Battery diagnostic device and operating method thereof

Abstract

A battery diagnostic device according to an embodiment disclosed in the present document may comprise: an information acquisition unit for acquiring voltages of a plurality of battery cells; and a controller for calculating a second-order derivative value of a capacity voltage with respect to the voltages of the plurality of battery cells, and configuring at least a part of an SOC section, in which the second-order derivative value is less than or equal to a first value, or at least a part of a voltage section, as a diagnosis section.

Description

Battery diagnostic device and its operating method

[0001] Cross-citation with related applications

[0002] This invention claims the benefit of priority from Korean Patent Application No. 10-2024-0016646, filed February 2, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

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

[0005] Recently, research and development on secondary batteries has been actively conducted. Here, secondary batteries are rechargeable and include both conventional Ni / Cd and Ni / MH batteries, as well as recent lithium-ion batteries. Among secondary batteries, lithium-ion batteries have the advantage of having a much higher energy density than conventional Ni / Cd and Ni / MH batteries. Furthermore, lithium-ion batteries can be manufactured in a compact and lightweight form, making them suitable for use as power sources for mobile devices. Recently, their use has expanded to include power sources for electric vehicles, attracting attention as a next-generation energy storage medium.

[0006] Diagnosing battery tab breaks and lithium deposition is essential for diagnosing battery performance and anomalies. While low-rate differential indicators can diagnose capacity and deposition based on laboratory data, their application to field data presents limitations. Because batteries with tab breaks and lithium deposition pose a risk of performance degradation or fire, a method for diagnosing battery anomalies based on field data is necessary.

[0007] One purpose of the embodiments disclosed in this document is to provide a battery diagnostic device and an operating method thereof that can immediately detect abnormal signs by applying a diagnostic technique utilizing second differentiation to field data.

[0008] One purpose of the embodiments disclosed in this document is to provide a battery diagnostic device and an operating method thereof capable of diagnosing relative capacity deviations of cells in a battery pack by utilizing the second derivative rather than the first derivative of open circuit voltage.

[0009] The technical problems of the embodiments disclosed 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 from the descriptions below.

[0010] A battery diagnostic device according to one embodiment disclosed in this document may include an information acquisition unit that acquires voltages of a plurality of battery cells, and a controller that calculates a capacity-voltage second derivative value for the voltages of the plurality of battery cells, and sets at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative value is less than or equal to a first value as a diagnostic section.

[0011] In one embodiment, the controller can diagnose the plurality of battery cells in the diagnostic section.

[0012] In one embodiment, the controller may calculate a partial capacity of each of the plurality of battery cells in the diagnostic section, and diagnose the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells.

[0013] In one embodiment, the controller can calculate the partial capacity of each of the plurality of battery cells through current accumulation.

[0014] In one embodiment, the controller can calculate a deviation in the partial capacity of each of the plurality of battery cells, and diagnose a battery cell with a deviation greater than or equal to a second value as an abnormal battery cell.

[0015] In one embodiment, the controller may calculate a second derivative of a capacity voltage for each of the plurality of battery cells, and set at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative of all of the plurality of battery cells is less than or equal to the first value as the diagnostic section.

[0016] In one embodiment, the controller may calculate an average voltage of the plurality of battery cells, calculate a second derivative of a capacity voltage with respect to the average voltage of the plurality of battery cells, and set at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative of a capacity voltage with respect to the average voltage of the plurality of battery cells is less than or equal to the first value as the diagnostic section.

[0017] In one embodiment, the voltage of the plurality of battery cells may be an open circuit voltage of the plurality of battery cells.

[0018] A method of operating a battery diagnostic device according to one embodiment disclosed in this document may include:

[0019] In one embodiment, the method may include an operation of obtaining voltages of a plurality of battery cells, an operation of calculating a second derivative of a capacity voltage with respect to the voltages of the plurality of battery cells, and an operation of setting at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative is less than or equal to a first value as a diagnostic section.

[0020] In one embodiment, the diagnostic section may further include an operation of diagnosing the plurality of battery cells.

[0021] In one embodiment, the diagnostic section may further include an operation of calculating a partial capacity of each of the plurality of battery cells and an operation of diagnosing the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells.

[0022] In one embodiment, the operation of calculating the partial capacity of each of the plurality of battery cells in the diagnostic section may calculate the partial capacity of each of the plurality of battery cells through current integration.

[0023] In one embodiment, the operation of diagnosing the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells may include the operation of calculating a deviation of the partial capacity of each of the plurality of battery cells and the operation of diagnosing a battery cell having a deviation greater than or equal to a second value as an abnormal battery cell.

[0024] A battery diagnostic device and its operating method according to one embodiment disclosed in this document can diagnose partial capacity reduction and lithium deposition of a battery cell based on a battery diagnostic technology utilizing second differentiation.

[0025] A battery diagnostic device and its operating method according to one embodiment disclosed in this document can diagnose a battery cell or a battery pack based on field data of the battery.

[0026] In addition, various effects may be provided, either directly or indirectly, through this document.

[0027] Figure 1 is a block diagram showing the configuration of a typical battery pack.

[0028] FIG. 2 is a drawing showing a battery diagnostic device according to one embodiment disclosed in this document.

[0029] FIG. 3a and FIG. 3b are diagrams showing examples of a battery diagnostic device according to one embodiment disclosed in the present document setting a diagnostic section.

[0030] FIG. 4 is a flowchart showing an operation method of a battery diagnostic device according to one embodiment disclosed in this document.

[0031] FIG. 5 and FIG. 6 are flowcharts specifically showing an operation method of a battery diagnostic device according to one embodiment disclosed in this document.

[0032] FIG. 7 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery diagnostic device according to one embodiment disclosed in this document.

[0033] Hereinafter, embodiments disclosed in this document will be described in detail with reference to exemplary drawings. When designating components in each drawing, it should be noted that, where possible, identical components are given the same reference numerals, even if they appear in different drawings. Furthermore, when describing embodiments disclosed in this document, detailed descriptions of related known structures or functions will be omitted if they are deemed to hinder understanding of the embodiments disclosed in this document.

[0034] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components and do not limit the nature, order, or sequence of the components. In addition, 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 the embodiments disclosed in this document belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0035] Figure 1 is a block diagram showing the configuration of a typical battery pack.

[0036] 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 of the present invention is schematically illustrated.

[0037] As illustrated in FIG. 1, a battery pack (1) is composed of one or more battery cells and includes a plurality of battery cells (10) that are rechargeable and dischargeable, a switching unit (14) that is connected in series to the (+) terminal side or the (-) terminal side of the plurality of battery cells (10) to control the charge and discharge current flow of the plurality of battery cells (10), and a battery management system (20) that monitors the voltage, current, temperature, etc. of the battery pack (1) and controls and manages to prevent overcharging, overdischarging, etc. In this case, the battery pack (1) may be equipped with a plurality of battery cells (10), sensors (12), switching units (14), and battery management systems (20).

[0038] Here, the switching unit (14) is a device for controlling the current flow for charging or discharging of a plurality of battery cells (10), and for example, at least one relay, magnetic contactor, etc. may be used depending on the specifications of the battery pack (1).

[0039] 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 the 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 plurality of battery cells (10) and monitor the status of each of the plurality of battery cells (10). According to an embodiment, the battery management system (20) may include the battery diagnosis device (100) of FIG. 2. According to another embodiment, the battery management system (20) may be a different system from the battery diagnosis device (100) of FIG. 2. That is, the battery diagnosis 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). In addition, the operation of the battery diagnostic device (100) below can be performed by a BMS (Battery management system) in a vehicle, and can also be performed in various devices such as a server, cloud, charger, or charger / discharger.

[0040] The upper controller (2) can transmit control signals for multiple battery cells (10) to the battery management system (20). Accordingly, the battery management system (20) can be controlled in operation based on the signals received from the upper controller (2).

[0041] FIG. 2 is a drawing showing a battery diagnostic device according to one embodiment disclosed in this document.

[0042] The battery diagnostic device (100) may be a variety of electronic devices for diagnosing or testing a battery. For example, the battery diagnostic device (100) may be included in a battery management system (BMS) within a vehicle, but may also be implemented as a separate external device distinct from the BMS within the vehicle.

[0043] According to another embodiment, the battery diagnostic device (100) may be included in a device for charge / discharge testing, such as a server, a cloud server, or a charge / discharge cycler, or may be included in various devices for diagnosing or testing batteries.

[0044] Referring to FIG. 2, the battery diagnostic device (100) may include an information acquisition unit (110) and a controller (120).

[0045] The information acquisition unit (110) can acquire the voltage of the plurality of battery cells. According to an embodiment, the information acquisition unit (110) can acquire the open circuit voltage of each of the plurality of battery cells. According to another embodiment, the information acquisition unit (110) can acquire the voltage and accumulated current of each of the plurality of battery cells at each specific voltage increase section when charging the plurality of battery cells. According to yet another embodiment, the information acquisition unit (110) can acquire the voltage and accumulated current of each of the plurality of battery cells at each specific voltage decrease section when discharging the plurality of battery cells. According to an embodiment, the information acquisition unit (110) can further acquire the temperature of each of the plurality of battery cells.

[0046] The controller (120) can calculate the second derivative of the capacity-voltage with respect to the voltage of a plurality of battery cells. For example, the second derivative of the capacity-voltage may include either the second derivative of the capacity with respect to the voltage or the second derivative of the voltage with respect to the capacity. As another example, the controller (120) can calculate the second derivative of the capacity-voltage with respect to the voltage of a plurality of battery cells that are being charged or discharged.

[0047] According to an embodiment, the controller (120) can calculate a capacity-voltage differential value (dQ / dV) of the voltage of a plurality of battery cells being charged or discharged, and can calculate a capacity-voltage second differential value (d2Q / dV2) based on the capacity-voltage differential value (dQ / dV).

[0048] According to another embodiment, the controller (120) can calculate a capacity-voltage derivative (dV / dQ) of the voltage of a plurality of battery cells being charged or discharged, and can calculate a capacity-voltage second derivative (d2V / dQ2) based on the capacity-voltage derivative (dV / dQ).

[0049] According to an embodiment, the controller (120) can calculate the second derivative of the capacity voltage of each of the plurality of battery cells. According to another embodiment, the controller (120) can calculate the second derivative of the capacity voltage of the average of the voltages of each of the plurality of battery cells.

[0050] The controller (120) can set at least a portion of the SOC section or at least a portion of the voltage section in which the second derivative is less than or equal to the first value as a diagnostic section. For example, if the section in which the second derivative (d2V / dQ2) is less than or equal to the first value is from SOC 60 to SOC 80, the controller (120) can set a portion of the section from SOC 60 to SOC 80 as a diagnostic section. For another example, if the voltage section in which the second derivative (d2Q / dV2) is less than or equal to the first value is from 3.8 V to 4.1 V, the controller (120) can set a portion of the section from 3.8 V to 4.1 V as a diagnostic section.

[0051] According to an embodiment, the first value may be set to, but is not limited to, 0.1, and the first value may be set to specify a section in which the change in the capacity-voltage differential value is less than the set value.

[0052] According to an embodiment, the controller (120) may calculate the second derivative of the capacity voltage for each of the plurality of battery cells. In addition, the controller (120) may set a portion of the SOC section in which the second derivative of all of the plurality of battery cells is less than or equal to a first value as a diagnostic section. For example, the controller (120) may identify a section in which the second derivative of the capacity voltage of each of the plurality of battery cells is less than or equal to the first value, and set the overlapping section as a diagnostic section.

[0053] According to an embodiment, the controller (120) can calculate the voltage average of a plurality of battery cells. In addition, the controller (120) can calculate the second derivative of the capacity voltage with respect to the voltage average of the plurality of battery cells, and can set a part of the SOC section or voltage section in which the second derivative of the capacity voltage with respect to the voltage average of the plurality of battery cells is equal to or less than a first value as a diagnostic section.

[0054] That is, the controller (120) can set a specific SOC section as a diagnostic section based on the second differentiation of the voltage of a plurality of battery cells into capacity, or can set a specific voltage section as a diagnostic section based on the second differentiation of the capacity of a plurality of battery cells into voltage.

[0055] The controller (120) can diagnose multiple battery cells in the diagnostic section. For example, the controller (120) can diagnose each of the multiple battery cells in the diagnostic section.

[0056] According to an embodiment, the controller (120) can calculate the partial capacity of each of the plurality of battery cells in the diagnosis section. In addition, the controller (120) can diagnose the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells. For example, the controller (120) can calculate the partial capacity of each of the plurality of battery cells through current integration. According to an embodiment, the current value required for current integration can be obtained from the information acquisition unit (110). As another example, the controller (120) can calculate the deviation of the partial capacity of each of the plurality of battery cells, and determine a battery cell with a deviation greater than or equal to a second value as an abnormal battery cell.

[0057] According to an embodiment, the controller (120) may calculate an average of the partial capacities of each of the plurality of battery cells, and may calculate a difference between the average of the partial capacities of each of the plurality of battery cells and the partial capacities of each of the plurality of battery cells. In this case, the controller (120) may determine a battery cell in which the difference is greater than or equal to a set value as an abnormal battery cell. As another example, the controller (120) may calculate a standard deviation of the partial capacities of each of the plurality of battery cells according to a normal distribution based on the average of the partial capacities of each of the plurality of battery cells, and may determine a battery cell in which the standard deviation is greater than or equal to a threshold value as an abnormal battery cell.

[0058] According to an embodiment, the controller (120) can diagnose that lithium deposition or tab disconnection has occurred in a battery cell in which the deviation of the partial capacity of each of the plurality of battery cells is greater than or equal to the second value.

[0059] A battery diagnostic device (100) according to one embodiment disclosed in this document can diagnose partial capacity reduction and lithium deposition of a battery cell based on a battery diagnostic technology utilizing differentiation.

[0060] A battery diagnostic device (100) according to one embodiment disclosed in this document can diagnose a battery cell or a battery pack based on field data of the battery.

[0061] FIG. 3a and FIG. 3b are diagrams showing examples of a battery diagnostic device according to one embodiment disclosed in the present document setting a diagnostic section.

[0062] Referring to FIGS. 3A and 3B, the information acquisition unit (110) of the battery diagnostic device (100) according to one embodiment disclosed in the present document can acquire the voltages (310, 320) of each of the plurality of battery cells. For example, the information acquisition unit (110) can acquire the voltage corresponding to the SOC of each of the plurality of battery cells being charged or discharged, or the SOC corresponding to the voltage.

[0063] The controller (120) of the battery diagnostic device (100) according to one embodiment disclosed in this document can calculate the voltage-capacity differential value based on the voltage (310) corresponding to the SOC of each of the plurality of battery cells or the SOC (320) corresponding to the voltage. For example, the controller (120) can calculate the voltage-capacity differential value (dQ / dV, 330) based on the voltage (310) corresponding to the SOC of each of the plurality of battery cells. As another example, the controller (120) can calculate the voltage-capacity differential value (dV / dQ, 350) based on the SOC (320) corresponding to the voltage of each of the plurality of battery cells.

[0064] According to an embodiment, the controller (120) can calculate the second derivative of the voltage-capacity derivative (dQ / dV, 330) and set at least a portion of a voltage range (340) in which the second derivative is less than or equal to a first value as a diagnostic range.

[0065] According to another embodiment, the controller (120) can calculate the second derivative of the voltage-capacity derivative (dV / dQ, 350) and set at least some of the SOC sections (360) in which the second derivative is less than or equal to the first value as a diagnostic section.

[0066] FIG. 4 is a flowchart illustrating an operating method of a battery diagnostic device according to one embodiment disclosed in this document. According to the embodiment, the operations illustrated in FIG. 4 may be performed through the battery diagnostic device (100) of FIG. 2.

[0067] Referring to FIG. 4, in operation 410, the information acquisition unit (110) may acquire voltages of a plurality of battery cells. According to an embodiment, the information acquisition unit (110) may acquire an open circuit voltage of each of the plurality of battery cells. According to another embodiment, the information acquisition unit (110) may acquire the voltage and accumulated current of each of the plurality of battery cells at each specific voltage increase section when charging the plurality of battery cells. According to yet another embodiment, the information acquisition unit (110) may acquire the voltage and accumulated current of each of the plurality of battery cells at each specific voltage decrease section when discharging the plurality of battery cells. According to an embodiment, the information acquisition unit (110) may further acquire the temperature of each of the plurality of battery cells.

[0068] In operation 420, the controller (120) may calculate a capacity-voltage second derivative with respect to the voltage of a plurality of battery cells. For example, the capacity-voltage second derivative may include either a value obtained by second differentiating capacity with respect to voltage or a value obtained by second differentiating voltage with respect to capacity. As another example, the controller (120) may calculate a capacity-voltage second derivative with respect to the voltage of a plurality of battery cells that are being charged or discharged.

[0069] According to an embodiment, the controller (120) can calculate a capacity-voltage differential value (dQ / dV) of the voltage of a plurality of battery cells being charged or discharged, and can calculate a capacity-voltage second differential value (d2Q / dV2) based on the capacity-voltage differential value (dQ / dV).

[0070] According to another embodiment, the controller (120) can calculate a capacity-voltage derivative (dV / dQ) of the voltage of a plurality of battery cells being charged or discharged, and can calculate a capacity-voltage second derivative (d2V / dQ2) based on the capacity-voltage derivative (dV / dQ).

[0071] According to an embodiment, the controller (120) can calculate the second derivative of the capacity voltage of each of the plurality of battery cells. According to another embodiment, the controller (120) can calculate the second derivative of the capacity voltage of the average of the voltages of each of the plurality of battery cells.

[0072] In operation 430, the controller (120) may set at least a portion of the SOC section or at least a portion of the voltage section in which the second derivative is less than or equal to a first value as a diagnostic section. For example, if the section in which the second derivative (d2V / dQ2) is less than or equal to the first value is from SOC 60 to SOC 80, the controller (120) may set a portion of the section from SOC 60 to SOC 80 as a diagnostic section. For another example, if the voltage section in which the second derivative (d2Q / dV2) is less than or equal to the first value is from 3.8 V to 4.1 V, the controller (120) may set a portion of the section from 3.8 V to 4.1 V as a diagnostic section.

[0073] According to an embodiment, the first value may be set to, but is not limited to, 0.1, and the first value may be set to specify a section in which the change in the capacity-voltage differential value is less than the set value.

[0074] According to an embodiment, the controller (120) may calculate the second derivative of the capacity voltage for each of the plurality of battery cells. In addition, the controller (120) may set a portion of the SOC section in which the second derivative of all of the plurality of battery cells is less than or equal to a first value as a diagnostic section. For example, the controller (120) may identify a section in which the second derivative of the capacity voltage of each of the plurality of battery cells is less than or equal to the first value, and set the overlapping section as a diagnostic section.

[0075] According to an embodiment, the controller (120) can calculate the voltage average of a plurality of battery cells. In addition, the controller (120) can calculate the second derivative of the capacity voltage with respect to the voltage average of the plurality of battery cells, and can set a part of the SOC section or voltage section in which the second derivative of the capacity voltage with respect to the voltage average of the plurality of battery cells is equal to or less than a first value as a diagnostic section.

[0076] That is, the controller (120) can set a specific SOC section as a diagnostic section based on the second differentiation of the voltage of a plurality of battery cells into capacity, or can set a specific voltage section as a diagnostic section based on the second differentiation of the capacity of a plurality of battery cells into voltage.

[0077] In operation 440, the controller (120) can diagnose multiple battery cells in the diagnostic section. For example, the controller (120) can diagnose each of the multiple battery cells in the diagnostic section.

[0078] FIG. 5 and FIG. 6 are flowcharts specifically showing an operation method of a battery diagnostic device according to one embodiment disclosed in this document.

[0079] Referring to FIG. 5, in operation 510, the controller (120) may calculate the partial capacity of each of the plurality of battery cells in the diagnostic section. For example, the controller (120) may calculate the partial capacity of each of the plurality of battery cells through current integration. According to an embodiment, the current value required for current integration may be acquired from the information acquisition unit (110).

[0080] In operation 520, the controller (120) can diagnose the plurality of battery cells based on the partial capacity of each of the plurality of battery cells produced.

[0081] Referring to FIG. 6, in operation 610, the controller (120) can calculate the deviation of the partial capacity of each of the plurality of battery cells.

[0082] In operation 620, the controller (120) can diagnose a battery cell with a deviation greater than or equal to the second value as an abnormal battery cell.

[0083] According to an embodiment, the controller (120) may calculate an average of the partial capacities of each of the plurality of battery cells, and may calculate a difference between the average of the partial capacities of each of the plurality of battery cells and the partial capacities of each of the plurality of battery cells. In this case, the controller (120) may determine a battery cell in which the difference is greater than or equal to a set value as an abnormal battery cell. As another example, the controller (120) may calculate a standard deviation of the partial capacities of each of the plurality of battery cells according to a normal distribution based on the average of the partial capacities of each of the plurality of battery cells, and may determine a battery cell in which the standard deviation is greater than or equal to a threshold value as an abnormal battery cell.

[0084] According to an embodiment, the controller (120) can diagnose that lithium deposition or tab disconnection has occurred in a battery cell in which the deviation of the partial capacity of each of the plurality of battery cells is greater than or equal to the second value.

[0085] According to an embodiment, operations 610 and 620 may be performed as included in operation 520 of FIG. 5.

[0086] FIG. 7 is a block diagram showing the hardware configuration of a computing system for performing an operating method of a battery diagnostic device according to one embodiment disclosed in this document.

[0087] Referring to FIG. 7, a computing system (1000) according to one embodiment disclosed in the present document may include an MCU (1010), a memory (1020), an input / output I / F (1030), and a communication I / F (1040).

[0088] The MCU (1010) may be a processor that executes various programs stored in the memory (1020) (e.g., a program for measuring voltages of multiple battery cells, a program for calculating second derivatives of capacity voltages of multiple battery cells, a program for setting diagnostic intervals of multiple battery cells, a program for calculating partial capacities and deviations of diagnostic intervals of multiple battery cells, etc.), and processes various information including voltages of multiple battery cells, second derivatives of capacity voltages of multiple battery cells, diagnostic intervals of multiple battery cells, partial capacities and deviations of diagnostic intervals of multiple battery cells, and diagnostic results of multiple battery cells, through these programs, and performs functions of the controller included in the battery diagnostic device illustrated in FIG. 2 described above.

[0089] The memory (1020) can store various programs, such as a plurality of battery cell voltage measurement programs, a plurality of battery cell capacity voltage second derivative calculation programs, a plurality of battery cell diagnostic section setting programs, and a plurality of battery cell diagnostic section partial capacity calculation and deviation calculation programs. In addition, the memory (1020) can store various information, including a plurality of battery cell voltages, a plurality of battery cell capacity voltage second derivatives, a plurality of battery cell diagnostic sections, a plurality of battery cell diagnostic section partial capacities and deviations, and a plurality of battery cell diagnostic results.

[0090] Such memories (1020) may be provided in multiple numbers as needed. The memories (1020) may be volatile memories or non-volatile memories. As volatile memories (1020), RAM, DRAM, SRAM, etc. may be used. As non-volatile memories (1020), ROM, PROM, EAROM, EPROM, EEPROM, flash memories, etc. may be used. The examples of the memories (1020) listed above are merely examples and are not limited to these examples.

[0091] The input / output I / F (1030) 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 (1010).

[0092] The communication I / F (1040) is a configuration capable of transmitting and receiving various data with the server, and may be various devices capable of supporting wired or wireless communication. For example, the battery diagnostic device can transmit and receive various information, including voltages of multiple battery cells, second derivatives of voltages of multiple battery cells, diagnosis sections of multiple battery cells, partial capacities and deviations of diagnosis sections of multiple battery cells, and diagnosis results of multiple battery cells, from a separately provided external server via the communication I / F (1040).

[0093] In this way, a computer program according to one embodiment disclosed in this document may be implemented as a module that is recorded in a memory (1020) and processed by an MCU (1010) to perform each function illustrated in FIG. 2, for example.

[0094] 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.

[0095] 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 acquires the voltage of multiple battery cells; and Calculate the second derivative of the capacity voltage for the voltage of the plurality of battery cells, A battery diagnostic device comprising a controller that sets at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative is less than or equal to a first value as a diagnostic section.

2. In paragraph 1, The above controller, A battery diagnostic device that diagnoses the plurality of battery cells in the above diagnostic section.

3. In paragraph 1, The above controller, In the above diagnostic section, the partial capacity of each of the plurality of battery cells is calculated, A battery diagnostic device that diagnoses a plurality of battery cells based on the partial capacity of each of the plurality of battery cells.

4. In paragraph 3, The above controller, A battery diagnostic device that calculates the partial capacity of each of the plurality of battery cells through current accumulation.

5. In paragraph 3, The above controller, Calculate the deviation of the partial capacity of each of the plurality of battery cells, A battery diagnostic device that diagnoses a battery cell with a deviation greater than or equal to a second value as an abnormal battery cell.

6. In paragraph 1, The above controller, Calculate the second derivative of the capacity voltage for each of the plurality of battery cells, A battery diagnostic device that sets at least a portion of the SOC section or at least a portion of the voltage section in which the second derivative of all of the plurality of battery cells is less than or equal to the first value as the diagnostic section.

7. In paragraph 1, The above controller, Calculate the average voltage of the above plurality of battery cells, Calculate the second derivative of the capacity voltage with respect to the voltage average of the above plurality of battery cells, A battery diagnostic device that sets at least a portion of the SOC section or at least a portion of the voltage section in which the second derivative of the capacity-voltage with respect to the voltage average of the plurality of battery cells is less than or equal to the first value as the diagnostic section.

8. In paragraph 1, A battery diagnostic device, wherein the voltage of the plurality of battery cells is an open circuit voltage of the plurality of battery cells.

9. An operation to obtain the voltage of multiple battery cells; An operation for calculating the second derivative of the capacity voltage with respect to the voltage of the plurality of battery cells; and An operating method of a battery diagnostic device, comprising: an operation of setting at least a portion of an SOC section or at least a portion of a voltage section in which the second derivative is less than or equal to a first value as a diagnostic section; 10. In paragraph 9, An operating method of a battery diagnostic device, further comprising: an operation of diagnosing the plurality of battery cells in the diagnostic section.

11. In paragraph 9, An operation of calculating the partial capacity of each of the plurality of battery cells in the above diagnostic section; and An operating method of a battery diagnosis device, further comprising: an operation of diagnosing a plurality of battery cells based on the partial capacity of each of the plurality of battery cells produced; 12. In paragraph 11, The operation of calculating the partial capacity of each of the plurality of battery cells in the above diagnostic section is: An operating method of a battery diagnostic device, which calculates the partial capacity of each of the plurality of battery cells through current accumulation.

13. In paragraph 11, The operation of diagnosing the plurality of battery cells based on the partial capacity of each of the plurality of battery cells calculated above is as follows: An operation for calculating the deviation of the partial capacity of each of the plurality of battery cells; and An operating method of a battery diagnosis device, comprising: an operation of diagnosing a battery cell having a deviation greater than or equal to a second value as an abnormal battery cell;

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