Battery charging control method, battery management system, battery pack and power-consuming equipment

Abstract

The present application provides a battery charging control method, a battery management system, a battery pack and an electrical device. The method includes: if the battery is in an incompletely activated state, obtaining the battery voltage of the battery during the charging process; in the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, the lookup current and the full charge current corresponding to the full charge SOC are determined from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature; the updated charging current is determined according to the lookup current, the full charge current, the current fixed value corresponding to the charging terminal and the current reduction coefficient, and the updated charging current is used to charge the battery; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage. The present application adopts one or more reductions in the charging current when charging an unactivated battery, which reduces the polarization inside the battery cell and increases the battery charge capacity.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery charging control method, a battery management system, a battery pack and an electrical device. Background Art

[0002] Lithium batteries are a type of battery that uses lithium metal or lithium alloy as positive / negative electrode materials and non-aqueous electrolyte solutions. They are widely used in new energy vehicles.

[0003] Among the lithium battery charging methods, the most widely used are constant current constant voltage charging method or step charging method, which are all designed to extend the battery's cycle life. For the first charging of a lithium battery, if the cells in the lithium battery are not fully activated, there is a problem of insufficient lithium battery charge during the charging process. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a charging control method, a battery management system, a battery pack and an electrical device for charging an incompletely activated lithium battery, thereby increasing the charging capacity.

[0005] In a first aspect, an embodiment of the present application provides a battery charging control method, comprising:

[0006] If the battery is in an incompletely activated state, the battery voltage during the charging process is obtained;

[0007] In the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, an updated charging current is determined according to the charge state corresponding to the battery voltage and the battery temperature, and the battery is continued to be charged with the updated charging current; the updated charging current is less than the current charging current; there are one or more voltage thresholds, and the voltage threshold is less than the charging cut-off voltage.

[0008] The updated charging current is determined according to the state of charge corresponding to the battery voltage and the battery temperature, including:

[0009] Determine the lookup current and the full charge current corresponding to the full charge SOC from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature;

[0010] The updated charging current is determined based on the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0011] When charging an unactivated battery, the embodiment of the present application reduces the charging current once or multiple times, thereby reducing the polarization inside the battery cell and slowing down the voltage rise rate. When the voltage reaches the charging cut-off voltage, the state of charge SOC of the lithium battery can reach a full charge state as much as possible, thereby increasing the battery charge capacity.

[0012] In any embodiment, determining the updated charging current according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient includes:

[0013] Determine the first intermediate current according to the table lookup current and the current reduction coefficient;

[0014] determining a second intermediate current according to the full charge current and the fixed current value;

[0015] The larger value of the first intermediate current and the second intermediate current is used as the updated charging current value.

[0016] The embodiment of the present application obtains a suitable updated charging current by using the larger value of the first intermediate current and the second intermediate current as the updated charging current value, thereby improving the charging efficiency while increasing the charging amount.

[0017] In any embodiment, determining the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature includes:

[0018] If the battery voltage reaches the last voltage threshold, the full charge current is determined from the charge window rule table based on the state of charge and battery temperature;

[0019] The updated charging current is determined based on the full charging current and the fixed current value corresponding to the charging terminal.

[0020] In any embodiment, determining the updated charging current according to the full charging current and the fixed current value corresponding to the charging terminal includes:

[0021] The smaller value between the full charge current and the fixed current value is used as the updated charge current value.

[0022] The embodiment of the present application determines the current of the last charging stage based on the updated charging current and the fixed current value corresponding to the full charging current and the charging end, and uses a smaller current for charging to charge the battery as much as possible while meeting the charging requirements.

[0023] In any embodiment, the method further comprises:

[0024] Determine the inactivated SOC amount of the battery based on the number of charging cycles of the battery and the battery temperature;

[0025] The voltage threshold is determined according to the inactive SOC amount.

[0026] In the embodiment of the present application, the battery is charged at different activation levels, and the corresponding voltage increase speed and rising trend are different. The embodiment of the present application determines the voltage threshold according to the inactivated SOC amount of the battery, so as to reasonably determine the timing of reducing the charging current.

[0027] In any embodiment, the method further comprises:

[0028] Obtaining platform voltages of multiple test batteries during charging; the multiple test batteries respectively correspond to different amounts of unactivated SOC;

[0029] determining a test voltage threshold for each test battery based on the platform voltage;

[0030] Fitting is performed according to the inactivated SOC amount of the test battery and the test voltage threshold to obtain a mapping relationship;

[0031] The voltage threshold is determined according to the inactive SOC amount, including:

[0032] Substitute the inactivated SOC amount of the battery into the mapping equation to determine the voltage threshold.

[0033] The embodiment of the present application constructs a mapping relationship between the inactivated SOC amount and the test voltage threshold. In the actual charging process, the inactivated SOC amount of the battery can be substituted into the mapping relationship to obtain a reasonable voltage threshold.

[0034] In a second aspect, an embodiment of the present application provides a battery management system, including: a sampling circuit and a controller;

[0035] The sampling circuit is used to collect the battery voltage and battery temperature of the battery that is not fully activated during the charging process;

[0036] The controller is used for determining an updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature each time the voltage of the battery reaches a voltage threshold during the process of the voltage of the battery reaching the charging cut-off voltage, and continuing to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage;

[0037] The updated charging current is determined according to the state of charge corresponding to the battery voltage and the battery temperature, including:

[0038] Determine the lookup current and the full charge current corresponding to the full charge SOC from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature;

[0039] The updated charging current is determined based on the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0040] In a third aspect, an embodiment of the present application provides a battery pack, comprising a battery and the battery management system described in the second aspect.

[0041] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising the battery pack described in the third aspect.

[0042] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the embodiments of the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A schematic flow chart of a battery charging control method provided in an embodiment of the present application;

[0045] Figure 2 A schematic flow chart of another battery charging control method provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of a voltage-SOC curve of a battery provided in an embodiment of the present application;

[0047] Figure 4 A schematic diagram of the structure of a battery management system provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of the structure of a battery charging control device provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0055] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0057] Battery activation refers to the process of restoring or improving the battery by performing a series of operations on the battery. Through the activation process, oxides, dirt and other substances inside the battery can be removed, the battery's charge and discharge performance can be improved, the internal resistance can be reduced, and the number of cycles can be increased, making the battery more stable and reliable during use. However, newly produced batteries may not be fully activated. For batteries that are not fully activated, greater polarization will occur inside the battery during charging, causing the battery voltage to rise faster. When the voltage rises to the charge cut-off voltage, charging will stop, but the SOC of the battery has not reached the fully charged state, so the amount of electricity charged to the battery is insufficient.

[0058] In order to solve the above technical problems, the embodiments of the present application provide a battery charging control method, device, electronic device, storage medium and computer program product. The charging control method reduces the charging current once or multiple times during the charging process of an incompletely activated battery, so that the polarization inside the battery becomes smaller and smaller, so that more electricity can be charged into the battery.

[0059] It should be noted that the embodiments of the present application are applicable to the charging control of lithium batteries, and further, can be power batteries or energy storage batteries.

[0060] Figure 1 A schematic flow chart of a battery charging control method provided in an embodiment of the present application is shown in FIG. Figure 1 The method comprises:

[0061] Step 101: If the battery is in an incompletely activated state, obtaining the battery voltage during the charging process;

[0062] Step 102: In the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, an updated charging current is determined according to the charge state corresponding to the battery voltage and the battery temperature, and the battery is continuously charged with the updated charging current; the updated charging current is less than the current charging current; there are one or more voltage thresholds, and the voltage threshold is less than the charging cut-off voltage.

[0063] In the specific implementation process, it is possible to detect in advance whether the battery is not fully activated. If it is detected that the battery is in an incompletely activated state, the charging control method of the present application can be used to control the charging. There are many ways to determine whether the battery is fully activated, for example: capacity test method and polarization curve test method can be used. Among them, capacity test method: discharge test the battery to measure the amount of electricity it can discharge. If the capacity of the battery is close to or reaches its nominal capacity, this may indicate that the battery has been activated. Polarization curve test method: obtain the first polarization curve of the activated battery and obtain the corresponding voltage under the rated current. Activate the battery again, and after the battery is working stably, collect and record the excitation response curve. By comparing different polarization curves and excitation response curves, the degree of activation of the battery can be determined.

[0064] The battery may include multiple cells. During the charging process, the voltage of each cell in the battery may be collected in real time or at a fixed time, and the maximum voltage value among the multiple cells may be used as the battery voltage. The charging method for charging the battery is constant current charging. At this time, the charging current for charging the battery is called the current charging current.

[0065] When the voltage of the battery reaches a voltage threshold, the updated charging current can be determined according to the current state of charge and battery temperature of the battery, and the battery is charged with the updated charging current. It should be noted that the updated charging current is less than the current charging current. The voltage threshold is one or more preset values, and the voltage threshold is less than the charging cut-off voltage.

[0066] For the case of multiple voltage thresholds, the values ​​of the multiple voltage thresholds are different. During the charging process, the voltage of the battery generally shows an upward trend. Therefore, the voltage will first reach the minimum voltage threshold. After the battery voltage of the battery reaches the minimum voltage threshold, the charging current is reduced on the basis of the current charging current to obtain an updated charging current; the updated charging current is used as the new current charging current to continue charging the battery. When the battery voltage reaches the second smallest voltage threshold, the charging current is reduced again on the basis of the current charging current to obtain an updated charging current again, and then the updated charging current is used as the new current charging current to continue charging the battery; and so on, until the battery is charged until the battery voltage reaches the charging cut-off voltage.

[0067] The updated charging current is determined according to the state of charge corresponding to the battery voltage and the battery temperature, including:

[0068] According to the state of charge corresponding to the battery voltage and the battery temperature, the lookup current and the full charge current corresponding to the full charge SOC are determined from the charging window rule table;

[0069] The updated charging current is determined based on the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0070] In a specific implementation process, if the battery voltage of the battery reaches the voltage threshold, the battery state of charge and battery temperature can be collected, and the corresponding table lookup current and the full charge current corresponding to the full charge SOC can be found from the charging window rule table based on the state of charge and battery temperature. Among them, each type of battery has its corresponding charging window rule table, and the charging window rule table is used to guide the charging parameters of the battery during the charging process. It includes battery voltage, battery temperature, battery SOC and battery current. Through the charging window rule table, it can be determined how much battery current should be used to charge the battery according to the battery voltage, battery temperature and battery SOC.

[0071] The table current is the charging current determined according to the battery's current state of charge and battery temperature; the full charge current refers to the charging current corresponding to the SOC corresponding to the upper limit of the battery's charge. It should be noted that not all batteries can be charged to 100% SOC, and some batteries may only be allowed to be charged to 97% SOC or 98% SOC, etc. Therefore, the charging current corresponding to 97% SOC or 98% SOC is the full charge current corresponding to the full charge SOC.

[0072] The fixed current value corresponding to the charging terminal refers to the charging current value used in the last stage of charging. Each type of battery has its corresponding fixed current value corresponding to the charging terminal, which is determined through testing during the battery design stage or after production.

[0073] The current reduction coefficient is also pre-set, and its value range is (0,1).

[0074] After obtaining the table lookup current and the full charge current by looking up the table, the updated charging current can be calculated based on the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0075] Specifically, the product of the table lookup current and the current reduction coefficient may be calculated first, and then a larger value may be selected from the product of the table lookup current and the current reduction coefficient, the full charge current, and the current fixed value as the updated charging current.

[0076] Alternatively, the product of the table-lookup current and the current reduction coefficient may be calculated first to obtain the first intermediate current, and then the smaller value is selected as the second intermediate current according to the full charge current and the fixed current value; finally, the larger value of the first intermediate current and the second intermediate current is used as the updated charging current. The calculation formula is as follows:

[0077]

[0078] in, is the updated charging current; To look up the current; is the current drop coefficient; is the full charge current; is a fixed current value.

[0079] In the embodiment of the present application, the purpose of selecting a larger value is to prevent the charging current from being reduced too low, thereby affecting the charging efficiency.

[0080] When charging an unactivated battery, the embodiment of the present application reduces the charging current once or multiple times, thereby reducing the polarization inside the battery cell and delaying the time it takes for the battery to reach the charging cut-off voltage, so that more electricity can be charged into the battery, that is, the charging capacity of the battery is increased, and the updated charging current is determined based on the table lookup current, the full charge current, the fixed current value corresponding to the charging end, and the current reduction coefficient, so that a suitable updated charging current is obtained, thereby improving the charging efficiency while increasing the charging capacity.

[0081] On the basis of the above embodiment, determining the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature includes:

[0082] If the battery voltage reaches the last voltage threshold, the full charge current is determined from the charge window rule table based on the state of charge and battery temperature;

[0083] The updated charging current is determined based on the full charging current and the fixed current value corresponding to the charging terminal.

[0084] In the specific implementation process, when the battery voltage reaches the last voltage threshold, it means that the battery is about to enter the last charging stage. In the last charging stage, the charging rate needs to be as small as possible. Therefore, the full charging current corresponding to the full charge SOC of the battery can be determined from the charging window rule table according to the battery's current state of charge and battery temperature.

[0085] Then, a smaller value is selected from the full charge current and the fixed current value as the updated charge current.

[0086] The embodiment of the present application determines the current of the last charging stage based on the updated charging current and the fixed current value corresponding to the full charging current and the charging end, and uses a smaller current for charging to charge the battery as much as possible while meeting the charging requirements.

[0087] Based on the above embodiment, the method further includes:

[0088] Determine the inactivated SOC amount of the battery based on the number of charging cycles of the battery and the battery temperature;

[0089] The voltage threshold is determined according to the inactive SOC amount.

[0090] In the specific implementation process, the inactivated SOC refers to the amount of SOC that has not been activated in the battery, which is used to characterize the activation degree of the battery, and can also characterize the degree of inactivation of the battery. Batteries with different activation degrees, when charged at the same rate, have different degrees of polarization inside the battery, and the rate of rise of the battery voltage is also different. When charging the battery, the timing of controlling the reduction of the charging current is also different. Therefore, the inactivated SOC of the battery can be determined first, and then the voltage threshold can be determined based on the inactivated SOC.

[0091] The inactivated SOC amount can be determined based on the number of charging cycles of the battery and the battery temperature. The number of charging cycles refers to the number of times the battery is charged and fully charged. The battery temperature can be the temperature of the battery at the current moment, or the average temperature over a period of time before the current moment.

[0092] When calculating the inactivated SOC of the battery, the corresponding relationship among the number of charging cycles, the battery temperature and the inactivated SOC can be pre-built, and then the inactivated SOC of the battery corresponding to the current number of charging cycles and the battery temperature can be determined based on the corresponding relationship.

[0093] The corresponding relationship between the inactivated SOC amount and the voltage threshold may be pre-constructed, and then the voltage threshold corresponding to the inactivated SOC amount of the battery may be determined based on the corresponding relationship.

[0094] In the embodiment of the present application, the battery is charged at different activation levels, and the corresponding voltage increase speed and rising trend are different. The embodiment of the present application determines the voltage threshold according to the inactivated SOC amount of the battery, so as to reasonably determine the timing of reducing the charging current.

[0095] Based on the above embodiment, the method further includes:

[0096] Obtaining platform voltages of multiple test batteries during charging; the multiple test batteries respectively correspond to different amounts of unactivated SOC;

[0097] determining a test voltage threshold for each test battery based on the platform voltage;

[0098] Fitting is performed according to the inactivated SOC amount of the test battery and the test voltage threshold to obtain a mapping relationship;

[0099] The voltage threshold is determined according to the inactive SOC amount, including:

[0100] Substitute the inactivated SOC amount of the battery into the mapping equation to determine the voltage threshold.

[0101] In the specific implementation process, the platform voltage refers to the voltage value at which the battery voltage tends to stabilize and remains for a long time after the potential difference between the positive and negative poles of the battery reaches a certain level during the charging process. Batteries with different unactivated SOC amounts have different corresponding platform voltages during the charging process. In order to distinguish from the batteries in the above embodiments, the embodiments of the present application adopt the test battery naming, and after the platform voltage period, the voltage of the test battery will accelerate to rise. Therefore, the specific value of the test voltage threshold can be set between the platform voltage and the charging cut-off voltage. For example: if three test voltage thresholds are to be set, the three test voltage thresholds can be evenly distributed between the platform voltage and the charging cut-off voltage; it is also possible not to pre-set the number of test voltage thresholds, and set the test voltage threshold according to the preset voltage interval.

[0102] After the test voltage threshold is obtained, the inactivated SOC amount of the test battery and the test voltage threshold may be fitted to obtain a mapping relationship.

[0103] In practical applications, after the inactivated SOC amount of the battery is calculated, the inactivated SOC amount is substituted into the mapping relationship to obtain the voltage threshold corresponding to the battery.

[0104] The embodiment of the present application constructs a mapping relationship between the inactivated SOC amount and the test voltage threshold. In the actual charging process, the inactivated SOC amount of the battery can be substituted into the mapping relationship to obtain a reasonable voltage threshold.

[0105] Figure 2 A schematic flow chart of another battery charging control method provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the method includes:

[0106] Step 201: Determine whether the battery is fully activated; if it is determined that the battery is fully activated, execute step 202; otherwise, execute step 205.

[0107] According to the test results of the battery cell, the unactivated SOC corresponding to different charging end currents, different charging cut-off temperatures and full charging times is obtained. When judging whether the battery is fully activated, the table is looked up according to the actual data, and the unactivated SOC is judged according to the table lookup results whether it is less than or equal to 0. If the unactivated SOC is less than or equal to 0, the lithium battery is considered to be fully activated, and the charging control is performed according to the charging strategy for activation completion.

[0108] Under low temperature conditions, the number of full charges required to fully activate the battery cell is more. For the case of a large number of full charges, a fitting formula can be generated through test data, and the unactivated SOC can be calculated using the fitting formula. The fitting formula is as follows:

[0109] ;

[0110] In the formula, is the amount of unactivated SOC, and is the fitting parameter, is the number of full charges. The fitting formulas for different temperatures are different.

[0111] Step 202 : Determine whether the maximum cell voltage reaches the voltage threshold; if the maximum cell voltage reaches the voltage threshold, it means that the charging end has been reached, and execute step 204 ; otherwise, execute step 302 .

[0112] Step 203: Look up the charging request current table value; look up the charging current from the charging window rule table based on the battery state of charge and battery temperature, and charge according to the charging current. During the charging process, step 202 can be executed according to a preset time interval until charging is completed.

[0113] Step 204: The charging terminal requests a fixed current value; at the charging terminal, charging is performed using a preset fixed current value until the battery voltage reaches a charging cut-off voltage.

[0114] Step 205: Determine whether the maximum cell voltage reaches the first voltage threshold U1; for an incompletely activated battery, determine whether the maximum cell voltage in the battery reaches U1, if so, execute step 207, otherwise execute step 206.

[0115] Step 206: Look up the table value of the charging request current: look up the charging current from the charging window rule table based on the battery state of charge and the battery temperature, and charge according to the charging current. During the charging process, step 205 can be executed according to a preset time interval.

[0116] Step 207: Determine the updated charging current; according to the formula An updated charging current is determined, and then the battery is charged using the updated charging current.

[0117] Step 208 : Determine whether the maximum cell voltage reaches the second voltage threshold value U2 ; if the maximum cell voltage reaches U2 , execute step 209 , otherwise continue to charge the battery according to the charging current determined in step 207 .

[0118] Step 209: Determine the updated charging current; according to the formula An updated charging current is determined, and then the battery is charged using the updated charging current.

[0119] Step 210 : Determine whether the maximum cell voltage reaches the third voltage threshold value U3 ; if the maximum cell voltage reaches U3 , execute step 211 , otherwise continue to charge the battery according to the charging current determined in step 209 .

[0120] Step 211: Determine the updated charging current; according to the formula An updated charging current is determined and then the battery is charged using the updated charging current until the battery voltage reaches a charging cut-off voltage.

[0121] Figure 3 A schematic diagram of the battery voltage and SOC after charging by three current reduction methods provided in the embodiment of the present application. When the battery voltage reaches U1, U2, and U3 respectively, the battery voltage has a process of decreasing. This is because after the charging current decreases, the internal polarization of the battery becomes smaller, and the battery voltage will decrease partially. However, the battery voltage is on an upward trend as a whole.

[0122] It should be noted that the embodiment of the present application provides a three-time current reduction method for charging. In practical applications, more or fewer current reduction methods can be set according to needs.

[0123] Figure 4 A schematic diagram of a battery management system structure provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the battery management system includes a sampling circuit 401 and a controller 402;

[0124] The sampling circuit 401 is used to collect the battery voltage and battery temperature of the incompletely activated battery during the charging process; and send the collected battery voltage and battery temperature to the controller.

[0125] The controller 402 is used to determine the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature each time the battery voltage reaches a voltage threshold during the process of the battery voltage reaching the charging cut-off voltage, and continue to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage. The state of charge is obtained by the controller based on the charging parameters.

[0126] When determining the updated charging current, the controller 402 calculates the following:

[0127] Determine, from a charging window rule table, a lookup current and a full charge current corresponding to a full charge SOC according to the state of charge corresponding to the battery voltage and the battery temperature;

[0128] The updated charging current is determined according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0129] It should be noted that the controller can also execute the specific methods for determining the updated charging current in the above embodiments. The battery management system can also include other components, such as a high-voltage monitoring box, a communication module, etc. The sampling circuit can also be used to collect the charging and discharging current of the battery. The controller can also be used to control the heating and cooling of the battery.

[0130] The present application also provides a battery pack, which includes a battery and a battery management system, wherein the battery management system is connected to the battery and is used to monitor and control the state of the battery. The battery management system can execute the above methods to implement the provided method.

[0131] An embodiment of the present application also provides an electrical device, which includes a battery pack, and the battery pack is used to provide electrical energy to the electrical device.

[0132] Figure 5 This is a schematic diagram of the structure of a battery charging control device provided in an embodiment of the present application. The device may be a module, program segment or code on an electronic device. It should be understood that the device is similar to the above-mentioned Figure 1 The method embodiment corresponds to and can be executed Figure 1 The various steps involved in the method embodiment and the specific functions of the device can be found in the above description. To avoid repetition, detailed description is appropriately omitted here. The device includes: a voltage acquisition module 501 and a charging control module 502, wherein:

[0133] The voltage acquisition module 501 is used to acquire the battery voltage of the battery during the charging process if the battery is in an incompletely activated state;

[0134] The charging control module 502 is used to determine an updated charging current according to the charge state corresponding to the battery voltage and the battery temperature each time the battery voltage reaches a voltage threshold during the process of the battery voltage reaching the charging cut-off voltage, and continue to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage;.

[0135] The charging control module 502 is specifically used for:

[0136] Determine, from a charging window rule table, a lookup current and a full charge current corresponding to a full charge SOC according to the state of charge corresponding to the battery voltage and the battery temperature;

[0137] The updated charging current is determined according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient.

[0138] Based on the above embodiment, the charging control module 502 is specifically used for:

[0139] Determine a first intermediate current according to the table lookup current and the current reduction coefficient;

[0140] determining a second intermediate current according to the full charge current and the fixed current value;

[0141] The larger value of the first intermediate current and the second intermediate current is used as the updated charging current value.

[0142] Based on the above embodiment, the charging control module 502 is specifically used for:

[0143] If the battery voltage reaches the last voltage threshold, determining a full charge current from a charging window rule table according to the state of charge and the battery temperature;

[0144] The updated charging current is determined according to the full charging current and a fixed current value corresponding to a charging terminal.

[0145] Based on the above embodiment, the charging control module 502 is specifically used for:

[0146] The smaller value between the full charge current and the fixed current value is used as the updated charge current value.

[0147] Based on the above embodiment, the device further includes a voltage threshold determination module, which is used to:

[0148] Determining an unactivated SOC amount of the battery according to the number of charging cycles of the battery and the battery temperature;

[0149] The voltage threshold is determined according to the inactive SOC amount.

[0150] Based on the above embodiment, the device further includes a mapping relationship obtaining module, which is used to:

[0151] Obtaining platform voltages of a plurality of test batteries during charging; the plurality of test batteries respectively corresponding to different unactivated SOC amounts;

[0152] Determining a test voltage threshold of each of the test cells based on the platform voltage;

[0153] Perform fitting according to the inactivated SOC amount of the test battery and the test voltage threshold to obtain a mapping relationship;

[0154] The voltage threshold determination module is specifically used for:

[0155] The inactivated SOC amount of the battery is substituted into the mapping equation to determine the voltage threshold.

[0156] Figure 6 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application, such as Figure 6 As shown, the electronic device includes: a processor (processor) 601, a memory (memory) 602 and a bus 603; wherein,

[0157] The processor 601 and the memory 602 communicate with each other via the bus 603;

[0158] The processor 601 is used to call the program instructions in the memory 602 to execute the methods provided by the above-mentioned method embodiments, for example, including: if the battery is in an incompletely activated state, obtaining the battery voltage, state of charge and battery temperature of the battery during the charging process; in the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, determining an updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature, and continuing to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage; wherein, determining the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature includes: determining the table lookup current and the full charge current corresponding to the full charge SOC from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature; determining the updated charging current according to the table lookup current, the full charge current, the fixed value of the current corresponding to the charging end, and the current reduction coefficient.

[0159] The processor 601 may be an integrated circuit chip with signal processing capabilities. The processor 601 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. It may implement or execute various methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0160] The memory 602 may include, but is not limited to, random access memory (RAM), read only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0161] The present embodiment discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the methods provided by the above-mentioned method embodiments, for example, including: if the battery is in an incompletely activated state, obtaining the battery voltage, state of charge and battery temperature of the battery during the charging process; in the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, determining an updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature, and continuing to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage; wherein, determining the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature includes: determining the table lookup current and the full charge current corresponding to the full charge SOC from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature; determining the updated charging current according to the table lookup current, the full charge current, the fixed value of the current corresponding to the charging terminal, and the current reduction coefficient.

[0162] The present embodiment provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, wherein the computer instructions enable the computer to execute the methods provided by the above-mentioned method embodiments, for example, including: if the battery is in an incompletely activated state, obtaining the battery voltage, state of charge and battery temperature of the battery during the charging process; in the process of the battery voltage reaching the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, determining an updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature, and continuing to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage; wherein determining the updated charging current according to the state of charge corresponding to the battery voltage and the battery temperature includes: determining the table lookup current and the full charge current corresponding to the full charge SOC from the charging window rule table according to the state of charge corresponding to the battery voltage and the battery temperature; determining the updated charging current according to the table lookup current, the full charge current, the fixed value of the current corresponding to the charging terminal and the current reduction coefficient.

[0163] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0164] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0165] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0166] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0167] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery charging control method, characterized in that: include: If the battery is in an incompletely activated state, obtaining the battery voltage, state of charge and battery temperature of the battery during the charging process; In the process that the voltage of the battery reaches the charging cut-off voltage, each time the battery voltage reaches a voltage threshold, an updated charging current is determined according to the state of charge corresponding to the voltage of the battery and the battery temperature, and the battery is continuously charged with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage; The step of determining the updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature includes: Determine, from a charging window rule table, a lookup current and a full charge current corresponding to a full charge SOC according to the state of charge corresponding to the battery voltage and the battery temperature; Determine the updated charging current according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient; The step of determining the updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature includes: If the battery voltage reaches the last voltage threshold, determining a full charge current from a charging window rule table according to the state of charge and the battery temperature; The updated charging current is determined according to the full charging current and a fixed current value corresponding to a charging terminal.

2. The method according to claim 1, characterized in that: The step of determining the updated charging current according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient includes: Determine a first intermediate current according to the table lookup current and the current reduction coefficient; determining a second intermediate current according to the full charge current and the fixed current value; A larger value of the first intermediate current and the second intermediate current is used as the updated charging current.

3. The method according to claim 1, characterized in that The step of determining the updated charging current according to the full charging current and the fixed current value corresponding to the charging terminal includes: The smaller value between the full charge current and the fixed current value is used as the updated charge current value.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Determining an unactivated SOC amount of the battery according to the number of charging cycles of the battery and the battery temperature; The voltage threshold is determined according to the inactive SOC amount.

5. The method according to claim 4, characterized in that The method further comprises: Obtaining platform voltages of a plurality of test batteries during charging; the plurality of test batteries respectively corresponding to different unactivated SOC amounts; Determining a test voltage threshold of each of the test cells based on the platform voltage; Perform fitting according to the inactivated SOC amount of the test battery and the test voltage threshold to obtain a mapping relationship; The determining the voltage threshold according to the inactivated SOC amount includes: The inactivated SOC amount of the battery is substituted into the mapping equation to determine the voltage threshold.

6. A battery management system, characterized in that: include: Sampling circuit and controller; The sampling circuit is used to collect the battery voltage, charge state and battery temperature of the battery that is not fully activated during the charging process; The controller is used for determining an updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature each time the voltage of the battery reaches a voltage threshold during the process of the voltage of the battery reaching the charging cut-off voltage, and continuing to charge the battery with the updated charging current; the updated charging current is less than the current charging current; the voltage threshold is one or more, and the voltage threshold is less than the charging cut-off voltage; The step of determining the updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature includes: Determine, from a charging window rule table, a lookup current and a full charge current corresponding to a full charge SOC according to the state of charge corresponding to the battery voltage and the battery temperature; Determine the updated charging current according to the table lookup current, the full charge current, the fixed current value corresponding to the charging terminal, and the current reduction coefficient; The step of determining the updated charging current according to the state of charge corresponding to the voltage of the battery and the battery temperature includes: If the battery voltage reaches the last voltage threshold, determining a full charge current from a charging window rule table according to the state of charge and the battery temperature; The updated charging current is determined according to the full charging current and a fixed current value corresponding to a charging terminal.

7. A battery pack, characterized in that: The invention comprises a battery and a battery management system as claimed in claim 6.

8. An electrical device, characterized in that: Comprising the battery pack as claimed in claim 7.

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