Battery management apparatus and method of controlling charge / discharge

Abstract

A battery management apparatus includes: a measurement unit including at least one sensor, the measurement unit being configured to measure a cell voltage of each of a plurality of battery cells in a battery module; and a processor configured to, if the battery module is charged or discharged, adjust the charging threshold voltage or the discharging threshold voltage based on a difference in cell voltages between the plurality of battery cells and a current state of charge (SOC) of the battery module.

Description

Technical Field

[0001] The embodiments relate to a battery management device and a method for controlling charging and discharging using the same. Background Technology

[0002] A battery pack consists of individual battery cells and peripheral circuitry, including charging and discharging circuitry. This peripheral circuitry is fabricated as a printed circuit board (PCB) and then coupled to the battery cells. If an external power source is connected to the external terminals of the battery pack, the battery cells are charged; if a load is connected to the external terminals, the battery cells are discharged. The charging and discharging circuitry controls the charging and discharging of the battery cells between the external terminals and the battery cells. Typically, multiple battery cells are connected in series and parallel according to the power consumption capacity of the load.

[0003] Even if the individual cells in a battery pack have the same capacity at the time of shipment, the available voltage range for charging and discharging varies depending on chemical properties such as chemical structure and particle size. As a result, even if cell balancing is performed to match the voltage range of the individual cells, repeated charging and discharging cause capacity variations within the individual cells, and continuous use leads to capacity degradation.

[0004] The information disclosed in this background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0005] The embodiment includes a battery management device, comprising: a measurement unit including at least one sensor, the measurement unit being configured to measure the cell voltage of each of a plurality of battery cells in a battery module; and a processor configured to adjust a charging threshold voltage or a discharging threshold voltage based on the difference in cell voltages between the plurality of battery cells and the current state of charge (SOC) of the battery module if the battery module is being charged or discharged.

[0006] The processor can also be configured to calculate the maximum voltage deviation of the battery module based on the cell voltage of each of the multiple battery cells at the start of charging of the battery module; and to set a first charging threshold voltage based on at least one of a predetermined reference charging threshold voltage, the maximum voltage deviation, and the current SOC.

[0007] The processor can also be configured to, during the charging of the battery module, if the maximum cell voltage among all cell voltages of the multiple battery cells reaches a first charging threshold voltage, compare the minimum cell voltage among all cell voltages with a predetermined reference charging threshold voltage, and terminate charging or calibrate the first charging threshold voltage based on the comparison result.

[0008] The processor can also be configured to terminate charging of the battery module if the minimum single-cell voltage is greater than or equal to a predetermined reference charging threshold voltage.

[0009] The processor can also be configured to increase a first charging threshold voltage to calibrate the first charging threshold voltage to a second charging threshold voltage if the minimum single cell voltage is less than or equal to a predetermined reference charging threshold, and continue charging the battery module.

[0010] The processor can also be configured to increase the first charging threshold voltage by the difference between the average voltage of all the individual cell voltages of the multiple battery cells and the minimum individual cell voltage.

[0011] The processor can also be configured to terminate the charging of the battery module if, during the charging of the battery module, the maximum cell voltage among all cell voltages of the plurality of battery cells reaches a second charging threshold voltage, or if the minimum cell voltage among all cell voltages reaches a predetermined reference charging threshold voltage.

[0012] The processor can also be configured to calculate the maximum voltage deviation of the battery module based on the cell voltage of each of the multiple battery cells at the start of discharge of the battery module; and to set a first discharge threshold voltage based on at least one of a predetermined reference discharge threshold voltage, the maximum voltage deviation, and the current SOC.

[0013] During the discharge of the battery module, if the minimum cell voltage among all cell voltages of multiple battery cells reaches the first discharge threshold voltage, the processor can compare the maximum cell voltage among all cell voltages with the reference discharge threshold voltage, and terminate the discharge or calibrate the first discharge threshold voltage based on the comparison result.

[0014] If the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage, the processor can terminate the discharge of the battery module.

[0015] If the maximum single cell voltage is not less than or equal to the reference discharge threshold voltage, the processor reduces the first discharge threshold voltage to calibrate the first discharge threshold voltage to the second discharge threshold voltage and continues to discharge the battery module.

[0016] The second discharge threshold voltage is the difference between the average voltage of all individual cell voltages of multiple battery cells minus the first discharge threshold voltage and the maximum individual cell voltage.

[0017] During the discharge of the battery module, if the minimum cell voltage among all cell voltages of the multiple battery cells reaches the second discharge threshold voltage, or if the maximum cell voltage among all cell voltages reaches the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

[0018] The embodiment includes a method for controlling charging using a battery management device, the method comprising: setting a first charging threshold voltage by a processor based on the difference in cell voltages among the multiple cell units at the start of charging of a battery module comprising multiple cell units and the current state of charge (SOC) of the battery module; during charging of the battery module, if the maximum cell voltage among all cell voltages reaches the first charging threshold voltage, comparing the minimum cell voltage among the multiple cell voltages with a predetermined reference charging threshold voltage by the processor; and if the minimum cell voltage is greater than or equal to the predetermined reference charging threshold voltage, terminating charging of the battery module by the processor.

[0019] When setting the first charging threshold voltage, the processor can calculate the maximum voltage deviation of the battery module based on the individual cell voltage of each of the multiple battery cells, and set the first charging threshold voltage based on at least one of a predetermined reference charging threshold voltage, the maximum voltage deviation, and the current SOC.

[0020] The method may further include: if the minimum cell voltage is not greater than or equal to a predetermined reference charging threshold voltage, the processor sets a second charging threshold voltage by increasing the first charging threshold voltage; and during the charging of the battery module, if the maximum cell voltage among all cell voltages of the plurality of battery cells reaches the second charging threshold voltage, or if the minimum cell voltage among all cell voltages reaches the predetermined reference charging threshold voltage, the processor terminates the charging of the battery module.

[0021] When setting the second charging threshold voltage, the processor can set the second charging threshold voltage by adding the difference between the average voltage of all individual cell voltages of multiple battery cells and the minimum individual cell voltage to the first charging threshold voltage.

[0022] The embodiment includes a method for controlling discharge using a battery management device, the method comprising: setting a first discharge threshold voltage by a processor based on the difference in cell voltages among the multiple cell units at the start of discharge of a battery module comprising multiple cell units and the current state of charge (SOC) of the battery module; during the discharge of the battery module, if the minimum cell voltage among all cell voltages reaches the first discharge threshold voltage, comparing the maximum cell voltage among the multiple cell voltages with a reference discharge threshold voltage by the processor; and if the maximum cell voltage is less than or equal to the reference discharge threshold voltage, terminating the discharge of the battery module by the processor.

[0023] The method may further include: if the maximum cell voltage is not less than or equal to a reference discharge threshold voltage, the processor sets a second discharge threshold voltage by decreasing the first discharge threshold voltage; and during the discharge of the battery module, if the minimum cell voltage among all cell voltages of the plurality of battery cells reaches the second discharge threshold voltage, or if the maximum cell voltage among all cell voltages reaches the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

[0024] The processor can also be configured to set a second discharge threshold voltage by reducing the first discharge threshold voltage to the difference between the average voltage of all cell voltages of the plurality of battery cells and the maximum cell voltage. Attached Figure Description

[0025] The features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, wherein:

[0026] Figure 1 This is a schematic diagram illustrating a battery pack according to one or more embodiments of the present disclosure;

[0027] Figure 2 This is a block diagram schematically illustrating the configuration of a battery management device according to one or more embodiments of the present disclosure;

[0028] Figure 3 This is a flowchart describing a method for controlling the charging of a battery module according to one or more embodiments of the present disclosure; and

[0029] Figure 4 This is a flowchart describing a method for controlling the discharge of a battery module according to one or more embodiments of the present disclosure. Detailed Implementation

[0030] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementation methods to those skilled in the art.

[0031] In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity. It should also be understood that if a layer or element is referred to as being "on" another layer or substrate, it may be directly on that layer or substrate, or there may be intermediate layers. Furthermore, it should be understood that if a layer is referred to as being "below" another layer, it may be directly below that layer, and one or more intermediate layers may be present. Additionally, it should be understood that if a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or one or more intermediate layers may be present. The same reference numerals always denote the same elements.

[0032] In the following, embodiments of this disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meaning, but should be interpreted as meanings and concepts consistent with the technical spirit of this disclosure, based on the principle that the inventor can appropriately define the concepts of terms by his / her own lexicographer to best interpret his / her disclosure.

[0033] The embodiments described in this specification and the configurations shown in the accompanying drawings are merely some embodiments of this disclosure and do not represent all technical ideas, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0034] It should be understood that if a component or layer is described as being "on," "connected to," or "coupled to" another component or layer, it can be directly on, connected to, or coupled to the other component or layer, or one or more intermediate components or layers may exist. If a component or layer is described as being "directly on," "directly connected to," or "directly coupled to" another component or layer, no intermediate components or layers exist. For example, if a first component is described as being "coupled" or "connected" to a second component, the first component can be directly coupled to or connected to the second component, or the first component can be indirectly coupled to or connected to the second component via one or more intermediate components.

[0035] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" refers to "one or more embodiments of this disclosure" when describing embodiments of the present disclosure. Expressions such as "at least one of..." and "any one of..." modify the entire list of elements if they precede the list of elements, without modifying individual elements of the list. If phrases such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one selected from the group consisting of A, B, and C", or "at least one selected from A, B, and C" are used to specify a list of elements A, B, and C, then the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms “use,” “using,” and “used” can be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to explain the inherent variations in measurements or calculations that will be recognized by one of ordinary skill in the art.

[0036] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section.

[0037] For ease of description, this document uses spatial relative terms such as “beneath,” “below,” “lower,” “above,” and “upper” to describe the relationship between one element or feature and another element(s) as shown in the figures. It should be understood that, in addition to the orientations shown in the figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “beneath” of other elements or features will be oriented as “above” or “over” of other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0038] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, if used in this specification, the terms “includes,” “including,” “comprises,” and / or “comprising” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0039] Furthermore, any numerical ranges disclosed and / or enumerated herein are intended to include all subranges containing the same numerical precision within the enumerated range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the minimum value of 1.0 and the maximum value of 10.0, i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly describe any subranges contained within the scope expressly described herein.

[0040] Referring to two compared elements, features, etc., as “same” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with what is considered a low deviation in the field, such as 5% or less. Additionally, if a parameter is said to be uniform in a given region, it can mean that it is uniform in terms of the mean.

[0041] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0042] If any element is described as being set (or located or positioned) "above" (or below) or "on" (or under) a component, it can mean that the element is placed in contact with the upper (or lower) surface of the component, and it can also mean that another component can be inserted between the component and any arbitrary element set (or located or positioned) on (or under) the component.

[0043] Furthermore, it should be understood that if a component is referred to as being "coupled," "linked," or "connected" to another component, then the components can be directly "coupled," "linked," or "connected" to each other, or there can be an intermediate component through which the components can be "coupled," "linked," or "connected" to the other component. Additionally, if a component is referred to as being "electrically coupled" to another component, then the component can be directly connected to the other component, or there can be an intermediate component through which the component and the other component are indirectly connected to each other.

[0044] Throughout this specification, the statement "A and / or B" means A, B, or A and B, unless otherwise stated. That is, "and / or" includes any or all of the listed items. The statement "C to D" means C or more and D or fewer, unless otherwise stated.

[0045] Figure 1 This is a schematic diagram illustrating a battery pack according to one or more embodiments of the present disclosure, and Figure 2 This is a block diagram schematically illustrating the configuration of a battery management device according to one or more embodiments of the present disclosure.

[0046] refer to Figure 1 According to one or more embodiments of the present disclosure, the battery pack 100 has a structure that can be electrically connected to an external device 10 via a positive electrode connection terminal P+ and a negative electrode connection terminal P-.

[0047] External device 10 can be a load that receives power from battery pack 100 or a charging device that supplies power to battery pack 100 to charge multiple battery modules 110. If the external device is a load, battery pack 100 operates as a power source supplying power to the load and discharges. External device 10 operating as a load can be, for example, an electronic device or a transportation device, and the transportation device can be, for example, an electric vehicle, a hybrid vehicle, or a smart mobility device.

[0048] The battery pack 100 may include at least one battery module 110, a switch 130, and a battery management device 120. Of course, in various embodiments, the battery pack 100 may further include other components.

[0049] Battery module 110 may include multiple individual cells connected in series or in parallel. Multiple battery modules 110 may be connected in series or in parallel.

[0050] Switch 130 can be connected in series with at least one of a plurality of group terminals P+ and P- between battery module 110 and external device 10, and can prevent or allow electrical connection between battery module 110 and external device 10. Switch 130 can be installed on the current path for charging and discharging battery module 110.

[0051] Switch 130 controls the electrical connection between battery pack 100 and external device 10. When switch 130 is turned on, battery pack 100 and external device 10 are electrically connected, and charging or discharging is performed. When switch 130 is turned off, battery pack 100 and external device 10 can be electrically disconnected. That is, when switch 130 is turned on, power can be supplied from battery module 110 to external device 10 or from external device 10 to battery module 110. When switch 130 is turned off, charging and discharging of battery module 110 can be interrupted. In this case, switch 130 can be turned on or off under the control of battery management device 120.

[0052] The switch 130 can be implemented as a mechanical relay (contactor) that is turned on / off by the magnetic force of a coil, or as a semiconductor switch, such as a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0053] The battery management device 120 can monitor the voltage, current and temperature of the battery module 110, and can calculate the state of charge (SOC) based on the monitoring results and control the charging and discharging of the battery module 110.

[0054] like Figure 2As shown, the battery management device 120 may include a memory 122, a measurement unit 124, and a processor 126. The memory 122, the measurement unit 124, and the processor 126 may constitute a battery management system (BMS).

[0055] Memory 122 may store at least one instruction executed by processor 126. Specifically, memory 122 may store instructions (programs, applications, applets, etc.) that, if charging or discharging the battery module 110, allow the battery module 110 to adjust the charging or discharging threshold voltage based on the difference in individual cell voltages and the current state of charge (SOC) of the battery module 110, and processor 126 may selectively utilize the stored information as needed. Memory 122 may be implemented as a volatile and / or non-volatile storage medium, such as read-only memory (ROM), random access memory (RAM), flash memory, or electrically erasable programmable read-only memory (EEPROM).

[0056] The measurement unit 124 can measure battery status data that indicates the state of the battery module 110 and send the measured battery status data to the processor 126. Here, the battery status data may include the individual cell voltage, individual cell current and temperature, and the state of charge (SOC) of the battery module 110, etc.

[0057] The measuring unit 124 can measure the individual cell voltages of multiple battery cells in the battery module 110. For example, the measuring unit 124 can measure the individual cell voltage by measuring the voltage across each of the multiple battery cells. In this case, the measuring unit 124 can measure the individual cell voltage of each battery cell using various methods, and this disclosure is not limited to these voltage measurement methods. The measuring unit 124 can also measure the individual cell current flowing into or out of the multiple battery cells.

[0058] Therefore, the measurement unit 124 may include a voltage sensor configured to measure the cell voltage of each of the plurality of battery cells. Additionally, the measurement unit 124 may also include a current sensor configured to measure the cell current of the plurality of battery cells.

[0059] The processor 126, which serves as the primary entity controlling the charging and discharging of the battery module 110, can be implemented as a central processing unit (CPU) or a system-on-a-chip (SoC). It can control multiple hardware or software components connected to the processor 126 by processing an operating system or application, and can perform various types of data processing and calculations. Specifically, in this embodiment, the processor 126 can correspond to the analog front-end (AFE) integrated circuit (IC) or microcontroller unit (MCU) of the battery management system (BMS), which monitors the battery's state, such as the voltage, current, temperature, and state of charge (SOC) of the battery module 110, and controls the charging or discharging of the battery module 110 based on the monitoring results.

[0060] The processor 126 can control the charging and discharging of the battery module 110 based on battery state data. For example, during the charging of the battery module 110, if the voltage of the battery module 110 reaches a predetermined reference charging threshold voltage, the processor 126 can terminate the charging of the battery module 110. During the discharging of the battery module 110, if the voltage of the battery module 110 reaches a predetermined reference discharging threshold voltage, the processor 126 can terminate the discharging of the battery module 110.

[0061] Furthermore, even if battery modules 110 have the same capacity at the time of shipment, the available voltage range for charging and discharging can vary depending on chemical properties such as chemical structure and particle size. Therefore, even if cell balancing is performed to match the voltage range of battery modules 110, capacity differences between battery modules 110 may occur continuously, and capacity degradation of battery modules 110 may occur with continuous use. Specifically, in the case of lithium iron phosphate batteries, the closer to full charge (SOC 100%) and full discharge (SOC 0%), the greater the polarization resistance. Therefore, the actual usable voltage range becomes significantly narrower, resulting in the battery's charging and discharging capacity becoming less than its chemically usable capacity. In other words, due to the high polarization resistance of battery modules 110, the capacity of battery modules 110 varies due to characteristics such as a significant drop in voltage after charging, a significant increase in voltage after discharging, and changes in polarization and electrochemical internal resistance at the end of charging / discharging, depending on the voltage at the start of charging / discharging. In particular, in the case of lithium iron phosphate batteries, charging begins at a low voltage, and the polarization resistance increases and varies between individual cells at the end of charging, resulting in capacity differences.

[0062] Therefore, this disclosure aims to maximize the capacity of the battery module 110 by applying a slightly more flexible charge / discharge threshold voltage compared to the conventional charge / discharge threshold voltage.

[0063] To this end, processor 126 can increase the charging threshold voltage as the voltage at the start of charging is lower, thereby maximizing the charging capacity of battery module 110. Furthermore, processor 126 can decrease the discharge threshold voltage as the voltage at the start of discharging is higher, thereby maximizing the discharge capacity of battery module 110.

[0064] At this time, the processor 126 can adjust the charging or discharging threshold voltage based on the voltage difference between the individual battery cells at the start of charging or discharging of the battery module 110 and the current SOC of the battery module 110. Here, the charging threshold voltage can mean a voltage set to terminate charging, and the discharging threshold voltage can mean a voltage set to terminate discharging. If the battery module 110 is fully charged, the SOC of the battery module 110 can increase to 100%, and can gradually decrease from 100% as the battery module 110 is discharged.

[0065] During the charging of battery module 110, if the voltage of battery module 110 measured by measurement unit 124 corresponds to (i.e., equals) the charging threshold voltage, processor 126 may terminate the charging of battery module 110. During the discharging of battery module 110, if the voltage of battery module 110 measured by measurement unit 124 corresponds to (i.e., equals) the discharging threshold voltage, processor 126 may terminate the discharging of battery module 110.

[0066] The operation of processor 126 will be described in detail below.

[0067] First, the method by which the processor 126 controls the charging of the battery module 110 will be described.

[0068] A reference charging threshold voltage is set in the battery module 110 to terminate charging. However, during the charging of the battery module 110, the polarization and electrochemical internal resistance at the end of charging vary according to the voltage at the start of charging for each battery cell, which may result in capacity differences between battery cells.

[0069] To address this issue, the charging threshold voltage can be adaptively set based on the current SOC of the battery module 110 and the battery voltage within the battery module 110, instead of simply using a reference charging threshold voltage to charge the battery module 110. Here, the term "SOC" represents the current state of charge of the battery module 110 as a percentage [%], and can have the same meaning as charging capacity, charging rate, etc.

[0070] The processor 126 can adjust the charging threshold voltage based on the difference in individual cell voltages between battery cells at the start of charging of the battery module 110 and the current state of charge (SOC) of the battery module 110. That is, at the start of charging of the battery module 110, the processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell, and set a first charging threshold voltage based on at least one of a reference charging threshold voltage, the maximum voltage deviation, and the current SOC. As the voltage at the start of charging becomes lower, a higher charging threshold voltage needs to be set; therefore, the processor 126 can utilize the maximum voltage deviation of the battery module 110 and the current SOC.

[0071] Specifically, the processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell. That is, the processor 126 can obtain the maximum and minimum cell voltages from the individual cell voltages of multiple battery cells measured at the start of charging. Additionally, the processor 126 can calculate the average voltage of the multiple battery cell voltages measured at the start of charging. Subsequently, the processor 126 can compare each of the minimum and maximum cell voltages with the average voltage of the battery module 110 to calculate the maximum voltage deviation. For example, the processor 126 can calculate the larger of the difference between the average voltage and the minimum cell voltage, and the difference between the average voltage and the maximum cell voltage, as the maximum voltage deviation.

[0072] The processor 126 can calculate the current SOC at the start of charging, or it can measure the current SOC via the measurement unit 124. In this case, the processor 126 can calculate the current SOC based on the cell voltage, cell current, temperature, etc., of each battery cell measured by the measurement unit 124. Conventional methods for measuring charging capacity, such as voltage measurement, current measurement, internal resistance calculation, and temperature measurement, can be used in calculating the current SOC.

[0073] Once the maximum voltage deviation at the start of charging of battery module 110 and the current SOC are calculated, processor 126 can use Equation 1 below to calculate the first charging threshold voltage.

[0074] [Equation 1]

[0075] First charging threshold voltage = Reference charging threshold voltage + Maximum voltage deviation * (100 - Current SOC)

[0076] Here, the reference charging threshold voltage can be a preset value.

[0077] Equation 1 shows that the first charging threshold voltage has a higher value than the reference charging threshold voltage. Furthermore, since the first charging threshold voltage is calculated using the formula "100 - current SOC at the start of charging", it is known that the lower the current SOC, the higher the value of the first charging threshold voltage.

[0078] Once the first charging threshold voltage is set, the processor 126 can charge the battery module 110 and determine whether any battery cell has reached the first charging threshold voltage. In other words, the processor 126 can determine whether the maximum cell voltage among the cell voltages measured by the measurement unit 124 for each battery cell has reached the first charging threshold voltage.

[0079] If the maximum single-cell voltage of the battery module 110 reaches the first charging threshold voltage, the processor 126 can compare the minimum single-cell voltage of each battery cell with the reference charging threshold voltage, and based on the comparison result, the processor 126 can terminate charging or calibrate the first charging threshold voltage.

[0080] In order to terminate the charging of the battery module 110, the individual cell voltage of all battery cells in the battery module 110 should be greater than or equal to the reference charging threshold voltage. Therefore, even if the maximum individual cell voltage of the battery module 110 reaches the first charging threshold voltage, the processor 126 can determine whether the minimum individual cell voltage of the battery module 110 is greater than or equal to the reference charging threshold voltage.

[0081] If the maximum single cell voltage of the battery module 110 reaches the first charging threshold voltage and the minimum single cell voltage of the battery module 110 is greater than or equal to the reference charging threshold voltage, then the single cell voltage of all battery cells in the battery module 110 is greater than or equal to the reference charging threshold voltage. Therefore, the processor 126 can terminate the charging of the battery module 110.

[0082] If the maximum single-cell voltage of battery module 110 reaches the first charging threshold voltage, but the minimum single-cell voltage of battery module 110 is not greater than or equal to the reference charging threshold voltage, then battery module 110 should be further charged. The first charging threshold voltage should be calibrated to a higher value to continue charging battery module 110.

[0083] Therefore, processor 126 can increase the first charging threshold voltage to calibrate it to a second charging threshold voltage. In this case, processor 126 can calculate the second charging threshold voltage by adding the difference between the average voltage of multiple battery cells and the minimum single-cell voltage to the first charging threshold voltage. That is, processor 126 can use Equation 2 below to calculate the second charging threshold voltage.

[0084] [Equation 2]

[0085] Second charging threshold voltage = First charging threshold voltage + (Average voltage - Minimum cell voltage)

[0086] Here, average voltage and minimum cell voltage can refer to the average voltage and minimum cell voltage when the maximum cell voltage of battery module 110 reaches the first charging threshold voltage.

[0087] Once the second charging threshold voltage is set, the processor 126 can continue to charge the battery module 110, and if the maximum single-cell voltage among the multiple battery cells reaches the second charging threshold voltage or if the minimum single-cell voltage among the single-cell voltages reaches the reference charging threshold voltage, the processor 126 can terminate the charging of the battery module 110.

[0088] As described above, the processor 126 can control the charging of the battery module 110 by setting the charging threshold voltage higher when the voltage (or SOC) is lower at the start of charging, thereby increasing the available voltage range and the available capacity of the battery module 110.

[0089] A method for controlling the charging of battery module 110 will be described. For example, if the reference charging threshold voltage is 3.65 V, the SOC is 0%, the minimum single-cell voltage is 2.75 V, the average voltage is 2.81 V, and the maximum single-cell voltage is 2.84 V, then processor 126 can use the formula "[3.65 + 0.06 x (100 - 0%)] = 3.71 V" to set the first charging threshold voltage to 3.71 V instead of 3.65 V. During the charging of battery module 110, if the maximum single-cell voltage in battery module 110 reaches 3.71 V and the minimum single-cell voltage is greater than or equal to the reference charging threshold voltage of 3.65 V, then processor 126 can terminate the charging of battery module 110. During the charging of battery module 110, if the maximum single-cell voltage in battery module 110 reaches 3.71 V, but the minimum single-cell voltage is not greater than or equal to a reference charging threshold voltage of 3.65 V, processor 126 can set a second charging threshold voltage by adding the difference between the average voltage and the minimum single-cell voltage of battery module 110 to the first charging threshold voltage of 3.71 V. For example, if the minimum single-cell voltage is 3.64 V and the average voltage is 3.67 V when the first charging threshold voltage is reached, processor 126 can set the second charging threshold voltage to "[3.71 + (3.67 - 3.64)] = 3.74 V".

[0090] Furthermore, a method for controlling the charging of battery module 110 will be described. For example, if the reference charging threshold voltage is 3.65 V, the SOC is 60%, the minimum single-cell voltage is 3.25 V, the average voltage is 3.29 V, and the maximum single-cell voltage is 3.36 V, then processor 126 can use the formula "[3.65 + 0.07 x (100 - 60%)] = 3.678 V" to set the first charging threshold voltage to 3.678 V instead of 3.65 V. During the charging of battery module 110, if the maximum single-cell voltage in battery module 110 reaches 3.678 V and the minimum single-cell voltage is greater than or equal to the reference charging threshold voltage of 3.65 V, then processor 126 can terminate the charging of battery module 110. During the charging of battery module 110, if the maximum single-cell voltage in battery module 110 reaches 3.678 V, but the minimum single-cell voltage is not greater than or equal to a reference charging threshold voltage of 3.65 V, processor 126 can set a second charging threshold voltage by adding the difference between the average voltage and the minimum single-cell voltage of battery module 110 to the first charging threshold voltage of 3.678 V. For example, if the minimum single-cell voltage is 3.63 V and the average voltage is 3.65 V when the first charging threshold voltage is reached, processor 126 can set the second charging threshold voltage to "[3.678 + (3.65 - 3.63)] = 3.698 V".

[0091] Next, the method by which the processor 126 controls the discharge of the battery module 110 will be described.

[0092] A reference discharge threshold voltage is set in the battery module 110 to terminate the discharge. However, during the discharge of the battery module 110, the polarization and electrochemical internal resistance at the end of the discharge vary according to the voltage at which each battery cell begins to discharge, which may result in differences in the capacity of each battery cell.

[0093] To address this issue, in this disclosure, the discharge threshold voltage can be adaptively set based on the current SOC of the battery module 110 and the individual cell voltages in the battery module 110, instead of simply using a reference discharge threshold voltage to discharge the battery module 110.

[0094] The processor 126 can adjust the discharge threshold voltage based on the difference in individual cell voltages between battery cells at the start of discharge of the battery module 110 and the current state of charge (SOC) of the battery module 110. That is, at the start of discharge of the battery module 110, the processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell, and set a first discharge threshold voltage based on at least one of a reference discharge threshold voltage, the maximum voltage deviation, and the current SOC. The higher the voltage at the start of discharge, the lower the discharge threshold voltage needs to be set; therefore, the processor 126 can utilize the maximum voltage deviation of the battery module 110 and the current SOC.

[0095] Specifically, the processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell. That is, the processor 126 can obtain the maximum and minimum cell voltages from the individual cell voltages of multiple battery cells measured at the start of discharge. Additionally, the processor 126 can calculate the average voltage of the multiple battery cell voltages measured at the start of discharge. Subsequently, the processor 126 can compare each of the minimum and maximum cell voltages with the average voltage of the battery module 110 to calculate the maximum voltage deviation. For example, the processor 126 can calculate the larger of the difference between the average voltage and the minimum cell voltage, and the difference between the average voltage and the maximum cell voltage, as the maximum voltage deviation.

[0096] The processor 126 can calculate the current SOC at the start of discharge, or by measuring the current SOC through the measurement unit 124. In this case, the processor 126 can calculate the current SOC based on the cell voltage, cell current, temperature, etc., of each battery cell measured by the measurement unit 124. Conventional methods for measuring charging capacity, such as voltage measurement, current measurement, internal resistance calculation, and temperature measurement, can be used in calculating the current SOC.

[0097] Once the maximum voltage deviation at the start of discharge of battery module 110 and the current SOC are calculated, processor 126 can use Equation 3 below to calculate the first discharge threshold voltage.

[0098] [Equation 3]

[0099] First discharge threshold voltage = Reference discharge threshold voltage - Maximum voltage deviation * (Current SOC)

[0100] Here, the reference discharge threshold voltage can be a preset value.

[0101] Equation 3 shows that the first discharge threshold voltage has a lower value than the reference discharge threshold voltage. Furthermore, since the first discharge threshold voltage is calculated by subtracting the reference discharge threshold voltage from the current state of charge (SOC) at the start of discharge, it is known that the higher the current SOC, the lower the value of the first discharge threshold voltage.

[0102] Once the first discharge threshold voltage is set, the processor 126 can discharge the battery module 110 and determine whether any battery cell has reached the first discharge threshold voltage. In other words, the processor 126 can determine whether the minimum cell voltage among the cell voltages measured by the measurement unit 124 for each battery cell has reached the first discharge threshold voltage.

[0103] If the minimum single cell voltage of the battery module 110 reaches the first discharge threshold voltage, the processor 126 can compare the maximum single cell voltage of each battery cell with the reference discharge threshold voltage, and based on the comparison result, the processor 126 can terminate the discharge or calibrate the first discharge threshold voltage.

[0104] In order to terminate the discharge of the battery module 110, the individual cell voltage of all battery cells in the battery module 110 should be less than or equal to the reference discharge threshold voltage. Therefore, even if the minimum individual cell voltage of the battery module 110 reaches the first discharge threshold voltage, the processor 126 can determine whether the maximum individual cell voltage is less than or equal to the reference discharge threshold voltage.

[0105] If the minimum single cell voltage of the battery module 110 reaches the first discharge threshold voltage and the maximum single cell voltage of the battery module 110 is less than or equal to the reference discharge threshold voltage, then the single cell voltage of all battery cells in the battery module 110 is less than or equal to the reference discharge threshold voltage. Therefore, the processor 126 can terminate the discharge of the battery module 110.

[0106] If the minimum single-cell voltage of battery module 110 reaches the first discharge threshold voltage, but the maximum single-cell voltage is not less than or equal to the reference discharge threshold voltage, then battery module 110 should be further discharged. The first discharge threshold voltage should be calibrated to a lower value to continue discharging battery module 110.

[0107] Therefore, processor 126 can reduce the first discharge threshold voltage to calibrate it to a second discharge threshold voltage. In this case, processor 126 can calculate the second discharge threshold voltage by reducing the first discharge threshold voltage by the difference between the average voltage of multiple battery cells and the maximum single-cell voltage. That is, processor 126 can use Equation 4 below to calculate the second discharge threshold voltage.

[0108] [Equation 4]

[0109] Second discharge threshold voltage = First discharge threshold voltage - (Maximum cell voltage - Average voltage)

[0110] Here, the average voltage and the maximum cell voltage can refer to the average voltage and the maximum cell voltage when the minimum cell voltage of the battery module 110 reaches the first discharge threshold voltage.

[0111] Once the second discharge threshold voltage is set, the processor 126 can continue to discharge the battery module 110, and if the minimum cell voltage among the multiple battery cells reaches the second discharge threshold voltage or if the maximum cell voltage among the cell voltages reaches the reference discharge threshold voltage, the processor 126 can terminate the discharge of the battery module 110.

[0112] As described above, the processor 126 can control the discharge of the battery module 110 by setting the discharge threshold voltage to a lower value when the voltage (or SOC) is higher at the start of discharge, thereby increasing the available voltage range and the available capacity of the battery module 110.

[0113] A method for controlling the discharge of battery module 110 will be described. For example, if the reference discharge threshold voltage is 2.75 V, the SOC is 100%, the minimum single-cell voltage is 3.60 V, the average voltage is 3.61 V, and the maximum single-cell voltage is 3.65 V, then processor 126 can use the formula "[2.75 - 0.04 x (100%)] = 2.71 V" to set the first discharge threshold voltage to 2.71 V instead of 2.75 V. During the discharge of battery module 110, if the minimum single-cell voltage in battery module 110 reaches 2.71 V and the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage of 2.75 V, then processor 126 can terminate the discharge of battery module 110. During the discharge of battery module 110, if the minimum single-cell voltage in battery module 110 reaches 2.71 V, but the maximum single-cell voltage is not less than or equal to a reference discharge threshold voltage of 2.75 V, processor 126 can set a second discharge threshold voltage by reducing the difference between the average voltage and the maximum single-cell voltage of battery module 110 from the first discharge threshold voltage of 2.71 V. For example, if the maximum single-cell voltage is 2.77 V and the average voltage is 2.75 V when the first discharge threshold voltage is reached, processor 126 can set the second discharge threshold voltage to "[2.71 - (2.77 - 2.75)] = 2.69 V".

[0114] Furthermore, a method for controlling the discharge of battery module 110 will be described. For example, if the reference discharge threshold voltage is 2.75 V, the SOC is 60%, the minimum single-cell voltage is 3.25 V, the average voltage is 3.29 V, and the maximum single-cell voltage is 3.35 V, then processor 126 can use the formula "[2.75 - 0.06 x (60%)] = 2.714 V" to set the first discharge threshold voltage to 2.714 V instead of 2.75 V. During the discharge of battery module 110, if the minimum single-cell voltage in battery module 110 reaches 2.714 V and the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage of 2.75 V, then processor 126 can terminate the discharge of battery module 110. During the discharge of battery module 110, if the minimum single-cell voltage in battery module 110 reaches 2.714 V, but the maximum single-cell voltage is not less than or equal to a reference discharge threshold voltage of 2.75 V, processor 126 can set a second discharge threshold voltage by reducing the first discharge threshold voltage of 2.714 V by the difference between the average voltage and the maximum single-cell voltage of battery module 110. For example, if the maximum single-cell voltage is 2.77 V and the average voltage is 2.75 V when the first discharge threshold voltage is reached, processor 126 can set the second discharge threshold voltage to "[2.714 - (2.77 - 2.75)] = 2.694 V".

[0115] Figure 3 This is a flowchart describing a method for controlling the charging of a battery module according to one or more embodiments of the present disclosure.

[0116] refer to Figure 3 If the battery module 110 starts charging (S302), the processor 126 sets a first charging threshold voltage based on the difference in individual cell voltages between multiple battery cells and the current SOC of the battery module 110 (S304).

[0117] The processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell. That is, the processor 126 can obtain the maximum and minimum individual cell voltages from the individual cell voltages of multiple battery cells measured at the start of charging. Additionally, the processor 126 can calculate the average voltage of the individual cell voltages measured at the start of charging. Subsequently, the processor 126 can compare each of the minimum and maximum individual cell voltages with the average voltage of the battery module 110 to calculate the maximum voltage deviation. The processor 126 can calculate the current State of Charge (SOC) at the start of charging or measure the current SOC via the measurement unit 124.

[0118] Once the maximum voltage deviation and current SOC at the start of charging of battery module 110 are calculated, processor 126 can use the reference charging threshold voltage, the maximum voltage deviation, and the current SOC to calculate the first charging threshold voltage.

[0119] After executing operation S304, processor 126 determines whether the maximum single-cell voltage of battery module 110 has reached the first charging threshold voltage (S306). That is, processor 126 can determine whether the maximum single-cell voltage among the single-cell voltages of each battery cell measured by measurement unit 124 during the charging of battery module 110 has reached the first charging threshold voltage.

[0120] As a result of the determination in operation S306, if the maximum single-cell voltage of battery module 110 reaches the first charging threshold voltage, then processor 126 determines whether the minimum single-cell voltage of battery module 110 is greater than or equal to the reference charging threshold voltage (S308). To terminate charging of battery module 110, the single-cell voltage of all battery cells in battery module 110 should be greater than or equal to the reference charging threshold voltage. Therefore, even if the maximum single-cell voltage of battery module 110 reaches the first charging threshold voltage, processor 126 can still determine whether the minimum single-cell voltage of battery module 110 is greater than or equal to the reference charging threshold voltage.

[0121] As a result of the determination in operation S308, if the minimum single cell voltage of battery module 110 is greater than or equal to the reference charging threshold voltage, then processor 126 terminates the charging of battery module 110 (S310).

[0122] As a result of the determination in operation S308, if the minimum single cell voltage of the battery module 110 is not greater than or equal to the reference charging threshold voltage, the processor 126 sets a second charging threshold voltage based on the difference between the average voltage of the battery module 110 when the maximum single cell voltage of the battery module 110 reaches the first charging threshold voltage and the minimum single cell voltage (S312), and continues to charge the battery module 110 (S314).

[0123] If the maximum single-cell voltage of battery module 110 reaches the first charging threshold voltage, but the minimum single-cell voltage of battery module 110 is not greater than or equal to the reference charging threshold voltage, then battery module 110 should be further charged. The first charging threshold voltage should be calibrated to a higher value to continue charging battery module 110. Therefore, processor 126 can increase the first charging threshold voltage to calibrate it to a second charging threshold voltage. At this time, processor 126 can calculate the second charging threshold voltage by adding the difference between the average voltage of multiple battery cells and the minimum single-cell voltage to the first charging threshold voltage.

[0124] While performing operation S314, if the maximum single cell voltage reaches the second charging threshold voltage or the minimum single cell voltage reaches the reference charging threshold voltage (S316), the processor 126 terminates the charging of the battery module 110.

[0125] While performing operation S314, if the maximum single cell voltage does not reach the second charging threshold voltage or the minimum single cell voltage does not reach the reference charging threshold voltage, the processor 126 continues to charge the battery module 110.

[0126] As described above, the processor 126 can control the charging of the battery module 110 by setting the charging threshold voltage to a higher value when the voltage (or SOC) is lower at the start of charging, thereby increasing the available voltage range and the available capacity of the battery module 110.

[0127] Figure 4 This is a flowchart describing a method for controlling the discharge of a battery module according to one or more embodiments of the present disclosure.

[0128] refer to Figure 4 If the battery module 110 starts discharging (S402), the processor 126 sets a first discharge threshold voltage based on the difference in individual cell voltages between the multiple battery cells and the current SOC of the battery module 110 (S404).

[0129] The processor 126 can calculate the maximum voltage deviation of the battery module 110 based on the individual cell voltage of each battery cell. That is, the processor 126 can obtain the maximum and minimum cell voltages from the individual cell voltages of multiple battery cells measured at the start of discharge. Additionally, the processor 126 can calculate the average voltage of the individual cell voltages measured at the start of discharge. Subsequently, the processor 126 can compare each of the minimum and maximum cell voltages with the average voltage of the battery module 110 to calculate the maximum voltage deviation. The processor 126 can calculate the current State of Charge (SOC) at the start of discharge, or the current SOC can be measured via the measurement unit 124.

[0130] Once the maximum voltage deviation and current SOC at the start of discharge of battery module 110 are calculated, processor 126 can use the reference discharge threshold voltage, the maximum voltage deviation, and the current SOC to calculate the first discharge threshold voltage.

[0131] After executing operation S404, processor 126 determines whether the minimum single-cell voltage of battery module 110 has reached the first discharge threshold voltage (S406). That is, processor 126 can determine whether the minimum single-cell voltage among the single-cell voltages of each battery cell measured by measurement unit 124 has reached the first discharge threshold voltage.

[0132] As a result of the determination in operation S406, if the minimum single-cell voltage of battery module 110 reaches the first discharge threshold voltage, then processor 126 determines whether the maximum single-cell voltage of battery module 110 is less than or equal to the reference discharge threshold voltage (S408). To terminate the discharge of battery module 110, the single-cell voltage of all battery cells in battery module 110 should be less than or equal to the reference discharge threshold voltage. Therefore, even if the minimum single-cell voltage of battery module 110 reaches the first discharge threshold voltage, processor 126 can still determine whether the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage.

[0133] As a result of the determination in operation S408, if the maximum single cell voltage of battery module 110 is less than or equal to the reference discharge threshold voltage, then processor 126 terminates the discharge of battery module 110 (S410).

[0134] As a result of the determination in operation S408, if the maximum single cell voltage of the battery module 110 is not less than or equal to the reference discharge threshold voltage, the processor 126 sets a second discharge threshold voltage based on the difference between the average voltage of the battery module 110 when the minimum single cell voltage of the battery module 110 reaches the first discharge threshold voltage and the maximum single cell voltage (S412), and continues to discharge the battery module 110 (S414).

[0135] If the minimum cell voltage of battery module 110 reaches a first discharge threshold voltage, but the maximum cell voltage is not less than or equal to a reference discharge threshold voltage, then battery module 110 should be further discharged. The first discharge threshold voltage should be calibrated to a lower value to continue discharging battery module 110. Therefore, processor 126 can decrease the first discharge threshold voltage to calibrate it to a second discharge threshold voltage. At this time, processor 126 can calculate the second discharge threshold voltage by subtracting the first discharge threshold voltage from the difference between the average voltage of multiple battery cells and the maximum cell voltage.

[0136] While performing operation S414, if the minimum cell voltage reaches the second discharge threshold voltage or the maximum cell voltage reaches the reference discharge threshold voltage (S416), the processor 126 terminates the discharge of the battery module 110.

[0137] While performing operation S414, if the minimum cell voltage does not reach the second discharge threshold voltage or the maximum cell voltage does not reach the reference discharge threshold voltage, the processor 126 continues to discharge the battery module 110.

[0138] As described above, the processor 126 can control the discharge of the battery module 110 by setting the discharge threshold voltage to a lower value when the voltage (or SOC) is higher at the start of discharge, thereby increasing the available voltage range and the available capacity of the battery module 110.

[0139] As described above, according to this disclosure, the capacity of a battery module can be increased by adaptively setting the charging / discharging threshold voltage based on the battery voltage and state of charge (SOC) at the start of charging / discharging of the battery module.

[0140] The embodiments described herein can be implemented as, for example, methods or processes, apparatus, software programs, data streams, or signals. Although discussed in the context of a single type of implementation (e.g., discussed only as a method), the features discussed herein can also be implemented in other forms (e.g., apparatus or program). The apparatus can be implemented by suitable hardware, software, firmware, etc. The method can be implemented on an apparatus, such as a processor, which generally refers to a processing apparatus including computers, microprocessors, integrated circuits, programmable logic devices, etc. Processors include communication devices (such as computers, cellular phones, personal digital assistants (PDAs)) and other means that facilitate information communication between the device and the end user.

[0141] According to this disclosure, the capacity of a battery module can be increased by adaptively setting the charging / discharging threshold voltage based on the battery voltage and state of charge (SOC) at the start of charging / discharging of the battery module.

[0142] However, the effects achievable through this disclosure are not limited to those described above, and other effects not described will be readily apparent to those skilled in the art from the detailed description.

[0143] Although this disclosure has been described with reference to embodiments and accompanying drawings illustrating various aspects of this disclosure, this disclosure is not limited thereto. Various modifications and variations can be made by those skilled in the art within the scope of the technical spirit of this disclosure and the claims and their equivalents.

[0144] Example embodiments have been disclosed herein, and although specific terminology has been used, they are used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be apparent to those skilled in the art upon filing this application, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless specifically stated otherwise. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A battery management device, comprising: A measuring unit, including at least one sensor, is configured to measure the cell voltage of each of a plurality of battery cells in a battery module. and The processor is configured to adjust the charging threshold voltage or discharging threshold voltage based on the difference in individual cell voltages between the plurality of battery cells and the current state of charge (SOC) of the battery module if the battery module is being charged or discharged.

2. The battery management device according to claim 1, wherein, The processor is also configured to: The maximum voltage deviation of the battery module is calculated based on the cell voltage of each of the plurality of battery cells at the start of charging of the battery module; as well as The first charging threshold voltage is set based on at least one of a predetermined reference charging threshold voltage, the maximum voltage deviation, and the current SOC.

3. The battery management device according to claim 2, wherein, The processor is further configured to, during the charging of the battery module, if the maximum cell voltage among all cell voltages of the plurality of battery cells reaches the first charging threshold voltage, compare the minimum cell voltage among all cell voltages with the predetermined reference charging threshold voltage, and terminate the charging or calibrate the first charging threshold voltage based on the comparison result.

4. The battery management device according to claim 3, wherein, The processor is also configured to terminate the charging of the battery module if the minimum single-cell voltage is greater than or equal to the predetermined reference charging threshold voltage.

5. The battery management device according to claim 3, wherein, The processor is also configured to, if the minimum single-cell voltage is less than or equal to the predetermined reference charging threshold, increase the first charging threshold voltage to calibrate the first charging threshold voltage to a second charging threshold voltage, and continue charging the battery module.

6. The battery management device according to claim 5, wherein, The processor is also configured to increase the first charging threshold voltage by the difference between the average voltage of all the individual cell voltages of the plurality of battery cells and the minimum individual cell voltage.

7. The battery management device according to claim 5, wherein, The processor is further configured to terminate the charging of the battery module if, during the charging of the battery module, the maximum cell voltage among all cell voltages of the plurality of battery cells reaches the second charging threshold voltage, or the minimum cell voltage among all cell voltages reaches the predetermined reference charging threshold voltage.

8. The battery management device according to claim 1, wherein, The processor is also configured to: The maximum voltage deviation of the battery module is calculated based on the cell voltage of each of the plurality of battery cells at the start of discharge of the battery module; as well as The first discharge threshold voltage is set based on at least one of a predetermined reference discharge threshold voltage, the maximum voltage deviation, and the current state of charge (SOC).

9. The battery management device according to claim 8, wherein, During the discharge of the battery module, if the minimum cell voltage among all cell voltages of the plurality of battery cells reaches the first discharge threshold voltage, the processor compares the maximum cell voltage among all cell voltages with the reference discharge threshold voltage, and terminates the discharge or calibrates the first discharge threshold voltage based on the comparison result.

10. The battery management device according to claim 9, wherein, If the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

11. The battery management device according to claim 9, wherein, If the maximum single-cell voltage is not less than or equal to the reference discharge threshold voltage, the processor reduces the first discharge threshold voltage to calibrate the first discharge threshold voltage to the second discharge threshold voltage, and continues to discharge the battery module.

12. The battery management device according to claim 11, wherein, The second discharge threshold voltage is the difference between the average voltage of all the cell voltages of the plurality of battery cells reduced from the first discharge threshold voltage and the maximum cell voltage.

13. The battery management device according to claim 11, wherein, During the discharge of the battery module, if the minimum cell voltage among all cell voltages of the plurality of battery cells reaches the second discharge threshold voltage, or if the maximum cell voltage among all cell voltages reaches the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

14. A method for controlling charging using a battery management device, the method comprising: The processor sets a first charging threshold voltage based on the difference in individual cell voltages between the multiple battery cells at the start of charging of the battery module, which includes multiple battery cells, and the current state of charge (SOC) of the battery module. During the charging of the battery module, if the maximum single-cell voltage among all single-cell voltages reaches the first charging threshold voltage, the processor compares the minimum single-cell voltage among the single-cell voltages of the plurality of battery cells with a predetermined reference charging threshold voltage. and If the minimum single-cell voltage is greater than or equal to the predetermined reference charging threshold voltage, the processor terminates the charging of the battery module.

15. The method according to claim 14, wherein, When setting the first charging threshold voltage The processor calculates the maximum voltage deviation of the battery module based on the individual cell voltage of each of the plurality of battery cells, and sets the first charging threshold voltage based on at least one of the predetermined reference charging threshold voltage, the maximum voltage deviation, and the current SOC.

16. The method of claim 14, further comprising: If the minimum single-cell voltage is not greater than or equal to the predetermined reference charging threshold voltage, the processor sets the second charging threshold voltage by increasing the first charging threshold voltage. and During the charging of the battery module, if the maximum cell voltage among all cell voltages of the plurality of battery cells reaches the second charging threshold voltage, or if the minimum cell voltage among all cell voltages reaches the predetermined reference charging threshold voltage, the processor terminates the charging of the battery module.

17. The method according to claim 16, wherein, When setting the second charging threshold voltage The processor sets the second charging threshold voltage by adding the first charging threshold voltage to the difference between the average voltage of all the individual cell voltages of the plurality of battery cells and the minimum individual cell voltage.

18. A method for controlling discharge using a battery management device, the method comprising: The processor sets a first discharge threshold voltage based on the difference in individual cell voltages between the multiple battery cells at the start of discharge of the battery module comprising multiple battery cells and the current state of charge (SOC) of the battery module. During the discharge of the battery module, if the minimum cell voltage among all cell voltages reaches the first discharge threshold voltage, the processor compares the maximum cell voltage among the cell voltages of the plurality of battery cells with the reference discharge threshold voltage. and If the maximum single-cell voltage is less than or equal to the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

19. The method of claim 18, further comprising: If the maximum single-cell voltage is not less than or equal to the reference discharge threshold voltage, the processor sets the second discharge threshold voltage by decreasing the first discharge threshold voltage; and During the discharge of the battery module, if the minimum cell voltage among all cell voltages of the plurality of battery cells reaches the second discharge threshold voltage, or if the maximum cell voltage among all cell voltages reaches the reference discharge threshold voltage, the processor terminates the discharge of the battery module.

20. The method according to claim 19, wherein, The processor is also configured to set the second discharge threshold voltage by reducing the first discharge threshold voltage by the difference between the average voltage of all the cell voltages of the plurality of battery cells and the maximum cell voltage.

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