Battery diagnostic device and method of operating the same

Abstract

A battery diagnostic device according to embodiments disclosed herein can include an information acquisition unit configured to acquire voltages of a plurality of battery cells, and a controller configured to calculate a capacity / voltage second derivative value with respect to the voltages of the plurality of battery cells, and set at least a portion of an SOC interval or at least a portion of a voltage interval, for which the second derivative value is less than or equal to a first value, as a diagnostic interval.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2024-0016646, filed on February 2, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments disclosed herein relate to battery diagnostic devices and their operating methods. Background Technology

[0004] In recent years, research and development of rechargeable batteries have been actively pursued. Here, rechargeable batteries refer to any rechargeable battery, encompassing all existing Ni / Cd batteries, Ni / MH batteries, and more recently, lithium-ion batteries. Among rechargeable batteries, lithium-ion batteries offer the advantage of significantly higher energy density than existing Ni / Cd and Ni / MH batteries. Furthermore, because lithium-ion batteries can be manufactured in small sizes and are lightweight, their use as power sources for mobile devices has expanded in recent years to include electric vehicles, making them a promising next-generation energy storage medium.

[0005] Methods for diagnosing electrode breakage and lithium deposition in batteries are essential for assessing battery performance and anomalies. While low-rate differential indexes can diagnose capacity and precipitation based on laboratory data, limitations exist when applying field data. Given the performance degradation or fire risks associated with batteries exhibiting electrode breakage and lithium deposition, a method capable of diagnosing battery anomalies based on field data is needed. Summary of the Invention

[0006] Technical issues

[0007] The embodiments disclosed herein relate to providing a battery diagnostic device and its operating method capable of immediately identifying abnormal signals by applying diagnostic techniques utilizing second-order derivatives to field data.

[0008] The embodiments disclosed herein also relate to providing a battery diagnostic device and its operating method capable of diagnosing the relative capacity deviation of battery cells in a battery pack by utilizing the second derivative of the open-circuit voltage instead of the first derivative.

[0009] The technical problems solved by the embodiments disclosed herein are not limited to those described above, and other purposes not mentioned will be clearly understood by those skilled in the art from the following description.

[0010] Technical solution

[0011] A battery diagnostic device according to an embodiment disclosed herein includes: an information acquisition unit configured to acquire the voltages of a plurality of battery cells; and a controller configured to: calculate the capacity / voltage second derivative of the voltages of the plurality of battery cells; and set at least a portion of a state of charge (SOC) range or at least a portion of a voltage range for which the second derivative is less than or equal to a first value as a diagnostic range.

[0012] In one implementation, the controller can diagnose the plurality of battery cells that are within the diagnostic range.

[0013] In one implementation, the controller can calculate a partial capacity of each of the plurality of battery cells within the diagnostic interval, and diagnose the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells.

[0014] In one implementation, the controller can calculate the partial capacity of each of the plurality of battery cells by accumulating current.

[0015] In one implementation, the controller can calculate the deviation of a portion of the capacity of each of the plurality of battery cells, and diagnose battery cells whose deviation is equal to or greater than a second value as abnormal battery cells.

[0016] In an implementation, the controller can calculate the capacity / voltage second derivative of each of the plurality of battery cells, and set at least a portion of the SOC range or at least a portion of the voltage range in which the second derivative of all battery cells in the plurality of battery cells is less than or equal to the first value as the diagnostic range.

[0017] In one implementation, the controller can calculate the average voltage of the plurality of battery cells, calculate the capacity / voltage second derivative with respect to the average voltage of the plurality of battery cells, and set at least a portion of the SOC interval or at least a portion of the voltage interval whose capacity / voltage second derivative with respect to the average voltage of the plurality of battery cells is less than or equal to the first value as the diagnostic interval.

[0018] In this embodiment, the voltage of the plurality of battery cells can be the open-circuit voltage of the plurality of battery cells.

[0019] It may include the operation method of the battery diagnostic device according to the embodiments disclosed herein.

[0020] In an implementation, the method may include: acquiring the voltage of a plurality of battery cells; calculating the capacity / voltage second derivative of the voltage of the plurality of battery cells; and setting at least a portion of the state of charge (SOC) range or at least a portion of the voltage range for which the second derivative is less than or equal to a first value as a diagnostic range.

[0021] In some embodiments, the method may further include diagnosing the plurality of battery cells that are within the diagnostic range.

[0022] In an implementation, the method may further include: calculating a partial capacity of each of the plurality of battery cells that is in the diagnostic range; and diagnosing the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells.

[0023] In one embodiment, when calculating the partial capacity of each of the plurality of battery cells in the diagnostic interval, the partial capacity of each of the plurality of battery cells can be calculated by current accumulation.

[0024] In one implementation, diagnosing the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells may include: calculating the deviation of the partial capacity of each of the plurality of battery cells; and diagnosing battery cells whose deviation is equal to or greater than a second value as abnormal battery cells.

[0025] Beneficial effects

[0026] The battery diagnostic apparatus and its operating method according to the embodiments disclosed herein can diagnose partial capacity reduction and lithium deposition in battery cells based on battery diagnostic techniques utilizing second-order differentials.

[0027] The battery diagnostic device and its operating method according to the embodiments disclosed herein can diagnose battery cells or battery packs based on field data of the battery.

[0028] In addition, various effects can be provided, either directly or indirectly, through this disclosure. Attached Figure Description

[0029] Figure 1 This is a block diagram illustrating the configuration of a general-purpose battery pack.

[0030] Figure 2 This is a diagram illustrating a battery diagnostic device according to an embodiment disclosed herein.

[0031] Figure 3a and Figure 3b This is a diagram illustrating an example of a battery diagnostic device with a diagnostic range set according to an embodiment disclosed herein.

[0032] Figure 4 This is a flowchart illustrating a method for operating a battery diagnostic device according to an embodiment disclosed herein.

[0033] Figure 5 and Figure 6 This is a flowchart specifically illustrating the operation method of a battery diagnostic device according to an embodiment disclosed herein.

[0034] Figure 7 This is a block diagram illustrating the hardware configuration of a computing system for performing a method for operating a battery diagnostic device according to an embodiment disclosed herein. Detailed Implementation

[0035] In the following, embodiments disclosed herein will be described in detail with reference to exemplary accompanying drawings. When adding reference numerals to components in each drawing, care should be taken to give the same components as many reference numerals as possible, even if they are shown in different drawings. Furthermore, in describing embodiments disclosed herein, detailed descriptions of related known configurations or functions are omitted when it is determined that such detailed descriptions hinder understanding of the embodiments disclosed herein.

[0036] Furthermore, in describing components of the embodiments disclosed herein, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are used only to distinguish components from other components, and the nature, order, or sequence of components is not limited by these terms. Moreover, unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments disclosed herein pertain. Terms (such as those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and unless expressly defined herein, they will not be construed as having an idealized or overly formal meaning.

[0037] Figure 1 This is a block diagram illustrating the configuration of a general-purpose battery pack.

[0038] Reference Figure 1 The diagram schematically illustrates a battery control system including a battery pack 1 according to an embodiment of the present invention and a higher-level controller 2 included in a higher-level system.

[0039] like Figure 1As shown, the battery pack 1 can be made of one or more battery cells and may include: a plurality of rechargeable battery cells 10; a switching unit 14 for controlling the charging and discharging current of the plurality of battery cells 10 by connecting in series to the positive (+) or negative (-) terminals of the plurality of battery cells 10; and a battery management system 20 for performing control and management by monitoring the voltage, current, temperature, etc. of the battery pack 1 to prevent overcharging, over-discharging, etc. In this case, multiple battery packs 1 equipped with multiple battery cells 10, sensors 12, switching unit 14 and battery management system 20 can be provided.

[0040] Here, the switching unit 14 is a device for controlling the charging or discharging current of the multiple battery cells 10, and for example, at least one relay, magnetic contactor, etc. can be used according to the specifications of the battery pack 1.

[0041] The battery management system 20 may be an interface for receiving values ​​obtained by measuring the various parameters described above, and may include multiple terminals, circuitry connected to the terminals for processing input values, etc. Furthermore, the battery management system 20 may control the on / off switching of the switching unit 14 (e.g., a relay, contactor, etc.), and may be connected to multiple battery cells 10 to monitor the state of each of the multiple battery cells 10. According to this embodiment, the battery management system 20 may include... Figure 2 The battery diagnostic device 100 is included. In another embodiment, the battery management system 20 can be integrated with... Figure 2 The battery diagnostic device in the system has 100 different systems. That is to say, Figure 2 The battery diagnostic device 100 can be included in the battery pack 1 or configured as another device outside the battery pack 1. Furthermore, the operation of the battery diagnostic device 100 can be performed by the battery management system (BMS) in the vehicle and various devices such as servers, cloud, chargers, or charger / dischargers.

[0042] The upper-level controller 2 can transmit control signals for multiple battery cells 10 to the battery management system 20. Therefore, the battery management system 20 can be controlled based on the signals received from the upper-level controller 2.

[0043] Figure 2 This is a diagram illustrating a battery diagnostic device according to an embodiment disclosed herein.

[0044] The battery diagnostic device 100 can be any electronic device used for diagnosing or testing a battery. For example, the battery diagnostic device 100 can be included in the battery management system (BMS) within a vehicle, but it can also be implemented as a separate external device different from the BMS within the vehicle.

[0045] According to another embodiment, the battery diagnostic device 100 may be included in a device for charging / discharging testing, such as a server, cloud server, or charge / discharge cycler, or may be included in various devices for diagnosing or testing batteries.

[0046] refer to Figure 2 The battery diagnostic device 100 may include an information acquisition unit 110 and a controller 120.

[0047] The information acquisition unit 110 can acquire the voltages of multiple battery cells. According to this embodiment, the information acquisition unit 110 can acquire the open-circuit voltage of each of the multiple battery cells. According to another embodiment, when charging the multiple battery cells, the information acquisition unit 110 can acquire the voltage and accumulated current of each of the multiple battery cells at each specific voltage increase range. According to yet another embodiment, when discharging the multiple battery cells, the information acquisition unit 110 can acquire the voltage and accumulated current of each of the multiple battery cells at each specific voltage decrease range. According to this embodiment, the information acquisition unit 110 can also acquire the temperature of each of the multiple battery cells.

[0048] The controller 120 can calculate the capacity / voltage second derivative of the voltage of multiple battery cells. For example, the capacity / voltage second derivative may include the capacity relative to voltage or the voltage relative to capacity. As another example, the controller 120 can calculate the capacity / voltage second derivative of the voltage of multiple battery cells that are being charged or discharged.

[0049] According to the implementation, the controller 120 can calculate the capacity / voltage derivative (dQ / dV) relative to the voltage of a plurality of battery cells that are being charged or discharged, and can calculate the capacity / voltage second derivative (d2Q / dV2) based on the capacity / voltage derivative (dQ / dV).

[0050] According to another embodiment, the controller 120 can calculate the capacity / voltage derivative (dV / dQ) relative to the voltage of a plurality of battery cells being charged or discharged, and can calculate the capacity / voltage second derivative (d2V / dQ2) based on the capacity / voltage derivative (dV / dQ).

[0051] According to this embodiment, the controller 120 can calculate the second-order derivative of the capacity / voltage of each of the plurality of battery cells. According to another embodiment, the controller 120 can calculate the second-order derivative of the capacity / voltage of the average voltage of each of the plurality of battery cells.

[0052] The controller 120 can set at least a portion of the SOC range or at least a portion of the voltage range where the second derivative value is less than or equal to a first value as a diagnostic range. For example, when the range where the second derivative value (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 range from SOC 60 to SOC 80 as a diagnostic range. As another example, when the voltage range where the second derivative value (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 range from 3.8 V to 4.1 V as a diagnostic range.

[0053] According to this implementation, the first value can be set to 0.1, etc., but is not limited to this, and the first value can be set to a range in which the change in the specified capacity / voltage differential value is less than a set value.

[0054] According to this embodiment, the controller 120 can calculate the second derivative of the capacity / voltage for each of the plurality of battery cells. Furthermore, the controller 120 can set a portion of the SOC (State of Charge) interval where the second derivative of all the plurality of battery cells is less than or equal to a first value as a diagnostic interval. For example, the controller 120 can examine the interval where the second derivative of the capacity / voltage for each of the plurality of battery cells is less than or equal to the first value, and set the overlapping interval as a diagnostic interval.

[0055] According to this embodiment, the controller 120 can calculate the average voltage of multiple battery cells. Furthermore, the controller 120 can calculate the capacity / voltage second derivative with respect to the average voltage of the multiple battery cells, and can set a portion of the SOC range or voltage range where the capacity / voltage second derivative with respect to the average voltage of the multiple battery cells is less than or equal to a first value as a diagnostic range.

[0056] In other words, the controller 120 can set a specific SOC range as a diagnostic range based on a value obtained by second-differentiating the voltage of multiple battery cells relative to the capacity, or set a specific voltage range as a diagnostic range based on a value obtained by second-differentiating the capacity of multiple battery cells relative to the voltage.

[0057] The controller 120 can diagnose multiple battery cells that are in the diagnostic range. For example, the controller 120 can diagnose each of the multiple battery cells that are in the diagnostic range.

[0058] According to an embodiment, the controller 120 can calculate the partial capacity of each of a plurality of battery cells within a diagnostic range. Furthermore, 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 by current accumulation. According to an embodiment, the current value required for current accumulation 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 identify battery cells with deviations equal to or greater than a second value as abnormal battery cells.

[0059] According to an implementation, the controller 120 can calculate the average partial capacity of each of the multiple battery cells, and can also calculate the difference between the average partial capacity of each of the multiple battery cells and the partial capacity of each of the multiple battery cells. In this case, the controller 120 can identify a cell whose difference is equal to or greater than a set value as an abnormal cell. Alternatively, the controller 120 can calculate the standard deviation of the partial capacity of each of the multiple battery cells based on the average partial capacity of each of the multiple battery cells according to a normal distribution, and can identify battery cells whose standard deviation is equal to or greater than a threshold as abnormal battery cells.

[0060] According to the implementation, the controller 120 can diagnose a battery cell in which the deviation of a portion of the capacity of each of the plurality of battery cells is equal to or greater than a second value as a battery that has experienced lithium deposition or tab breakage.

[0061] The battery diagnostic device 100 according to the embodiments disclosed herein can diagnose partial capacity reduction and lithium deposition in battery cells based on differential battery diagnostic technology.

[0062] The battery diagnostic device 100 according to the embodiments disclosed herein can diagnose battery cells or battery packs based on field data of the battery.

[0063] Figure 3a and Figure 3b This is a view illustrating an example of setting diagnostic intervals in a battery diagnostic device according to an embodiment disclosed herein.

[0064] refer to Figure 3a and Figure 3b According to the embodiments disclosed herein, the information acquisition unit 110 of the battery diagnostic apparatus 100 can acquire the voltages 310 and 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 that is being charged or discharged, or the SOC corresponding to the voltage.

[0065] The controller 120 of the battery diagnostic device 100 according to the embodiments disclosed herein can calculate a voltage / capacity differential value based on a voltage 310 corresponding to the SOC of each of the plurality of battery cells or a SOC 320 corresponding to the voltage. For example, the controller 120 can calculate a voltage / capacity differential value (dQ / dV) 330 based on a voltage 310 corresponding to the SOC of each of the plurality of battery cells. As another example, the controller 120 can calculate a voltage / capacity differential value (dV / dQ) 350 based on a SOC 320 corresponding to the voltage of each of the plurality of battery cells.

[0066] According to this embodiment, the controller 120 can calculate the second derivative of the voltage / capacity differential value (dQ / dV) 330, and set at least a portion of the voltage range 340 in which the second derivative value is less than or equal to the first value as a diagnostic range.

[0067] According to another embodiment, the controller 120 can calculate the second derivative of the voltage / capacity differential (dV / dQ) 350, and set at least a portion of the SOC interval 360 in which the second derivative is less than or equal to the first value as a diagnostic interval.

[0068] Figure 4 This is a flowchart illustrating a method for operating a battery diagnostic device according to an embodiment disclosed herein. According to this embodiment, Figure 4 The operation shown can be performed by Figure 2 The battery diagnostic device 100 in the middle is used to perform the operation.

[0069] refer to Figure 4 In operation 410, the information acquisition unit 110 can acquire the voltages of multiple battery cells. According to this embodiment, the information acquisition unit 110 can acquire the open-circuit voltage of each of the multiple battery cells. According to another embodiment, the information acquisition unit 110 can acquire the voltage and accumulated current of each of the multiple battery cells at each specific voltage increase range when charging the multiple battery cells. According to yet another embodiment, the information acquisition unit 110 can acquire the voltage and accumulated current of each of the multiple battery cells at each specific voltage decrease range when discharging the multiple battery cells. According to this embodiment, the information acquisition unit 110 can also acquire the temperature of each of the multiple battery cells.

[0070] In operation 420, controller 120 can calculate the capacity / voltage second derivative of the voltage of multiple battery cells. For example, the capacity / voltage second derivative may include the capacity second derivative with respect to voltage or the voltage second derivative with respect to capacity. As another example, controller 120 can calculate the capacity / voltage second derivative of the voltage of multiple battery cells that are being charged or discharged.

[0071] According to the implementation, the controller 120 can calculate the capacity / voltage derivative (dQ / dV) relative to the voltage of a plurality of battery cells that are being charged or discharged, and can calculate the capacity / voltage second derivative (d2Q / dV2) based on the capacity / voltage derivative (dQ / dV).

[0072] According to another embodiment, the controller 120 can calculate the capacity / voltage derivative (dV / dQ) relative to the voltage of a plurality of battery cells being charged or discharged, and can calculate the capacity / voltage second derivative (d2V / dQ2) based on the capacity / voltage derivative (dV / dQ).

[0073] According to this embodiment, the controller 120 can calculate the second-order derivative of the capacity / voltage of each of the plurality of battery cells. According to another embodiment, the controller 120 can calculate the second-order derivative of the capacity / voltage of the average voltage of each of the plurality of battery cells.

[0074] In operation 430, controller 120 may set at least a portion of the SOC range or at least a portion of the voltage range in which the second derivative value is less than or equal to the first value as a diagnostic range. For example, when the range in which the second derivative value (d²V / dQ²) is less than or equal to the first value is from SOC 60 to SOC 80, controller 120 may set a portion of the range from SOC 60 to SOC 80 as a diagnostic range. As another example, when the voltage range in which the second derivative value (d²Q / dV²) is less than or equal to the first value is from 3.8 V to 4.1 V, controller 120 may set a portion of the range from 3.8 V to 4.1 V as a diagnostic range.

[0075] According to this implementation, the first value can be set to 0.1, etc., but is not limited to this, and the first value can be set to a range in which the change in the specified capacity / voltage differential value is less than a set value.

[0076] According to this embodiment, the controller 120 can calculate the second derivative of the capacity / voltage for each of the plurality of battery cells. Furthermore, the controller 120 can set a portion of the SOC (State of Charge) interval where the second derivative of all the plurality of battery cells is less than or equal to a first value as a diagnostic interval. For example, the controller 120 can examine the interval where the second derivative of the capacity / voltage for each of the plurality of battery cells is less than or equal to the first value, and set the overlapping interval as a diagnostic interval.

[0077] According to this embodiment, the controller 120 can calculate the average voltage of multiple battery cells. Furthermore, the controller 120 can calculate the capacity / voltage second derivative with respect to the average voltage of the multiple battery cells, and can set a portion of the SOC range or voltage range where the capacity / voltage second derivative with respect to the average voltage of the multiple battery cells is less than or equal to a first value as a diagnostic range.

[0078] In other words, the controller 120 can set a specific SOC range as a diagnostic range based on a value obtained by second-differentiating the voltage of multiple battery cells relative to the capacity, or set a specific voltage range as a diagnostic range based on a value obtained by second-differentiating the capacity of multiple battery cells relative to the voltage.

[0079] In operation 440, controller 120 can diagnose multiple battery cells that are within the diagnostic range. For example, controller 120 can diagnose each of the multiple battery cells that are within the diagnostic range.

[0080] Figure 5 and Figure 6 This is a flowchart specifically illustrating the operation method of a battery diagnostic device according to an embodiment disclosed herein.

[0081] refer to Figure 5 In operation 510, the controller 120 can calculate the partial capacity of each of the multiple battery cells in the diagnostic range. For example, the controller 120 can calculate the partial capacity of each of the multiple battery cells by current accumulation. According to this embodiment, the current value required for current accumulation can be obtained from the information acquisition unit 110.

[0082] In operation 520, controller 120 can diagnose multiple battery cells based on the calculated partial capacity of each of the multiple battery cells.

[0083] refer to Figure 6 In operation 610, controller 120 can calculate the deviation of a portion of the capacity of each of the multiple battery cells.

[0084] In operation 620, controller 120 can diagnose battery cells with deviations equal to or greater than the second value as abnormal battery cells.

[0085] According to this embodiment, the controller 120 can calculate the average of the partial capacity of each of the multiple battery cells, and can calculate the difference between the average of the partial capacity of each of the multiple battery cells and the partial capacity of each of the multiple battery cells. In this case, the controller 120 can set the difference to be equal to or greater than a set value. electricity The cell is identified as an abnormal cell. For example, the controller 120 can calculate the standard deviation of the partial capacity of each of the multiple battery cells according to a normal distribution based on the average of the partial capacity of each of the multiple battery cells, and can identify battery cells whose standard deviation is equal to or greater than a threshold as abnormal battery cells.

[0086] According to this embodiment, the controller 120 can diagnose a battery cell in which the deviation of a portion of the capacity of each of the plurality of battery cells is equal to or greater than a second value as a battery that has experienced lithium deposition or tab breakage.

[0087] According to the implementation method, operations 610 and 620 can be performed as follows: Figure 5 Perform as described in operation 520.

[0088] Figure 7 This is a block diagram illustrating the hardware configuration of a computing system for performing a method for operating a battery diagnostic device according to an embodiment disclosed herein.

[0089] refer to Figure 7 The computing system 1000 according to the embodiments disclosed herein may include a microcontroller unit (MCU) 1010, a memory 1020, an input / output interface (I / F) 1030, and a communication I / F 1040.

[0090] MCU 1010 can be a processor that executes various programs stored in memory 1020 (e.g., programs for measuring the voltage of multiple battery cells, programs for calculating the second derivative of the capacity / voltage of multiple battery cells, programs for setting the diagnostic range of multiple battery cells, programs for calculating the partial capacity and deviation of the diagnostic range of multiple battery cells, etc.). It processes various information through these programs, including the voltage of multiple battery cells, the second derivative of the capacity / voltage of multiple battery cells, the diagnostic range of multiple battery cells, the partial capacity and deviation of the diagnostic range of multiple battery cells, the diagnostic results of multiple battery cells, etc., and executes the functions described above. Figure 2 The function of the controller in the battery diagnostic device shown.

[0091] The memory 1020 can store various programs, such as programs for measuring the voltage of multiple battery cells, programs for calculating the second derivative of the capacity / voltage of multiple battery cells, programs for setting diagnostic intervals for multiple battery cells, and programs for calculating partial capacity and deviation within the diagnostic intervals of multiple battery cells. Furthermore, the memory 1020 can store various information, including the voltage of multiple battery cells, the second derivative of the capacity / voltage of multiple battery cells, the diagnostic intervals of multiple battery cells, partial capacity and deviation within the diagnostic intervals of multiple battery cells, and the diagnostic results of multiple battery cells.

[0092] Multiple memories 1020 can be provided as needed. Memory 1020 can be volatile or non-volatile memory. As volatile memory, memory 1020 can be random access memory (RAM), dynamic RAM (DRAM), static RAM (SRAM), etc. As non-volatile memory, memory 1020 can be read-only memory (ROM), programmable ROM (PROM), electrically variable ROM (EAROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, etc. The examples of memory 1020 listed above are merely exemplary and are not limited to these examples.

[0093] The Input / Output I / F 1030 provides an interface for connecting input devices (not shown), such as keyboards, mice, touch panels, etc., and output devices (not shown), such as displays, to the MCU 1010 to enable data transmission and reception.

[0094] The Communication I / F 1040 is a component capable of sending and receiving various data from a server, and can be any device supporting wired or wireless communication. For example, a battery diagnostic device can use the Communication I / F 1040 to send and receive various information from a separately provided external server, including the voltage of multiple battery cells, the second-order derivative of the capacity / voltage of multiple battery cells, the diagnostic range of multiple battery cells, partial capacity and deviation within the diagnostic range of multiple battery cells, and the diagnostic results of multiple battery cells, etc.

[0095] By recording in memory 1020 in this manner and processing by MCU 1010, a computer program according to the embodiments disclosed herein can be implemented to, for example, execute... Figure 2 The modules for each function are shown.

[0096] The above description is merely an example of the technical concept disclosed herein, and those skilled in the art to which the embodiments disclosed herein pertain can make various modifications and changes without departing from the basic characteristics of the embodiments disclosed herein.

[0097] Therefore, the embodiments disclosed herein are not intended to limit the technical concepts disclosed herein, but rather to interpret them, and the scope of the technical concepts disclosed herein is not limited by these embodiments. The scope of protection disclosed herein should be interpreted by the appended claims, and all technical ideas within the equivalent scope should be interpreted as included within the scope of the claims herein.

Claims

1. A battery diagnostic device, the battery diagnostic device comprising: An information acquisition unit is configured to acquire the voltage of multiple battery cells; as well as Controller, the controller is configured to: Calculate the capacity / voltage second-order derivative of the voltage of the plurality of battery cells; and At least a portion of the State of Charge (SOC) range or at least a portion of the voltage range whose second-order differential value is less than or equal to the first value is set as the diagnostic range.

2. The battery diagnostic device according to claim 1, wherein, The controller diagnoses the plurality of battery cells that are in the diagnostic range.

3. The battery diagnostic device according to claim 1, wherein, The controller: Calculate the partial capacity of each of the plurality of battery cells within the diagnostic range; and The plurality of battery cells are diagnosed based on the calculated partial capacity of each of the plurality of battery cells.

4. The battery diagnostic device according to claim 3, wherein, The controller calculates the partial capacity of each of the plurality of battery cells by accumulating current.

5. The battery diagnostic device according to claim 3, wherein, The controller: Calculate the deviation of a portion of the capacity of each of the plurality of battery cells; and Battery cells with deviations equal to or greater than the second value are diagnosed as abnormal battery cells.

6. The battery diagnostic device according to claim 1, wherein, The controller: Calculate the second-order derivative of the capacity / voltage for each of the plurality of battery cells; and The diagnostic interval is defined as at least a portion of the SOC interval or at least a portion of the voltage interval in which the second derivative value of all battery cells in the plurality of battery cells is less than or equal to the first value.

7. The battery diagnostic device according to claim 1, wherein, The controller: Calculate the average voltage of the plurality of battery cells; Calculate the second-order capacity / voltage derivative with respect to the average voltage of the plurality of battery cells; and The diagnostic interval is defined as at least a portion of the SOC interval or at least a portion of the voltage interval in which the capacity / voltage second derivative value relative to the average voltage of the plurality of battery cells is less than or equal to the first value.

8. The battery diagnostic device according to claim 1, wherein, The voltage of the plurality of battery cells is the open-circuit voltage of the plurality of battery cells.

9. A method for operating a battery diagnostic device, the method comprising the following steps: Obtain the voltage of multiple battery cells; Calculate the capacity / voltage second derivative of the voltage of the plurality of battery cells; as well as At least a portion of the State of Charge (SOC) range or at least a portion of the voltage range whose second-order differential value is less than or equal to the first value is set as the diagnostic range.

10. The operating method according to claim 9, further comprising the following steps: Diagnose the plurality of battery cells that are within the diagnostic range.

11. The operating method according to claim 9, further comprising the following steps: Calculate the partial capacity of each of the plurality of battery cells that are in the diagnostic range; as well as The plurality of battery cells are diagnosed based on the calculated partial capacity of each of the plurality of battery cells.

12. The operating method according to claim 11, wherein, When calculating the partial capacity of each of the plurality of battery cells within the diagnostic range, the partial capacity of each of the plurality of battery cells is calculated by current accumulation.

13. The operating method according to claim 11, wherein, The steps for diagnosing the plurality of battery cells based on the calculated partial capacity of each of the plurality of battery cells include: Calculate the deviation of a portion of the capacity of each of the plurality of battery cells; and Battery cells with deviations equal to or greater than the second value are diagnosed as abnormal battery cells.

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