Battery diagnosis device and operating method thereof

Abstract

A battery diagnosis device according to an embodiment disclosed in the present document comprises: an information acquisition unit that measures a current and a voltage of each of a plurality of battery cells; a resistance measurement unit that measures a cell resistance of each of the plurality of battery cells on the basis of a discharge current and a discharge voltage of each of the plurality of battery cells; and a controller that, prior to the resistance measurement by the resistance measurement unit, applies a preset charging current to each of the plurality of battery cells for a preset charging time and determines an assembly state of each of the plurality of battery cells on the basis of the cell resistance.

Description

Battery diagnostic device and method of operation thereof

[0001] Cross-citation with related applications

[0002] This invention claims the benefit of priority from Korean Patent Application No. 10-2023-0133745, filed on October 6, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] Embodiments disclosed in this document relate to a battery diagnostic device and an operating method thereof.

[0005] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and the development of electric vehicles, rechargeable batteries for energy storage, robots, and satellites has been in full swing, research on high-performance secondary batteries capable of repeated charging and discharging is actively being conducted.

[0006] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0007] Meanwhile, among these secondary batteries, lithium iron phosphate (LFP) batteries experience an increase in resistance due to self-discharge during storage after cell manufacturing. In other words, if a long period of time elapses between cell manufacturing and pack assembly, the State of Charge (SOC) decreases and cell resistance increases due to cell self-discharge. The assembly status of multiple battery cells in a battery pack is determined by measuring the resistance of each cell, but the accuracy of determining assembly defects is reduced and efficiency is reduced because the increase in resistance due to self-discharge and the increase in resistance due to assembly defects are not distinguishable.

[0008] One purpose of the embodiments disclosed in this document is to provide a battery diagnostic device and an operating method thereof capable of determining the assembly status of a battery cell.

[0009] One purpose of the embodiments disclosed in this document is to provide a battery diagnostic device and an operating method thereof that improve the accuracy of determining the assembly status of a battery cell by compensating for an increase in resistance of the battery cell.

[0010] The technical problems of the embodiments described in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0011] A battery diagnosis device according to an embodiment disclosed in this document includes an information acquisition unit that measures current and voltage of each of a plurality of battery cells, a resistance measurement unit that measures cell resistance of each of the plurality of battery cells based on the discharge current and discharge voltage of each of the plurality of battery cells, and a controller that applies a preset charging current to each of the plurality of battery cells for a preset charging time before resistance measurement by the resistance measurement unit, and determines an assembly state of each of the plurality of battery cells based on the cell resistance.

[0012] According to one embodiment, the information acquisition unit acquires the manufacturing date of each of the plurality of battery cells, and the controller determines whether the manufacturing date of each of the plurality of battery cells is before a reference date, and selects a compensation battery cell among the plurality of battery cells based on the determination result.

[0013] In one embodiment, the controller can apply the charging current to the compensation battery cell.

[0014] According to one embodiment, the information acquisition unit acquires the SOC (State of Charge) of each of the plurality of battery cells, and the controller determines whether the SOC of each of the plurality of battery cells is less than a reference SOC, and selects a compensation battery cell among the plurality of battery cells based on the determination result.

[0015] In one embodiment, the controller can adjust the magnitude of the charging current to be at least twice the magnitude of the discharging current.

[0016] In one embodiment, the controller can maintain the current of each of the plurality of battery cells within a preset range between the charging time and the resistance measurement of the resistance measuring unit.

[0017] According to one embodiment, the resistance measuring unit measures the cell resistance of each of the plurality of battery cells by discharging each of the plurality of battery cells for a preset discharge time, and the controller can adjust the preset charging time to be longer than the preset discharge time.

[0018] According to one embodiment, the resistance measuring unit can measure the cell resistance of each of the plurality of battery cells using the DCIR (Direct Current Internal Resistance) method.

[0019] According to one embodiment, the controller can determine that the assembly status of a battery cell among the plurality of battery cells, in which the cell resistance is greater than or equal to a preset resistance, is defective.

[0020] A battery diagnosis method according to an embodiment disclosed in this document includes a step of applying a preset charging current for a preset charging time to each of a plurality of battery cells, a step of measuring cell resistance of each of the plurality of battery cells based on a discharge current and a discharge voltage of each of the plurality of battery cells, and a step of determining an assembly state of each of the plurality of battery cells based on the cell resistance.

[0021] According to one embodiment, the method may further include a step of obtaining a manufacturing date or a State of Charge (SOC) of each of the plurality of battery cells, and a step of selecting a compensation battery cell among the plurality of battery cells based on at least one of the manufacturing date or the SOC.

[0022] In one embodiment, the magnitude of the charging current may be at least twice the magnitude of the discharging current.

[0023] According to one embodiment, the step of measuring the cell resistance is a step of measuring the cell resistance of each of the plurality of battery cells by discharging each of the plurality of battery cells for a preset discharge time, and the preset charging time may be longer than the preset discharge time.

[0024] According to one embodiment, the step of measuring the cell resistance may be a step of measuring the cell resistance of each of the plurality of battery cells using a DCIR (Direct Current Internal Resistance) method.

[0025] According to one embodiment, the step of determining the assembly status may determine that the assembly status of a battery cell among the plurality of battery cells, in which the cell resistance is greater than or equal to a preset resistance, is defective.

[0026] Specific details of other embodiments are included in the detailed description and drawings.

[0027] The battery diagnostic device and its operating method according to the embodiments disclosed in this document can determine the assembly status of a battery cell.

[0028] The battery diagnostic device and its operating method according to the embodiments disclosed in this document can improve the accuracy of determining the assembly status of a battery cell by compensating for an increase in the resistance of the battery cell.

[0029] The effects of the battery diagnostic device and the operating method thereof according to the disclosure of this document are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art according to the disclosure of this document.

[0030] FIG. 1 is a block diagram showing a battery pack according to one embodiment disclosed in this document.

[0031] FIG. 2 is a block diagram showing a battery diagnostic device according to one embodiment disclosed in this document.

[0032] FIG. 3 is a drawing showing an operation of a battery diagnostic device according to an embodiment disclosed in this document to compensate for an increase in resistance of a battery cell.

[0033] FIG. 4 is a flowchart showing a battery diagnosis method according to an embodiment disclosed in this document.

[0034] FIG. 5 is a block diagram showing a computing system that executes a battery diagnosis method according to an embodiment disclosed in this document.

[0035] In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0036] Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0037] The embodiments and terminology used in this document are not intended to limit the technical features described in this document to a specific embodiment, but should be understood to encompass various modifications, equivalents, or alternatives of the embodiment. In connection with the description of the drawings, similar reference numerals may be used to refer to similar or related components. The singular form of a noun corresponding to an item may include one or more of the item, unless the relevant context clearly indicates otherwise.

[0038] In this document, the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", "first", "second", "A", "B", "(a)", or "(b)" may be used merely to distinguish the corresponding component from other corresponding components, and do not limit the corresponding components in any other respect (e.g., importance or order) unless specifically stated otherwise.

[0039] In this document, when a component (e.g., a first component) is referred to as being “connected,” “coupled,” or “connected,” with or without the terms “functionally” or “communicatively,” or “coupled” or “connected,” it means that the component can be connected to the other component directly (e.g., wired or wirelessly), or indirectly (e.g., via a third component).

[0040] The methods according to various embodiments disclosed in this document may be provided as included in a computer program product. The computer program product may be traded as a commodity between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory, CD-ROM), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices. In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0041] According to the embodiments disclosed in this document, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to the embodiments disclosed in this document, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to the embodiments disclosed in this document, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0042] FIG. 1 is a block diagram showing a battery pack according to one embodiment disclosed in this document.

[0043] Referring to FIG. 1, a battery control system including a battery pack (1) and an upper controller (2) included in an upper system according to one embodiment disclosed in the present document is schematically illustrated.

[0044] As illustrated in FIG. 1, a battery pack (1) may include one or more battery cells (11), a switching unit (14) connected in series to a first terminal side and / or a second terminal side of the battery cell (11) to control a charge or discharge current flow of the battery cell (11), and a battery management system (20) that monitors voltage, current, temperature, etc. of the battery pack (1) to prevent overcharging and overdischarging, etc.

[0045] In this case, the battery pack (1) may be equipped with a plurality of battery cells (11), sensors (12), switching units (14), and battery management systems (20). For example, the first terminal may be the (+) terminal of the battery cell (11), and the second terminal may be the (-) terminal.

[0046] Here, the switching unit (14) is a device for controlling the current flow for charging or discharging of a plurality of battery cells (11), and for example, at least one relay, magnetic contactor, etc. may be used depending on the specifications of the battery pack (1).

[0047] The battery management system (20) is an interface that receives values ​​measured from the various parameters described above, and may include a plurality of terminals and a circuit that is connected to these terminals and processes the values ​​received. In addition, the battery management system (20) may control the ON / OFF of a switching unit (14), for example, a relay or a contactor, and may be connected to a battery cell (11) to monitor the status of each battery cell (11).

[0048] The upper controller (2) can transmit a control signal for the battery cell (11) to the battery management system (20). Accordingly, the battery management system (20) can be controlled in operation based on the signal received from the upper controller (2).

[0049] According to an embodiment, the battery management system (20) may include the battery diagnostic device (100) of FIG. 2. According to another embodiment, the battery management system (20) may be a different system from the battery diagnostic device (100) of FIG. 2. That is, the battery diagnostic device (100) of FIG. 2 may be included in the battery pack (1) or may be configured as another device external to the battery pack (1).

[0050] For convenience of explanation, the following description assumes that the battery diagnostic device (100) is configured as another device external to the battery pack (1), but is not limited thereto. For example, the operation of the battery diagnostic device (100) below may be performed by an in-vehicle BMS (Battery Management System), as well as by various devices such as a server, cloud, charger, or charger / discharger.

[0051] FIG. 2 is a block diagram showing a battery diagnostic device according to one embodiment disclosed in this document.

[0052] Referring to FIG. 2, the battery diagnostic device (100) may include an information acquisition unit (110), a resistance measurement unit (120), and a controller (130). The battery diagnostic device (100) may determine the assembly state of a battery cell through the information acquisition unit (110), the resistance measurement unit (120), and the controller (130). That is, the battery diagnostic device (100) may diagnose the assembled state of each of the plurality of battery cells (11) included in the battery pack.

[0053] The information acquisition unit (110) can acquire information on battery cells. The information acquisition unit (110) can acquire information on each of the plurality of battery cells (11) included in the battery pack. According to an embodiment, the information acquisition unit (110) can acquire information on the current and voltage of each of the plurality of battery cells (11). The information acquisition unit (110) can measure the current or voltage of each of the plurality of battery cells (11), but is not limited thereto. For example, the information acquisition unit (110) may not measure the voltage or current, but may receive information such as the voltage or current of each of the plurality of battery cells (11) from a separate device or server.

[0054] According to an embodiment, the information acquisition unit (110) can acquire manufacturing date information. That is, the information acquisition unit (110) can acquire manufacturing date information for each of the plurality of battery cells (11). For example, the information acquisition unit (110) can acquire manufacturing date information by receiving manufacturing date information corresponding to each of the plurality of battery cells (11) from a separate storage unit or server.

[0055] According to an embodiment, the information acquisition unit (110) can acquire SOC (State of Charge) information. That is, the information acquisition unit (110) can acquire SOC information of each of the plurality of battery cells (11). For example, the information acquisition unit (110) can acquire SOC information by directly measuring the SOC of each of the plurality of battery cells (11) or by receiving SOC information corresponding to each of the plurality of battery cells (11) from a separate storage unit or server.

[0056] The resistance measuring unit (120) can measure the cell resistance of a battery cell. The resistance measuring unit (120) can measure the cell resistance of each of the plurality of battery cells (11) included in the battery pack.

[0057] According to an embodiment, the resistance measuring unit (120) can measure cell resistance using the DCIR (Direct Current Internal Resistance) method. In this case, the resistance measuring unit (120) can measure the voltage drop while discharging each of the plurality of battery cells (11) at a preset discharge current, and measure the cell resistance of each of the plurality of battery cells (11) based on the discharge current value and the voltage drop value. That is, the resistance measuring unit (120) can measure the cell resistance of each of the plurality of battery cells (11) by discharging each of the plurality of battery cells (11) for a discharge time based on the discharge current and the discharge voltage.

[0058] The controller (130) can apply a charging current to the battery cells. The controller (130) can apply a charging current directly to each of the plurality of battery cells (11), or can control a separately provided charger, etc. to apply a charging current to each of the plurality of battery cells (11).

[0059] According to an embodiment, the controller (130) may apply a charging current before the resistance measuring unit (120) measures the cell resistance. That is, after the controller (130) applies the charging current to each of the plurality of battery cells (11), the resistance measuring unit (120) may measure the cell resistance of each of the plurality of battery cells (11). That is, the application of the charging current by the controller (130) and the measurement of the cell resistance by the resistance measuring unit (120) constitute one set, and the measurement of the cell resistance by the resistance measuring unit (120) may be performed after the application of the charging current by the controller (130).

[0060] The controller (130) can adjust the size of the charging current. According to an embodiment, the controller (130) can adjust the size of the charging current to be more than twice the size of the discharge current. That is, the controller (130) can set the size of the charging current applied to each of the plurality of battery cells (11) to a specific value. For example, the controller (130) can set the size of the charging current to 2 C-rate, but is not limited thereto.

[0061] The controller (130) can adjust the charging time. According to an embodiment, the controller (130) can adjust the charging time to be longer than the discharge time of the resistance measuring unit (120). That is, the controller (130) can adjust the length of the charging time for applying the charging current to each of the plurality of battery cells (11) to be longer than the discharge time for discharging each of the plurality of battery cells (11) by the resistance measuring unit (120).

[0062] The controller (130) can set a pause time. The controller (130) can set a pause time between the charging time and the discharging time. Here, the pause time can be defined as the time between the charging time and the discharging time. In addition, if the diagnostic time of each of the multiple battery cells (11) is fixed, the length of the pause time can be the total time minus the charging time and the discharging time.

[0063] The controller (130) can maintain the current of each of the plurality of battery cells (11) within a preset range during the idle time. For example, the controller (130) can maintain the current of each of the plurality of battery cells (11) at 0 during the idle time.

[0064] According to an embodiment, the controller (130) can select a compensation battery cell. The controller (130) can select a compensation battery cell from among a plurality of battery cells (11) included in the battery pack.

[0065] According to an embodiment, the controller (130) may select a compensation battery cell based on the manufacturing date. The controller (130) may determine whether the manufacturing date of each of the plurality of battery cells (11) is before a reference date, and may select a compensation battery cell based on the determination result. For example, the controller (130) may extract battery cells whose manufacturing date is before the reference date among the plurality of battery cells (11) and select the extracted battery cells as compensation battery cells. That is, the controller (130) may select battery cells for which a certain amount of time has passed since the manufacturing date as compensation battery cells.

[0066] According to an embodiment, the controller (130) may select a compensation battery cell based on the SOC. The controller (130) may determine whether the SOC of each of the plurality of battery cells (11) is less than the reference SOC, and may select a compensation battery cell based on the determination result. For example, the controller (130) may extract battery cells having an SOC less than the reference SOC among the plurality of battery cells (11) and select the extracted battery cells as compensation battery cells. That is, the controller (130) may select battery cells whose SOC decreases due to storage of the battery cells as compensation battery cells.

[0067] According to an embodiment, the controller (130) can charge the compensation battery cells by applying current to them. That is, the controller (130) can apply a charging current to selected compensation battery cells among a plurality of battery cells (11).

[0068] The controller (130) can determine the assembly status. The controller (130) can determine the assembly status of a plurality of battery cells (11) included in the battery pack. According to an embodiment, the controller (130) can determine the assembly status of each of the plurality of battery cells (11) based on the cell resistance of each of the plurality of battery cells (11). For example, the controller (130) can determine the assembly status of a battery cell having a cell resistance higher than a preset resistance among the plurality of battery cells (11) as defective. In addition, the controller (130) can determine the assembly status of a battery cell having a cell resistance lower than a preset resistance among the plurality of battery cells (11) as normal. Here, the preset resistance can be set based on the type of battery cell, the type of battery pack, etc.

[0069] According to an embodiment, the battery diagnostic device (100) can provide assembly status information to a user. For example, the battery diagnostic device (100) can provide battery cell assembly status information to a user terminal or PC, etc., via a communication unit (not shown), and can also provide battery cell assembly status information through a display equipped in a vehicle or charger, etc.

[0070] FIG. 3 is a drawing showing an operation of a battery diagnostic device according to an embodiment disclosed in this document to compensate for an increase in resistance of a battery cell.

[0071] Referring to FIG. 3, the battery diagnostic device (100) can determine the assembly status of each of the plurality of battery cells (11). The battery diagnostic device (100) can measure the cell resistance of each of the plurality of battery cells (11) based on charging, resting, and resistance measurement operations, and determine the assembly status based on the cell resistance.

[0072] The charging current applied by the controller (130) to each of the plurality of battery cells (11) may be a [A], and the discharging current discharged by the resistance measuring unit (120) may be b [A]. At this time, the controller (130) may adjust the size a of the charging current to be greater than the size b of the discharging current. That is, a may be greater than b. According to an embodiment, the controller (130) may adjust the size a of the charging current to be greater than 2b, which is twice the size of the discharging current.

[0073] The time for which the controller (130) applies the charging current to each of the plurality of battery cells (11) may be t1, and the resistance measurement time for which the resistance measurement unit (120) discharges each of the plurality of battery cells (11) may be t3-t2. At this time, the controller (130) may adjust the charging time t1 to be longer than the resistance measurement time t3-t2. That is, the time for which the controller (130) applies the charging current may be longer than the time for which the resistance measurement unit (120) measures the resistance through discharging.

[0074] A pause time may be provided between the charging time and the resistance measurement time. That is, the pause time may be the time from t1, when the charging time ends, to t2, when the resistance measurement time begins. The controller (130) may maintain the current of the plurality of battery cells (11) within a preset range during the pause time.

[0075] The battery diagnostic device (100) can determine the assembly status of a battery cell. The battery diagnostic device (100) can determine the assembly status of a battery cell based on the cell resistance of the battery cell.

[0076] The battery diagnostic device (100) can improve the accuracy of determining the assembly status of a battery cell by compensating for an increase in the resistance of the battery cell through application of a charging current.

[0077] FIG. 4 is a flowchart showing a battery diagnosis method according to an embodiment disclosed in this document.

[0078] The embodiment illustrated in FIG. 4 is only one embodiment, and the order of operations according to various embodiments of the present invention may be different from that illustrated in FIG. 4, and some of the steps illustrated in FIG. 4 may be omitted, the order between the steps may be changed, or the steps may be merged.

[0079] Referring to FIG. 4, the battery diagnosis method may include an operation of obtaining a manufacturing date or a State of Charge (SOC) of each of a plurality of battery cells (S100), an operation of selecting a compensation battery cell among the plurality of battery cells based on at least one of the manufacturing date or the SOC (S200), an operation of applying a preset charging current for a preset charging time to each of the compensation battery cells (S300), an operation of measuring the cell resistance of each of the compensation battery cells based on the discharge current and discharge voltage of each of the compensation battery cells (S400), an operation of determining whether the cell resistance is equal to or greater than a preset value (S500), an operation of determining the assembly state of the battery cell as defective (S600), and an operation of determining the assembly state of the battery cell as normal (S700).

[0080] Below, the above operations S100 to S700 are specifically described with reference to FIGS. 1 to 4.

[0081] In operation S100, the battery diagnostic device (100) can obtain the manufacturing date or SOC (State of Charge) of each of the plurality of battery cells (11).

[0082] According to an embodiment, the battery diagnostic device (100) can obtain manufacturing date information. That is, the battery diagnostic device (100) can obtain manufacturing date information for each of the plurality of battery cells (11). For example, the battery diagnostic device (100) can obtain manufacturing date information by receiving manufacturing date information corresponding to each of the plurality of battery cells (11) from a separate storage unit or server.

[0083] According to an embodiment, the battery diagnosis device (100) can obtain SOC (State of Charge) information. That is, the battery diagnosis device (100) can obtain SOC information of each of the plurality of battery cells (11). For example, the battery diagnosis device (100) can obtain SOC information by directly measuring the SOC of each of the plurality of battery cells (11) or by receiving SOC information corresponding to each of the plurality of battery cells (11) from a separate storage unit or server.

[0084] In operation S200, the battery diagnostic device (100) can select a compensation battery cell among a plurality of battery cells (11) based on at least one of the manufacturing date or SOC.

[0085] According to an embodiment, the battery diagnostic device (100) can select a compensation battery cell. The battery diagnostic device (100) can select a compensation battery cell from among a plurality of battery cells (11) included in the battery pack.

[0086] According to an embodiment, the battery diagnosis device (100) can select a compensation battery cell based on the manufacturing date. The battery diagnosis device (100) can determine whether the manufacturing date of each of the plurality of battery cells (11) is before a reference date, and select a compensation battery cell based on the determination result. For example, the battery diagnosis device (100) can extract battery cells whose manufacturing date is before the reference date among the plurality of battery cells (11) and select the extracted battery cells as compensation battery cells. That is, the battery diagnosis device (100) can select battery cells for which a certain amount of time has passed since the manufacturing date as compensation battery cells.

[0087] According to an embodiment, the battery diagnosis device (100) can select a compensation battery cell based on the SOC. The battery diagnosis device (100) can determine whether the SOC of each of the plurality of battery cells (11) is less than the reference SOC, and select a compensation battery cell based on the determination result. For example, the battery diagnosis device (100) can extract battery cells having an SOC less than the reference SOC among the plurality of battery cells (11) and select the extracted battery cells as compensation battery cells. That is, the battery diagnosis device (100) can select battery cells whose SOC decreases due to storage of the battery cells as compensation battery cells.

[0088] According to an embodiment, operations S100 and S200 may be omitted. In this case, the battery diagnosis device (100) may perform operation S300 on all battery cells included in the battery pack without selecting a compensation battery cell. For convenience of explanation, the battery diagnosis method is described below on the premise that it includes operations S100 and S200.

[0089] In operation S300, the battery diagnostic device (100) can apply a preset charging current for a preset charging time to each compensation battery cell.

[0090] The battery diagnostic device (100) can apply a charging current to the compensation battery cells. The battery diagnostic device (100) can apply a charging current directly to each of the plurality of compensation battery cells, or can control a separately provided charger, etc. to apply a charging current to each of the plurality of compensation battery cells.

[0091] In operation S400, the battery diagnostic device (100) can measure the cell resistance of each compensation battery cell based on the discharge current and discharge voltage of each compensation battery cell.

[0092] The battery diagnostic device (100) can measure the cell resistance of a battery cell. The battery diagnostic device (100) can measure the cell resistance of each of a plurality of battery cells (11) included in a battery pack.

[0093] According to an embodiment, the battery diagnosis device (100) can measure cell resistance using the DCIR (Direct Current Internal Resistance) method. In this case, the battery diagnosis device (100) can discharge each of the plurality of battery cells (11) at a preset discharge current and measure the voltage drop, and measure the cell resistance of each of the plurality of battery cells (11) based on the discharge current value and the voltage drop value. That is, the battery diagnosis device (100) can measure the cell resistance of each of the plurality of battery cells (11) by discharging each of the plurality of battery cells (11) for a discharge time based on the discharge current and the discharge voltage.

[0094] In operation S500, the battery diagnostic device (100) can determine whether the cell resistance is greater than or equal to a set value. If the cell resistance is greater than or equal to the set value, operation S600 can be performed. If the cell resistance is less than the set value, operation S700 can be performed.

[0095] In operation S600, the battery diagnostic device (100) can determine that the assembly status of a battery cell is defective. The battery diagnostic device (100) can determine that the assembly status of a battery cell among a plurality of battery cells (11) having a cell resistance higher than a preset resistance is defective.

[0096] In operation S700, the battery diagnostic device (100) can determine that the assembly status of the battery cell is normal. The battery diagnostic device (100) can determine that the assembly status of a battery cell among a plurality of battery cells (11) having a cell resistance lower than a preset resistance is normal.

[0097] FIG. 5 illustrates a computing system executing another battery diagnostic method according to one embodiment disclosed in this document.

[0098] Referring to FIG. 5, a computing system (200) according to an embodiment disclosed in the present document may include an MCU (210), a memory (220), an input / output I / F (230), and a communication I / F (240).

[0099] The MCU (210) may be a processor that executes various programs stored in the memory (220) (e.g., an SOH calculation program, a cell balancing target determination program, etc.), processes various data including SOC, SOH, etc. of multiple battery cells through these programs, and performs the functions of the battery diagnosis device (100) described with reference to the aforementioned FIGS. 1 to 3.

[0100] The memory (220) can store various programs related to calculating the SOH of a battery cell and determining whether to perform cell balancing. In addition, the memory (220) can store various data, such as SOC and SOH data for each battery cell.

[0101] Such memories (220) may be provided in multiple numbers as needed. The memories (220) may be volatile memories or non-volatile memories. As volatile memories (220), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (220), ROM, PROM, EAROM, EPROM, EEPROM, flash memories, etc. may be used. The examples of the memories (220) listed above are merely examples and are not limited to these examples.

[0102] The input / output I / F (230) can provide an interface that enables data transmission and reception between an input device (not shown) such as a keyboard, mouse, or touch panel, and an output device (not shown) such as a display and the MCU (210).

[0103] The communication I / F (240) is a component capable of transmitting and receiving various data with a server, and may be any device capable of supporting wired or wireless communication. For example, programs for calculating the SOH of battery cells or determining balancing targets, as well as various data, can be transmitted and received from a separately provided external server via the communication I / F (240).

[0104] In this way, the battery diagnosis method according to one embodiment disclosed in this document can be recorded in the memory (220) and executed by the MCU (210).

[0105] The above description is merely an example of the technical idea disclosed in this document, and those skilled in the art to which the embodiments disclosed in this document pertain may make various modifications and variations without departing from the essential characteristics of the embodiments disclosed in this document.

[0106] Accordingly, the embodiments disclosed in this document are intended to illustrate, rather than limit, the technical concepts disclosed in this document, and the scope of the technical concepts disclosed in this document is not limited by these embodiments. The scope of protection of the technical concepts disclosed in this document should be interpreted by the claims below, and all technical concepts within the equivalent scope should be interpreted as being included within the scope of the rights of this document.

Claims

1. An information acquisition unit that measures the current and voltage of each of multiple battery cells; A resistance measuring unit for measuring the cell resistance of each of the plurality of battery cells based on the discharge current and discharge voltage of each of the plurality of battery cells; and Before measuring the resistance of the resistance measuring unit, a preset charging current is applied to each of the plurality of battery cells for a preset charging time, A battery diagnostic device including a controller that determines the assembly status of each of the plurality of battery cells based on the cell resistance.

2. In paragraph 1, The above information acquisition unit acquires the manufacturing date of each of the plurality of battery cells, The controller determines whether the manufacturing date of each of the plurality of battery cells is before the reference date, A battery diagnostic device that selects a compensation battery cell among the plurality of battery cells based on the judgment result.

3. In paragraph 2, The above controller is a battery diagnostic device that applies the charging current to the compensation battery cell.

4. In paragraph 1, The above information acquisition unit acquires the SOC (State of Charge) of each of the plurality of battery cells, The controller determines whether the SOC of each of the plurality of battery cells is less than the reference SOC, A battery diagnostic device that selects a compensation battery cell among the plurality of battery cells based on the judgment result.

5. In paragraph 1, The above controller is a battery diagnostic device that adjusts the size of the charging current to be more than twice the size of the discharging current.

6. In paragraph 1, A battery diagnostic device in which the controller maintains the current of each of the plurality of battery cells within a preset range between the charging time and the resistance measurement of the resistance measuring unit.

7. In paragraph 1, The resistance measuring unit measures the cell resistance of each of the plurality of battery cells by discharging each of the plurality of battery cells for a preset discharge time, The above controller is a battery diagnostic device that adjusts the preset charging time to be longer than the preset discharge time.

8. In paragraph 1, The above resistance measurement unit is a battery diagnostic device that measures the cell resistance of each of the plurality of battery cells using the DCIR (Direct Current Internal Resistance) method.

9. In paragraph 1, The above controller is a battery diagnostic device that determines the assembly status of a battery cell among the plurality of battery cells, wherein the cell resistance is greater than a preset resistance, as defective.

10. A step of applying a preset charging current for a preset charging time to each of a plurality of battery cells; A step of measuring the cell resistance of each of the plurality of battery cells based on the discharge current and discharge voltage of each of the plurality of battery cells; and A battery diagnosis method comprising a step of determining the assembly status of each of the plurality of battery cells based on the cell resistance.

11. In paragraph 10, A step of obtaining the manufacturing date or SOC (State of Charge) of each of the plurality of battery cells; and A battery diagnosis method further comprising a step of selecting a compensation battery cell among the plurality of battery cells based on at least one of the manufacturing date or the SOC.

12. In paragraph 10, A battery diagnosis method wherein the size of the above charging current is at least twice the size of the above discharging current.

13. In paragraph 10, The step of measuring the cell resistance is a step of discharging each of the plurality of battery cells for a preset discharge time and measuring the cell resistance of each of the plurality of battery cells. A battery diagnosis method wherein the above preset charging time is longer than the above preset discharge time.

14. In paragraph 10, A battery diagnosis method in which the step of measuring the cell resistance is a step of measuring the cell resistance of each of the plurality of battery cells using the DCIR (Direct Current Internal Resistance) method.

15. In paragraph 10, A battery diagnosis method wherein the step of determining the above assembly status is a step of determining that the assembly status of a battery cell among the plurality of battery cells, the cell resistance of which is higher than a preset resistance, is defective.

Images