the maximum current values corresponding to different third parameters under each second parameter includes:

[0014] Determine a second parameter and test the current value under the third parameter;

[0015] Obtain the cut-off voltage according to the current value, and obtain the difference between the cut-off voltage and the preset cut-off voltage. If the difference is within the preset range, the current value is recorded as the maximum current value;

[0016] Repeat the test to obtain the maximum current values corresponding to different third parameters under each second parameter.

[0017] Optionally, obtaining the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve includes:

[0018] According to the reference relationship curve, obtain the second maximum current value under the second parameter and the third parameter that are the same as the first maximum current value;

[0019] Determine the conversion coefficient according to the first maximum current value and the second maximum current value;

[0020] According to the conversion coefficient, convert the axis values of the reference relationship curve to obtain the target relationship curve.

[0021] Optionally, the first parameter, the second parameter, and the third parameter are temperature, charge state, and pulse time respectively; or, the first parameter, the second parameter, and the third parameter are pulse time, temperature, and charge state respectively; or, the first parameter, the second parameter, and the third parameter are pulse time, charge state, and temperature respectively.

[0022] Optionally, before setting the first parameter as the first fixed parameter and obtaining the relationship curve between different third parameters and the maximum current value under each second parameter as the reference relationship curve, it further includes:

[0023] Calibrate the battery capacity;

[0024] Adjust the battery capacity to the preset charge state;

[0025] Adjust the battery to the preset test temperature.

[0026] Optionally, calibrating the battery capacity includes:

[0027] Discharge the battery at a fixed rate at a preset temperature, leave it for a preset time after discharge, cycle the discharge and leave process at least twice, and take the last discharge capacity as the calibration value of the battery.

[0028] Optionally, adjusting the battery capacity to a preset charge state includes:

[0029] Charge the battery to the preset charge state with a charging current at a preset rate, where the preset rate is between 0.2C and 1C.

[0030] In a second aspect, an embodiment of the present invention further provides a maximum current test system for a battery, including:

[0031] A determination module, configured to determine state parameters affecting the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter;

[0032] An acquisition module, configured to set the first parameter as a first fixed parameter, and acquire a relationship curve between different third parameters and the maximum current value under each second parameter as a reference relationship curve;

[0033] A measurement module, configured to set the first parameter as a target parameter, and measure a first maximum current value corresponding to at least one of the second parameter and the third parameter;

[0034] A target module, configured to obtain a target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve.

[0035] In a third aspect, an embodiment of the present invention further provides an electronic device, where the electronic device includes:

[0036] At least one processor; and

[0037] A memory communicatively connected to the at least one processor; where

[0038] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute any of the maximum current test methods for the battery in the embodiments of the present invention.

[0039] The technical solution provided by the embodiment of the present invention determines the first parameter, the second parameter, and the third parameter that affect the maximum current of the battery. First, the first parameter is used as a fixed parameter, and the relationship curve between the second parameter and the third parameter and the maximum current value is obtained. This relationship curve is used as the reference relationship curve. Then, under the condition that the first parameter is the target parameter, the first maximum current value corresponding to at least one set of the first parameter and the second parameter is measured. Through the method of mathematical fitting, the target relationship curve corresponding to the target parameter is obtained according to the first maximum current value and the reference relationship curve. Therefore, when changing one influencing factor, it is only necessary to measure at least one set of data again by dotting, and the maximum current values of the second parameter and the third parameter under the target parameter can be obtained, so as to obtain the maximum current of the battery under full temperature, full SOC, and full pulse time, greatly saving the test time, improving the test efficiency, and reducing the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic flow chart of a method for testing the maximum current of a battery provided by an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of the change curve of the maximum current with the pulse time at different SOCs at a specified temperature;

[0042] Figure 3 is a schematic flow chart of another method for testing the maximum current of a battery provided by an embodiment of the present invention;

[0043] Figure 4 is a schematic flow chart of another method for testing the maximum current of a battery provided by an embodiment of the present invention;

[0044] Figure 5 is a schematic diagram of the change curve of the maximum current with the SOC at different temperatures at a specified pulse time;

[0045] Figure 6 is a schematic diagram of the change curve of the maximum current with the temperature at different SOCs at a specified pulse time;

[0046] Figure 7 is a schematic flow chart for testing the maximum pulse current at different pulse times;

[0047] Figure 8 is a schematic flow chart for testing the maximum pulse current at different SOCs;

[0048] Figure 9 is a schematic flow chart for testing the maximum pulse current at different temperatures;

[0049] Figure 10 is a schematic structural diagram of a maximum current test system for a battery provided by an embodiment of the present invention;

[0050] Figure 11 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0052] Figure 1 A flowchart of a method for testing the maximum current of a battery provided by an embodiment of the present invention. This embodiment is applicable to the situation of testing the maximum current of a battery. This method can be executed by a maximum current testing system of the battery, and the device can be implemented in a hardware and / or software manner. The method specifically includes the following steps:

[0053] S110. Determine the state parameters that affect the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter;

[0054] Among them, the state parameters that affect the maximum current at least include the ambient temperature of the battery, the state of charge (SOC), and the pulse time. Generally, under charging conditions, the higher the ambient temperature, the shorter the pulse time, and the lower the SOC of the battery, the larger the acceptable charging current, and vice versa; under discharging conditions, the higher the ambient temperature, the shorter the pulse time, and the higher the SOC state of the battery, the larger the acceptable discharging current, and vice versa. Therefore, the ranges of the three influencing factors are relatively wide. Among them, the temperature is generally -30°C - 60°C, the pulse time is generally 1S - 120S, and the state of charge is generally 10% - 100%. For the convenience of description, by way of example, the first parameter in the embodiments of the present invention is the temperature, the second parameter is the state of charge, and the third parameter is the pulse time.

[0055] S120. Set the first parameter as a fixed parameter, and obtain the relationship curve between the second parameter and the third parameter and the maximum current value as a reference relationship curve;

[0056] Specifically, set the first parameter as a fixed value, use the second parameter and the third parameter as variables, measure the maximum current value, and obtain the relationship curve between the third parameter and the maximum current value, that is, the reference relationship curve through data fitting. By way of example, the process of determining the reference relationship curve is as follows: Set the first parameter, that is, the temperature, to X°C, where X°C is any value within -30°C - 60°C, and the temperature can be selected according to the test requirements. Measure the pulse time as a variable at X°C and the maximum current at a certain state of charge.Figure 2 It is a schematic diagram of the variation curve of the maximum current with the pulse time at different SOCs for a specified temperature. Refer to Figure 2 , at least three test points should be selected for the pulse time. For example, the first pulse time is 1 s, the second pulse time is 10 s, and the third pulse time is 60 s. Set the classification values of the state of charge to 5%, 10%, 20%, 30%, 40%, 50%, 60% and 70%. That is, obtain the maximum current values at the first pulse time, the second pulse time and the third pulse time for each state of charge. According to the measured data, the relationship curve between the pulse time and the maximum current value can be obtained by data fitting, and this relationship curve is used as the reference relationship curve. Among them, the number of value points of the second parameter and the third parameter is only for illustration and is not specifically limited. In order to improve the curve accuracy, the number of value points can be increased accordingly.

[0057] S130. Set the first parameter as the target parameter, and measure the first maximum current value corresponding to at least one second parameter and third parameter;

[0058] Specifically, the target parameter refers to the test target determined according to the test requirements of the battery. For example, according to the test requirements of the battery, the maximum current values at each state of charge and pulse time at a required temperature of 30 °C are required, then the target parameter is set to 30 °C. Under the test target, measure the maximum current values corresponding to at least one set of second parameter and third parameter. Among them, the value points of the second parameter and the third parameter can be any set of value points in the reference relationship curve. For example, select the state of charge as 50% and the pulse time as 10 s, then a first maximum current value can be obtained correspondingly.

[0059] S140. Obtain the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve.

[0060] Specifically, read the maximum current value corresponding to the same value points of the second parameter and the third parameter in the reference relationship curve, and fit the first maximum current value and this maximum current value to obtain the maximum current values at each state of charge and pulse time under the target parameter. Exemplarily, the process of obtaining the target relationship curve corresponding to the target parameter is as follows: compare the first maximum current value with this maximum current value to obtain a ratio, and use this ratio to convert the reference relationship curve, so as to obtain the relationship curve under this target parameter. That is, when changing the influencing factors of the maximum current of the battery, only need to measure the data again by dotting, and the maximum current values of each second parameter and third parameter under the target parameter can be obtained.

[0061] The technical solution provided by the embodiments of the present invention determines the first parameter, the second parameter, and the third parameter that affect the maximum current of the battery. First, the first parameter is used as a fixed parameter to obtain the relationship curve between the second parameter and the third parameter and the maximum current value, and this relationship curve is used as the reference relationship curve. Then, when the first parameter is used as the target parameter, at least one set of the first parameter and the second parameter corresponding to the first maximum current value is measured. Through the method of mathematical fitting, the target relationship curve corresponding to the target parameter is obtained according to the first maximum current value and the reference relationship curve. Therefore, when changing one influencing factor, it is only necessary to measure at least one set of data again by dotting, and then the maximum current values of each second parameter and the third parameter under the target parameter can be obtained, so as to obtain the maximum current of the battery under all temperatures, all SOCs, and all pulse times, greatly saving the test time, improving the test efficiency, and reducing the test cost.

[0062] Based on the above embodiments, Figure 3 FIG. is a schematic flow chart of another method for testing the maximum current of a battery provided by the embodiments of the present invention. Refer to Figure 3 and the steps of the method include:

[0063] S210. Determine the state parameters that affect the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter;

[0064] S220. Set the first parameter as a fixed parameter, and measure the maximum current values corresponding to different third parameters under each second parameter;

[0065] Specifically, set the second parameter as a fixed value, and use the third parameter as a variable to conduct tests in sequence, so as to obtain the maximum current values corresponding to different third parameters under each second parameter. Exemplarily, in the embodiments of the present invention, the first parameter is temperature, the second parameter is charge state, and the third parameter is pulse time. The first parameter is a fixed parameter, that is, the test temperature is a fixed parameter, and the maximum current values corresponding to the changes of other parameters are tested. Exemplarily, the fixed parameter can be selected as X °C, and X °C is any point between -30 °C and 60 °C. First, adjust the battery capacity to the specified SOC of M%, that is, set the second parameter as the fixed value M%, where M ranges from 10 to 100. After the battery is placed and stabilized, start the test. Adjust the temperature to the required test temperature X °C, and measure the maximum current value of the first pulse time. In the same process, the maximum current values corresponding to the second pulse time and the third pulse time under the SOC of M% can be measured, so as to obtain the maximum current values corresponding to different pulse times under each charge state.

[0066] S230. Establish the relationship between the third parameter and the maximum current under the same second parameter, and form the relationship curve between the third parameter and the maximum current as the reference relationship curve.

[0067] Specifically, when the first parameter is temperature, the second parameter is charge state, and the third parameter is pulse time, by changing the SOC and repeating the tests, multiple curves showing the variation of the maximum current value with time under different SOCs can be obtained through mathematical fitting based on the test data. These curves are the reference relationship curves, as Figure 2 shown.

[0068] S240. Set the first parameter as the target parameter, and measure the first maximum current value corresponding to at least one second parameter and the third parameter;

[0069] S250. Obtain the target relationship curve corresponding to the target parameter based on the first maximum current value and the reference relationship curve.

[0070] Figure 4 The flowchart of another method for testing the maximum current of a battery provided by an embodiment of the present invention is shown in Figure 4 , and the steps of this method include:

[0071] S310. Determine the state parameters that affect the maximum current. Among them, the state parameters include the first parameter, the second parameter, and the third parameter;

[0072] S320. Determine a second parameter, and test the current value at the third parameter; obtain the cut-off voltage based on the current value, and obtain the difference between the cut-off voltage and the preset cut-off voltage. If the difference is within the preset range, the current value is recorded as the maximum current value;

[0073] Specifically, for the sake of description, by way of example, in an embodiment of the present invention, the first parameter is temperature, the second parameter is charge state, and the third parameter is pulse time. The first parameter is a fixed parameter, that is, the test temperature is a fixed parameter, and the maximum current values corresponding to the changes of other parameters are tested. By way of example, the fixed parameter can be selected as X °C, and X °C can be any point between -30 °C and 60 °C. First, adjust the battery capacity to the specified SOC of M%, that is, set the second parameter as the fixed value of M% SOC. Among them, M ranges from 10 to 100. After the battery is left to stand until it is stable, start the test. Adjust the temperature to the required test temperature X °C, measure the current value at the first pulse time, substitute the measured current value into the cut-off voltage calculation model, calculate the cut-off voltage, and compare it with the preset cut-off voltage of the battery. If the difference between the cut-off voltage and the preset cut-off voltage is within the preset range, the current value is recorded as the maximum current value at the first pulse time. By way of example, the preset range is from 0 to 0.5 V. If the difference between the cut-off voltage and the preset cut-off voltage is not within the preset range, the test needs to be repeated until a suitable current value is obtained. Through the same process, the maximum current values corresponding to the second pulse time and the third pulse time at M% SOC can be measured.

[0074] Similarly, if the first parameter, the second parameter, and the third parameter are the pulse time, the temperature, and the charge state respectively. That is, the test pulse is a fixed parameter, and the maximum current value corresponding to the change of other parameters is tested. Exemplarily, the pulse time is selected as 10 s, that is, the second pulse time. First, the battery capacity is adjusted to the specified SOC of M%, and the battery is left to stand until it is stable and then the test is started. The temperature is adjusted to the test temperature of X °C, that is, the second parameter is set to the fixed test temperature of X °C. At the specified second pulse time, the current value of M% of the SOC is measured. The measured current value is substituted into the cut-off voltage calculation model to calculate the cut-off voltage, which is compared with the preset cut-off voltage of the battery. If the difference between the cut-off voltage and the preset cut-off voltage is within the preset range, this current value is recorded as the maximum current value at the second pulse time. If the difference between the cut-off voltage and the preset cut-off voltage is not within the preset range, the test needs to be repeated until a suitable current value is obtained. Through the same process, the maximum current value corresponding to the remaining SOC at the temperature of X °C can be tested.

[0075] Similarly, if the first parameter, the second parameter, and the third parameter are the pulse time, the charge state, and the temperature respectively. That is, the test pulse is a fixed parameter, and the maximum current value corresponding to the change of other parameters is tested. Exemplarily, the pulse time is selected as 10 s, that is, the second pulse time. First, the battery capacity is adjusted to the specified SOC of M%, that is, the second parameter is set to the fixed SOC of M%. The battery is left to stand until it is stable and then the test is started. The temperature is adjusted to the test temperature of X °C. At the specified pulse time, the current value at the test temperature of X °C is measured. The measured current value is substituted into the cut-off voltage calculation model to calculate the cut-off voltage, which is compared with the preset cut-off voltage of the battery. If the difference between the cut-off voltage and the preset cut-off voltage is within the preset range, this current value is recorded as the maximum current value at the second pulse time. If the difference between the cut-off voltage and the preset cut-off voltage is not within the preset range, the test needs to be repeated until a suitable current value is obtained. Through the same process, the maximum current value corresponding to the remaining test temperature at the SOC of M% can be tested, so as to obtain the maximum current values corresponding to different temperatures under each charge state.

[0076] S340. Repeatedly test to obtain the maximum current values corresponding to different third parameters under each second parameter.

[0077] S350. Establish the relationship between the third parameter and the maximum current under the same second parameter, and form a relationship curve between the third parameter and the maximum current as the reference relationship curve.

[0078] Specifically, when the first parameter is the temperature, the second parameter is the charge state, and the third parameter is the pulse time, by changing the SOC and repeating the test, based on the test data, multiple regular curves of the maximum current value changing with time under different SOCs can be obtained through mathematical fitting, that is, the reference relationship curves, as Figure 2 shown.Figure 5 Schematic diagram of the curve of the maximum current varying with the SOC at different temperatures for a specified pulse time. Refer to Figure 5 , when the first parameter, the second parameter, and the third parameter are the pulse time, the temperature, and the state of charge respectively, based on the test data, multiple curves of the maximum current varying with the SOC at different temperatures, that is, the reference relationship curves, can be obtained through mathematical fitting. Figure 6 Schematic diagram of the curve of the maximum current varying with the temperature at different SOCs for a specified pulse time. Refer to Figure 6 , when the first parameter, the second parameter, and the third parameter are the pulse time, the state of charge, and the temperature respectively, based on the test data, multiple curves of the maximum current varying with the temperature at different SOCs, that is, the reference relationship curves, can be obtained through mathematical fitting.

[0079] S360. Set the first parameter as the target parameter, and measure the first maximum current value corresponding to at least one second parameter and third parameter;

[0080] S370. Obtain the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve.

[0081] Based on the above embodiments, optionally, obtaining the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve includes:

[0082] According to the reference relationship curve, obtain the second maximum current value at the second parameter and the third parameter that are the same as the first maximum current value;

[0083] Determine the conversion coefficient according to the first maximum current value and the second maximum current value;

[0084] According to the conversion coefficient, convert the axis values of the reference relationship curve to obtain the target relationship curve.

[0085] Specifically, when the first parameter is temperature, the second parameter is charge state, and the third parameter is pulse time, for example, the measurement parameters corresponding to the first maximum current value are a temperature of 30 °C, a charge state of 50%, and a pulse time of 10 s. If the first maximum current value measured is A, then the maximum current value corresponding to a charge state of 50% and a pulse time of 10 s is read according to the reference relationship curve, that is, the second maximum current value B. Then the conversion coefficient C is the first maximum current value A divided by the second maximum current value B. Based on the reference relationship curve, the numerical values of the horizontal and vertical coordinates are both multiplied by the conversion coefficient C, and the target relationship curve at a temperature of 30 °C is obtained. Similarly, when the first parameter, the second parameter, and the third parameter are pulse time, temperature, and charge state respectively; or when the first parameter, the second parameter, and the third parameter are pulse time, charge state, and temperature respectively, the target relationship curve of any parameter can be obtained. Thus, according to the reference relationship curve of the maximum current varying with temperature, time, and SOC, the maximum current of the battery at all temperatures, all times, and all SOCs can be predicted, greatly reducing the test time and test cost.

[0086] Optionally, the first parameter, the second parameter, and the third parameter are temperature, charge state, and pulse time respectively; or the first parameter, the second parameter, and the third parameter are pulse time, temperature, and charge state respectively; or the first parameter, the second parameter, and the third parameter are pulse time, charge state, and temperature respectively. Specifically, by taking two of the first parameter, the second parameter, and the third parameter as fixed quantities for analysis, the regular curves of the maximum current value varying with time at different SOCs, the regular curves of the maximum current varying with SOC at different temperatures, and the regular curves of the maximum current varying with temperature at different SOCs can be obtained respectively, that is, the reference relationship curves. Using the reference relationship curves for conversion, the target relationship curves of any parameter are obtained. Thus, according to the reference relationship curve of the maximum current varying with temperature, time, and SOC, the maximum current of the battery at all temperatures, all times, and all SOCs can be predicted, greatly reducing the test time and test cost.

[0087] Optionally, before setting the first parameter as the first fixed parameter and obtaining the relationship curve between different third parameters and the maximum current value at each second parameter as the reference relationship curve, it further includes:

[0088] Calibrating the battery capacity;

[0089] Adjusting the battery capacity to the preset charge state;

[0090] Adjusting the battery to the preset test temperature.

[0091] Specifically, calibrate the battery capacity to avoid inaccurate data caused by battery capacity errors. At the same time, adjust the battery capacity to the preset charge state and the preset test temperature before testing to improve the consistency of the initial conditions during the testing process and reduce testing errors.

[0092] Figure 7 For the flow diagram of testing the maximum pulse current at different pulse times, see Figure 7 , and the method steps include:

[0093] S410. Calibrate the battery capacity. Discharge the battery at a fixed rate at the preset temperature, and set it aside for a preset time after discharge. Cycle the discharge and set-aside process at least twice, and take the last discharge capacity as the calibration value of the battery. Exemplarily, the preset temperature is taken as 25 °C room temperature, discharge at a 1C rate and set it aside for 10 - 30 minutes, cycle this step at least twice, and take the last discharge capacity as the cell capacity calibration value.

[0094] S420. Adjust the battery capacity to the preset charge state. Optionally, charge the battery to the preset charge state with a charging current at the preset rate, where the preset rate is between 0.2C and 1C. Use a small charging rate to reduce the impact on the battery.

[0095] S430. Adjust the temperature to the required test temperature X °C, and set it aside for 6 - 15 hours. Conduct the maximum current test for the first pulse time T1, substitute the measured current value I1 to obtain the cut-off voltage V1, and compare the cut-off voltage V1 with the preset cut-off voltage V. If 0V ≤ V1 - V ≤ 0.5V, end this test, and take the measured current value I1 as the maximum current value at the first pulse time T1. If the cut-off voltage V1 is not within this range, repeat the test until a suitable current value I1 is obtained.

[0096] S440. Restore to the initial test conditions, keep the initial conditions the same, change the pulse time, and repeat the test to measure the current value I2 at the second pulse time T2 and the current value I3 at the third pulse time T3 at this temperature and this SOC.

[0097] S450. Repeat S420 - S440 to complete the current values I1 at the first pulse time T1, the current value I2 at the second pulse time T2, and the current value I3 at the third pulse time T3 at other SOC states at this temperature. The values of the three points of the current values I1, I2, and I3 at each SOC can be used to fit N different curves of the maximum current changing with time under different SOCs. As Figure 2 shown.

[0098] Figure 8Schematic diagram of the process for testing the maximum pulse current at different SOCs, see Figure 8 , the method steps include:

[0099] S510. Calibrate the battery capacity. Discharge the battery at a fixed rate under a preset temperature, and leave it idle for a preset time after discharge. Cycle the discharge and idle process at least twice, and take the last discharge capacity as the calibrated value of the battery. Exemplarily, the preset temperature is taken as 25°C room temperature, discharge at a rate of 1C and then leave it idle for 10 - 30 minutes. Cycle this step at least twice, and take the last discharge capacity as the calibrated value of the battery cell capacity.

[0100] S520. Adjust the battery capacity to a specified SOC of M%. Optionally, charge the battery to a state of charge of M% with a charging current at a preset rate, where the preset rate is between 0.2C and 1C. Charge with a small rate to reduce the impact on the battery. Exemplarily, take three points for testing, adjust the capacity to the state of charge (M = 0 - 100), take three points for testing SOC, and the values of M% are 5%, 50%, and 90%, which are respectively denoted as SOC1, SOC2, and SOC3.

[0101] S530. Adjust the temperature to the required test temperature X°C, and leave it idle for 6 - 15 hours. Conduct a maximum current test at the first pulse time T1, substitute the measured current value I1 to obtain the cut-off voltage V1, and compare the cut-off voltage V1 with the preset cut-off voltage V. If 0V ≤ V1 - V ≤ 0.5V, end this test, and take the measured current value I1 as the maximum current value at SOC1 at the first pulse time T1. If the cut-off voltage V1 is not within this range, repeat the test until a suitable current value I1 is obtained.

[0102] S540. Restore to the initial test conditions, keep the initial conditions the same, change the SOC of M%, and repeat the test to measure the current values I2 and I3 corresponding to SOC1 and SOC2.

[0103] S550. Repeat S520 - S540 to complete the current values I1 of SOC1, I2 of SOC2, and I3 of SOC3 at other temperatures at this pulse time. The values of the three points of the current values I1, I2, and I3 at each SOC can be used to fit N curves showing the variation law of the maximum current with SOC at different temperatures at the first pulse time T1, as Figure 5 shown.

[0104] Figure 9 Schematic diagram of the process for testing the maximum pulse current at different temperatures, see Figure 9 , the method steps include:

[0105] S610. Calibrate the battery capacity. Discharge the battery at a fixed rate under a preset temperature, and leave it standing for a preset time after discharge. Repeat the discharge and standing process at least twice, and take the last discharge capacity as the calibration value of the battery. Exemplarily, the preset temperature is taken as the room temperature of 25°C, discharge at a rate of 1C and then leave it standing for 10 - 30 minutes. Repeat this step at least twice, and take the last discharge capacity as the calibration value of the battery cell capacity.

[0106] S620. Adjust the battery capacity to a specified SOC of M%. Optionally, charge the battery to a state of charge of M% with a charging current at a preset rate, where the preset rate is between 0.2C and 1C. Use a small charging rate to reduce the impact on the battery.

[0107] S630. Adjust the temperature to temperature X1 (exemplarily, take three points for testing, the temperatures are -20°C, 25°C and 60°C, denoted as X1, X2 and X3 respectively. Among them, the starting test temperature for adjustment can be arbitrarily selected according to the test requirements), and leave it standing for 6 - 15 hours. Conduct a maximum current test at the third pulse time T3 (select a longer discharge third pulse time T3 for convenient data collection). Substitute the measured current value I1 to obtain the cut-off voltage V1, and compare the cut-off voltage V1 with the preset cut-off voltage V. If 0v ≤ V1 - V ≤ 0.5v, end this test, and take the measured current value I1 as the maximum current value at temperature X1°C and the third pulse time T3. If the cut-off voltage V1 is not within this range, the test needs to be repeated until a suitable current value I1 is obtained.

[0108] S640. Restore to the starting test conditions, keep the starting conditions the same, change the test temperature, and repeat the test to measure the current values I2 and I3 corresponding to temperature X2 and temperature X3.

[0109] S650. Repeat S620 - S640 to complete the current values I1 at temperature X1, current values I2 at temperature X2 and current values I3 at temperature X3 under other SOCs at this pulse time. The values of the three points of the current values I1, I2, and I3 at each temperature can be used to fit N curves of the variation law of the maximum current with temperature under different SOCs at the third pulse time T3, as Figure 6 shown.

[0110] Figure 10 is a schematic structural diagram of a maximum current test system for a battery provided by an embodiment of the present invention. Refer to Figure 10 , including:

[0111] A determination module 110, configured to determine state parameters affecting the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter;

[0112] An acquisition module 120 is configured to set a first parameter as a first fixed parameter, and acquire a relationship curve between different third parameters and a maximum current value under each second parameter as a reference relationship curve.

[0113] A measurement module 130 is configured to set the first parameter as a target parameter, and measure a first maximum current value corresponding to at least one second parameter and a third parameter.

[0114] A target module 140 is configured to obtain a target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve.

[0115] Specifically, a determination module 110 determines state parameters that affect the maximum current. The state parameters that affect the maximum current at least include the ambient temperature of the battery, the state of charge (SOC), and the pulse time. Generally, under charging conditions, the higher the ambient temperature, the shorter the pulse time, and the lower the SOC of the battery, the larger the acceptable charging current, and vice versa; under discharging conditions, the higher the ambient temperature, the shorter the pulse time, and the higher the SOC state of the battery, the larger the acceptable discharging current, and vice versa. Therefore, the ranges of the three influencing factors are relatively wide. Among them, the temperature is generally -30°C to 60°C, the pulse time is generally 1S to 120S, and the state of charge is generally 10% to 100%. For the convenience of description, by way of example, the first parameter in the embodiments of the present invention is temperature, the second parameter is the state of charge, and the third parameter is the pulse time.

[0116] The acquisition module 120 sets the first parameter as a fixed value, takes the second parameter and the third parameter as variables, measures the maximum current value, and obtains a relationship curve between the third parameter and the maximum current value through data fitting, that is, the reference relationship curve. By way of example, the process of determining the reference relationship curve is as follows: Set the first parameter, that is, the temperature, as X°C, where X°C is any value between -30°C and 60°C, and the temperature can be selected according to the test requirements. Measure the pulse time as a variable at X°C and the maximum current at a certain state of charge. Refer to Figure 2 , at least three test points are selected for the pulse time. For example, the first pulse time is 1S, the second pulse time is 10S, and the third pulse time is 60S. Set the classification values of the state of charge as 5%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. That is to say, the acquisition module 120 acquires the maximum current values of the first pulse time, the second pulse time, and the third pulse time under each state of charge. According to the measured data, a relationship curve between the pulse time and the maximum current value can be obtained through data fitting, and this relationship curve is used as the reference relationship curve. Among them, the number of value points of the second parameter and the third parameter is only for illustration and is not specifically limited. In order to improve the curve accuracy, the number of value points can be increased accordingly.

[0117] The target parameter refers to the test target determined according to the test requirements of the battery. For example, according to the test requirements of the battery, if the required temperature is 30°C and the maximum current values for each state of charge and pulse time are needed, then the target parameter is set to 30°C. Under the test target, the measurement module 130 measures the maximum current values corresponding to at least one set of second parameters and third parameters. Among them, the value points of the second parameter and the third parameter can be any set of value points in the reference relationship curve. For example, if the state of charge is selected as 50% and the pulse time is 10S, then a first maximum current value can be correspondingly obtained.

[0118] The target module 140 reads the maximum current values corresponding to the value points of the same second parameter and third parameter in the reference relationship curve, and obtains the maximum current values for each state of charge and pulse time under the target parameter through fitting the first maximum current value and this maximum current value. Exemplarily, the process of obtaining the target relationship curve corresponding to the target parameter is as follows: comparing the first maximum current value and this maximum current value to obtain a ratio, and using this ratio to transform the reference relationship curve, so as to obtain the relationship curve under this target parameter. That is to say, when changing the influencing factors of the maximum current of the battery, only need to measure the data again by dotting once, and then the maximum current values of each second parameter and third parameter under the target parameter can be obtained.

[0119] In the technical solution provided by the embodiment of the present invention, the determination module determines the first parameter, the second parameter, and the third parameter that affect the maximum current of the battery. The acquisition module takes the first parameter as a fixed parameter, obtains the relationship curve between the second parameter and the third parameter and the maximum current value, and takes this relationship curve as the reference relationship curve. The measurement module measures the first maximum current values corresponding to at least one set of the first parameter and the second parameter with the first parameter as the target parameter. Through the method of mathematical fitting, the target module obtains the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve. Thus, when changing one influencing factor, only need to measure at least one set of data again by dotting, and then the maximum current values of each second parameter and third parameter under the target parameter can be obtained, so as to obtain the maximum current of the battery under full temperature, full SOC, and full pulse time, greatly saving the test time, improving the test efficiency, and reducing the test cost.

[0120] The embodiment of the present invention also provides an electronic device, and the electronic device includes:

[0121] At least one processor; and

[0122] A memory communicatively connected to at least one processor; wherein,

[0123] The memory stores a computer program executable by at least one processor. The computer program is executed by the at least one processor to enable the at least one processor to execute the maximum current test method of the battery in any item of the embodiments of the present invention.

[0124] Figure 11 It is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0125] As Figure 11 shown, the electronic device 10 includes at least one processor 11, and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. Among them, the memory stores a computer program executable by the at least one processor. The processor 11 can execute various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The input / output (I / O) interface 15 is also connected to the bus 14.

[0126] A plurality of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0127] The processor 11 may be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the maximum current of a battery, characterized in that, Including: Determine the state parameters that affect the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter; Set the first parameter as a fixed parameter, and obtain the relationship curve between the second parameter and the third parameter and the maximum current value as a reference relationship curve; Set the first parameter as the target parameter, and measure the first maximum current value corresponding to at least one of the second parameter and the third parameter; Obtain the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve; Obtaining the target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve includes: According to the reference relationship curve, obtain the second maximum current value at the second parameter and the third parameter that are the same as the first maximum current value; Determine the conversion coefficient according to the first maximum current value and the second maximum current value; According to the conversion coefficient, convert the coordinate axis values of the reference relationship curve to obtain the target relationship curve; Obtaining the relationship curve between the second parameter and the third parameter and the maximum current value as a reference relationship curve includes: Measure the maximum current value corresponding to different third parameters at each second parameter.

2. The method for testing the maximum current of the battery according to claim 1, characterized in that, Obtaining the relationship curve between the second parameter and the third parameter and the maximum current value as a reference relationship curve includes: Establish the relationship between the third parameter and the maximum current under the same second parameter to form the relationship curve between the third parameter and the maximum current as the reference relationship curve.

3. The method for testing the maximum current of the battery according to claim 1, wherein Measuring the maximum current value corresponding to different third parameters at each second parameter includes: Determine a second parameter and test the current value at the third parameter; Obtain the cut-off voltage according to the current value, obtain the difference between the cut-off voltage and the preset cut-off voltage, and if the difference is within the preset range, record the current value as the maximum current value; Repeat the test to obtain the maximum current value corresponding to different third parameters at each second parameter.

4. The maximum current testing method of the battery according to claim 1, characterized in that The first parameter, the second parameter, and the third parameter are temperature, charge state, and pulse time respectively; or, the first parameter, the second parameter, and the third parameter are pulse time, temperature, and charge state respectively; or, the first parameter, the second parameter, and the third parameter are pulse time, charge state, and temperature respectively.

5. The method for testing the maximum current of the battery according to claim 1, characterized in that, Before setting the first parameter as the first fixed parameter and obtaining the relationship curve between each second parameter and different third parameters and the maximum current value as the reference relationship curve, it further includes: Calibrate the battery capacity; Adjust the battery capacity to the preset charge state; Adjust the battery to the preset test temperature.

6. The method for testing the maximum current of the battery according to claim 5, wherein Calibrating the battery capacity includes: Discharge the battery at a fixed rate at the preset temperature, set it aside for a preset time after discharge, cycle at least two discharge and set-aside processes, and take the last discharge capacity as the calibration value of the battery.

7. The maximum current test method of the battery according to claim 5, characterized in that Adjusting the battery capacity to the preset charge state includes: Charge the battery to the preset charge state with a charging current at a preset rate, where the preset rate is between 0.2C and 1C.

8. A maximum current testing system for a battery, which is controlled by using the maximum current testing method for a battery according to any one of claims 1-7, characterized in that, Comprising: A determination module for determining state parameters that affect the maximum current, where the state parameters include a first parameter, a second parameter, and a third parameter; An acquisition module for setting the first parameter as a first fixed parameter and obtaining a relationship curve between different third parameters and the maximum current value under each second parameter as a reference relationship curve; A measurement module for setting the first parameter as a target parameter and measuring a first maximum current value corresponding to at least one of the second parameter and the third parameter; A target module for obtaining a target relationship curve corresponding to the target parameter according to the first maximum current value and the reference relationship curve.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for testing the maximum current of the battery according to any one of claims 1-7.

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