Battery management device, battery pack, and battery pack charge control method

Abstract

A battery pack according to an embodiment of the present invention may include a battery management device including a plurality of battery cells connected in series; and a cell balancing module that performs balancing on the plurality of battery cells, and when the cell balancing module is in operation, the battery management device may limit a charging current of the battery pack to perform charging depending on whether the battery pack is in a charging control activation time range and whether the charging state of the battery pack is equal to or greater than a preset threshold.

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0155029, filed with the Korean Intellectual Property Office on November 18, 2022, and all of the contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery management device, a battery pack, and a charge control method for a battery pack, and more particularly to a battery management device, a battery pack, and a charge control method for a battery pack that control charging in consideration of cell balancing in a battery pack including a plurality of battery cells. [Background technology]

[0003] Secondary batteries, which can be recharged and reused after use, are manufactured into battery modules or battery packs consisting of a number of battery cells connected in series according to the output capacity required by the device, and are used as power sources for various devices. Such batteries are used in a variety of fields, including small, cutting-edge electronic devices such as smartphones, as well as electric bicycles, electric vehicles, and energy storage systems (ESS).

[0004] A battery module or a battery pack is a structure in which a number of battery cells are combined, and if some of the battery cells experience overvoltage, overcurrent, overheating, etc., this can cause problems in the safety and operating efficiency of the battery module or the battery pack, so a means for detecting these is essential. For this reason, a battery module or a battery pack is equipped with a BMS (Battery Management System) that measures the voltage value of each battery cell and monitors and controls the voltage state of the battery cells based on the measured value.

[0005] Meanwhile, voltage variations between battery cells occur due to various factors, but these variations can be reduced by cell balancing using a BMS. However, cell balancing has a capacity limit due to hardware limitations, and if the voltage variations between cells exceed the cell balancing capacity, problems such as the battery becoming unusable can occur. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a battery pack in which cell balancing is maintained to the maximum extent possible through charge control.

[0007] Another object of the present invention to solve the above problems is to provide a battery management device that controls charging so that cell balancing is maintained to the maximum extent possible.

[0008] Another object of the present invention to solve the above problems is to provide a method for controlling charging of a battery pack, which can maintain cell balancing to the maximum extent possible. [Means for solving the problem]

[0009] To achieve the above object, one embodiment of the present invention provides a battery pack including a plurality of battery cells connected in series; and a cell balancing module that balances the plurality of battery cells, and when the cell balancing module is operating, the battery management device limits a charging current of the battery pack to charge depending on whether the charging control activation time range is in effect and whether the state of charge of the battery pack is equal to or greater than a preset threshold.

[0010] The battery management device may limit the charging current of the battery pack when the charging state of the battery pack is within the charging control activation time range and is equal to or greater than a preset threshold value.

[0011] The charge control activation time range may be set to a time range in which there is a high probability that a system to which the battery pack is applied will not be used.

[0012] If the charging control activation time range does not exist or the charging state of the battery pack is less than a preset threshold, the battery management device can proceed with the existing charging process without limiting the charging current for the battery pack.

[0013] The newly applied charging rate according to the charging current limit can be set by calculating the required operation time of the cell balancing module in consideration of the voltage variation between the cells.

[0014] The cell balancing module may include a resistor and a switch arranged for each cell.

[0015] According to one embodiment of the present invention, there is provided a battery management device for a battery pack including a plurality of battery cells connected in series, the battery management device including: a cell balancing module that balances the plurality of battery cells; a processor; and a memory that stores at least one instruction to be executed by the processor. The at least one instruction may include an instruction to determine whether the battery pack is being charged and an operation of the cell balancing module has started; an instruction to determine whether the battery pack is within a charge control activation time range if the cell balancing module is operating; an instruction to determine whether the state of charge of the battery pack is equal to or greater than a predetermined threshold if the cell balancing module is operating; and an instruction to limit a charge current of the battery pack and charge the battery pack depending on whether the state of charge of the battery pack is within the charge control activation time range and whether the state of charge of the battery pack is equal to or greater than a predetermined threshold.

[0016] The command to limit the charging current of the battery pack and charge the battery pack may include a command to limit the charging current of the battery pack and charge the battery pack when the charging state of the battery pack is within the charging control activation time range and is equal to or greater than a preset threshold.

[0017] Here, the charge control activation time range may be set to a time range during which a system to which the battery pack is applied is likely not to be used.

[0018] Meanwhile, the at least one command may further include a command to proceed with an existing charging process without limiting a charging current for the battery pack if the charging control activation time range does not fall or if the charging state of the battery pack is less than a preset threshold.

[0019] The newly applied charging rate according to the charging current limit can be set by calculating the required operation time of the cell balancing module in consideration of the voltage variation between the cells.

[0020] The cell balancing module may include a resistor and a switch arranged for each cell.

[0021] To achieve the above-mentioned still another object, a method for controlling charging of a battery pack according to one embodiment of the present invention includes the steps of: determining whether the battery pack is being charged and whether a cell balancing module has started operating; determining whether the cell balancing module is operating and whether it is within a charge control activation time range; determining whether the state of charge of the battery pack is equal to or greater than a preset threshold value and, depending on whether the state of charge of the battery pack is within the charge control activation time range and whether it is equal to or greater than a preset threshold value, limiting the charging current of the battery pack and performing charging.

[0022] The step of charging the battery pack by limiting the charging current may include the step of charging the battery pack by limiting the charging current when the charging state of the battery pack is within the charging control activation time range and is equal to or greater than a preset threshold.

[0023] The method for controlling charging of the battery pack may further include a step of proceeding with an existing charging process without limiting a charging current for the battery pack if the charging control activation time range does not fall or if the charging state of the battery pack is less than a preset threshold.

[0024] The newly applied charging rate according to the charging current limit can be set by calculating the required operation time of the cell balancing module in consideration of the voltage variation between the cells. [Effects of the Invention]

[0025] According to the above-described embodiment of the present invention, when voltage variations occur between series-connected cells, the charging current is controlled to maintain cell balancing to the maximum extent possible, and the voltage variations between cells can be reduced to the maximum extent possible within a charging cycle to a level that does not cause problems for the user's system use.

[0026] By reducing this cell-to-cell voltage variation, the present invention allows the battery pack to deliver more energy to the system. [Brief explanation of the drawings]

[0027] [Figure 1] 1 shows the structure of a battery pack to which the present invention can be applied. [Figure 2] 1 shows the operation flow of an existing cell balancing control method. [Figure 3] 1 is a block diagram of a battery management device according to an embodiment of the present invention; [Figure 4] 3 shows an operational flow of a charging control method for a battery pack according to an embodiment of the present invention. [Figure 5]10A and 10B are diagrams showing examples of charge control activation conditions and the operation of the battery management device according to the present invention; [Figure 6] 10 is a graph showing charging and cell balancing results when the charging control according to the present invention is not applied; [Figure 7] 10 is a graph showing charging and cell balancing results when charging control according to the present invention is applied; DETAILED DESCRIPTION OF THE INVENTION

[0028] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it is understood that this is not intended to limit the present invention to the specific embodiments, but rather to include all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. Like reference numerals are used to refer to like elements throughout the drawings.

[0029] Terms such as "first," "second," "A," and "B" may be used to describe various components, but the components should not be limited by these terms. These terms are used only to distinguish one component from another. For example, a first component may be termed a "second component," and similarly, a second component may be termed a "first component," without departing from the scope of the present invention. The term "and / or" includes a combination of multiple associated listed items or any of multiple associated listed items.

[0030] When a component is referred to as being "coupled" or "connected" to another component, it is understood that the component may be directly coupled or connected to the other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly coupled" or "directly connected" to another component, it is understood that there are no other components in between.

[0031] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly indicates otherwise. It should be understood that in this application, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and do not preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] FIG. 1 shows the structure of a battery pack to which the present invention can be applied.

[0035] In FIG. 1, a battery pack (or battery module) can be configured to include a plurality of battery cells connected in series. The most commonly used battery cells are lithium-ion (Li-Ion) battery cells. The battery pack can be connected to a load through the positive and negative terminals to perform charging / discharging operations. The battery pack can be configured to be connected in series or parallel depending on the requirements of the system in which the battery is used.

[0036] Such a battery pack may be provided with a battery management system (BMS) 100. The battery management system (BMS) monitors the current, voltage, and temperature of each battery pack under its management, and calculates the SOC (Status of Charge) based on the monitoring results to control charging and discharging. Here, the SOC (State of Charge) is the current charged state of the battery expressed as a percentage [%]. Meanwhile, the SOH (State of Health) is the current deterioration state of the battery expressed as a percentage [%].

[0037] In this way, the BMS can monitor the battery cells, read the cell voltages, and transmit the cell voltages to a system connected to the battery. To this end, the BMS includes a communication module for communicating with other systems within the device that includes the battery system. The communication module of the BMS can communicate with other systems within the device using a communication method such as a Controller Area Network (CAN) or Ethernet. When using CAN communication, components, modules, or systems within the BMS are connected to each other via a CAN bus.

[0038] CAN (Controller Area Network) communication is a standard designed for in-vehicle communication between microcontrollers and devices without a host computer. CAN communication is a non-host bus-based message-based network protocol primarily used for communication between controllers, and is primarily used in vehicles.

[0039] The BMS also balances the charge of the battery cells to extend the life of the battery pack. To perform this operation, the BMS 100 may include various components such as fuses, current sensing elements, thermistors, switches, and balancers, and may further include an MCU (Micro Controller Unit) or BMIC (Battery Monitoring Integrated Chip) for interlocking and controlling these components. Here, the BMIC may be an IC-type component located inside the BMS that measures information such as the voltage, temperature, and current of the battery cells / battery modules.

[0040] However, the battery cells included in a battery pack cannot have completely identical characteristics, and voltage variations may occur between the series-connected cells due to natural discharge of each cell, environmental factors during use, etc.

[0041] The BMS100 has a CB (Cell Balancing) function that performs passive balancing during charging, but its capacity is limited by hardware limitations. For example, the available cell balancing capacity is limited by limitations on the wattage, resistance, and thermal durability of the CB circuit.

[0042] In an extreme example, the voltage variation (or capacity variation due to voltage variation) that occurs during one cycle of battery pack use may exceed the cell balancing capacity, and the difference may continue to increase over time, causing the battery to reach a permanent fail (PF) state.

[0043] Even if such an extreme situation does not occur, voltage variations occurring between battery cells within a battery pack mean that the energy corresponding to the variation cannot be used in a certain cell. In particular, the voltage of a cell with a small capacity drops sharply at the end of discharge, reaching UVP (Under Voltage Protection) mode, which can cause a problem where the remaining energy cannot be consumed even in cells with remaining capacity.

[0044] FIG. 2 shows the operation flow of an existing cell balancing control method.

[0045] Passive cell balancing included in a BMS is generally performed by disposing a circuit including a switch (e.g., a transistor) and a resistor in each cell, and a controller controls the balancing circuit.

[0046] The existing cell balancing operation begins when charging begins and the BMS recognizes the charging current (S210, S220). The cell balancing operation is maintained if the maximum voltage variation between cells is above a certain value (Yes in S230) and is discontinued if the voltage variation between cells decreases below the certain value (No in S230). For example, as shown in Figure 2, the cell balancing operation can be maintained if the difference between the highest and lowest measured cell voltages (Cell Voltage max - Cell Voltage min) is 50mV or more.

[0047] With existing cell balancing, for example, if charging at a 0.3C-rate according to standard cell charging conditions, and the time required to fully charge from 0 to 100% SOC is calculated to be 3.8 hours, even if cell balancing continues to operate during charging, the balancing operation can only be performed for 3.8 hours. In other words, cell balancing cannot be performed for a time longer than the value designed by hardware in one charging cycle.

[0048] That is, the existing cell balancing control method is a matter of controlling whether to operate or suspend cell balancing, and is unrelated to charge control and charge rate adjustment. That is, in the existing charging and cell balancing method, charging proceeds at a fixed charge rate (C-rate: current rate) while cell balancing is being performed, and the cell balancing maintenance time is also fixed according to the charge rate. Here, the charge rate (C-rate) is a value that indicates the rate at which a battery is charged or discharged, and is also called the charge / discharge rate. The unit of charge rate is C (Capacity), which means capacity. The charge rate (C-rate) is the value obtained by dividing the charge / discharge current (A) by the rated capacity value (Ah) of the battery, and the standard value is 1C.

[0049] In the present invention, voltage variations are checked above a set SOC, the time required for cell balancing operation to account for the voltage variations is calculated, and charging control is performed to limit the charging current in order to increase the cell balancing operation time.

[0050] FIG. 3 is a block diagram of a battery management device according to an embodiment of the present invention.

[0051] 3, a battery management device 100 according to the present invention may include a control unit (MCU; Micro Control Unit) 110, a cell balancing module 130, and a communication module 150. In this specification, the control unit may be referred to as a processor, controller, MCU, etc., and may also refer to a dedicated processor on which a method according to an embodiment of the present invention is performed.

[0052] The battery management device 100 according to the present invention may also include a memory for storing at least one instruction executed by the control unit, and the at least one instruction may include an instruction to check whether the battery pack is being charged and the operation of a cell balancing module has started; an instruction to check whether the cell balancing module is operating and the battery pack is within a charge control activation time range; an instruction to check whether the state of charge of the battery pack is equal to or greater than a preset threshold and the battery pack is within a charge control activation time range and the state of charge of the battery pack is equal to or greater than a preset threshold; and an instruction to limit the charge current of the battery pack and charge the battery pack depending on whether the state of charge of the battery pack is within the charge control activation time range and the state of charge of the battery pack is equal to or greater than a preset threshold.

[0053] The command to limit the charging current of the battery pack and charge the battery pack may include a command to limit the charging current of the battery pack and charge the battery pack when the charging state of the battery pack is within the charging control activation time range and is equal to or greater than a preset threshold.

[0054] Here, the charge control activation time range may be set to a time range during which a system to which the battery pack is applied is likely not to be used.

[0055] Meanwhile, the at least one command may further include a command to proceed with an existing charging process without limiting a charging current for the battery pack if the charging control activation time range does not fall or if the charging state of the battery pack is less than a preset threshold.

[0056] The newly applied charging rate according to the charging current limit can be set by calculating the required operation time of the cell balancing module in consideration of the voltage variation between the cells.

[0057] The cell balancing module 130 may be configured to include resistors and switches arranged for each cell. The communication module 150 may communicate with other control devices or other components in the system using a controller area network (CAN), Ethernet, etc. Although not shown in FIG. 3, the battery management device 100 may further include a battery monitoring integrated chip (BMIC), etc.

[0058] The battery management device 100 according to the present invention aims to improve energy utilization efficiency by reducing the inherent limitations of the cell balancing module 130 due to hardware factors such as wattage, resistance, and thermal durability through charging control.

[0059] To this end, the control unit 110 in the battery management device 100 checks whether the cell balancing module 130 is operating, and if the cell balancing module 130 is operating, checks whether the corresponding time falls within a charge control activation time range and whether the charge state of the battery pack is equal to or greater than a preset threshold. If the corresponding time falls within the charge control activation time range and the charge state of the battery pack is equal to or greater than a preset threshold, the control unit 110 can limit the charge current of the battery pack and perform charging.

[0060] Meanwhile, the battery management unit 100 measures cell voltages in real time according to task cycles and checks whether the variation in cell voltages exceeds a preset reference value. If the voltage variation exceeds the preset reference value, the cell balancing module 130 is activated. If the cell balancing module is operating during charging and determines that charging current limitation is necessary, the battery management unit 100 checks the capacity (mAh) corresponding to the voltage variation. To resolve the identified capacity variation, the battery management unit calculates the time required for cell balancing and limits the charging current, i.e., resets the charging rate, according to the calculated time.

[0061] According to the present invention, by limiting the charging current and adjusting the charging rate according to the time required for cell balancing, the state of charge (the condition under which balancing can operate) can be extended, thereby extending the time for which cell balancing operates.

[0062] Meanwhile, the user can set the SOC range, which is one of the conditions for activating the charging control according to the present invention. The reason why the charging control according to the present invention is activated only within the set SOC range is to ensure the minimum energy required when the system is suddenly used. For example, if the charging control according to the present invention is set to operate only when the SOC is 80% or higher, even if the system is suddenly used during charging control, a minimum SOC of 80% can be used.

[0063] In addition, the user can set a charge control activation time range, i.e., an activation time period, which is another one of the charge control activation conditions according to the present invention. This is to prevent inconvenience in using the system due to the application of charge control by making the charge control according to the present invention operate only during the activation time (a time period when it is predicted or expected that the user will not use the system).

[0064] The charging control according to the present invention is performed for each task and can be continued until the voltage variation level falls below a set standard within the operating conditions or until the user starts using the system.

[0065] FIG. 4 shows an operational flow of a battery pack charge control method according to an embodiment of the present invention.

[0066] The charging control method for the battery pack shown in FIG. 4 can be performed by a battery management device or a control unit in the battery management device.

[0067] When the battery management unit detects that charging has started through the recognition of the charging current (S410), it starts the cell balancing operation (S420).

[0068] In the charge control method according to the present invention, two conditions are checked to activate the charge control. First, if the cell balancing module is in operation, it is checked whether the current time falls within the charge control activation time range (S430). Also, the state of charge (SOC) of the battery pack is checked. pack ) is the preset threshold (SOC set ) or more (S450).

[0069] If the charging control activation time range is reached and the charging state of the battery pack is above the preset threshold (Yes in S450), the capacity variation due to the voltage difference between the cells is checked (S451), and the charging current of the battery pack is limited to charge (S452).

[0070] On the other hand, if the charging control activation time range does not exist or the charging state of the battery pack is less than the preset threshold, the charging current for the battery pack is not limited and the existing charging process is continued (S470).

[0071] The cell balancing operation is maintained (S420) if the maximum voltage variation between cells (Vmax - Vmin) is equal to or greater than the threshold value (Vth) (Yes in S471), and is discontinued (S490) if the voltage variation between cells decreases below the threshold value (No in S471). For example, the cell balancing operation can be maintained if the difference between the maximum and minimum voltages among the measured cell voltages (Cell Voltage max - Cell Voltage min) is equal to or greater than 20mV (the threshold value (Vth)).

[0072] FIG. 5 is a diagram showing examples of charge control activation conditions and the operation of the battery management device according to the conditions.

[0073] In the example of Figure 5, the cell balancing capacity is assumed to be 50 mAh, and the capacity variation due to voltage difference, current control, etc. are arbitrarily set values ​​for illustrative purposes. In the table of Figure 5, various cases depending on the pack state and user-set parameters are shown as case numbers 1 to 5, and the application of charge control and the charge rate when charge control is applied for each case are shown.

[0074] The pack status includes information about the maximum cell-to-cell voltage variation, the SOC measured at that time, and the time. The user-specified parameters include the user-specified charge control activation time range and the user-specified minimum SOC value for which charge control is applied. In the example of Figure 5, for each of the five cases, the user-specified charge control activation time range is from 8:00 PM to 9:00 AM, and the user-specified minimum pack SOC is 80%, all of which are set to the same value.

[0075] More specifically, in case 1, the maximum voltage variation between cells is 50 mV and the measured SOC of the battery pack is 50%, but since the SOC of the battery pack does not reach the threshold value of 80%, the charging control according to the present invention is not performed.

[0076] In the second case, the maximum voltage variation between cells is 50 mV, and the measured SOC of the battery pack is 80%. Since the SOC of the battery pack reaches the threshold value of 80% and the corresponding time is 7:00 a.m., the charging control according to the present invention can be performed. In this case, considering the cell balancing capacity variation of 50 mAh and the maximum voltage variation between cells of 50 mV, the time required for cell balancing operation can be calculated as 1, and the charging rate at this time can be set to 0.2 C.

[0077] In case 3, the maximum voltage variation between cells is 50 mV and the measured SOC of the battery pack is 80%, but the corresponding time is 2:00 PM, which is outside the charge control activation time range, so charge control according to the present invention is not performed.

[0078] In case 4, the maximum voltage variation between cells is 100mV and the measured SOC of the battery pack is 50%. Since the SOC of the battery pack does not reach the threshold value of 80%, the charging control according to the present invention is not performed.

[0079] In case 5, the maximum voltage variation between cells is 100 mV, the measured SOC of the battery pack is 80%, and the corresponding time is 7:00 a.m., so it falls within the charge control activation time range and charge control according to the present invention can be performed. In this case, considering the cell balancing capacity variation of 50 mAh and the maximum voltage variation between cells of 100 mV, the time required for cell balancing operation can be calculated as 2, and the corresponding charge rate can be set to 0.1 C.

[0080] On the other hand, the charge current control value based on the required time for cell balancing operation shown in Figure 5 is merely an arbitrary value and must be optimized through testing.

[0081] FIG. 6 is a graph showing the results of charging and cell balancing when the charging control according to the present invention is not applied.

[0082] In Figure 6, the horizontal axis represents time, the vertical axis on the left represents charge capacity, and the vertical axis on the right represents cell balancing capacity.

[0083] The battery pack to which the test in Figure 6 is applied is assumed to have a significant imbalance between cells. The standard charging rate is assumed to charge 1 capacity per hour, and 100% charging corresponds to charging up to 50 capacity. Assuming that cell balancing of 0.05 is performed for 1 hour, it can be seen that a total capacity equivalent to 2.5 is balanced during charging. Note that in this example, the increase in charging time due to capacity reduction caused by balancing is ignored.

[0084] FIG. 7 is a graph showing the results of charging and cell balancing when the charging control according to the present invention is applied.

[0085] In FIG. 7 as well, the horizontal axis represents time, the vertical axis on the left represents charge capacity, and the vertical axis on the right represents cell balancing capacity.

[0086] The assumptions applied to the test in Figure 7 are the same as those applied to the test in Figure 6. That is, the standard charging rate is assumed to charge 1 capacity per hour, and 100% charging corresponds to charging up to 50 capacity.

[0087] In this test example, charging current control began when the SOC reached 80%, and charging was continued by changing the charge rate to 0.2 for 1 hour through charging current control. By changing the charge current, the time to charge to a capacity of 50 increased to 90. In addition, as the charging time increased, the cell balancing capacity was also shown to be balanced to a capacity of 4.5 at the end of charging, confirming a significant increase in balancing capacity compared to the results in Figure 6.

[0088] In this way, the charging time can be increased through the charging control according to the present invention, thereby maximizing the balancing effect in one cycle operation.

[0089] The operations of the methods according to the embodiments of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all kinds of storage devices in which data that can be read by a computer system is stored. In addition, the computer-readable recording medium can be distributed among computer systems connected via a network, so that the computer-readable program or code can be stored and executed in a distributed manner.

[0090] Furthermore, the computer-readable recording medium may include a hardware device specially configured to store and execute program instructions, such as a ROM, a RAM, a flash memory, etc. The program instructions may include not only machine language code, such as that produced by a compiler, but also high-level language code that can be executed by a computer using an interpreter, etc.

[0091] Some aspects of the invention have been described in the context of an apparatus, but they may also be described in terms of a corresponding method, where a block or apparatus corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may be described in terms of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps may be performed by such an apparatus.

[0092] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention as set forth in the following claims. [Explanation of symbols]

[0093] 100: Battery management system (BMS) 110: Control unit (MCU) 130: Cell balancing module 150: Communication module

Claims

1. A battery pack, A plurality of battery cells connected in series; a battery management device including a cell balancing module that performs balancing for the plurality of battery cells, wherein, when the cell balancing module is operating, the battery management device limits a charging current of the battery pack depending on whether the battery pack is within a charge control activation time range and whether the state of charge of the battery pack is equal to or greater than a preset threshold; Including the battery pack.

2. The battery management device 2. The battery pack according to claim 1, wherein when the charging control activation time range is within and the state of charge of the battery pack is equal to or greater than a preset threshold, charging is performed with a limited charging current of the battery pack.

3. The charge control activation time range is: The battery pack according to claim 1 , wherein the battery pack is set to a time range in which there is a high probability that a system to which the battery pack is applied will not be used.

4. The battery management device 2. The battery pack of claim 1, wherein if the charging control activation time range is not met or the state of charge of the battery pack is less than a preset threshold, the existing charging process is continued without limiting the charging current for the battery pack.

5. The newly applied charging rate due to the limitation of the charging current is:

5. The battery pack according to claim 1, wherein the required operation time of the cell balancing module is calculated and set in consideration of voltage variations between cells.

6. The cell balancing module 10. The battery pack according to claim 1, further comprising a passive circuit including a resistor and a switch disposed for each cell.

7. A battery management device for a battery pack including a plurality of battery cells connected in series, a cell balancing module that performs balancing on the plurality of battery cells; a processor; a memory for storing at least one instruction to be executed by said processor; Including, The at least one instruction: instructions for determining whether the battery pack is charging and whether the cell balancing module has started operating; If the cell balancing module is active, instructions for determining whether the cell balancing module is active within a charge control activation time range; If the cell balancing module is active, instructions for determining whether the state of charge of the battery pack is greater than or equal to a predetermined threshold; a command to limit the charging current of the battery pack and charge the battery pack according to whether the charging control activation time range is within and whether the charging state of the battery pack is equal to or greater than a preset threshold; A battery management device comprising:

8. The instruction to charge the battery pack while limiting the charging current of the battery pack includes:

8. The battery management device according to claim 7, further comprising a command to limit a charging current of the battery pack and charge the battery pack when the charging control activation time range is within the charging control activation time range and the charging state of the battery pack is equal to or greater than a preset threshold value.

9. The charge control activation time range is: The battery management device according to claim 7 , wherein the battery management device is set to a time range in which there is a high probability that a system to which the battery pack is applied will not be used.

10. The at least one instruction:

8. The battery management device of claim 7, further comprising: an instruction to proceed with an existing charging process without limiting a charging current to the battery pack when the charging control activation time range is not within or the charging state of the battery pack is below a preset threshold.

11. The newly applied charging rate due to the limitation of the charging current is: The battery management device according to any one of claims 7 to 10, wherein the required operation time of the cell balancing module is calculated and set in consideration of voltage variations between cells.

12. The cell balancing module The battery management device according to claim 7, further comprising a passive circuit including a resistor and a switch arranged for each cell.

13. A method for controlling charging of a battery pack including a plurality of battery cells connected in series, comprising: determining whether the battery pack is being charged and whether the cell balancing module has started operating; If the cell balancing module is in operation, determining whether it is within a charge control activation time range; When the cell balancing module is in operation, determining whether the state of charge of the battery pack is equal to or greater than a preset threshold; charging the battery pack by limiting the charging current of the battery pack according to whether the charging control activation time range is within and whether the charging state of the battery pack is equal to or greater than a preset threshold value; A method for controlling charging of a battery pack, including:

14. The step of charging the battery pack while limiting the charging current of the battery pack includes:

14. The method for controlling charging of a battery pack according to claim 13, further comprising the step of limiting a charging current of the battery pack when the charging control activation time is within the charging control activation time range and the charging state of the battery pack is equal to or greater than a preset threshold.

15. The charge control activation time range is: The method for controlling charging of a battery pack according to claim 13, wherein the method is set to a time range in which there is a high probability that a system to which the battery pack is applied will not be used.

16. 14. The method of claim 13, further comprising: when the charging control activation time range is not reached or the state of charge of the battery pack is less than a preset threshold, continuing an existing charging process without limiting a charging current to the battery pack.

17. The newly applied charging rate due to the limitation of the charging current is: The method for controlling charging of a battery pack according to any one of claims 13 to 16, wherein the required operation time of the cell balancing module is calculated and set in consideration of voltage variations between cells.

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