A method and device for testing the power characteristics of a battery

Abstract

An embodiment of the present invention discloses a method and device for testing the power characteristics of a battery. The method includes performing an electrical test on a battery under test with a set state of charge at a set temperature at a first set power P1 to obtain a first test time; if the first test time is less than a set time, adjusting the state of charge of the battery under test to the set state of charge and performing an electrical test at a second set power P2 to obtain a second test time; if the m-th test time is not equal to the set time, calculating the difference ΔP between the m-th set power Pm and the (m - 1)-th set power Pm - 1, and if ΔP meets the set error condition, determining the m-th set power Pm as the power value to be measured of the battery under test at the set temperature and the set state of charge. The power characteristic test in the embodiment of the present invention adopts a method of successive approximation iteration combined with setting the test power error, which improves the test accuracy, meets the requirements of automated large-scale testing, and shortens the test cycle.

Description

Technical Field

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

[0002] With the development and wide application of electric vehicles in the new energy field, state estimation such as the state of charge, state of health, and state of power of lithium-ion batteries has become one of the research hotspots, and its test and estimation accuracy directly affects the utilization efficiency and use safety of the battery system. The power state (State Of Power, SOP) of a power battery is used to characterize the maximum peak charge and discharge power that the battery can withstand under a certain state (temperature / state of charge / duration / preset cut-off voltage). This parameter has important evaluation and strategy control significance for the acceleration start, climbing, and braking energy recovery performance of electric vehicles. Existing SOP test methods have the problem of long test cycles. Summary of the Invention

[0003] The present invention provides a method and device for testing battery power characteristics. By using a method of successive approximation iteration combined with setting the test power error, the test accuracy is improved, and while meeting the requirements of automated large-scale testing, the test cycle is shortened.

[0004] In a first aspect, an embodiment of the present invention provides a method for testing battery power characteristics, the method comprising:

[0005] At a set temperature, for a battery under test with a set state of charge, perform an electrical test at a first set power P1 to obtain a first test time; wherein, the electrical test includes a charge test or a discharge test; the charge test includes charging the battery under test to an upper cut-off voltage; the discharge test includes discharging the battery under test to a lower cut-off voltage. If the first test time is less than the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at a second set power P2 to obtain a second test time; wherein, the second set power is half of the first set power;

[0006] If the second test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at a third set power P3 to obtain a third test time;

[0007] ……;

[0008] If the nth test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time;

[0009] ……;

[0010] If the m-th test time is not equal to the set time, calculate the m-th set power P m and the difference ΔP from the (m - 1)-th set power P m-1 . If ΔP meets the set error condition, then determine the m-th set power P m as the power value to be measured of the battery under test at the set temperature and set state of charge;

[0011] wherein, when the n-th test time is greater than the set time, the (n + 1)-th set power when the n-th test time is less than the set time, the (n + 1)-th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, and P n is the n-th set power.

[0012] Optionally, if the first test time is equal to the set time, determine the first set power as the power value to be measured of the battery under test at the set temperature and set state of charge;

[0013] The first set power is the maximum power of the test equipment for performing an electrical test on the battery under test. If the first test time is greater than the set time, perform an electrical test on the battery under test at the next set state of charge at the set temperature.

[0014] Optionally, if the n-th test time is equal to the set time, determine the n-th set power as the power value to be measured of the battery under test at the set temperature and set state of charge.

[0015] Optionally, the charging test includes charging the battery under test to the upper cut-off voltage; the discharging test includes discharging the battery under test to the lower cut-off voltage.

[0016] Optionally, adjusting the state of charge of the battery under test to the set state of charge includes:

[0017] Constantly charging the battery under test to the full charge state at a preset temperature and discharging the battery under test to the set state of charge at the set temperature.

[0018] Optionally, after determining the power value to be measured of the battery under test at the set temperature and set state of charge, further include:

[0019] Performing a test on the power value to be measured of the battery under test at the next state of charge at the set temperature;

[0020] After determining the measured power values of the battery under test at all states of charge at the set temperature, perform the test on the measured power values at different states of charge at the next set temperature.

[0021] Optionally, the packaging form of the battery under test includes square, soft-pack, and cylindrical batteries; the battery material of the battery under test includes a ternary layered material battery or a lithium iron phosphate battery.

[0022] In a second aspect, an embodiment of the present invention further provides a battery power characteristic test device, which includes:

[0023] A test module for performing an electrical test on the battery under test at a set charge state at a set temperature with a first set power P1 to obtain a first test time; wherein, the electrical test includes a charge test or a discharge test; the charge test includes charging the battery under test to the upper cut-off voltage; the discharge test includes discharging the battery under test to the lower cut-off voltage;

[0024] A first test time judgment module for, if the first test time is less than the set time, adjusting the state of charge of the battery under test to the set state of charge and performing an electrical test with a second set power P2 to obtain a second test time; wherein, the second set power is half of the first set power;

[0025] A second test time judgment module for, if the second test time is not equal to the set time, adjusting the state of charge of the battery under test to the set state of charge and performing an electrical test with a third set power P3 to obtain a third test time;

[0026] ……;

[0027] The nth test time judgment module for, if the nth test time is not equal to the set time, adjusting the state of charge of the battery under test to the set state of charge and performing an electrical test with the (n + 1)th set power P n+1 to obtain the (n + 1)th test time;

[0028] ……;

[0029] The mth test time judgment module for, if the mth test time is not equal to the set time, calculating the difference ΔP between the mth set power P m and the (m - 1)th set power P m-1 If ΔP meets the set error condition, then determine the mth set power P m as the measured power value of the battery under test at the set temperature and set state of charge;

[0030] wherein, when the nth test time is greater than the set time, the (n + 1)th set power When the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, and m is a positive integer greater than or equal to 3, P n is the nth set power.

[0031] Optionally, the first test time judgment module is further configured to, if the first test time is equal to the set time, determine that the first set power is the power value to be measured of the battery to be tested at the set temperature and the set state of charge;

[0032] The first set power is the maximum power of the test equipment for performing an electrical test on the battery to be tested. The first test time judgment module is further configured to, if the first test time is greater than the set time, perform an electrical test on the battery to be tested at the next set state of charge at the set temperature;

[0033] The nth test time judgment module is further configured to, if the nth test time is equal to the set time, determine that the nth set power is the power value to be measured of the battery to be tested at the set temperature and the set state of charge.

[0034] Optionally, the battery power characteristic test device further includes:

[0035] The first power value to be measured test module is configured to, after determining the power value to be measured of the battery to be tested at the set temperature and the set state of charge, test the power value to be measured of the battery to be tested at the next state of charge at the set temperature;

[0036] The second power value to be measured test module is configured to, after determining the power values to be measured of the battery to be tested at all states of charge at the set temperature, test the power values to be measured of different states of charge at the next set temperature.

[0037] The technical solution of this embodiment tests the battery to be tested in multiple dimensions such as temperature and state of charge, with a wide coverage and complete battery power characteristic test results; the test uses a successive approximation iteration method to set the test power error, improving the test accuracy, meeting the requirements of automated large - batch testing, and shortening the test cycle. The technical solution of this embodiment solves the problems of too long test time and relatively low test efficiency in the prior art, and has the technical effects of effectively shortening the test time, improving the flexibility of the test multiple, and improving the test efficiency. Description of the Drawings

[0038] Figure 1 is a flowchart of a battery power characteristic test method provided in Embodiment 1 of the present invention;

[0039] Figure 2It is a flowchart of a method for testing the charging power characteristics of a battery provided in Embodiment 3 of the present invention;

[0040] Figure 3 It is a schematic structural diagram of a device for testing the power characteristics of a battery provided in Embodiment 4 of the present invention. Specific embodiments

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0042] Embodiment 1

[0043] Figure 1 It is a flowchart of a method for testing the power characteristics of a battery provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation of testing the power characteristics of a battery. This method can be executed by a device for testing the power characteristics of a battery, and this device can be implemented by software and / or hardware. Refer to Figure 1 , and the method specifically includes the following steps:

[0044] S110. At a set temperature, perform an electrical test on a battery under test with a set state of charge at a first set power P1 to obtain a first test time; wherein, the electrical test includes a charging test or a discharging test; the charging test includes charging the battery under test to an upper cut-off voltage; the discharging test includes discharging the battery under test to a lower cut-off voltage.

[0045] Specifically, select a test device according to the parameters of the battery under test. The test device can be a charge-discharge device with an adjustable power range. The charge-discharge device can charge the battery under test or discharge the battery under test. The adjustable power range of the charge-discharge device specifically means |P|≥αγUW, where P is the maximum charge / discharge power of the charge-discharge device, α is the maximum pulse coefficient, γ is the maximum power error of the device, U is the upper cut-off voltage of the battery under test, and W is the nominal capacity of the battery under test. Select an incubator with an adjustable temperature range according to the highest temperature point Tmax and the lowest temperature point Tmin required for the test. The temperature range of the incubator includes [Tmin - 5°C, Tmax + 5°C]. During the test, the battery under test can be placed in the incubator and the temperature of the incubator can be adjusted to make the battery at the set temperature.

[0046] Use the selected charge and discharge device and incubator to perform electrical tests on the battery under test. The electrical tests include charge tests and discharge tests. At the temperature set by the incubator, perform electrical tests on the battery under test with a set charge and discharge device at the first set power P1 for a battery under test with a set state of charge to obtain a first test time. The first set power P1 is the maximum power of the charge and discharge device for performing electrical tests on the battery under test, and the first test time is the duration for which the battery under test actually undergoes electrical tests. For example, perform a charge test on the battery under test at the first set power P1 to obtain a first charge time; perform a discharge test on the battery under test at the first set power P1 to obtain a first discharge time.

[0047] The charge test includes charging the battery under test to the upper cut-off voltage; the discharge test includes discharging the battery under test to the lower cut-off voltage.

[0048] Among them, the upper cut-off voltage for charging the ternary layered material battery under test can be 4.2V, and the lower cut-off voltage for discharging can be 2.5V - 3.0V. The upper cut-off voltage for charging the lithium iron phosphate battery under test can be 3.65V, and the lower cut-off voltage for discharging can be 2.0V - 2.5V. The specific values of the upper cut-off voltage and the lower cut-off voltage in the embodiments of the present invention are not limited and can be set according to the type of the battery under test.

[0049] S120. If the first test time is less than the set time, adjust the state of charge of the battery under test to the set state of charge and perform electrical tests at the second set power P2 to obtain a second test time; where the second set power is half of the first set power.

[0050] Among them, if the first test time is less than the set time, it indicates that the first set power for performing electrical tests on the battery under test is too large at this time, and it is necessary to reduce the first set power and perform the next more accurate iterative test. Therefore, adjust the state of charge of the battery under test and enter the electrical test of the next state of charge. Adjusting the state of charge of the battery under test to the set state of charge specifically means constantly charging the battery under test to the full charge state at the preset temperature and discharging the battery under test to the set state of charge at the preset temperature. Perform electrical tests at the second set power P2 to obtain a second test time, and the second set power P2 is half of the first set power.

[0051] It should be noted that the set time is the target charge time or target discharge time for the battery power characteristic test. Exemplarily, the preset time can be 10S, 30S, or 90S.

[0052] S130. If the second test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge and perform electrical tests at the third set power P3 to obtain a third test time.

[0053] ……;

[0054] S140. If the nth test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time.

[0055] ……;

[0056] S150. If the mth test time is not equal to the set time, then calculate the difference ΔP between the mth set power P m and the (m - 1)th set power P m-1 . If ΔP meets the set error condition, then determine the mth set power P m as the power value to be measured of the battery under test at the set temperature and the set state of charge;

[0057] wherein, when the nth test time is greater than the set time, the (n + 1)th set power when the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, and P n is the nth set power.

[0058] Specifically, after the above-mentioned multiple iterative tests, the power to be measured may still not be accurate. At this time, error estimation will be carried out. The more iterations, the smaller the error. When iterating to the mth time, if the mth test time is not equal to the set time, conditional judgment is required, and the difference ΔP between the mth set power P m and the (m - 1)th set power P m-1 is calculated. After linear parameter correction, if ΔP meets the set error condition, the mth set power P m is determined as the power value to be measured of the battery under test at the set temperature and the set state of charge, and the next state of charge test is carried out. If ΔP does not meet the set error condition, continue the iterative test until the optimal power is searched and then end. It should be noted that the error condition is the preset acceptable error range of the power characteristic test.

[0059] Exemplarily, m can be 3, 4, 5, 6... If the 3rd test time is not equal to the set time, calculate the difference ΔP between the 3rd set power P3 and the 2nd set power P2, that is, ΔP = P3 - P2. If ΔP meets the set error condition, then determine the 3rd set power P3 as the power value to be measured of the battery under test at the set temperature and the set state of charge. If ΔP does not meet the set error condition, continue the test and repeat the above operation.

[0060] The technical solution of this embodiment tests the battery under test in multiple dimensions such as temperature and state of charge, with a wide coverage and complete test results of the battery power characteristics. The test uses a method of successive approximation iteration combined with setting the test power error, which improves the test accuracy, meets the requirements of automated large-scale testing, and shortens the test cycle. The technical solution of this embodiment solves the problems of too long test time and relatively low test efficiency in the prior art, and has the technical effects of effectively shortening the test time, improving the flexibility of the test rate, and improving the test efficiency.

[0061] Embodiment 2

[0062] Optionally, on the basis of the above embodiment, if the first test time is equal to the set time, the first set power is the power value to be measured of the battery under test at the set temperature and the set state of charge; the first set power is the maximum power of the test equipment for performing electrical tests on the battery under test. If the first test time is greater than the set time, an electrical test is performed on the battery under test at the next set state of charge at the set temperature.

[0063] Specifically, when the first test time is equal to the set time, the first set power for performing an electrical test on the battery under test is the power required for the power characteristic test. When the first test time is greater than the set time, it indicates that the first set power is too small and needs to be increased. However, at this time, the first set power has reached the limit of the maximum power of the charge and discharge equipment and cannot be increased further, and the maximum power of the actual power characteristic test cannot be detected in this test. Therefore, an electrical test is performed on the battery under test at the next set state of charge at the set temperature.

[0064] Optionally, if the nth test time is equal to the set time, the nth set power is the power value to be measured of the battery under test at the set temperature and the set state of charge.

[0065] Among them, if the nth test time is equal to the set time, the nth set power is the power value to be measured of the battery under test at the set temperature and the set state of charge, and a test of the next state of charge at the same temperature needs to be performed on the battery under test.

[0066] Optionally, adjusting the state of charge of the battery under test to the set state of charge includes:

[0067] Constantly charging the battery under test at a constant current to a fully charged state at a preset temperature, and discharging the battery under test to the set state of charge at the set temperature.

[0068] Exemplarily, the battery under test is fully charged in a constant current and constant voltage charging mode at a preset temperature of 25 ± 1°C. The temperature of the temperature chamber is adjusted to the specified temperature K. After the temperature stabilizes, it is discharged at 0.33C to the set state of charge (SOC). Here, C represents the current intensity when the battery is fully discharged in one hour. SOC ∈ [100%, 95%, 90%, …… 10%, 5%, 0%]. The specific range of SOC is not limited in this embodiment and can be set as needed.

[0069] Optionally, after determining the power value to be measured of the battery under test at the set temperature and the set state of charge, it further includes:

[0070] At the set temperature, perform the measurement of the power value to be measured for the next state of charge of the battery under test;

[0071] After determining the power values to be measured of all states of charge of the battery under test at the set temperature, perform the measurement of the power values to be measured for different states of charge at the next set temperature.

[0072] Specifically, after multiple iterative tests, the power value to be measured of the battery under test at the set temperature and the set state of charge can be determined, indicating that the test process at this set temperature and set state of charge is completed. It is necessary to adjust the state of charge of the battery under test at the current set temperature to perform the measurement of the power value to be measured for the next state of charge. After determining the power values to be measured of all states of charge of the battery under test at the set temperature, adjust the set temperature of the temperature chamber to perform the measurement of the power values to be measured for different states of charge at the next set temperature. Finally, draw the power characteristic map and build a model of the battery under test based on the above test results.

[0073] Optionally, the packaging form of the battery under test includes square, soft pack, and cylindrical batteries; the battery material of the battery under test includes a ternary layered material battery or a lithium iron phosphate battery.

[0074] Embodiment III

[0075] Figure 2 is a flowchart of a method for testing the charging power characteristics of a battery provided in Embodiment III of the present invention. Refer to Figure 2 , and the following takes the test of the power characteristics of the battery under test during charging as an example for description:

[0076] S201. At the set temperature, for the battery under test in the set state of charge, perform a charging test at the first set power P1 to obtain the first test time; the charging test includes charging the battery under test to the upper cut-off voltage.

[0077] S202. Determine the relationship between the first test time and the set time. If the first test time is equal to the set time, execute S203; if the first test time is greater than the set time, execute S204; if the first test time is less than the set time, execute S205.

[0078] S203. The first set power for the charging test of the battery under test is the power required for the power characteristic test, and the power characteristic test is completed.

[0079] S204. Conduct a charging test on the battery under test at the next set state of charge at the set temperature.

[0080] S205. Adjust the state of charge of the battery under test to the set state of charge and conduct a charging test at the second set power P2 to obtain the second test time; where the second set power is half of the first set power.

[0081] Among them, if the first test time is less than the set time, it indicates that the first set power for the charging test of the battery under test is too large at this time, and it is necessary to reduce the first set power and conduct the next more accurate iterative test.

[0082] S206. If the second test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge and conduct a charging test at the third set power P3 to obtain the third test time.

[0083] ……;

[0084] S207. Determine the relationship between the nth test time and the set time. If the nth test time is not equal to the set time, execute S208; if the nth test time is equal to the set time, execute S209.

[0085] S208. Adjust the state of charge of the battery under test to the set state of charge and conduct a charging test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time.

[0086] When the nth test time is greater than the set time, the (n + 1)th set power When the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, P n is the nth set power.

[0087] ……;

[0088] S210. If the mth test time is not equal to the set time, calculate the mth set power P m and the (m - 1)th set power P m-1The difference ΔP. If ΔP meets the set error condition, then the m-th set power P m is determined as the power value to be measured of the battery under test at the set temperature and set state of charge.

[0089] S211. Perform a charging test on the battery under test at the next set state of charge at the set temperature.

[0090] When iterating to the m-th time, if the m-th test time is not equal to the set time, conditional judgment is required. Calculate the m-th set power P m and the difference ΔP from the (m - 1)-th set power P m-1 After performing linear parameter correction, if ΔP is less than the set error, the m-th set power P m is determined as the power value to be measured of the battery under test at the set temperature and set state of charge, and the next state of charge test is performed. If ΔP is greater than the set error, continue the iterative test until the optimal power is searched and then end.

[0091] S209. The n-th set power is the power value to be measured of the battery under test at the set temperature and set state of charge. It is necessary to perform the next state of charge test on the battery under test at the same temperature.

[0092] It should be noted that the power characteristic test of the battery under test during discharge is the same as that during the charging power characteristic test, except that the charging process is changed to the discharging process. Other processes can refer to the above, and will not be elaborated here.

[0093] Embodiment 4

[0094] Figure 3 is a schematic structural diagram of a battery power characteristic test device provided in Embodiment 4 of the present invention. Refer to Figure 3 , the battery power characteristic test device 300 includes:

[0095] A test module 301, configured to perform an electrical test on the battery under test at the set temperature and set state of charge at a first set power P1 to obtain a first test time; wherein, the electrical test includes a charging test or a discharging test; the charging test includes charging the battery under test to the upper cut-off voltage; the discharging test includes discharging the battery under test to the lower cut-off voltage;

[0096] A first test time judgment module 302, configured to if the first test time is less than the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at a second set power P2 to obtain a second test time; wherein, the second set power is half of the first set power;

[0097] The second test time determination module 303 is configured to, if the second test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at a third set power P3 to obtain a third test time;

[0098] ……;

[0099] The nth test time determination module 304 is configured to, if the nth test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time;

[0100] ……;

[0101] The mth test time determination module 305 is configured to, if the mth test time is not equal to the set time, calculate the difference ΔP between the mth set power P m and the (m - 1)th set power P m-1 If ΔP meets the set error condition, then determine the mth set power P m as the power value to be measured of the battery under test at the set temperature and the set state of charge;

[0102] wherein, when the nth test time is greater than the set time, the (n + 1)th set power when the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, and P n is the nth set power.

[0103] The battery power characteristic test device provided by the embodiments of the present invention can execute the battery power characteristic test method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0104] It should be noted that in the embodiments of the above battery power characteristic test device, the included modules are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the modules are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0105] Optionally, the first test time determination module 302 is further configured to, if the first test time is equal to the set time, determine the first set power as the power value to be measured of the battery under test at the set temperature and the set state of charge;

[0106] The first set power is the maximum power of the test device for performing electrical tests on the battery under test. The first test time determination module 302 is further configured to, if the first test time is greater than the set time, perform an electrical test on the battery under test at the set temperature under the next set state of charge.

[0107] The nth test time determination module 304 is further configured to, if the nth test time is equal to the set time, the nth set power is the power value to be measured of the battery under test at the set temperature and the set state of charge.

[0108] Optionally, the battery power characteristic test device further includes:

[0109] The first power value to be measured test module is configured to, after determining the power value to be measured of the battery under test at the set temperature and the set state of charge, perform a test on the power value to be measured of the battery under test at the next state of charge at the set temperature.

[0110] The second power value to be measured test module is configured to, after determining the power values to be measured of the battery under test at all states of charge at the set temperature, perform a test on the power values to be measured of the battery under test at different states of charge at the next set temperature.

[0111] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for testing the power characteristics of a battery, characterized in that, Including: At a set temperature, for a battery under test with a set state of charge, conduct an electrical test at a first set power P1 to obtain a first test time; wherein, the electrical test includes a charge test or a discharge test; the charge test includes charging the battery under test to an upper cut-off voltage; the discharge test includes discharging the battery under test to a lower cut-off voltage; If the first test time is less than the set time, adjust the state of charge of the battery under test to the set state of charge, and conduct an electrical test at a second set power P2 to obtain a second test time; wherein, the second set power is one-half of the first set power; If the second test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and conduct an electrical test at a third set power P3 to obtain a third test time; ……； If the nth test time is not equal to the set time, adjust the state of charge of the battery under test to the set state of charge, and perform an electrical test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time; ……； If the m-th test time is not equal to the set time, calculate the m-th set power P m and the (m - 1)-th set power P m-1 to obtain the difference ΔP. If ΔP meets the set error condition, then determine the m-th set power P m as the measured power value of the battery under test at the set temperature and set state of charge; Among them, when the nth test time is greater than the set time, the (n + 1)th set power When the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, P n is the nth set power; If the first test time is equal to the set time, determine the first set power as the power value to be measured of the battery under test at the set temperature and set state of charge; The first set power is the maximum power of the test equipment for conducting an electrical test on the battery under test. If the first test time is greater than the set time, conduct an electrical test on the battery under test at the next set state of charge at the set temperature; If the nth test time is equal to the set time, determine the nth set power as the power value to be measured of the battery under test at the set temperature and set state of charge.

2. The method according to claim 1, characterized in that, Adjusting the state of charge of the battery under test to the set state of charge includes: Constant current charging the battery under test to a full charge state at a preset temperature, and discharging the battery under test to the set state of charge at the set temperature.

3. The method according to claim 1, wherein After determining the power value to be measured of the battery under test at the set temperature and set state of charge, further including: At the set temperature, conduct a test on the power value to be measured of the battery under test at the next state of charge; After determining the power values to be measured of the battery under test at all states of charge at the set temperature, conduct tests on the power values to be measured of different states of charge at the next set temperature.

4. The method according to claim 1, characterized in that, The packaging form of the battery under test includes square, soft pack, and cylindrical batteries; the battery material of the battery under test includes a ternary layered material battery or a lithium iron phosphate battery.

5. A battery power characteristic testing device, characterized in that, Including: A test module, configured to conduct an electrical test on a battery under test with a set state of charge at a first set power P1 at a set temperature to obtain a first test time; wherein, the electrical test includes a charge test or a discharge test; the charge test includes charging the battery under test to an upper cut-off voltage; the discharge test includes discharging the battery under test to a lower cut-off voltage; A first test time judgment module, configured to, if the first test time is less than the set time, adjust the state of charge of the battery under test to the set state of charge, and conduct an electrical test at a second set power P2 to obtain a second test time; wherein, the second set power is one-half of the first set power; The second test time judgment module is used to adjust the state of charge of the battery under test to the set state of charge and perform an electrical test at the third set power P3 to obtain the third test time if the second test time is not equal to the set time; ……； The nth test time determination module is used to adjust the state of charge of the battery under test to the set state of charge if the nth test time is not equal to the set time, and perform an electrical test at the (n + 1)th set power P n+1 to obtain the (n + 1)th test time; ……； The m-th test time judgment module is used to calculate the m-th set power P if the m-th test time is not equal to the set time. m And the (m - 1)-th set power P m-1 The difference ΔP. If ΔP meets the set error condition, then the m-th set power P m Is determined as the measured power value of the battery under test at the set temperature and the set state of charge. Among them, when the nth test time is greater than the set time, the (n + 1)th set power When the nth test time is less than the set time, the (n + 1)th set power n is a positive integer greater than or equal to 2 and less than or equal to m - 1, m is a positive integer greater than or equal to 3, P n is the nth set power; The first test time judgment module is further used to determine the first set power as the power value to be measured of the battery under test at the set temperature and the set state of charge if the first test time is equal to the set time; The first set power is the maximum power of the test equipment for performing an electrical test on the battery under test. The first test time judgment module is further used to perform an electrical test on the battery under test at the next set state of charge at the set temperature if the first test time is greater than the set time; The nth test time judgment module is further used to determine the nth set power as the power value to be measured of the battery under test at the set temperature and the set state of charge if the nth test time is equal to the set time.

6. The test device according to claim 5, characterized in that It further includes: The first power value to be measured test module is used to perform a test on the power value to be measured of the battery under test at the next state of charge at the set temperature after determining the power value to be measured of the battery under test at the set temperature and the set state of charge; The second power value to be measured test module is used to perform a test on the power value to be measured of different states of charge at the next set temperature after determining the power values to be measured of all states of charge of the battery under test at the set temperature.

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