Charging control method, device and power management controller

Abstract

An embodiment of the present application provides a charging control method, device and power management controller, the charging control method including: determining whether the battery status of a battery pack meets a preset condition, the battery pack including a plurality of battery cells, the preset condition being: the battery pack has been stationary for a preset period of time, and the open circuit voltage of each battery cell in the battery pack is within a preset range; charging the battery pack according to a charging strategy corresponding to the judgment result so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a charging control method, device, and power management controller. Background Art

[0002] Current lithium-ion battery designs increase energy density by reducing the coating weight of the negative electrode, thereby lowering the N / P ratio (N / P is the negative electrode capacity per unit area divided by the positive electrode capacity per unit area). However, this reduction in N / P shortens the battery's lifespan. Therefore, how to maintain the battery's lifespan while reducing N / P is a pressing issue. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a charging control method, device and power management controller to ensure the service life of a lithium-ion battery while reducing the N / P ratio of the lithium-ion battery.

[0004] In a first aspect, the present invention provides a charging control method, the method comprising: determining whether the battery status of the battery pack meets a preset condition, the battery pack comprising a plurality of battery cells, the preset condition being: the battery pack has been stationary for a preset period of time, and the open circuit voltage of each battery cell in the battery pack is within a preset range; charging the battery pack according to a charging strategy corresponding to the judgment result so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

[0005] The charging control method designed above selects different charging strategies to charge the battery pack based on whether the battery pack's battery status meets preset conditions. Each strategy ensures that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches its corresponding nominal capacity. Because the capacity differences between individual battery cells within the battery pack are relatively small, after the battery pack is fully charged, the capacity of all battery cells is close to their respective nominal capacities. This ensures that the lithium-ion batteries experience virtually no degradation during the charging process, thereby ensuring the service life of the lithium-ion batteries while reducing the N / P ratio.

[0006] In an optional embodiment of the first aspect, the battery pack is charged according to the charging strategy corresponding to the judgment result, including: if the judgment result is that the preset condition is met, obtaining the remaining capacity corresponding to each battery cell according to the open circuit voltage of each battery cell, and obtaining the maximum remaining capacity among the remaining capacities of the multiple battery cells; determining the capacity to be charged of the battery pack according to the nominal capacity of the battery cell with the maximum remaining capacity and the maximum remaining capacity; and charging the battery pack with the capacity to be charged to complete the charging of the battery pack.

[0007] In the implementation of the above design, since the capacity to be charged is calculated based on the nominal capacity and the maximum remaining capacity of the battery cell with the largest remaining capacity, the capacity to be charged is used as the charging cut-off condition. When the charging of the battery pack is completed, the capacity of the battery cell with the largest remaining capacity can reach the nominal capacity; since multiple battery cells in the battery pack are connected in series in sequence, the battery cells except the battery cell with the largest remaining capacity will also increase in the same capacity; since the capacity value difference between each battery cell in the battery pack will not be too large, after charging is completed, the capacity of all battery cells in the battery pack will be relatively close to their respective nominal capacities, thereby achieving basically no attenuation of the lithium-ion battery during the charging process, and thus ensuring the service life of the lithium-ion battery while reducing the N / P ratio of the lithium-ion battery.

[0008] In an optional implementation manner of the first aspect, the battery pack is charged according to the charging strategy corresponding to the judgment result, including: if the judgment result is that the preset condition is not met, obtaining the corresponding full charge voltage of each stored battery cell; charging the battery pack until the charging voltage of any battery cell reaches the corresponding full charge voltage.

[0009] In an optional implementation manner of the first aspect, acquiring the stored full-charge voltage corresponding to each battery cell includes: acquiring the full-charge voltage corresponding to each battery cell determined in the last charging cycle in which the preset condition is met.

[0010] In the implementation of the above design, when the preset conditions are not met, the full charge voltage determined by the last charging cycle that met the preset conditions is used as the charging cut-off condition, so that the cut-off condition of this charging can be made the same as the cut-off condition of the last charging that met the preset conditions, that is, after the current charging is completed, the capacity presented by the battery pack is the same as the capacity presented when the preset conditions were met last time. After both charging are completed, each battery cell is close to its own nominal capacity. Therefore, basically no attenuation of the lithium-ion battery during the charging process is achieved, and the service life of the lithium-ion battery is guaranteed while reducing the N / P ratio of the lithium-ion battery.

[0011] In an optional implementation manner of the first aspect, acquiring the stored full-charge voltage corresponding to each battery cell includes: acquiring a preset full-charge voltage corresponding to each battery cell.

[0012] In an optional embodiment of the first aspect, after charging the battery pack with the capacity to be charged to complete the charging of the battery pack, the method further includes: obtaining the charging voltage of the battery cell with the largest remaining capacity when charging is cut off to obtain the full charge voltage of the battery cell with the largest remaining capacity; obtaining the remaining chargeable capacity of each of the multiple remaining battery cells when charging is cut off, wherein the multiple remaining battery cells include all battery cells except the battery cell with the largest remaining capacity among the multiple battery cells; determining the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity, and then obtaining the full charge voltage corresponding to each battery cell in the multiple battery cells; and storing the full charge voltage corresponding to each battery cell in the multiple battery cells.

[0013] In an optional embodiment of the first aspect, obtaining the remaining rechargeable capacity of each remaining battery cell in the multiple remaining battery cells at the time of charging cutoff includes: calculating a first difference between the nominal capacity and the maximum remaining capacity; calculating a second difference between the first difference and the remaining capacity of each remaining battery cell in the multiple remaining battery cells, the second difference corresponding to each remaining battery cell is its corresponding remaining rechargeable capacity.

[0014] In an optional embodiment of the first aspect, determining the full charge voltage corresponding to each remaining battery cell according to each remaining rechargeable capacity includes: obtaining a first dynamic voltage value of each remaining battery cell according to the remaining power of each remaining battery cell at the time of charging cutoff; obtaining a second dynamic voltage value of each remaining battery cell according to each remaining rechargeable capacity; and calculating the sum of the first dynamic voltage value and the second dynamic voltage value, wherein the second full charge voltage of each remaining battery cell is the sum of the corresponding first dynamic voltage value and the second dynamic voltage value.

[0015] In an optional implementation manner of the first aspect, the determining whether the battery status of the battery pack satisfies a preset condition includes: when the battery pack enters a charging state, determining whether the battery status of the battery pack satisfies a preset condition.

[0016] In a second aspect, the present invention provides a charging control device, comprising: a judgment module for judging whether the battery status of the battery pack meets a preset condition, the battery pack comprising a plurality of battery cells, and the preset condition being: the battery pack has been left stationary for a preset period of time, and the open circuit voltage of each battery cell in the battery pack is within a preset range; a charging module for charging the battery pack according to a charging strategy corresponding to the judgment result, so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

[0017] In the implementation of the above design, different charging strategies are selected to charge the battery pack according to whether the battery status of the battery pack meets the preset conditions, so that the capacity of the battery cell with the largest remaining capacity in the battery pack can reach the nominal capacity of the battery cell with the largest remaining capacity. Since the capacity difference between the battery cells in the battery pack is not too large, the capacity of all battery cells after the battery pack is charged is close to their respective nominal capacities, so that the lithium-ion battery has basically no attenuation during the charging process, thereby ensuring the service life of the lithium-ion battery while reducing the N / P ratio of the lithium-ion battery.

[0018] In an optional embodiment of the second aspect, the charging module is specifically used to obtain the remaining capacity corresponding to each battery cell according to the open-circuit voltage of each battery cell and obtain the maximum remaining capacity among the remaining capacities of the multiple battery cells if the judgment result is that the preset condition is met; determine the capacity to be charged of the battery pack according to the nominal capacity of the battery cell with the maximum remaining capacity and the maximum remaining capacity; and charge the battery pack with the capacity to be charged to complete the charging of the battery pack.

[0019] In an optional embodiment of the second aspect, the charging module is further specifically used to obtain the corresponding full charge voltage of each stored battery cell if the judgment result is that the preset condition is not met; and charge the battery pack until the charging voltage of any battery cell reaches the corresponding full charge voltage.

[0020] In an optional embodiment of the second aspect, the device also includes an acquisition module for acquiring the charging voltage of the battery cell with the largest remaining capacity when charging is cut off, so as to obtain the full charge voltage of the battery cell with the largest remaining capacity; and acquiring the remaining chargeable capacity of each remaining battery cell among the multiple remaining battery cells when charging is cut off, wherein the multiple remaining battery cells include all battery cells among the multiple battery cells except the battery cell with the largest remaining capacity; a determination module for determining the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity, and thereby obtaining the full charge voltage corresponding to each battery cell among the multiple battery cells; and a storage module for storing the full charge voltage corresponding to each battery cell among the multiple battery cells.

[0021] In an optional implementation manner of the second aspect, the acquisition module is specifically used to calculate a first difference between the nominal capacity and the maximum remaining capacity; calculate a second difference between the first difference and the remaining capacity of each battery cell in the remaining battery cells, and the second difference corresponding to each remaining battery cell is its corresponding remaining rechargeable capacity.

[0022] In an optional implementation manner of the second aspect, the determination module is specifically used to obtain a first dynamic voltage value of each remaining battery cell when charging is cut off; obtain a second dynamic voltage value of each remaining battery cell according to each remaining rechargeable capacity; and calculate the sum of the first dynamic voltage value and the second dynamic voltage value, wherein the second full charge voltage of each remaining battery cell is the sum of the corresponding first dynamic voltage value and the second dynamic voltage value.

[0023] In an optional implementation manner of the second aspect, the judgment module is specifically configured to judge whether the battery status of the battery pack meets a preset condition when the battery pack enters a charging state.

[0024] In a third aspect, the present invention provides a power management controller, which includes a chip having instructions solidified therein. When the instructions are executed by the chip, the charging control method described in the first aspect or any optional implementation method of the first aspect is executed.

[0025] In a fourth aspect, the present application provides a storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the charging control method described in the first aspect or any optional implementation of the first aspect is executed.

[0026] In a fifth aspect, the present application provides a computer program product, which, when running on a computer, enables the computer to execute the charging control method described in the first aspect or any optional implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0028] Figure 1 A first flow chart of the charging control method provided in an embodiment of the present application;

[0029] Figure 2 A second flow chart of the charging control method provided in an embodiment of the present application;

[0030] Figure 3 A third flow chart of the charging control method provided in an embodiment of the present application;

[0031] Figure 4 A fourth flow chart of the charging control method provided in an embodiment of the present application;

[0032] Figure 5A fifth flow chart of the charging control method provided in an embodiment of the present application;

[0033] Figure 6 A sixth flow chart of the charging control method provided in an embodiment of the present application;

[0034] Figure 7 A seventh flow chart of the charging control method provided in an embodiment of the present application;

[0035] Figure 8 A schematic diagram of the structure of a charging control device provided in an embodiment of the present application;

[0036] Figure 9 A schematic diagram of the structure of the chip provided in an embodiment of the present application.

[0037] Description of the markings: 800 - judgment module; 801 - charging module; 802 - acquisition module; 803 - determination module; 804 - storage module; 9 - chip; 901 - processor; 902 - memory; 903 - communication bus. DETAILED DESCRIPTION

[0038] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0039] In the description of this application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0040] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0041] The embodiment of the present application provides a charging control method. After using this method to charge a lithium-ion battery with a low N / P ratio, the capacity of the lithium-ion battery can be close to the nominal capacity, and charging without substantial attenuation can be achieved, thereby ensuring the service life of the lithium-ion battery. N / P is the negative electrode capacity per unit area / positive electrode capacity per unit area. Substantially no attenuation means that the capacity of the battery after charging is close to or equal to its nominal capacity. This method can be executed by the vehicle's power management controller, or by a chip with integrated power control function. The following description will be made using the power management controller as an example. This method is as follows: Figure 1 As shown, the following steps are included:

[0042] Step S100: Determine whether the battery status of the battery pack meets a preset condition. In step S100, the battery pack refers to a lithium-ion battery pack containing lithium-ion battery cells with a low N / P ratio designed for production, specifically a lithium-ion battery pack with an N / P ratio less than 1, and the lithium-ion battery pack includes multiple battery cells connected in series.

[0043] In step S100, the preset condition refers to the battery pack being at rest for a preset time and the open-circuit voltage of each battery cell in the battery pack being within a preset range. As one possible embodiment, the battery pack being at rest for the preset time may be a battery pack dormancy time of a preset length. As another possible embodiment, the battery pack being at rest for the preset time may be a battery pack charge / discharge current of less than a preset current for a preset duration.

[0044] In step S100, the power management controller can collect the open circuit voltage of each battery cell in the battery pack, the duration of the charge and discharge current being less than the preset current, etc., and then determine whether the battery pack has been stationary for a preset time based on these collected parameters, and whether the open circuit voltage of each battery cell in the battery pack is within a preset range, to determine whether the battery status meets the preset conditions.

[0045] As a possible implementation, the power management controller can execute a judgment process when the battery pack enters the charging state. The battery pack entering the charging state can be understood as the battery pack is in a state about to be charged. For example, the battery pack is connected to the power supply, but the power supply has not yet been connected to the battery pack for charging. In this case, the state can be determined as the battery pack entering the charging state. In the above process, the power management controller can detect whether the battery pack is connected to the power supply, and can control whether the power supply and the battery pack are connected; as another possible implementation, the power management controller can also perform the judgment of step S100 during the battery pack charging process.

[0046] Step S110 : charging the battery pack according to the charging strategy corresponding to the judgment result, so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

[0047] In step S110, the power management controller selects different charging strategies to charge the battery pack based on different judgment results. Different judgment results, such as whether the preset conditions are met or not, correspond to different charging strategies. However, regardless of the selected charging strategy, the objective of the present application is to ensure that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches its corresponding nominal capacity, thereby reducing the capacity differences between the individual battery cells in the battery pack.

[0048] The following is a detailed introduction to different charging strategies corresponding to different judgment results.

[0049] As a possible implementation, after the power management controller performs step S100 to determine whether the battery status of the battery pack meets the preset conditions, the power management controller may switch to the following charging strategy to charge the battery pack, such as Figure 2 As shown, including:

[0050] Step S200 : obtaining the remaining capacity corresponding to each battery cell according to the open circuit voltage of each battery cell, and obtaining the maximum remaining capacity among the remaining capacities of the plurality of battery cells.

[0051] In step S200 , referring to the description of step S100 , the power management controller may obtain the open circuit voltage of each battery cell, and the power management controller may obtain the remaining capacity corresponding to each battery cell according to the open circuit voltage of each battery cell.

[0052] As a possible implementation, the power management controller can query the remaining capacity corresponding to each battery cell based on the open circuit voltage of each battery cell and the open circuit voltage-remaining capacity relationship curve, wherein the remaining capacity of each battery cell is represented by [Q1, Q2, Q3, ..., Q n ] indicates that after obtaining the remaining capacity corresponding to each battery cell, the maximum value of all remaining capacities in multiple battery cells can be determined to obtain the maximum remaining capacity Q max , where Q max =max[Q1,Q2,Q3,...,Q n ].

[0053] Step S210: determining the capacity to be charged of the battery pack according to the nominal capacity and the maximum remaining capacity of the battery cell with the largest remaining capacity.

[0054] In step S210, the power management controller calculates the maximum remaining capacity Q obtained in step S200. max and the nominal capacity Q of the battery cell with the maximum remaining capacity cn Calculate the capacity to be charged Q 差 As a possible implementation method, it can be obtained by subtracting the maximum remaining capacity from the nominal capacity, that is, Q 差 =Q cn -Q max .

[0055] Step S220: charging the battery pack to the capacity to be charged to complete the charging of the battery pack.

[0056] As a possible implementation, step S220 charges the battery pack to the capacity to be charged Q 差 Specifically, the capacity to be charged Q 差 Convert it into the amount of electricity required for charging, and then realize the capacity to be charged Q for the amount of electricity required to charge the battery 差 The charging.

[0057] In the above embodiment, since the capacity to be charged Q 差 It is calculated based on the nominal capacity and the maximum remaining capacity. Therefore, the capacity to be charged Q 差 As the charging cut-off condition, when the battery pack is fully charged, the battery cell with the largest remaining capacity can reach the nominal capacity; since multiple battery cells in the battery pack are connected in series, the battery cells other than the battery cell with the largest remaining capacity will also increase Q 差 Although the remaining capacity of the remaining battery cells is lower than that of the battery cell with the largest remaining capacity, the remaining battery cells increase Q 差 After charging, the capacity of each battery cell may not reach its respective nominal capacity. However, since the capacity values ​​of the individual battery cells in the battery pack will not vary too much, the capacity of all battery cells in the battery pack will be relatively close to their respective nominal capacity after charging, thereby achieving essentially no attenuation of the lithium-ion battery during the charging process. Since the above method is for lithium-ion batteries with N / P < 1, thus, by reducing the N / P of the lithium-ion battery, essentially no attenuation charging of the battery pack is achieved, thus ensuring the service life of the lithium-ion battery.

[0058] Since each battery cell has different attenuation and self-discharge, it is impossible to determine which battery cell will be fully charged first when the battery is fully charged. Therefore, it is necessary to calculate the full charge voltage of each battery cell, which can be used as the charging cut-off condition when the preset conditions are not met. As a possible implementation method, after executing step S220 to complete the charging of the battery pack, the power management controller can also perform the following steps to record the full charge voltage of each battery cell when the preset conditions are met and the charging is completed, such as Figure 3 As shown, the following steps are included:

[0059] Step S300: obtaining the charging voltage of the battery cell with the largest remaining capacity at the time of charging cutoff.

[0060] In step S300, after the battery pack is charged to the capacity to be charged, charging is terminated. The power management controller can obtain the charging voltage of the battery cell with the maximum remaining capacity when charging is terminated, record the charging voltage of the battery cell with the maximum remaining capacity when charging is terminated, and then use it as the full charging voltage of the battery cell with the maximum remaining capacity.

[0061] Step S310 : obtaining the remaining chargeable capacity of each of the plurality of remaining battery cells when charging is terminated.

[0062] In step S310, the plurality of remaining battery cells represent all battery cells in the battery pack except the battery cell with the largest remaining capacity. As described above, the battery cells except the battery cell with the largest remaining capacity may not reach the nominal capacity when charging is completed. Therefore, the plurality of remaining battery cells still have a certain remaining chargeable capacity. When executing step S310, the power management controller can obtain the remaining chargeable capacity of each remaining battery cell at the time of charging termination, and then execute step S320, wherein the remaining chargeable capacity of each remaining battery cell is calculated, such as Figure 4 As shown, the process may include the following steps:

[0063] Step S400: Calculating a first difference between the nominal capacity and the maximum remaining capacity.

[0064] Step S410 : Calculating a second difference between the first difference and the remaining capacity of each of the plurality of remaining battery cells to obtain the remaining chargeable capacity of each of the remaining battery cells.

[0065] In step S400, the first difference between the nominal capacity and the maximum remaining capacity is the aforementioned capacity difference Q 差 , that is, Q 差 =Q cn -Q max .

[0066] In step S410, the power management controller calculates the first difference Q 差 The corresponding remaining chargeable capacity can be determined by the second difference between the remaining capacity of each remaining battery cell and the remaining chargeable capacity of each remaining battery cell. Specifically, the remaining chargeable capacity Q of each remaining battery cell can be obtained by the following formula: remain [1,2,3,...,n]:

[0067] Q remain [1,2,3,...,n]=Qcn -Q max -[Q1,Q2,Q3,...,Q n ];

[0068] Step S320: determining the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity.

[0069] In step S320, the power management controller may determine the full charge voltage of each remaining battery cell based on the remaining chargeable capacity of each remaining battery cell. As a possible implementation, Figure 5 As shown, it can be determined by the following steps:

[0070] Step S500: Obtaining a first dynamic voltage value of each remaining battery cell when charging is terminated.

[0071] As a possible implementation, in step S500, when charging of the battery pack is terminated, the power management controller may obtain a first dynamic voltage value of each remaining battery cell at the time of charging termination. The first dynamic voltage value may be the voltage value of the remaining battery cell at the time of charging termination, which is assumed to be represented by V[1,2,3,...,n].

[0072] Step S510 : Obtaining a second dynamic voltage value of each remaining battery cell according to each remaining chargeable capacity.

[0073] As a possible implementation, in step S510, the power management controller may determine a corresponding second dynamic voltage value according to the remaining chargeable capacity of each remaining battery cell. As a possible implementation, the power management controller may estimate the second dynamic voltage value of each remaining battery cell based on a dynamic voltage-capacity (OCV_Q) curve at the end of battery pack charging (at the end of charging) and the remaining chargeable capacity of each remaining battery cell. Assuming that the second dynamic voltage value is represented by ΔV, the second dynamic voltage value of each remaining battery cell is:

[0074] ΔV=Q remain [1,2,3,...,n](OCV_Q);

[0075] Among them, Q remain [1,2,3,...,n](OCV_Q) represents the dynamic voltage value estimated based on the OCV_Q curve at the charging end and the remaining chargeable capacity of each remaining battery cell.

[0076] Step S520: Calculate the sum of the first dynamic voltage value and the second dynamic voltage value to obtain the full charge voltage of each remaining battery cell. In step S520, the power management controller adds the first dynamic voltage value and the second dynamic voltage value of each remaining battery cell to obtain the full charge voltage of each remaining battery cell. Assume that the full charge voltage is V fullchrg Indicates that the full charge voltage of each remaining battery cell is:

[0077] V fullchrg =V[1,2,3,...,n]+ΔV.

[0078] Step S330: storing the full charge voltage corresponding to each battery cell in the plurality of battery cells.

[0079] In step S330, the full charge voltage of the battery cell with the largest remaining capacity and the full charge voltage of the remaining battery cells can be obtained through the aforementioned steps S300 to S320, that is, the full charge voltage of each battery cell in the battery pack is obtained, and the full charge voltage of each battery cell can be stored.

[0080] The aforementioned description is based on the scenario when the battery status meets the preset conditions. Here, the description is given of the scenario when the battery status of the battery pack does not meet the preset conditions.

[0081] As a possible implementation, after the power management controller performs step S100 to determine that the battery state of the battery pack does not meet the preset conditions, the power management controller may switch to the charging strategy of the following steps to charge the battery pack, such as Figure 6 As shown, including:

[0082] Step S600: Obtain the full charge voltage corresponding to each battery cell.

[0083] The above step S600 includes the following two possible implementations:

[0084] The first embodiment is: the battery pack has met the preset conditions in the previous charging cycle, and after executing steps S300 to S330 to store the estimated full charge voltage of each battery cell, Figure 7 As shown, step S600 may specifically include the following steps:

[0085] Step S700: Obtaining the full charge voltage corresponding to each battery cell determined in the last charging cycle in which the preset condition is met.

[0086] In step S700, since the acquired full charge voltage is the last charging cycle in which the preset condition is satisfied, the stored full charge voltage V fullchrg Therefore, the power management controller sets the full charge voltage V corresponding to each battery cell fullchrgAs a charging cut-off condition for not meeting the preset conditions, the cut-off condition of this charging can be made the same as the cut-off condition of the last time the preset conditions were met. That is, after the charging is completed this time, the capacity presented by the battery pack is the same as the capacity presented last time the preset conditions were met, and both are close to the nominal capacity. Therefore, basically attenuation-free charging of the battery pack is achieved, and the service life of the lithium-ion battery is guaranteed while reducing the N / P ratio of the lithium-ion battery.

[0087] The second embodiment is: if the charging history of the battery pack does not meet the preset conditions, for example, the battery pack has just been produced or has not been at rest for a preset time, then the battery management controller will not store the estimated full charge voltage V of each battery cell. fullchrg In this case, the full charge voltage corresponding to each battery cell obtained in step S600 may be a pre-set full charge voltage for each battery cell. For example, during the battery pack production and shipment stage, an initial full charge voltage may be set for each battery cell in the battery pack. This initial full charge voltage may be set based on the experience of the staff. It should be noted that after the battery pack meets the preset conditions in a subsequent charging cycle, steps S300 to S330 may be executed to store the estimated full charge voltage of each battery cell to update the set initial full charge voltage, which may then be used as the charging cut-off condition for the next charging cycle that does not meet the preset conditions.

[0088] Step S610: charging the battery pack until the charging voltage of any battery cell reaches the corresponding full-charge voltage.

[0089] In the above steps, when the battery status of the battery pack does not meet the preset conditions, that is, the static time does not reach the preset time and / or the open circuit voltage of any battery cell is not within the preset range, the power management controller can obtain the stored full charge voltage corresponding to each battery cell, and then charge the battery pack until the charging voltage of a battery cell reaches the corresponding full charge voltage.

[0090] Figure 8 The schematic structural diagram of a charging control device provided by the present application is shown. It should be understood that the device is similar to the above-mentioned Figures 1 to 7The method embodiment executed by the power management controller corresponds to the embodiment of the method, and can execute the steps involved in the method executed by the power management controller in the aforementioned embodiment. The device includes at least one software function module that can be stored in the memory in the form of software or firmware or solidified in the operating system (OS) of the device. The device includes: a judgment module 800, used to judge whether the battery state of the battery pack meets the preset conditions, the battery pack includes a plurality of battery cells, and the preset conditions are: the battery pack is stationary for a preset time, and the open circuit voltage of each battery cell in the battery pack is within a preset range; a charging module 801, used to charge the battery pack according to the charging strategy corresponding to the judgment result, so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

[0091] In the charging control device designed as above, different charging strategies are selected to charge the battery pack according to whether the battery status of the battery pack meets the preset conditions, so that the capacity of the battery cell with the largest remaining capacity in the battery pack can reach its corresponding nominal capacity. Since the capacity difference between the battery cells in the battery pack is not too large, after the battery pack is charged, the capacity of all battery cells is close to their respective nominal capacities, so that the lithium-ion battery has basically no attenuation during the charging process, thereby ensuring the service life of the lithium-ion battery while reducing the N / P ratio of the lithium-ion battery.

[0092] In an optional implementation manner of this embodiment, the charging module 801 is specifically used to obtain the remaining capacity corresponding to each battery cell according to the open-circuit voltage of each battery cell, and obtain the maximum remaining capacity among the remaining capacities of multiple battery cells if the judgment result is that the preset conditions are met; determine the capacity to be charged of the battery pack according to the nominal capacity and the maximum remaining capacity of the battery cell with the largest remaining capacity; and charge the battery pack with the capacity to be charged to complete the charging of the battery pack.

[0093] In an optional implementation manner of this embodiment, the charging module 801 is further specifically used to obtain the corresponding full charge voltage of each stored battery cell if the judgment result is that the preset condition is not met; and charge the battery pack until the charging voltage of any battery cell reaches the corresponding full charge voltage.

[0094] In an optional implementation of this embodiment, the device also includes an acquisition module 802, which is used to obtain the charging voltage of the battery cell with the largest remaining capacity when charging is cut off, so as to obtain the full charge voltage of the battery cell with the largest remaining capacity; and, obtain the remaining chargeable capacity of each remaining battery cell among the multiple remaining battery cells when charging is cut off, wherein the multiple remaining battery cells include all battery cells among the multiple battery cells except the battery cell with the largest remaining capacity; a determination module 803, which is used to determine the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity, and then obtain the full charge voltage corresponding to each battery cell among the multiple battery cells; a storage module 804, which is used to store the full charge voltage corresponding to each battery cell among the multiple battery cells.

[0095] In an optional implementation of this embodiment, the acquisition module 802 is specifically used to calculate a first difference between the nominal capacity and the maximum remaining capacity; calculate a second difference between the first difference and the remaining capacity of each battery cell in the remaining battery cells, and the second difference corresponding to each remaining battery cell is its corresponding remaining rechargeable capacity.

[0096] In an optional implementation manner of this embodiment, the determination module 803 is specifically used to obtain the first dynamic voltage value of each remaining battery cell when charging is cut off; obtain the second dynamic voltage value of each remaining battery cell according to each remaining rechargeable capacity; calculate the sum of the first dynamic voltage value and the second dynamic voltage value, wherein the second full charge voltage of each remaining battery cell is the sum of the corresponding first dynamic voltage value and the second dynamic voltage value.

[0097] In an optional implementation manner of this embodiment, the judgment module 800 is specifically configured to judge whether the battery status of the battery pack meets a preset condition when the battery pack enters a charging state.

[0098] like Figure 9As shown, the present application provides a power management controller, which includes a chip 9, and the chip 9 has instructions fixed therein. When the instructions are executed by the chip, they execute the charging control method described in the first aspect and any optional implementation of the first aspect. Specifically, the chip 9 includes: a processor 901 and a memory 902. The processor 901 and the memory 902 are interconnected and communicate with each other through a communication bus 903 and / or other forms of connection mechanisms (not marked). The memory 902 stores a computer program executable by the processor 901. When the computing device is running, the processor 901 executes the computer program to execute the method process in any of the aforementioned implementations, such as steps S100 to S110: determining whether the battery status of the battery pack meets the preset conditions; charging the battery pack according to the charging strategy corresponding to the judgment result, so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity.

[0099] The present application provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps in any implementation of the aforementioned charging control method are executed.

[0100] Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0101] The present application provides a computer program product, which, when running on a computer, enables the computer to execute the charging control method in any of the aforementioned implementations.

[0102] In the embodiments provided in this 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 interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0103] In addition, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across 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.

[0104] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0105] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0106] 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 actual relationship or order between these entities or operations.

[0107] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, various modifications and variations of the present application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0108] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A charging control method, the method comprising: Determining whether a battery state of a battery pack satisfies a preset condition, the battery pack comprising a plurality of battery cells, the preset condition being that the battery pack has been stationary for a preset period of time and the open circuit voltage of each battery cell in the battery pack is within a preset range; charging the battery pack according to the charging strategy corresponding to the judgment result so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity; The charging of the battery pack according to the charging strategy corresponding to the judgment result includes: If the judgment result is that the preset condition is met, obtaining the remaining capacity corresponding to each battery cell in the battery pack according to the open circuit voltage of each battery cell, and obtaining the maximum remaining capacity among the remaining capacities of the plurality of battery cells; determining the capacity to be charged of the battery pack according to the nominal capacity of the battery cell with the largest remaining capacity and the maximum remaining capacity; Charging the battery pack to the capacity to be charged to complete charging of the battery pack; Obtaining the charging voltage of the battery cell with the largest remaining capacity at the time of charging cutoff to obtain the full charging voltage of the battery cell with the largest remaining capacity; Obtaining a remaining chargeable capacity of each of a plurality of remaining battery cells at the time of charging cutoff, wherein the plurality of remaining battery cells include all battery cells except a battery cell with the largest remaining capacity among the plurality of battery cells; Determine the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity, and obtain the full charge voltage corresponding to each battery cell in the plurality of battery cells; The full charge voltage corresponding to each battery cell of the plurality of battery cells is stored.

2. The method according to claim 1, wherein The charging of the battery pack according to the charging strategy corresponding to the judgment result includes: If the judgment result is that the preset condition is not met, obtaining the full charge voltage corresponding to each battery cell; The battery pack is charged until the charging voltage of any battery cell reaches the corresponding full-charge voltage.

3. The method according to claim 2, wherein: The obtaining of the stored full charge voltage corresponding to each battery cell includes: Obtain the full charge voltage corresponding to each battery cell determined in the last charging cycle that meets the preset condition.

4. The method according to claim 2, wherein: The acquiring of the stored full charge voltage corresponding to each battery cell includes: acquiring a preset full charge voltage corresponding to each battery cell.

5. The method according to claim 1, wherein The obtaining of the remaining chargeable capacity of each of the plurality of remaining battery cells at the time of charging cutoff includes: calculating a first difference between the nominal capacity and the maximum remaining capacity; A second difference between the first difference and the remaining capacity of each of the plurality of remaining battery cells is calculated, and the second difference corresponding to each remaining battery cell is the corresponding remaining chargeable capacity.

6. The method according to claim 1, wherein The step of determining the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity includes: Obtaining a first dynamic voltage value of each remaining battery cell when charging is terminated; Obtaining a second dynamic voltage value of each remaining battery cell according to each remaining chargeable capacity; The sum of the first dynamic voltage value and the second dynamic voltage value is calculated, wherein the full charge voltage of each remaining battery cell is the sum of the corresponding first dynamic voltage value and the second dynamic voltage value.

7. The method according to claim 1, wherein The determining whether the battery status of the battery pack meets a preset condition includes: When the battery pack enters a charging state, it is determined whether the battery state of the battery pack meets a preset condition.

8. A charging control device, comprising: a determination module, configured to determine whether a battery state of a battery pack satisfies a preset condition, wherein the battery pack includes a plurality of battery cells, and the preset condition is that the battery pack has been stationary for a preset period of time, and the open circuit voltage of each battery cell in the battery pack is within a preset range; a charging module, configured to charge the battery pack according to a charging strategy corresponding to the judgment result, so that the capacity of the battery cell with the largest remaining capacity in the battery pack reaches the nominal capacity of the battery cell with the largest remaining capacity; The charging module is specifically configured to obtain the remaining capacity corresponding to each battery cell according to the open circuit voltage of each battery cell if the result of the judgment is that the preset condition is met, and obtain the maximum remaining capacity among the remaining capacities of the plurality of battery cells; determining the capacity to be charged of the battery pack according to the nominal capacity of the battery cell with the maximum remaining capacity and the maximum remaining capacity; Charging the battery pack to the capacity to be charged to complete charging of the battery pack; The device also includes an acquisition module for acquiring the charging voltage of the battery cell with the largest remaining capacity when charging is cut off, so as to obtain the full charge voltage of the battery cell with the largest remaining capacity; and acquiring the remaining chargeable capacity of each remaining battery cell among the multiple remaining battery cells when charging is cut off, wherein the multiple remaining battery cells include all battery cells among the multiple battery cells except the battery cell with the largest remaining capacity; a determination module for determining the full charge voltage corresponding to each remaining battery cell according to each remaining chargeable capacity, and thereby obtaining the full charge voltage corresponding to each battery cell among the multiple battery cells; and a storage module for storing the full charge voltage corresponding to each battery cell among the multiple battery cells.

9. A power management controller, comprising a chip, wherein instructions are embedded in the chip, and when the instructions are executed by the chip, the charging control method according to any one of claims 1 to 7 is executed.

Images