Battery management device and method

Abstract

A battery management device according to an embodiment of the present disclosure includes a battery information obtaining unit configured to obtain a plurality of battery information for a plurality of battery cells, and a control unit configured to calculate a whisker for the plurality of battery information based on a standard distribution curve for a group of the plurality of battery cells, generate a box plot for the plurality of battery cells based on the plurality of battery information and the calculated whisker, and determine a state of each of the plurality of battery cells according to whether each of the plurality of battery information is included in a threshold region corresponding to the generated box plot.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2021-0004852, filed in Korea on January 13, 2021, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to a battery management apparatus and method, and more specifically, to a battery management apparatus and method capable of determining the state of each of a plurality of battery cells. Background Technology

[0003] Recently, demand for portable electronic products such as laptops, video cameras, and mobile phones has increased dramatically, and serious development has been undertaken in areas such as electric vehicles, energy storage batteries, robots, and satellites. Therefore, high-performance batteries that allow for repeated charging and discharging are being actively researched.

[0004] Currently available batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have attracted much attention because they have almost no memory effect compared to nickel-based batteries and also have a very low self-charge rate and high energy density.

[0005] Even for identical products, differences in electrochemical properties can increase due to deviations in the manufacturing process and in the actual use environment after shipment. For example, gaps between batteries can cause behavioral deviations during charge / discharge cycles, and the resulting heat generation and voltage differences may accelerate in a non-linear manner.

[0006] Conventionally, a fixed threshold or a fixed threshold range is set, and the set threshold or threshold range is used to diagnose batteries in abnormal conditions. However, this conventional method has a problem: it cannot reflect battery degradation over time. Furthermore, the complexity of the numerical determination model used to set the threshold or threshold range by reflecting battery degradation makes practical implementation very difficult. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to address problems in the relevant field, and therefore relates to providing a battery management apparatus and method capable of diagnosing the state of each of a plurality of battery cells currently in operation based on a normal distribution of a population.

[0009] These and other objectives and advantages of this disclosure will become apparent from the following detailed description and will become even more fully apparent from exemplary embodiments of this disclosure. Furthermore, it will be readily understood that the objectives and advantages of this disclosure can be achieved by the means shown in the appended claims and combinations thereof.

[0010] Technical solution

[0011] A battery management apparatus according to one aspect of the present disclosure may include: a battery information acquisition unit configured to acquire multiple battery information for multiple battery cells; and a control unit configured to calculate a whisker for the multiple battery information based on a standard distribution curve of a group of multiple battery cells, generate a box plot for the multiple battery cells based on the multiple battery information and the calculated whisker, and determine the state of each of the multiple battery cells based on whether each of the multiple battery information is included in a threshold region corresponding to the generated box plot.

[0012] A standard distribution curve can be a curve that represents the distribution pattern of battery information for multiple batteries in a population that are in the BOL (Bearing Open) state.

[0013] The control unit can be configured to calculate the must based on the average value of a standard distribution curve, a reference value corresponding to a predetermined probability density from the average value, and a threshold set to correspond to the defect rate for the population.

[0014] The control unit can be configured to calculate the reference deviation between a reference value and the average value, calculate the threshold deviation between a threshold and the reference value, and calculate the must based on the calculated reference deviation and the calculated threshold deviation.

[0015] The control unit can be configured to calculate the whiskers using the following formula:

[0016] [formula]

[0017] W = Td ÷ (2 × Rd)

[0018] Here, W can be a beard, Td can be a threshold deviation, and Rd can be a reference deviation.

[0019] The defect rate can be set to correspond to the ratio of defective monomers among the multiple monomers included in the population.

[0020] The control unit can be configured to determine the state of a battery cell among multiple battery cells whose corresponding battery information is included in the threshold range of the box plot as a normal state.

[0021] The control unit can be configured to identify the state of a battery cell among multiple battery cells whose corresponding battery information is outside the threshold range of the box plot as a defective state.

[0022] The control unit can be configured to select at least one of the top and bottom regions included in the generated box plot based on the obtained battery information, and determine a threshold region based on the selected region.

[0023] A battery pack according to another aspect of this disclosure may include a battery management device according to aspects of this disclosure.

[0024] A battery management method according to another aspect of this disclosure may include: a battery information acquisition step, acquiring multiple battery information for multiple battery cells; a must calculation step, calculating must for the multiple battery information based on a standard distribution curve of a group of multiple battery cells; a box plot generation step, generating a box plot for the multiple battery cells based on the multiple battery information and the calculated must; and a state determination step, determining the state of each of the multiple battery cells based on whether each of the multiple battery information is included in a threshold region corresponding to the generated box plot.

[0025] Beneficial effects

[0026] According to one aspect of this disclosure, an advantage is that the state of each of the multiple cells can be diagnosed taking into account the defect rate of the group of multiple cell units and their current state of degradation.

[0027] The effects of this disclosure are not limited to those described above, and other unmentioned effects will be clearly understood by those skilled in the art from the description of the claims. Attached Figure Description

[0028] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are intended to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure should not be construed as limited to the drawings.

[0029] Figure 1 This is a schematic diagram illustrating a battery management device according to an embodiment of the present disclosure.

[0030] Figure 2 This is a schematic diagram illustrating a standard distribution curve according to an embodiment of the present disclosure.

[0031] Figure 3 It is a schematic diagram illustrating a general box plot.

[0032] Figure 4 This is a schematic diagram illustrating a box plot generated based on a standard distribution curve according to an embodiment of the present disclosure.

[0033] Figure 5 This is a diagram schematically illustrating an exemplary configuration of a battery pack according to another embodiment of the present disclosure.

[0034] Figure 6 This is a schematic diagram illustrating a battery management method according to another embodiment of the present disclosure. Detailed Implementation

[0035] It should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general and dictionary meaning, but rather interpreted based on the meaning and concept corresponding to the technical aspects of this disclosure, while allowing the inventors to appropriately define the terminology for the best illustration.

[0036] Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes only and are not intended to limit the scope of this disclosure. It should be understood that other equivalents and modifications can be made to this disclosure without departing from its scope.

[0037] In addition, in describing this disclosure, a detailed description of a known element or function is omitted here when it is considered to obscure the key subject matter of the disclosure.

[0038] Ordinal terms such as “first” and “second” can be used to distinguish one element from another among various elements, but are not intended to limit these elements.

[0039] Throughout this specification, when a part is referred to as “comprising” or “including” any element, it means that the part may further include other elements, without excluding other elements, unless otherwise specifically stated.

[0040] Furthermore, throughout this specification, when a part is referred to as being “connected” to another part, it is not limited to the case where they are “directly connected” but also includes the case where they are “indirectly connected” by means of another element inserted between them.

[0041] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0042] Figure 1 This is a schematic diagram illustrating a battery management device 100 according to an embodiment of the present disclosure.

[0043] refer to Figure 1 The battery management device 100 may include a battery information acquisition unit 110 and a control unit 120.

[0044] The battery information acquisition unit 110 can be configured to acquire multiple battery information for multiple battery cells.

[0045] Here, a battery cell refers to a physically separable, independent unit comprising a negative terminal and a positive terminal. For example, a lithium-ion battery or a lithium polymer battery can be considered a battery cell.

[0046] For example, the battery information obtainable by the battery information acquisition unit 110 may include at least one of the following for each of the plurality of battery cells: voltage, current, temperature, SOC (state of charge), SOH (state of health), and resistance. Specifically, the battery information acquisition unit 110 may obtain at least one of the following for each of the plurality of battery cells: voltage, current, and temperature. Furthermore, the battery information acquisition unit 110 may obtain battery information such as SOC, SOH, and resistance based on at least one of the obtained voltage, current, and temperature.

[0047] The control unit 120 can be configured to calculate the whisker for multiple battery information based on a standard distribution curve for a group of multiple battery cells.

[0048] Here, the standard distribution curve can be a curve representing the continuous probability distribution of battery information for multiple batteries in the population that are in the BOL (Bearing Open) state.

[0049] Specifically, a population may include multiple batteries comprising multiple individual battery cells. For example, a population may include batteries manufactured through the same production line. Alternatively, a population may include multiple individual battery cells. As a specific example, the number of individual battery cells may be 100, and the number of batteries included in a population may be 1000. That is, a population (1000 batteries) may include 100 individual battery cells according to embodiments of the present disclosure and a remaining 900 individual battery cells.

[0050] Figure 2 This is a schematic diagram illustrating a standard distribution curve according to an embodiment of the present disclosure.

[0051] exist Figure 2 In one embodiment, the standard distribution curve for batteries in the BOL state included in the population can be a normal distribution with a mean of 0.

[0052] Specifically, the control unit 120 can be configured to calculate the must based on the average value of the standard distribution curve, a reference value corresponding to a predetermined probability density from the average value, and a threshold set to correspond to the defect rate for the population.

[0053] exist Figure 2 In some embodiments, the standard distribution curve may be a distribution curve that follows a normal distribution.

[0054] The reference value can be a value corresponding to a predetermined probability density (x%) based on the average of a standard distribution curve. For example, in Figure 2 In one embodiment, the reference value is a value corresponding to a predetermined probability density of 25%, and may be 0.6745.

[0055] Furthermore, the defect rate can be set to correspond to the ratio of defective monomers among the multiple monomers included in the population. Additionally, the threshold can be set to a value corresponding to the probability density corresponding to the defect rate. For example, in... Figure 2 In this embodiment, the defect rate is the ratio of actual defective monomers among the multiple monomers included in the population, and can be 0.7%. Additionally, the threshold is a value corresponding to the defect rate, and can be 2.698.

[0056] The control unit 120 can be configured to calculate the reference deviation between a reference value and an average value, calculate the threshold deviation between a threshold and a reference value, and calculate the must based on the calculated reference deviation and the calculated threshold deviation.

[0057] Specifically, the control unit 120 can be configured to calculate the whiskers using the following formula:

[0058] [formula]

[0059] W = Td ÷ (2 × Rd)

[0060] Here, W can be a beard, Td can be a threshold deviation, and Rd can be a reference deviation. The threshold deviation Td can be calculated using the formula "threshold – reference value", and the reference deviation Rd can be calculated using the formula "reference value – average value".

[0061] For example, in Figure 2 In this embodiment, the reference deviation Rd can be 0.6745, which is the difference between the reference value (0.6745) and the average value (0). Furthermore, the threshold deviation Td can be 2.024 (or 2.0235), which is the difference between the threshold (2.698) and the reference value (0.6745). Therefore, W can be calculated as 1.5 according to the formula "2.024 ÷ (2 × 0.6745)".

[0062] The control unit 120 can be configured to generate a box diagram for multiple battery cells based on multiple battery information and calculated parameters.

[0063] Figure 3 It is a schematic diagram illustrating a general box plot.

[0064] refer to Figure 3 A box plot may include a lower inner border, an interquartile range (IQR), and an upper inner border. Here, the interquartile range (IQR) can be defined as the range from the first quartile Q1 to the third quartile Q3.

[0065] Specifically, according to the general definition of a box plot, the lower inner fence can be derived based on the interquartile range (IQR) and the whisker (W). For example, the lower inner fence can be defined as “first quartile Q1 – (interquartile range IQR × whisker W)”.

[0066] Additionally, the upper inner fence can be derived based on the interquartile range (IQR) and the whisker (W). For example, the upper inner fence can be defined as "the third quartile Q3 + (interquartile range IQR × whisker W)".

[0067] Figure 4 This is a schematic diagram illustrating a box plot generated based on a standard distribution curve according to an embodiment of the present disclosure.

[0068] refer to Figure 4 The control unit 120 can be based on Figure 2 The standard distribution curve is used to calculate the whiskers. Additionally, the control unit 120 can use the calculated whiskers to generate a box plot for multiple battery cells.

[0069] Preferably, the control unit 120 can generate a box plot based on the median of multiple battery information values. That is, in Figure 4 In one embodiment, the second quartile Q2 can be set based on the median of multiple battery information values.

[0070] Specifically, Figure 4 The embodiment is a graph illustrating the ideal correspondence between the standard distribution curve and the box plot. Here, it should be noted that the standard distribution curve is based on the battery information of the population, while the box plot is based on the battery information of multiple individual cells. That is, the box plot is generated by calculation based on the standard distribution curve and the battery information of multiple individual cells, and the standard distribution curve is not simply replaced by a box plot. Therefore, based on... Figure 4 In an ideal embodiment, the standard distribution curve for the population should not be interpreted as a simple replacement for the box plot for multiple individual cells.

[0071] The control unit 120 can be configured to determine the state of each of the multiple battery cells based on whether each of the multiple battery information is included in a threshold region corresponding to the generated box plot.

[0072] For example, the control unit 120 can be configured to determine the state of a battery cell among a plurality of battery cells whose corresponding battery information is included in the threshold range of the box plot as a normal state. Conversely, the control unit 120 can be configured to determine the state of a battery cell among a plurality of battery cells whose corresponding battery information is outside the threshold range of the box plot as a defective state.

[0073] In other words, the battery management device 100 according to the embodiments of this disclosure can determine the state of multiple battery cells based on a standard distribution curve of a group including multiple battery cells.

[0074] In other words, when the number of individual battery cells is small, in some cases, it is not possible to obtain an ideal continuous probability distribution using only battery information for each individual cell. In such cases, due to the insufficient number of samples, the accuracy and reliability of determining the state of multiple battery cells solely through a continuous probability distribution may be low.

[0075] Therefore, when the number of samples (multiple battery cells) is small, the battery management device 100 can generate a box plot for multiple battery cells by calculating the required values ​​based on a standard distribution curve for a population including the samples. Furthermore, since the battery management device 100 can determine the state of multiple battery cells based on the generated box plot, the accuracy and reliability of determining the state of multiple battery cells can be improved.

[0076] For example, when the number of individual battery cells is 100 but the number of the group is 10,000, the accuracy and reliability of determining the state of the individual battery cells can be improved because the box plot generated by the battery management device 100 for the individual battery cells is generated with consideration of the normal distribution of the group.

[0077] Furthermore, since the control unit 120 calculates the defect rate based on the population, the accuracy and reliability of determining the state of multiple battery cells based on the box plot can be higher.

[0078] For example, in Figure 4 In this embodiment, the defect rate of the population is 0.7%, and therefore the calculated must can be 1.5. That is, according to Figure 4 The box plot of an embodiment can be a box plot that can determine the state of multiple battery cells included in a population based on a standard distribution curve of a population whose defect rate is detected as 0.7%.

[0079] When the defect rate of the population increases, the whiskers calculated according to the formula become smaller, and therefore, the threshold region of the box plot can also decrease. Conversely, when the defect rate of the population decreases, the whiskers calculated according to the formula become larger, and therefore, the threshold region of the box plot can also increase.

[0080] In other words, since the battery management device 100 according to embodiments of this disclosure can generate a box plot that can adaptively change depending on the defect rate of the group, the state of multiple battery cells can be determined more accurately. This means that the higher the defect rate of the group, the greater the probability that the multiple battery cells included in the group are also defective. Therefore, when determining the state of multiple battery cells in the MOL (Mid-Life) or EOL (End-of-Life) state, the battery management device 100 can more accurately and probabilistically determine the state of multiple battery cells by taking into account the defect rate of the group.

[0081] Meanwhile, the control unit 120 provided in the battery management device 100 may selectively include processors, application-specific integrated circuits (ASICs), other chipsets, logic circuits, registers, communication modems, data processing devices, etc., known in the art to execute the various control logics performed in this disclosure. Furthermore, when the control logic is implemented in software, the control unit 120 can be implemented as a collection of program modules. In this case, the program modules can be stored in memory and executed by the control unit 120. The memory can be located inside or outside the control unit 120 and can be connected to the control unit 120 by various known means.

[0082] Additionally, the battery management device 100 may further include a storage unit 130. The storage unit 130 may store data necessary for the operation and function of each component of the battery management device 100, data generated during the execution of operations or functions, etc. The storage unit 130 is not particularly limited in type, as long as it is a known information storage device capable of recording, erasing, updating, and retrieving data. As examples, the information storage device may include RAM, flash memory, ROM, EEPROM, registers, etc. Furthermore, the storage unit 130 may store program code, defining processes that can be executed by the control unit 120.

[0083] For example, storage unit 130 can store a standard distribution curve. Furthermore, storage unit 130 can store the population's mean, reference value, threshold, reference deviation Rd, threshold deviation Td, and defect rate based on the standard distribution curve. Control unit 120 can access storage unit 130 to obtain information necessary for calculating and generating box plots.

[0084] Furthermore, the storage unit 130 can store battery information for multiple individual battery cells. The battery information acquisition unit 110 can obtain battery information by accessing the storage unit 130, or by directly receiving battery information from an external source.

[0085] The control unit 120 can be configured to select at least one of the top and bottom regions included in the generated box plot based on the obtained battery information, and determine a threshold region based on the selected region.

[0086] A box plot can include a top region and a bottom region based on the median of multiple battery information values. The top region can be a region that includes values ​​greater than or equal to the median, and the bottom region can be a region that includes values ​​less than the median.

[0087] For example, in Figure 4In one embodiment, the top region of the box plot may correspond to the region that is equal to or greater than the second quartile Q2 and equal to or less than the upper inner fence, and the bottom region may correspond to the region that is less than the second quartile Q2 and equal to or greater than the lower inner fence.

[0088] Generally, the threshold region can be determined to include both the top and bottom regions. However, the threshold region can be determined to be at least one of the top and bottom regions based on battery information.

[0089] For example, when the battery information is the voltage of a single battery cell at the end of the charging process, only the top region can be included in the threshold region to identify overcharged battery cells as defective.

[0090] As another example, when the battery information is the voltage of a battery cell at the end of discharge, only the top region can be included in the threshold region to identify over-discharged battery cells as defective states.

[0091] In other words, the control unit 120 can prevent unnecessary system resources from being wasted on setting and storing threshold regions by determining the threshold region as at least one of the top and bottom regions based on battery information. Furthermore, since the optimized threshold region can be set based on battery information, the control unit 120 can determine the state of individual battery cells more quickly.

[0092] The battery management device 100 according to this disclosure can be applied to a BMS (Battery Management System). That is, the BMS according to this disclosure may include the aforementioned battery management device 100. In this configuration, at least some components of the battery management device 100 can be implemented by supplementing or adding functions included in a conventional BMS. For example, the battery information acquisition unit 110, the control unit 120, and the storage unit 130 can be implemented as components of the BMS.

[0093] Furthermore, the battery management device 100 according to this disclosure can be disposed in the battery pack 1. That is, the battery pack 1 according to this disclosure may include the aforementioned battery management device 100 and one or more individual battery cells. In addition, the battery pack 1 may further include electrical devices (relays, fuses, etc.) and a housing.

[0094] Figure 5 This is a diagram schematically illustrating an exemplary configuration of battery pack 1 according to another embodiment of the present disclosure.

[0095] Specifically, in Figure 5In this embodiment, the measurement unit 200 can be connected to a first sensing line SL1, a second sensing line SL2, and a third sensing line SL3. The measurement unit 200 can be connected to the positive terminal of battery B via the first sensing line SL1 and to the negative terminal of battery B via the second sensing line SL2. Furthermore, the measurement unit 200 can measure the voltage of battery B by calculating the difference between the voltage measured via the first sensing line SL1 and the voltage measured via the second sensing line SL2. While battery B is being charged at a charging rate C-, the measurement unit 200 can measure the charging voltage of battery B via the first sensing line SL1 and the second sensing line SL2. Conversely, while battery B is being discharged at a discharging rate C-, the measurement unit 200 can measure the discharging voltage of battery B via the first sensing line SL1 and the second sensing line SL2.

[0096] Additionally, the measurement unit 200 can be connected to the ammeter A via the third sensing line SL3 to measure the charging and discharging currents of the battery B. Here, the battery B can be charged at a charging rate C-using a constant current or discharged at a discharging rate C-using a constant current.

[0097] For example, ammeter A can be a current sensor or shunt resistor positioned in the charging and discharging path of battery B to measure the charging and discharging current of battery B. Here, the charging and discharging path of battery B can be a high-current path, where a charging current is applied to battery B or a discharging current is output from battery B. Figure 5 In this embodiment, the ammeter can be connected between the negative terminal of battery B and the negative terminal P- of battery pack 1 in the charging path of battery B. However, it should be noted that, as long as it is in the discharging path of battery B, the ammeter can also be connected between the positive terminal of battery B and the positive terminal P+ of battery pack 1.

[0098] In addition, the measurement unit 200 can measure the temperature of battery B via the fourth sensing line SL4.

[0099] Battery information, including at least one of the current, voltage, and temperature of battery B measured by the measuring unit 200, can be sent to the battery management device 100. For example, the battery information sent from the measuring unit 200 can be stored in the storage unit 130, or it can be sent directly to the battery information acquisition unit.

[0100] Figure 6 This is a schematic diagram illustrating a battery management method according to another embodiment of the present disclosure.

[0101] Preferably, each step of the battery management method can be performed by the battery management device 100. In the following text, content overlapping with the foregoing will be omitted or briefly described.

[0102] refer to Figure 6 The battery management method may include a battery information acquisition step (S100), a calculation step (S200), a box plot generation step (S300), and a state determination step (S400).

[0103] The battery information acquisition step (S100) is a step of acquiring multiple battery information for multiple battery cells, and can be executed by the battery information acquisition unit 110.

[0104] The calculation step (S200) is a step of calculating the requirements for multiple battery information based on the standard distribution curve of a group of multiple battery cells, and can be executed by the control unit 120.

[0105] For example, suppose in Figure 4 In this embodiment, the defect rate of the population is 0.7%. The control unit 120 can calculate the defect rate by substituting the threshold deviation Td and reference deviation Rd from the standard distribution curve into the formula.

[0106] The box plot generation step (S300) is a step of generating a box plot for multiple battery cells based on multiple battery information and the calculated values, and can be executed by the control unit 120.

[0107] For example, in Figure 4 In one embodiment, the control unit 120 can generate a box plot for multiple battery cells based on the calculated whiskers corresponding to the standard distribution curve.

[0108] The state determination step (S400) is a step of determining the state of each of the multiple battery cells based on whether each of the multiple battery information is included in the threshold region corresponding to the generated box plot, and can be executed by the control unit 120.

[0109] For example, in Figure 4 In this embodiment, the control unit 120 can determine the state of a battery cell whose battery information belongs to the threshold region of the box plot as a normal state. Conversely, the control unit 120 can determine the state of a battery cell whose battery information does not belong to the threshold region of the box plot as a defective state.

[0110] Furthermore, according to the above embodiment, since the threshold region of the box plot can be determined to correspond to the type of battery information, the control unit 120 can determine the state of multiple battery cells more quickly based on the type of battery information.

[0111] The embodiments of this disclosure described above can be implemented not only by apparatus and methods, but also by a program that implements the functions corresponding to the configurations of the embodiments of this disclosure, or by a recording medium on which the program is recorded. The program or recording medium can be readily implemented by those skilled in the art from the above description of the embodiments.

[0112] This disclosure has been described in detail. However, it should be understood that the detailed description and specific examples are given by way of illustration only while indicating preferred embodiments of this disclosure, as various changes and modifications within the scope of this disclosure will become apparent to those skilled in the art from the detailed description.

[0113] Furthermore, many substitutions, modifications and alterations can be made to the above-described disclosure by those skilled in the art without departing from the technical aspects of this disclosure, and this disclosure is not limited to the above embodiments and drawings, and each embodiment can be selectively combined in part or in whole to allow various modifications.

[0114] (See attached image labels)

[0115] 1: Battery pack

[0116] 100: Battery Management Device

[0117] 110: Battery Information Acquisition Unit

[0118] 120: Control Unit

[0119] 130: Storage unit

[0120] 200: Measurement Unit

Claims

1. A battery management device, comprising: A battery information acquisition unit, configured to acquire multiple battery information for multiple battery cells; as well as A control unit is configured to calculate whiskers for the plurality of battery cells based on a standard distribution curve for a group of the plurality of battery cells; generate a box plot for the plurality of battery cells based on the plurality of battery information and the calculated whiskers; and determine the state of each of the plurality of battery cells based on whether each of the plurality of battery information is included in a threshold region corresponding to the generated box plot. The control unit is configured to calculate the whiskers based on the average value of the standard distribution curve, a reference value corresponding to a predetermined probability density at a distance from the average value, and a threshold set to correspond to the defect rate for the population.

2. The battery management device according to claim 1, in, The standard distribution curve is a curve that represents the distribution pattern of battery information for multiple batteries in the group that are in the beginning of their lifespan.

3. The battery management device according to claim 1, in, The control unit is configured to calculate a reference deviation between the reference value and the average value, calculate a threshold deviation between the threshold and the reference value, and calculate the must based on the calculated reference deviation and the calculated threshold deviation.

4. The battery management device according to claim 3, in, The control unit is configured to calculate the whiskers using the following formula: W = Td ÷ (2 × Rd) Wherein, W is the whisker, Td is the threshold deviation, and Rd is the reference deviation.

5. The battery management device according to claim 1, in, The defect rate is set to correspond to the ratio of defective monomers among the plurality of monomers included in the population.

6. The battery management device according to claim 1, in, The control unit is configured to determine the state of a battery cell among the plurality of battery cells whose corresponding battery information is included in the threshold range of the box plot as a normal state, and The control unit is configured to determine the state of a battery cell whose corresponding battery information is outside the threshold range of the box plot as a defective state.

7. The battery management device according to claim 6, in, The control unit is configured to select at least one of the top and bottom regions included in the generated box plot based on the obtained battery information, and to determine the threshold region based on the selected region.

8. A battery pack comprising a battery management device according to any one of claims 1 to 7.

9. A battery management method, comprising: The battery information acquisition step obtains multiple battery information for multiple individual battery cells; The calculation step involves calculating the required parameters for the multiple battery cells based on the standard distribution curves for the group of the multiple battery cells. The box plot generation step generates a box plot for the multiple battery cells based on the multiple battery information and the calculated values. as well as The state determination step determines the state of each of the multiple battery cells based on whether each piece of battery information is included in a threshold region corresponding to the generated box plot. The whiskers are calculated based on the average value of the standard distribution curve, a reference value corresponding to a predetermined probability density at a distance from the average value, and a threshold set to correspond to the defect rate for the population.

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