A method, apparatus, controller, and storage medium for assembling lithium batteries

Abstract

This invention relates to a lithium battery grouping method, apparatus, controller, and storage medium, and pertains to the field of lithium battery technology. The lithium battery grouping method classifies N lithium batteries to be grouped into different levels based on their average capacity, average voltage difference, and preset rules, resulting in capacity level, voltage difference level, and voltage drop level. Grouping is then performed according to these levels, resulting in better consistency among the N lithium battery groups. Furthermore, the capacity level classification reduces the number of battery management system (BMS) equalization cycles caused by unstable battery capacity, thus minimizing battery life degradation. The lithium battery grouping method provided by this invention also reduces energy consumption and improves the efficiency of the grouped lithium battery packs.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a lithium battery packing method, apparatus, controller and storage medium. Background Technology

[0002] Inhomogeneity in battery raw materials and process deviations during production can lead to minute differences in electrode thickness, activation level of active materials, and porosity of positive and negative electrodes. Therefore, batteries produced from the same batch of raw materials cannot be completely identical in weight, capacity, internal resistance, and voltage parameters. To meet usage requirements, large-scale series and parallel connection of lithium batteries is typically necessary. Common screening methods include static capacity matching, internal resistance matching, voltage matching, and dynamic characteristic matching. Often, to achieve better range, companies use a combination of various matching methods. Even so, after screening, excessive voltage differences may occur at the end of charge and discharge cycles, requiring the Battery Management System (BMS) to initiate equalization. However, this equalization often fails to accurately reflect the actual battery capacity, resulting in incorrect BMS operation and reduced range. Existing battery pack matching methods suffer from low efficiency and high energy consumption. Summary of the Invention

[0003] This invention provides a lithium battery packing method, apparatus, controller, and storage medium to solve the problems of low efficiency and high energy consumption of the lithium battery packs produced by existing packing methods.

[0004] In a first aspect, the present invention provides a method for pairing lithium batteries, the method comprising:

[0005] All N lithium batteries to be matched are charged to a first preset voltage at a constant current value, where N is an integer greater than 1.

[0006] After a first preset dormancy period, the individual charge of each of the N lithium batteries is recorded and the total charge of the N lithium batteries is calculated.

[0007] Calculate the average charge of N lithium batteries based on the total charge.

[0008] Based on the average power consumption, a power consumption level is obtained by classifying the power consumption.

[0009] All N lithium batteries are charged at a constant current of a second preset current value, and the voltage values ​​of the N lithium batteries at the beginning and end of a preset time period are recorded.

[0010] Calculate the voltage difference of N lithium batteries within the preset time period, where the voltage difference is the voltage value of the lithium battery at the end of the preset time period minus the voltage value of the lithium battery at the beginning of the preset time period.

[0011] Calculate the average pressure difference of the N lithium batteries based on the pressure difference;

[0012] The pressure differential levels are determined by classifying the average pressure differential.

[0013] All N lithium batteries are charged at a constant current value of a third preset current. After a second preset time of sleep, the second preset voltage is recorded. After a third preset time of sleep, the third preset voltage is recorded. The voltage drop of the N lithium batteries is calculated. The voltage drop is the difference between the third preset voltage and the second preset voltage divided by the third preset time.

[0014] The voltage drop of the lithium battery is classified into different levels according to preset rules to obtain voltage drop levels;

[0015] The N lithium batteries are grouped according to the power rating, the differential pressure rating, and the voltage drop rating.

[0016] A further technical solution is that the step of classifying the power consumption based on the average power consumption to obtain power consumption levels includes:

[0017] The average power consumption is divided into five levels: first power consumption level, second power consumption level, third power consumption level, fourth power consumption level, and fifth power consumption level.

[0018] Wherein, the first power level is the range of less than 97% of the average power, the second power level is the range of greater than or equal to 97% and less than 100% of the average power, the third power level is the range of greater than or equal to 100% and less than 103% of the average power, the fourth power level is the range of greater than or equal to 103% and less than or equal to 106% of the average power, and the fifth power level is the range of greater than 106% of the average power.

[0019] A further technical solution is that the step of classifying pressure differentials based on the average pressure differential to obtain pressure differential levels includes:

[0020] The average pressure difference is divided into four levels: first pressure difference level, second pressure difference level, third pressure difference level, and fourth pressure difference level.

[0021] Wherein, the first differential pressure level is the range less than 20% of the average differential pressure, the second differential pressure level is the range greater than or equal to 20% of the average differential pressure and less than 40% of the average differential pressure, the third differential pressure level is the range greater than or equal to 40% of the average differential pressure and less than 60% of the average differential pressure, and the fourth differential pressure level is the range greater than or equal to 60% of the average differential pressure.

[0022] A further technical solution is that the voltage drop of the lithium battery is classified into levels according to preset rules to obtain voltage drop levels, including:

[0023] The voltage drop of the lithium battery is classified into three levels: first voltage drop level, second voltage drop level, and third voltage drop level.

[0024] Wherein, the first voltage drop level is the range of less than 2 millivolts per hour, the second voltage drop level is the range of greater than or equal to 2 millivolts per hour and less than or equal to 5 millivolts per hour, and the third voltage drop level is the range of greater than 5 millivolts per hour.

[0025] A further technical solution is that the step of grouping N lithium batteries according to the capacity level, the differential pressure level, and the voltage drop level includes:

[0026] Lithium batteries with the same capacity rating, differential pressure rating, and voltage drop rating are configured as a group.

[0027] A further technical solution is that, after a first preset hibernation time, the following steps are taken:

[0028] The N lithium batteries are discharged to a preset cutoff voltage using a fourth preset current value.

[0029] A further technical solution is that, before all N lithium batteries to be paired are charged to a first preset voltage at a constant current value, the following steps are taken:

[0030] All N lithium batteries to be matched are charged at a constant current of the fifth preset current value for the fourth preset time.

[0031] In a second aspect, the present invention provides a lithium battery packing device, including a unit for performing the method as described in the first aspect.

[0032] Thirdly, the present invention provides a controller, which includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0033] Memory, used to store computer programs;

[0034] When a processor executes a program stored in memory, it implements the steps of the method described in the first aspect.

[0035] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0036] The beneficial effects of this invention are:

[0037] This invention classifies N lithium batteries into groups based on their average capacity, average voltage difference, and preset rules, resulting in capacity level, voltage difference level, and voltage drop level. Grouping is then performed according to these levels, leading to better consistency among the resulting lithium battery packs. Furthermore, the capacity level classification reduces the number of battery management system (BMS) equalization cycles caused by unstable battery capacity, thus minimizing battery pack range degradation. The lithium battery grouping method also reduces energy consumption and improves the efficiency of the grouped lithium battery packs. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic flowchart of a lithium battery packing method provided in Embodiment 1 of the present invention;

[0041] Figure 2 This is a schematic flowchart of a lithium battery packing method provided in Embodiment 2 of the present invention;

[0042] Figure 3 This is a structural diagram of a lithium battery matching device provided in Embodiment 3 of the present invention;

[0043] Figure 4 This is a structural diagram of a lithium battery matching device provided in Embodiment 4 of the present invention;

[0044] Figure 5 This is a structural diagram of a controller. Detailed Implementation

[0045] To better understand the technical content of the present invention, the technical solution of the present invention will be further introduced and explained below with reference to specific embodiments, but is not limited thereto.

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0048] It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0049] Example 1

[0050] See Figure 1 Embodiment 1 of the present invention provides a lithium battery pairing method, which includes steps S101-S111.

[0051] S101, all N lithium batteries to be matched are charged to the first preset voltage at a constant current value of the first preset current value, where N is an integer greater than 1.

[0052] In this embodiment of the invention, N can be any integer greater than 1, such as 800, 1000, etc., and is not limited here. The first preset current value is 0.2 multiplied by the capacity of the lithium battery. The magnitude of the first preset current value is determined according to the capacity of the lithium battery. For example, if the capacity of the lithium battery is 50 amp-hours (AH), then the first preset current value is 10A; if the capacity of the lithium battery is 100 amp-hours (AH), then the first preset current value is 20A. Among the N lithium batteries, there will be lithium batteries with different capacities, so the first preset current value will be calculated according to the different capacities of the lithium batteries. The first preset voltage can be specifically 3.2V. When the lithium battery is charged to 3.2V by constant current through the first preset current value, 3.2V is equivalent to a cutoff voltage in a charging state. At this time, the charge of the lithium battery will fluctuate due to the polarization internal resistance.

[0053] S102, after a first preset sleep time, record the individual charge of each of the N lithium batteries and calculate the total charge of the N lithium batteries.

[0054] In this embodiment of the invention, the first preset time can be specifically 30 minutes. Specifically, as mentioned above, when the lithium battery is charged to 3.2V by a constant current through the first preset current value, the battery charge will fluctuate due to the polarization internal resistance, making it impossible to obtain the most accurate maximum charge. Therefore, after 30 minutes of rest, the battery charge is stabilized, and the charge of a single lithium battery at this time is recorded. The total charge is obtained by summing the charges of N lithium batteries.

[0055] S103, calculate the average charge of N lithium batteries based on the total charge.

[0056] Specifically, the average capacity of N lithium batteries can be obtained by dividing the total capacity by N. This step S103 is to make the following classification of capacity levels more balanced and improve the rationality of the classification of capacity levels.

[0057] S104, classify the power consumption according to the average power consumption to obtain the power consumption level.

[0058] Specifically, as mentioned above, the average capacity of N lithium batteries is obtained, and the batteries are classified into different levels based on the average capacity to make the classification of capacity levels more reasonable and balanced.

[0059] In one embodiment, the step of classifying the power consumption based on the average power consumption to obtain the power consumption level includes:

[0060] The average power consumption is divided into five levels: first power consumption level, second power consumption level, third power consumption level, fourth power consumption level, and fifth power consumption level.

[0061] Wherein, the first power level is the range of less than 97% of the average power, the second power level is the range of greater than or equal to 97% and less than 100% of the average power, the third power level is the range of greater than or equal to 100% and less than 103% of the average power, the fourth power level is the range of greater than or equal to 103% and less than or equal to 106% of the average power, and the fifth power level is the range of greater than 106% of the average power.

[0062] Specifically, this embodiment of the invention provides five power levels, including a range exceeding 100% of the power capacity. It should be noted that 100% of the average power capacity refers to a standard value; however, a single battery may have a power capacity greater than, less than, or equal to the average power capacity. Therefore, the power capacity of a single battery could be 97% or 103% of the average power capacity, depending on the actual situation. For example, if there are five batteries with power capacities of 104, 105, 106, 107, and 105, the average power capacity is 105.4. Clearly, 105 falls within the range greater than or equal to 97% of the average power capacity and less than 100% of the average power capacity. Therefore, 105 can be classified into the second power level. In subsequent battery pairing, other power levels besides the second power level can be excluded. Then, based on the voltage difference level and voltage drop level corresponding to the battery with a power capacity of 105, the corresponding pairing is found, and then pairing is performed.

[0063] S105, charge all N lithium batteries with a constant current of the second preset current value, and record the voltage values ​​of the N lithium batteries at the beginning and end of the preset time period.

[0064] In this embodiment of the invention, the second preset current value can be specifically 25A, and the preset time period can be specifically 1 second. That is, the lithium battery voltage before and after 1 second is recorded to obtain the instantaneous voltage difference. The voltage difference can be classified into different levels by the instantaneous voltage difference, which can reduce the need for the battery management system (BMS) to work too much due to the long-term polarization internal resistance of the lithium battery, thereby reducing the excessive energy consumption caused by the excessive work of the battery management system (BMS).

[0065] S106, calculate the voltage difference of N lithium batteries within the preset time period, where the voltage difference is the voltage value of the lithium battery at the end of the preset time period minus the voltage value of the lithium battery at the beginning of the preset time period.

[0066] Specifically, as mentioned above, if a lithium battery has an initial voltage of 2.9V and a final voltage of 3.1V, then the voltage difference of that lithium battery within 1 second is 0.2V. Similarly, by calculating the voltage differences of N lithium batteries, the average voltage difference of N lithium batteries can be calculated, and the voltage difference level can be classified based on the average voltage difference.

[0067] S107, Calculate the average pressure difference of the N lithium batteries based on the pressure difference.

[0068] Specifically, classifying pressure differential levels by average pressure differential can make the classification of pressure differential levels more balanced and improve the rationality of the classification.

[0069] S108, Based on the average pressure difference, the pressure difference level is divided into levels to obtain the pressure difference level.

[0070] Specifically, the pressure difference levels derived from the average pressure difference can make the pressure difference levels more reasonable. For example, if the pressure differences of five lithium batteries are 0.2, 0.3, 0.4, 0.5, and 0.6 respectively, then the average pressure difference is 0.4. This average pressure difference reflects the overall pressure difference of these five lithium batteries, and the pressure difference levels derived from the overall perspective are more reasonable. Similarly, the average pressure difference calculated from the pressure differences of N lithium batteries can also make the overall pressure difference levels more balanced and reasonable, further improving the reliability of the battery pack.

[0071] In one embodiment, the step of classifying pressure differentials based on the average pressure differential to obtain pressure differential levels includes:

[0072] The average pressure difference is divided into four levels: first pressure difference level, second pressure difference level, third pressure difference level, and fourth pressure difference level.

[0073] Wherein, the first differential pressure level is the range less than 20% of the average differential pressure, the second differential pressure level is the range greater than or equal to 20% of the average differential pressure and less than 40% of the average differential pressure, the third differential pressure level is the range greater than or equal to 40% of the average differential pressure and less than 60% of the average differential pressure, and the fourth differential pressure level is the range greater than or equal to 60% of the average differential pressure.

[0074] Specifically, as mentioned above, the voltage differential is classified according to its average differential pressure. The range less than 20% of the average differential pressure is designated as the first differential pressure level; the range greater than or equal to 20% and less than 40% of the average differential pressure is designated as the second differential pressure level; the range greater than or equal to 40% and less than 60% of the average differential pressure is designated as the third differential pressure level; and the range greater than or equal to 60% of the average differential pressure is designated as the fourth differential pressure level. For example, if four lithium batteries have differential pressures of 0.4, 0.6, 0.8, and 1.0, the average differential pressure is 0.7. Clearly, 1.0 is greater than 60% of 0.7, so 1.0 can be classified as the fourth differential pressure level. In subsequent battery grouping, other differential pressure levels besides the fourth level can be filtered out, and the batteries can then be grouped according to their corresponding capacity and voltage drop levels.

[0075] S109, charge N lithium batteries at a constant current value with a third preset current value, record the second preset voltage after a second preset time of sleep, record the third preset voltage after a third preset time of sleep, and calculate the voltage drop of the N lithium batteries; the voltage drop is the difference between the third preset voltage and the second preset voltage divided by the third preset time.

[0076] In this embodiment of the invention, the third preset current value can be specifically 0.8A, the second preset time can be specifically 15 minutes, and the second preset voltage is determined according to the actual situation of the lithium battery. The second preset voltage will be different for lithium batteries of different capacities. The third preset time can be specifically 12 hours, and the third preset voltage is also determined according to the actual situation of the lithium battery. The second preset voltage will be different for lithium batteries of different capacities. For example, if the second preset voltage and the third preset voltage of a certain lithium battery are 3.04V and 3.05V respectively, then the voltage drop of a single lithium battery can be obtained by dividing (3.05V-3.04V) / 12, and the voltage drop of the lithium battery is 0.08 millivolts / hour.

[0077] S110, the voltage drop of the lithium battery is classified into levels according to preset rules to obtain voltage drop levels.

[0078] Specifically, the preset rule can be to divide the voltage drop of the lithium battery into three voltage drop levels, namely, a range of less than 2 mV / h, a range of greater than or equal to 2 mV / h and less than or equal to 5 mV / h, and a range of greater than 5 mV / h.

[0079] In one embodiment, classifying the voltage drop of the lithium battery into voltage drop levels according to preset rules includes:

[0080] The voltage drop of the lithium battery is classified into three levels: first voltage drop level, second voltage drop level, and third voltage drop level.

[0081] Wherein, the first voltage drop level is the range of less than 2 millivolts per hour, the second voltage drop level is the range of greater than or equal to 2 millivolts per hour and less than or equal to 5 millivolts per hour, and the third voltage drop level is the range of greater than 5 millivolts per hour.

[0082] Specifically, the range of less than 2 mV / h is designated as the first voltage drop level, the range of greater than or equal to 2 mV / h and less than or equal to 5 mV / h is designated as the second voltage drop level, and the range of greater than 5 mV / h is designated as the third voltage drop level. The voltage drop is calculated based on the second and third preset voltages obtained from the test, and the corresponding voltage drop level is determined based on the voltage drop.

[0083] S111, N lithium batteries are grouped according to the power rating, the differential pressure rating, and the voltage drop rating.

[0084] Specifically, grouping N lithium batteries according to their capacity level, differential voltage level, and voltage drop level can greatly reduce the problem of excessive energy consumption caused by excessive operation of the battery management system (BMS) due to the polarization resistance of the lithium batteries. Compared with the existing grouping method based on capacity level, the grouping method based on capacity level in this invention is more stable, resulting in better consistency of the grouped lithium battery packs. This reduces the number of times the BMS initiates equalization at the end, reduces the problem of differential voltage expansion due to polarization, and avoids the probability of misjudgment in the BMS equalization process.

[0085] In one embodiment, the step of grouping N lithium batteries according to the capacity level, the differential voltage level, and the voltage drop level includes:

[0086] Lithium batteries with the same capacity rating, differential pressure rating, and voltage drop rating are configured as a group.

[0087] Specifically, the embodiments of the present invention have 5 capacity levels, 4 differential voltage levels, and 3 voltage drop levels, resulting in 5×4×3=60 grouping schemes. From the N lithium batteries tested, lithium batteries with the same capacity level, differential voltage level, and voltage drop level are selected and configured into a group, resulting in a total of sixty grouping schemes, ensuring that each lithium battery can find a corresponding grouping scheme among the 60 grouping schemes.

[0088] Example 2

[0089] See Figure 2 Embodiment 2 of the present invention provides a method for matching lithium batteries, the method for matching lithium batteries includes steps S201-S213.

[0090] S201, all N lithium batteries to be matched are charged at a constant current of the fifth preset current value for the fourth preset time.

[0091] Specifically, the fifth preset current value is 0.01 multiplied by the lithium battery capacity. For example, if the lithium battery capacity is 50 ampere-hours (AH), then the fifth preset current value is 0.5A. The fifth preset current value is determined based on the lithium battery capacity. The fourth preset time is 30 minutes. Charging the lithium battery at the fifth preset current value for 30 minutes serves as a pre-charging protection measure in subsequent steps S202-S203, preventing damage to the lithium battery due to excessive charging current.

[0092] S202, all N lithium batteries to be matched are charged to the first preset voltage at a constant current value of the first preset current value, where N is an integer greater than 1.

[0093] In this embodiment of the invention, N can be any integer greater than 1, such as 800, 1000, etc., and is not limited here. The first preset current value is 0.2 multiplied by the capacity of the lithium battery. The magnitude of the first preset current value is determined according to the capacity of the lithium battery. For example, if the capacity of the lithium battery is 50 amp-hours (AH), then the first preset current value is 10A; if the capacity of the lithium battery is 100 amp-hours (AH), then the first preset current value is 20A. Among the N lithium batteries, there will be lithium batteries with different capacities, so the first preset current value will be calculated according to the different capacities of the lithium batteries. The first preset voltage can be specifically 3.2V. When the lithium battery is charged to 3.2V by constant current through the first preset current value, 3.2V is equivalent to a cutoff voltage in a charging state. At this time, the charge of the lithium battery will fluctuate due to the polarization internal resistance.

[0094] S203, after a first preset sleep time, record the individual charge of each of the N lithium batteries and calculate the total charge of the N lithium batteries.

[0095] In this embodiment of the invention, the first preset time can be specifically 30 minutes. Specifically, as mentioned above, when the lithium battery is charged to 3.2V by a constant current through the first preset current value, the battery charge will fluctuate due to the polarization internal resistance, making it impossible to obtain the most accurate maximum charge. Therefore, after 30 minutes of rest, the battery charge is stabilized, and the charge of a single lithium battery at this time is recorded. The total charge is obtained by summing the charges of N lithium batteries.

[0096] S204, calculate the average charge of N lithium batteries based on the total charge.

[0097] Specifically, the average capacity of N lithium batteries can be obtained by dividing the total capacity by N. This step S103 is to make the following classification of capacity levels more balanced and improve the rationality of the classification of capacity levels.

[0098] S205, classify the power consumption according to the average power consumption to obtain the power consumption level.

[0099] Specifically, as mentioned above, the average capacity of N lithium batteries is obtained, and the batteries are classified into different levels based on the average capacity to make the classification of capacity levels more reasonable and balanced.

[0100] In one embodiment, the step of classifying the power consumption based on the average power consumption to obtain the power consumption level includes:

[0101] The average power consumption is divided into five levels: first power consumption level, second power consumption level, third power consumption level, fourth power consumption level, and fifth power consumption level.

[0102] Wherein, the first power level is the range of less than 97% of the average power, the second power level is the range of greater than or equal to 97% and less than 100% of the average power, the third power level is the range of greater than or equal to 100% and less than 103% of the average power, the fourth power level is the range of greater than or equal to 103% and less than or equal to 106% of the average power, and the fifth power level is the range of greater than 106% of the average power.

[0103] Specifically, this embodiment of the invention provides five power levels, including a range exceeding 100% of the power capacity. It should be noted that 100% of the average power capacity refers to a standard value; however, a single battery may have a power capacity greater than, less than, or equal to the average power capacity. Therefore, the power capacity of a single battery could be 97% or 103% of the average power capacity, depending on the actual situation. For example, if there are five batteries with power capacities of 104, 105, 106, 107, and 105, the average power capacity is 105.4. Clearly, 105 falls within the range greater than or equal to 97% of the average power capacity and less than 100% of the average power capacity. Therefore, 105 can be classified into the second power level. In subsequent battery pairing, other power levels besides the second power level can be excluded. Then, based on the voltage difference level and voltage drop level corresponding to the battery with a power capacity of 105, the corresponding pairing is found, and then pairing is performed.

[0104] S206, discharge the N lithium batteries to the preset cutoff voltage using the fourth preset current value.

[0105] Specifically, the fourth preset current value can be 0.7A. By discharging the lithium battery with a current of 0.7A, the preset cutoff voltage can be 2.5V. The cutoff voltage in the discharge state can prepare for the subsequent recording of the instantaneous voltage difference of the lithium battery. The recording of the instantaneous voltage difference of the battery needs to be based on the cutoff voltage of the battery discharge value to further ensure the accuracy of the data.

[0106] S207, charge all N lithium batteries with a constant current of the second preset current value, and record the voltage values ​​of the N lithium batteries at the beginning and end of the preset time period.

[0107] In this embodiment of the invention, the second preset current value can be specifically 25A, and the preset time period can be specifically 1 second. That is, the lithium battery voltage before and after 1 second is recorded to obtain the instantaneous voltage difference. The voltage difference can be classified into different levels by the instantaneous voltage difference, which can reduce the need for the battery management system (BMS) to work too much due to the long-term polarization internal resistance of the lithium battery, thereby reducing the excessive energy consumption caused by the excessive work of the battery management system (BMS).

[0108] S208, calculate the voltage difference of N lithium batteries within the preset time period, where the voltage difference is the voltage value of the lithium battery at the end of the preset time period minus the voltage value of the lithium battery at the beginning of the preset time period.

[0109] Specifically, as mentioned above, if a lithium battery has an initial voltage of 2.9V and a final voltage of 3.1V, then the voltage difference of that lithium battery within 1 second is 0.2V. Similarly, by calculating the voltage differences of N lithium batteries, the average voltage difference of N lithium batteries can be calculated, and the voltage difference level can be classified based on the average voltage difference.

[0110] S209, calculate the average pressure difference of the N lithium batteries based on the pressure difference.

[0111] Specifically, classifying pressure differential levels by average pressure differential can make the classification of pressure differential levels more balanced and improve the rationality of the classification.

[0112] S210, Based on the average pressure difference, the pressure difference level is divided into levels to obtain the pressure difference level.

[0113] Specifically, the pressure difference levels derived from the average pressure difference can make the pressure difference levels more reasonable. For example, if the pressure differences of five lithium batteries are 0.2, 0.3, 0.4, 0.5, and 0.6 respectively, then the average pressure difference is 0.4. This average pressure difference reflects the overall pressure difference of these five lithium batteries, and the pressure difference levels derived from the overall perspective are more reasonable. Similarly, the average pressure difference calculated from the pressure differences of N lithium batteries can also make the overall pressure difference levels more balanced and reasonable, further improving the reliability of the battery pack.

[0114] In one embodiment, the step of classifying pressure differentials based on the average pressure differential to obtain pressure differential levels includes:

[0115] The average pressure difference is divided into four levels: first pressure difference level, second pressure difference level, third pressure difference level, and fourth pressure difference level.

[0116] Wherein, the first differential pressure level is the range less than 20% of the average differential pressure, the second differential pressure level is the range greater than or equal to 20% of the average differential pressure and less than 40% of the average differential pressure, the third differential pressure level is the range greater than or equal to 40% of the average differential pressure and less than 60% of the average differential pressure, and the fourth differential pressure level is the range greater than or equal to 60% of the average differential pressure.

[0117] Specifically, as mentioned above, the voltage differential is classified according to its average differential pressure. The range less than 20% of the average differential pressure is designated as the first differential pressure level; the range greater than or equal to 20% and less than 40% of the average differential pressure is designated as the second differential pressure level; the range greater than or equal to 40% and less than 60% of the average differential pressure is designated as the third differential pressure level; and the range greater than or equal to 60% of the average differential pressure is designated as the fourth differential pressure level. For example, if four lithium batteries have differential pressures of 0.4, 0.6, 0.8, and 1.0, the average differential pressure is 0.7. Clearly, 1.0 is greater than 60% of 0.7, so 1.0 can be classified as the fourth differential pressure level. In subsequent battery grouping, other differential pressure levels besides the fourth level can be filtered out, and the batteries can then be grouped according to their corresponding capacity and voltage drop levels.

[0118] S211, charge N lithium batteries at a constant current value with a third preset current value, record the second preset voltage after a second preset time of sleep, record the third preset voltage after a third preset time of sleep, and calculate the voltage drop of the N lithium batteries; the voltage drop is the difference between the third preset voltage and the second preset voltage divided by the third preset time.

[0119] In this embodiment of the invention, the third preset current value can be specifically 0.8A, the second preset time can be specifically 15 minutes, and the second preset voltage is determined according to the actual situation of the lithium battery. The second preset voltage will be different for lithium batteries of different capacities. The third preset time can be specifically 12 hours, and the third preset voltage is also determined according to the actual situation of the lithium battery. The second preset voltage will be different for lithium batteries of different capacities. For example, if the second preset voltage and the third preset voltage of a certain lithium battery are 3.04V and 3.05V respectively, then the voltage drop of a single lithium battery can be obtained by dividing (3.05V-3.04V) / 12, and the voltage drop of the lithium battery is 0.08 millivolts / hour.

[0120] S212, The voltage drop of the lithium battery is classified into levels according to preset rules to obtain voltage drop levels.

[0121] Specifically, the preset rule can be to divide the voltage drop of the lithium battery into three voltage drop levels, namely, a range of less than 2 mV / h, a range of greater than or equal to 2 mV / h and less than or equal to 5 mV / h, and a range of greater than 5 mV / h.

[0122] In one embodiment, classifying the voltage drop of the lithium battery into voltage drop levels according to preset rules includes:

[0123] The voltage drop of the lithium battery is classified into three levels: first voltage drop level, second voltage drop level, and third voltage drop level.

[0124] Wherein, the first voltage drop level is the range of less than 2 millivolts per hour, the second voltage drop level is the range of greater than or equal to 2 millivolts per hour and less than or equal to 5 millivolts per hour, and the third voltage drop level is the range of greater than 5 millivolts per hour.

[0125] Specifically, the range of less than 2 mV / h is designated as the first voltage drop level, the range of greater than or equal to 2 mV / h and less than or equal to 5 mV / h is designated as the second voltage drop level, and the range of greater than 5 mV / h is designated as the third voltage drop level. The voltage drop is calculated based on the second and third preset voltages obtained from the test, and the corresponding voltage drop level is determined based on the voltage drop.

[0126] S213, group the N lithium batteries according to the power level, the differential pressure level, and the voltage drop level.

[0127] Specifically, grouping N lithium batteries according to their capacity level, differential voltage level, and voltage drop level can greatly reduce the problem of excessive energy consumption caused by excessive operation of the battery management system (BMS) due to the polarization resistance of the lithium batteries. Compared with the existing grouping method based on capacity level, the grouping method based on capacity level in this invention is more stable, resulting in better consistency of the grouped lithium battery packs. This reduces the number of times the BMS initiates equalization at the end, reduces the problem of differential voltage expansion due to polarization, and avoids the probability of misjudgment in the BMS equalization process.

[0128] In one embodiment, the step of grouping N lithium batteries according to the capacity level, the differential voltage level, and the voltage drop level includes:

[0129] Lithium batteries with the same capacity rating, differential pressure rating, and voltage drop rating are configured as a group.

[0130] Specifically, the embodiments of the present invention have 5 capacity levels, 4 differential voltage levels, and 3 voltage drop levels, resulting in 5×4×3=60 grouping schemes. From the N lithium batteries tested, lithium batteries with the same capacity level, differential voltage level, and voltage drop level are selected and configured into a group, resulting in a total of sixty grouping schemes, ensuring that each lithium battery can find a corresponding grouping scheme among the 60 grouping schemes.

[0131] Example 3

[0132] See Figure 3Embodiment 3 of the present invention provides a lithium battery matching device 400, which includes: a first charging unit 401, a first recording unit 402, a first calculation unit 403, a first division unit 404, a second charging unit 405, a second calculation unit 406, a third calculation unit 407, a second division unit 408, a third charging unit 409, a third division unit 410, and a matching unit 411.

[0133] The first charging unit 401 is used to charge all N lithium batteries to be matched to a first preset voltage at a constant current value, where N is an integer greater than 1.

[0134] The first recording unit 402 is used to record the individual charge of N lithium batteries and calculate the total charge of N lithium batteries after a first preset dormancy period.

[0135] The first calculation unit 403 is used to calculate the average charge of N lithium batteries based on the total charge.

[0136] The first division unit 404 is used to divide the power consumption into levels based on the average power consumption to obtain power consumption levels.

[0137] The second charging unit 405 is used to charge N lithium batteries at a constant current value with a second preset current value, and to record the voltage values ​​of the N lithium batteries at the beginning and end of a preset time period.

[0138] The second calculation unit 406 is used to calculate the voltage difference of N lithium batteries within the preset time period, wherein the voltage difference is the voltage value of the lithium battery at the end of the preset time period minus the voltage value of the lithium battery at the beginning of the preset time period.

[0139] The third calculation unit 407 is used to calculate the average pressure difference of N lithium batteries based on the pressure difference.

[0140] The second division unit 408 is used to classify the pressure difference according to the average pressure difference to obtain the pressure difference level.

[0141] The third charging unit 409 is used to charge N lithium batteries at a constant current value of a third preset current, record the second preset voltage after a second preset time of sleep, record the third preset voltage after a third preset time of sleep, and calculate the voltage drop of the N lithium batteries; the voltage drop is the difference between the third preset voltage and the second preset voltage divided by the third preset time.

[0142] The third division unit 410 is used to classify the voltage drop of the lithium battery according to preset rules to obtain the voltage drop level.

[0143] Grouping unit 411 is used to group N lithium batteries according to the power level, the differential voltage level, and the voltage drop level.

[0144] In one embodiment, the step of classifying the power consumption based on the average power consumption to obtain the power consumption level includes:

[0145] The average power consumption is divided into five levels: first power consumption level, second power consumption level, third power consumption level, fourth power consumption level, and fifth power consumption level.

[0146] Wherein, the first power level is the range of less than 97% of the average power, the second power level is the range of greater than or equal to 97% and less than 100% of the average power, the third power level is the range of greater than or equal to 100% and less than 103% of the average power, the fourth power level is the range of greater than or equal to 103% and less than or equal to 106% of the average power, and the fifth power level is the range of greater than 106% of the average power.

[0147] In one embodiment, the step of classifying pressure differentials based on the average pressure differential to obtain pressure differential levels includes:

[0148] The average pressure difference is divided into four levels: first pressure difference level, second pressure difference level, third pressure difference level, and fourth pressure difference level.

[0149] Wherein, the first differential pressure level is the range less than 20% of the average differential pressure, the second differential pressure level is the range greater than or equal to 20% of the average differential pressure and less than 40% of the average differential pressure, the third differential pressure level is the range greater than or equal to 40% of the average differential pressure and less than 60% of the average differential pressure, and the fourth differential pressure level is the range greater than or equal to 60% of the average differential pressure.

[0150] In one embodiment, classifying the voltage drop of the lithium battery into voltage drop levels according to preset rules includes:

[0151] The voltage drop of the lithium battery is classified into three levels: first voltage drop level, second voltage drop level, and third voltage drop level.

[0152] Wherein, the first voltage drop level is the range of less than 2 millivolts per hour, the second voltage drop level is the range of greater than or equal to 2 millivolts per hour and less than or equal to 5 millivolts per hour, and the third voltage drop level is the range of greater than 5 millivolts per hour.

[0153] In one embodiment, the step of grouping N lithium batteries according to the capacity level, the differential voltage level, and the voltage drop level includes:

[0154] Lithium batteries with the same capacity rating, differential pressure rating, and voltage drop rating are configured as a group.

[0155] Example 4

[0156] See Figure 4 Embodiment 4 of the present invention provides a lithium battery matching device 400. The lithium battery matching device 400 of Embodiment 4 differs from the lithium battery matching device 400 of Embodiment 3 in that it further includes: a fourth charging unit 412 and a discharging unit 413.

[0157] The fourth charging unit 412 is used to charge all N lithium batteries to be matched with a fifth preset current value at a constant current for a fourth preset time.

[0158] The discharge unit 413 is used to discharge N of the lithium batteries to the cutoff voltage at a fourth preset current value.

[0159] Example 5

[0160] See Figure 5 The present invention provides a controller including a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112 and the memory 113 communicate with each other through the communication bus 114.

[0161] Memory 113 is used to store computer programs;

[0162] The processor 111 is used to execute the program stored in the memory 113 to implement the lithium battery packing method provided in Embodiment 1 or 2.

[0163] Embodiment 5 of the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by processor 111, implements the steps of the lithium battery packing method provided in Embodiment 1 or Embodiment 2.

[0164] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0165] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for pairing lithium batteries, characterized in that, include: All N lithium batteries to be matched are charged to a first preset voltage at a constant current value, where N is an integer greater than 1. After a first preset dormancy period, the individual charge of each of the N lithium batteries is recorded and the total charge of the N lithium batteries is calculated. Calculate the average charge of N lithium batteries based on the total charge. The average power consumption is used to classify the power consumption levels, resulting in power consumption levels. All N lithium batteries are charged at a constant current of a second preset current value, and the voltage values ​​of the N lithium batteries at the beginning and end of a preset time period are recorded. Calculate the voltage difference of N lithium batteries within the preset time period, where the voltage difference is the voltage value of the lithium battery at the end of the preset time period minus the voltage value of the lithium battery at the beginning of the preset time period. Calculate the average pressure difference of the N lithium batteries based on the pressure difference; The pressure differential levels are determined by classifying the average pressure differential. All N lithium batteries are charged at a constant current value of a third preset current. After a second preset time of sleep, the second preset voltage is recorded. After a third preset time of sleep, the third preset voltage is recorded. The voltage drop of the N lithium batteries is calculated. The voltage drop is the difference between the third preset voltage and the second preset voltage divided by the third preset time. The voltage drop of the lithium battery is classified into different levels according to preset rules to obtain voltage drop levels; The N lithium batteries are grouped according to the power rating, the differential pressure rating, and the voltage drop rating.

2. The lithium battery packing method according to claim 1, characterized in that, The step of classifying electricity levels based on the average electricity consumption to obtain electricity consumption levels includes: The average power consumption is divided into five levels: first power consumption level, second power consumption level, third power consumption level, fourth power consumption level, and fifth power consumption level. Wherein, the first power level is the range of less than 97% of the average power, the second power level is the range of greater than or equal to 97% and less than 100% of the average power, the third power level is the range of greater than or equal to 100% and less than 103% of the average power, the fourth power level is the range of greater than or equal to 103% and less than or equal to 106% of the average power, and the fifth power level is the range of greater than 106% of the average power.

3. The lithium battery packing method according to claim 2, characterized in that, The step of classifying pressure differentials based on the average pressure differential to obtain pressure differential levels includes: The average pressure difference is divided into four levels: first pressure difference level, second pressure difference level, third pressure difference level, and fourth pressure difference level. Wherein, the first differential pressure level is the range less than 20% of the average differential pressure, the second differential pressure level is the range greater than or equal to 20% of the average differential pressure and less than 40% of the average differential pressure, the third differential pressure level is the range greater than or equal to 40% of the average differential pressure and less than 60% of the average differential pressure, and the fourth differential pressure level is the range greater than or equal to 60% of the average differential pressure.

4. The lithium battery packing method according to claim 3, characterized in that, The step of classifying the voltage drop of the lithium battery according to preset rules to obtain voltage drop levels includes: The voltage drop of the lithium battery is classified into three levels: first voltage drop level, second voltage drop level, and third voltage drop level. Wherein, the first voltage drop level is the range of less than 2 millivolts per hour, the second voltage drop level is the range of greater than or equal to 2 millivolts per hour and less than or equal to 5 millivolts per hour, and the third voltage drop level is the range of greater than 5 millivolts per hour.

5. The lithium battery packing method according to claim 4, characterized in that, The process of grouping N lithium batteries according to their capacity rating, differential pressure rating, and voltage drop rating includes: Lithium batteries with the same capacity rating, differential pressure rating, and voltage drop rating are configured as a group.

6. The lithium battery packing method according to claim 1, characterized in that, After a first preset hibernation time, the following is included: The N lithium batteries are discharged to a preset cutoff voltage using a fourth preset current value.

7. The lithium battery packing method according to claim 1, characterized in that, Before all N lithium batteries to be paired are charged to a first preset voltage at a constant current value, the process includes: All N lithium batteries to be matched are charged at a constant current of the fifth preset current value for the fourth preset time.

8. A lithium battery matching device, characterized in that, Includes methods for performing any one of claims 1-7.

9. A controller, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the steps of the method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-7.

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