Battery diagnostic apparatus and method

Abstract

A battery diagnostic method according to an embodiment of the present application diagnoses a battery including a plurality of cells, and can include the steps of measuring a cell voltage at regular time intervals, calculating a cell voltage slope for each time section determined according to the regular time intervals, and determining whether to initiate one or more cell diagnostic procedures performed in a steady state of the cell voltage, according to a change trend of the cell voltage slope of each time section and the accumulated cell voltage slope.

Description

Technical Field

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2024-0137245, filed with the Korean Intellectual Property Office on October 10, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to apparatus and methods for diagnosing batteries, and more particularly, to apparatus and methods for determining the conditions for entering a diagnostic procedure when the battery is in a resting state. Background Technology

[0003] Rechargeable and reusable secondary batteries are manufactured into battery modules or battery packs by connecting multiple battery cells in series based on the required output capacity, and are used as power sources for a variety of applications. These batteries are used in small, high-tech electronic devices such as smartphones, as well as in various fields including electric bicycles, electric vehicles, and energy storage systems (ESS).

[0004] A battery pack is a structure comprising multiple battery cells. Overvoltage, overcurrent, and overheating in some battery cells can impair the safety and operational efficiency of the battery pack, making the detection of these defects necessary. Therefore, battery modules or battery packs are typically equipped with a Battery Management System (BMS), which measures the voltage of each battery cell and monitors and controls the voltage state of these cells based on these measurements. Batteries used in automobiles are also equipped with these BMSs.

[0005] Micro-short circuits are one of the faults detected by the BMS. A micro-short circuit within the battery can cause leakage current. In a battery pack containing multiple cells, if a micro-short circuit occurs within a single cell, causing leakage current, the voltage of that cell can gradually decrease compared to the voltages of the other cells. A sustained increase in voltage deviation between cells can cause inrush current, surge current, or overcurrent within the battery pack, potentially leading to hard short circuits such as sparking, overheating, and circuit damage.

[0006] Therefore, techniques used to diagnose micro-short circuits within batteries are commonly applied to the BMS (Battery Management System). The BMS uses cell voltage to diagnose micro-short circuits. Prerequisites for this diagnosis include checking whether the contactor is open or closed, and the time required for the cell voltage to stabilize.

[0007] However, when these prerequisites are met, the method of using cell voltage to diagnose micro-short circuits has limitations in terms of diagnostic opportunities and insufficient diagnostic accuracy.

[0008] Among the prior art documents related to this invention, 2020-0011014 is somewhat relevant. Summary of the Invention

[0009] Technical issues

[0010] To eliminate one or more problems of the related technologies, embodiments of this disclosure provide a method for determining the conditions for entering a diagnostic procedure when the battery is in a static state.

[0011] To eliminate one or more problems of the related technologies, embodiments of this disclosure also provide an apparatus using a battery diagnostic method.

[0012] Technical solution

[0013] To achieve the objectives of this disclosure, a method for diagnosing a battery comprising multiple cells may include the following steps: measuring cell voltage at predetermined time intervals; calculating cell voltage slope for each time segment determined based on the predetermined time intervals; and determining whether to initiate one or more cell diagnostic procedures performed under stable cell voltage conditions based on the cell voltage slope for each time segment and the cumulative variation pattern of the cell voltage slope.

[0014] The steps for determining whether to initiate a cell diagnostic procedure may include: determining whether the cell voltage slope decreases within a predetermined number or more consecutive time intervals; and determining whether the cell voltage slope is below a threshold in the last time interval.

[0015] The step of determining whether to initiate a cell diagnostic procedure may also include the following steps: if the cell voltage slope decreases during a predetermined number or more consecutive time intervals and the cell voltage slope of the last time interval is below a threshold, then it is determined that the cell diagnostic procedure should be initiated.

[0016] One or more cell diagnostic procedures that diagnose under stable cell voltage conditions may include diagnostics for detecting the occurrence of micro-short circuits within the cell.

[0017] The step of measuring cell voltage at predetermined time intervals may include the following steps: initiating cell voltage measurement upon receiving a signal indicating the termination of operation of a load connected to the battery.

[0018] Diagnostics used to detect the occurrence of micro-short circuits within a battery cell can include relaxation difference (delta) voltage diagnostics.

[0019] To achieve another objective of this disclosure, an apparatus for diagnosing a battery having multiple cells may include: at least one processor; and a memory configured to store at least one instruction executed by the at least one processor, wherein the at least one instruction may include: an instruction to measure cell voltage at predetermined time intervals; an instruction to calculate cell voltage slope for each time segment determined based on the predetermined time intervals; and an instruction to determine whether to initiate one or more cell diagnostic procedures to be executed in a stable cell voltage state based on the cell voltage slope of each time segment and the cumulative cell voltage slope variation pattern.

[0020] Instructions for determining whether to initiate one or more cell diagnostic procedures may include: instructions to determine whether the cell voltage slope decreases within a predetermined number or more consecutive time segments; and instructions to determine whether the cell voltage slope is below a threshold in the last time segment.

[0021] The instruction to determine whether to initiate one or more cell diagnostic procedures may also include: determining to initiate a cell diagnostic procedure if the cell voltage slope decreases during a predetermined number or more consecutive time segments and the cell voltage slope of the last time segment is below a threshold.

[0022] One or more cell diagnostic procedures that diagnose under stable cell voltage conditions may include diagnostics for detecting the occurrence of micro-short circuits within the cell.

[0023] Instructions for measuring cell voltage at predetermined time intervals may include: initiating cell voltage measurement upon receiving a signal indicating the termination of operation of a load connected to the battery.

[0024] Diagnostics used to detect micro-short circuits within battery cells can include relaxation difference voltage diagnostics.

[0025] Beneficial effects

[0026] According to embodiments of this disclosure, by actively and effectively determining whether the cell voltage is stable, the opportunity to perform battery diagnostics that can be performed when the battery is in an idle state can be more reliably ensured, and the accuracy of diagnostic performance can be improved. Attached Figure Description

[0027] Figure 1 An example of a battery pack structure to which embodiments of the present invention can be applied is shown.

[0028] Figure 2 This is a conceptual diagram illustrating an example of a battery pack installed in a vehicle, to which one of the applications of the present invention can be applied.

[0029] Figure 3This is a flowchart illustrating a general method for determining whether to initiate a battery diagnostic procedure.

[0030] Figure 4 This is a schematic flowchart illustrating a battery diagnostic method according to an embodiment of the present invention.

[0031] Figure 5 This is a detailed flowchart of a method for determining whether to initiate battery diagnostics according to an embodiment of the present invention.

[0032] Figure 6 This is a graph illustrating the concept of determining whether to perform a diagnostic based on the cell voltage slope and slope change pattern according to an embodiment of the present invention.

[0033] Figure 7 This is a block diagram of a battery diagnostic device according to an embodiment of the present invention.

[0034] 100: Battery; 121, 122: Contactor

[0035] 200: Battery Management System (BMS) 201: Microcontroller Unit (MCU)

[0036] 202: Memory; 300: Inverter

[0037] 700: Battery Diagnostic Equipment Detailed Implementation

[0038] This invention can be modified in various forms and has various embodiments, and specific embodiments thereof are illustrated by way of example in the accompanying drawings and will be described in detail below. However, it should be understood that the invention is not intended to be limited to the specific embodiments; rather, the invention is intended to cover all modifications, equivalents, and substitutions falling within the spirit and technical scope of the invention. Throughout the description of the drawings, the same reference numerals denote the same elements.

[0039] It should be understood that although terms such as first, second, A, B, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element without departing from the scope of the invention, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes a combination of or any one of the associated listed items.

[0040] It should be understood that when a component is referred to as "connected" or "attached" to another component, the component may be directly connected or attached to the other component, or there may be intermediate components. Conversely, when a component is referred to as "directly connected" or "directly attached" to another component, there are no intermediate components.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” “containing,” “covering,” and / or “having” as used herein specify the presence of stated features, integers, steps, operations, constituent elements, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, constituent elements, components, and / or combinations thereof.

[0042] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that 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 will not be interpreted in an idealized or overly formalized sense, unless expressly defined herein.

[0043] In the following, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0044] Figure 1 An example of a battery pack structure to which embodiments of the present invention can be applied is shown.

[0045] exist Figure 1 In this module, battery module 100 may include multiple battery cells connected in series and parallel. A battery cell is the basic unit for storing electricity, and a battery module can refer to an assembly of multiple electrically connected battery cells. The most commonly used battery cell is the lithium-ion (Li-Ion) battery cell.

[0046] A battery pack may include one or more battery modules, as well as the circuitry and control devices required to manage the battery cells and modules. The battery pack can be connected to a load via positive and negative terminals and perform charging and discharging operations. A battery management system (BMS) may be installed in each battery pack. The BMS 200 installed in each battery pack (e.g., a battery pack used in a vehicle) can monitor the current, voltage, and temperature of each battery pack under its control, calculate the state of charge (SOC) based on the monitoring results, and control charging and discharging. Here, SOC represents the current state of charge of the battery as a percentage [%).

[0047] To perform these operations, the BMS 200 may include various components such as fuses, current sensing elements, thermistors, switches, and balancers. The BMS 200 typically includes a microcontroller unit (MCU) 201 or a battery monitoring integrated chip (BMIC) for connecting to and controlling these components. Here, the BMIC can be an IC-type component located within the BMS and capable of measuring information such as the voltage, temperature, and current of the battery cells / modules.

[0048] BMS 200 may also include a memory 202 configured to store at least one command executed by MCU 201 and various data generated during BMS operation. Furthermore, the BMS can monitor battery cells, read cell voltages, and transmit this data to other systems connected to the battery. For this purpose, the BMS may include a communication module 203 for communicating with other systems within the device, including the battery system. The BMS's communication module can communicate with other systems within the device using a Controller Area Network (CAN). Here, components, modules, or systems within the BMS can be interconnected via a CAN bus.

[0049] The processor of the battery diagnostic device according to an embodiment of the present invention described below can be implemented as part of the battery pack BMS and integrated into the battery pack BMS.

[0050] Furthermore, the battery pack can drive the load by supplying power to the motor via inverter 300. Battery module 100 can be connected to or disconnected from the load via contactors 121 and 122. The contactors function as switches connecting the battery pack and the load and controlling the power supply, and may include a positive contactor 121 and a negative contactor 122. The positive contactor 121 can be located on the charging / discharging path connected to the positive terminal (+) of the battery pack, and the negative contactor 122 can be located on the charging / discharging path connected to the negative terminal (-) of the battery pack.

[0051] Figure 2 This is a conceptual diagram illustrating an example of a battery pack installed in a vehicle, to which one of the applications of the present invention can be applied.

[0052] The battery pack according to an embodiment of the present invention can be applied to a vehicle. The vehicle according to an embodiment of the present invention can be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. Here, the vehicle may include a four-wheeled vehicle or a two-wheeled vehicle. The battery pack supplies power to the motor via an inverter installed in the vehicle, thereby driving the vehicle.

[0053] Operating such a vehicle may require control operations such as motor drive control, regenerative braking control, air conditioning load control, and electrical load power (12V) supply control. (See reference...) Figure 2A vehicle may include multiple electronic control units (ECUs) for these control operations. Among these ECUs, the top-level controller that comprehensively oversees the operation and control of the vehicle can be called the vehicle control unit (VCU).

[0054] An ECU may include internal storage devices such as random access memory (RAM) and read-only memory (ROM). The RAM within the ECU temporarily stores various signals generated during vehicle operation. This stored data gradually decays over time and is completely lost if power is cut off. Conversely, the ROM within the ECU records the control data required to operate the vehicle, and this data cannot be arbitrarily erased or altered. When applied to electric vehicles (including hybrid vehicles), the ECU is sometimes called an electric control unit (EPCU), which controls the motors and the overall movement of the vehicle.

[0055] Furthermore, multiple ECUs within a vehicle can communicate with each other via the CAN bus. The Controller Area Network (CAN) protocol is a standard communication protocol designed for microcontrollers and other devices to communicate with each other without a master. CAN is a non-master, bus-type message-based network protocol primarily used for communication between controllers, and is mainly used in vehicles.

[0056] The CAN protocol uses a multi-master communication method, in which all CAN controllers share a communication bus. Figure 2 The ECU, VCU, and BMS in the system act as the master station, allowing each controller to use the CAN bus when desired. The CAN protocol also uses a message-oriented transmission protocol and two twisted pairs for electrical differentiation, which are highly resistant to electrical noise.

[0057] Furthermore, the battery pack, including battery module 100 and BMS 200, can be installed on the vehicle. BMS 200 can communicate with the vehicle's ECU and VCU using communication methods such as the CAN protocol. BMS 200 can report battery status information to the vehicle and control the connection between the vehicle and the battery based on vehicle operating information. When vehicle operation terminates, BMS 200 can receive a vehicle shutdown signal from the vehicle's ECU or VCU and stop supplying power to the vehicle from the battery module.

[0058] Here, contactors 121 and 122 connecting the battery module and the load are controlled to be in the off state, and the battery pack can perform various diagnostics to check the battery status during periods of rest or idleness.

[0059] Figure 3 This is a flowchart illustrating a general method for determining whether to initiate a battery diagnostic procedure.

[0060] For battery packs installed in vehicles, various diagnostics can be performed on the battery when it is not in use. (See reference...) Figure 3 When the battery pack receives a vehicle operation termination signal (S31), it determines whether the contactor connecting the battery to the vehicle body is open or closed (S32). Here, the vehicle operation termination signal may include a vehicle shutdown command or an engine stop signal.

[0061] If the contactor disconnects, it is determined whether the voltage stabilization time has elapsed (S33). Here, the voltage stabilization time is estimated as the time required for the battery voltage to stabilize after battery operation is terminated, and this time is a fixed value that can be preset by the user or administrator.

[0062] If it is determined that the voltage has been stable within a predetermined time period, the diagnostic start condition (S34) is activated. In other words, since the prerequisites for battery diagnostics have been met, the battery diagnostic program can be started. Here, battery diagnostics may include one or more cell diagnostic programs executed when the cell voltage is stable. A representative cell diagnostic is relaxation difference voltage diagnostics, which detects micro-short circuits within the cell.

[0063] Therefore, the prerequisites for initiating battery diagnostics typically include determining whether the contactor is closed or open and whether the voltage stabilization time has elapsed. However, there are cases where the contactor remains closed even after the vehicle's operation has ceased (e.g., when charging a 12V battery). In this situation, although the cell voltage is relatively stable, the prerequisites for performing battery diagnostics are not met, and therefore, battery diagnostics are not performed.

[0064] Furthermore, this method is disadvantageous in terms of accuracy because even though the cell voltage stability trend may vary depending on the battery environment, the method requires waiting for a fixed period of time before performing a diagnosis.

[0065] To address these issues, this invention proposes a more proactive and effective method for determining the stability of cell voltage.

[0066] Figure 4 This is a schematic flowchart illustrating a battery diagnostic method according to an embodiment of the present invention.

[0067] The battery diagnostic method according to embodiments of the present invention can be performed by a battery diagnostic device. The battery diagnostic device according to embodiments of the present invention may include a battery management system (BMS) for managing battery packs, or may include a portion of a BMS.

[0068] Reference Figure 4When the battery pack receives a signal indicating the termination of operation of the load connected to the battery (S410), the cell voltage can be measured at predetermined time intervals (S420). Here, the signal indicating the termination of operation of the load connected to the battery may include an operation termination signal of the vehicle equipped with the battery. In addition, the vehicle operation termination signal may include a vehicle shutdown command or an engine shutdown signal.

[0069] When measuring the cell voltage value at predetermined time intervals, the cell voltage slope can be calculated for each time segment determined by the predetermined time interval (S430). Here, the cell voltage slope calculated for each time segment can be defined as the ratio of the cell voltage measured in the current cycle to the cell voltage measured in the previous cycle.

[0070] When the cell voltage slope for each time period is calculated and a certain number of cycles are accumulated, it can be determined whether to initiate one or more cell diagnostic procedures that are executed under stable cell voltage conditions based on the cell voltage slope for each time period and the change pattern of the accumulated cell voltage slope (S440). If it is determined to initiate a cell diagnostic procedure, then a cell diagnostic procedure that can be executed under stable cell voltage conditions is initiated (S450). Here, the one or more cell diagnostic procedures that are performed under stable cell voltage conditions are diagnostic procedures that can be executed when the battery is in a static state, and may include diagnostics for detecting the occurrence of micro-short circuits within the cell. Furthermore, the diagnostics for detecting the occurrence of micro-short circuits within the cell may include relaxation difference voltage diagnostics.

[0071] In addition, relaxation difference voltage diagnosis can be performed, for example, by following these steps: calculating the voltage deviation between multiple battery cells, monitoring the pattern of voltage deviation changes, identifying the pattern of voltage deviation changes for each cell, and detecting defective cells exhibiting abnormal patterns.

[0072] Below Figure 5 The document describes in more detail the steps for determining whether to initiate one or more cell diagnostic procedures when the cell voltage is stable, based on the cell voltage slope and the cumulative pattern of cell voltage slope changes in each time period.

[0073] Figure 5 This is a detailed flowchart of a method for determining whether to initiate battery diagnostics according to an embodiment of the present invention.

[0074] Reference Figure 5The variable n, representing time segments divided by a predetermined time interval, is initialized (S510), and the cell voltage is measured at the predetermined time interval (S520). By measuring the cell voltage at the predetermined time interval, the cell voltage slope in the nth time segment can be calculated using the cell voltage measured in the (n-1)th time segment and the cell voltage measured in the nth time segment (S530).

[0075] Cell voltage measurement and slope calculation are performed within multiple consecutive time segments (S570). Once cell voltage measurement and slope calculation are completed within a predetermined number of time segments (N), it can be determined whether the measured voltage slope continuously decreases within the N consecutive time segments (S540). In one embodiment, the procedure for determining whether the measured voltage slope continuously decreases within the N consecutive time segments may include determining whether the slope has a negative value within the N consecutive time segments (i.e., whether the voltage value decreases in each segment). According to another embodiment, the procedure for determining whether the measured voltage slope continuously decreases within the N consecutive time segments may include the following process: determining whether the cell voltage slope not only has a negative value (i.e., the voltage value decreases) within the N consecutive time segments, but also whether the absolute value of the slope decreases with periodic repetition, i.e., whether the amount of voltage decrease gradually decreases with periodic repetition. Furthermore, it is determined whether the voltage slope in the last time segment in which cell voltage measurement and slope calculation are performed (i.e., the Nth measurement) is less than a threshold (S550). Here, N is a natural number that can be preset by the administrator or user.

[0076] although Figure 5 The flowchart shows that after determining whether the voltage slope decreases within a predetermined number of consecutive time intervals (S540), there is a step of comparing the voltage slope of the last iteration with a threshold (S550), but the order of these two steps can be interchanged. In other words, the step of comparing the voltage slope of the last iteration with the threshold (S550) can be performed first, and then the step of determining whether the voltage slope decreases within a predetermined number of consecutive time intervals (S540) can be performed.

[0077] According to an embodiment of the present invention, if the voltage slope decreases within a predetermined number of consecutive time intervals and the voltage slope of the last iteration is below a threshold, it can be determined to initiate a cell diagnostic procedure (S560).

[0078] Figure 6 This is a graph illustrating the concept of determining whether to perform a diagnostic based on the cell voltage slope and slope change pattern according to an embodiment of the present invention.

[0079] exist Figure 6In the graph, the x-axis represents time (s), and the y-axis represents cell voltage (V). Measurement points (T_0, T_1, T_2, T_3, T_4, T_5, T_6) for periodically measuring cell voltage are indicated on the x-axis. Using the first and second cell voltages measured at the two measurement points, the slope within the corresponding time interval can be calculated. Since this invention determines the decreasing trend based on the assumption of voltage decrease, the cell voltage slope here can be defined as the change in cell voltage within the interval T_(n-1) to T_(n) divided by the time from T_(n-1) to T_(n).

[0080] If the cell voltage slope in the first time interval (between T_0 and T_1) is slope 1 and the cell voltage slope in the second time interval (between T_1 and T_2) is slope 2, then slope 1 is positive and slope 2 is negative. In other words, the cell voltage increases in the first time interval and decreases in the second time interval. Subsequently, the cell voltage continues to decrease in the third, fourth, fifth, and sixth time intervals.

[0081] According to one embodiment of the invention, it is assumed that the number of time segments in which the continuous voltage slope decreases within a continuous time interval is set to four. Here, for example, if a decision on whether to perform battery diagnostics is made in the fourth time segment, such as... Figure 6 As shown in the curve, the cell voltage slope values ​​calculated in the first, second, third, and fourth time segments are all determined to be higher than the threshold used to start the battery cell diagnosis, preventing the diagnosis process from continuing.

[0082] As another example, consider the scenario where a decision to perform battery diagnostics is made in the sixth time segment. Here, the cell voltage slope is negative from the third to the sixth time segment, meaning the cell voltage decreases from the third to the sixth time segment. Furthermore, the absolute value of the slope continuously decreases throughout these time segments. In other words, not only is the voltage slope negative (i.e., the voltage decreases) across four consecutive time segments, but the absolute value of the slope also decreases with each iteration, meaning the magnitude of the voltage decrease gradually decreases with each iteration.

[0083] Furthermore, the slope in the sixth time segment was confirmed to be below a threshold, which is the condition for initiating battery cell diagnostics. Therefore, battery diagnostics can be initiated because the voltage decreases and the voltage slope decreases over a certain number of consecutive time segments, and the voltage slope in the last time segment is below the threshold.

[0084] Figure 7 This is a block diagram of a battery diagnostic device according to an embodiment of the present invention.

[0085] Reference Figure 7 A battery diagnostic device 700 according to an embodiment of the present invention may include a processor 710 and a memory 720 storing at least one instruction executed by the processor. Here, the processor may be, for example, a microcontroller unit (MCU) or another type of controller. The battery diagnostic device 700 may also be connected to one or more devices for measuring cell voltage and may receive cell voltage measurements from these devices.

[0086] Here, at least one instruction executed by the processor may include: an instruction to measure the cell voltage at predetermined time intervals; an instruction to calculate the cell voltage slope for each time segment determined based on the predetermined time intervals; and an instruction to determine whether to initiate one or more cell diagnostic procedures to be executed when the cell voltage is stable, based on the cell voltage slope of each time segment and the variation pattern of the accumulated cell voltage slope.

[0087] Instructions for determining whether to initiate one or more cell diagnostic procedures may include: instructions to determine whether the cell voltage slope decreases within a predetermined number or more consecutive time segments; and instructions to determine whether the cell voltage slope is below a threshold in the last time segment.

[0088] The instruction to determine whether to initiate one or more cell diagnostic procedures may also include: determining to initiate a cell diagnostic procedure if the cell voltage slope decreases during a predetermined number or more consecutive time segments and the cell voltage slope of the last time segment is below a threshold.

[0089] One or more cell diagnostic procedures that diagnose under stable cell voltage conditions may include diagnostics for detecting the occurrence of micro-short circuits within the cell.

[0090] Instructions for measuring cell voltage at predetermined time intervals may include: initiating cell voltage measurement upon receiving a signal indicating the termination of operation of a load connected to the battery.

[0091] Diagnostics used to detect micro-short circuits within battery cells can include relaxation difference voltage diagnostics.

[0092] The controller (e.g., processor 710) of the battery diagnostic device according to an embodiment of the present invention may be included and configured in the BMS. In other words, the controller of the battery diagnostic device according to an embodiment of the present invention may be an MCU within the BMS or another type of controller.

[0093] Furthermore, the battery diagnostic device 700 according to an embodiment of the present invention may also include an input interface device 740, an output interface device 750, a storage device 760, etc. The components included in the battery diagnostic device 700 can be connected via a bus 770 and can communicate with each other.

[0094] Furthermore, the memory 720 may include at least one of volatile storage media and non-volatile storage media. For example, the memory may include at least one of read-only memory (ROM) and random access memory (RAM), and may include electrically erasable programmable read-only memory (EEPROM).

[0095] According to the embodiments of the present invention described above, by actively and effectively determining whether the cell voltage is stable, the opportunity to perform battery diagnostics (which can be performed when the battery is in an idle state) can be more reliably ensured, and the accuracy of the diagnostics can be improved.

[0096] The operation of the method according to embodiments of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. This computer-readable recording medium includes all types of recording devices storing data readable by a computer system. Furthermore, the computer-readable recording medium can be distributed across network-connected computer systems to store and execute the computer-readable program or code in a distributed manner.

[0097] Although some aspects of the invention have been described in the context of a device, they may also refer to a description of a corresponding method, wherein a block or device corresponds to a method step or feature of a method step. Similarly, aspects described in the context of a method may also refer to features of a corresponding block or item or a corresponding device. Some or all of the method steps may be performed by (or using) hardware means such as a microprocessor, a programmable computer, or electronic circuitry. In some embodiments, one or more of the most important method steps may be performed by such a device.

[0098] In the foregoing, the present invention has been described with reference to exemplary embodiments thereof. However, those skilled in the art will understand that various modifications and changes may be made to the present invention within the scope of the appended claims without departing from the spirit and scope of the invention as described therein.

Claims

1. A method for diagnosing a battery, the battery comprising a plurality of cells, the method comprising the following steps: Measure cell voltage at predetermined time intervals; Calculate the cell voltage slope for each time segment determined based on the predetermined time interval; as well as Based on the cell voltage slope and the cumulative cell voltage slope variation pattern for each time period, determine whether to initiate one or more cell diagnostic procedures that are executed when the cell voltage is stable.

2. The method for diagnosing a battery according to claim 1, wherein, The steps to determine whether to initiate the cell diagnostic procedure include the following: Determine whether the cell voltage slope decreases within a predetermined number or more consecutive time intervals; and Determine whether the cell voltage slope is below a threshold in the last time segment.

3. The method for diagnosing a battery according to claim 2, wherein, The step of determining whether to initiate the cell diagnostic procedure also includes the following steps: If the cell voltage slope decreases during the predetermined number or more consecutive time intervals and the cell voltage slope in the last time interval is below the threshold, then the cell diagnostic procedure is initiated.

4. The method for diagnosing a battery according to claim 1, wherein, The one or more cell diagnostic procedures performed under the stable cell voltage state include diagnostics for detecting the occurrence of micro-short circuits within the cell.

5. The method for diagnosing a battery according to claim 1, wherein, The step of measuring the cell voltage at predetermined time intervals includes the following steps: Cell voltage measurement is initiated upon receiving a signal indicating that the operation of the load connected to the battery has terminated.

6. The method for diagnosing a battery according to claim 5, wherein, The signal indicating the termination of operation of the load connected to the battery includes a signal indicating the termination of operation of a vehicle equipped with the battery.

7. The method for diagnosing a battery according to claim 4, wherein, The diagnostics used to detect the occurrence of micro-short circuits within the battery cell include relaxation difference voltage diagnostics.

8. An apparatus for diagnosing a battery, the battery comprising a plurality of cells, the apparatus for diagnosing the battery comprising: At least one processor; as well as A memory configured to store at least one instruction executed by the at least one processor. Wherein, the at least one instruction includes: Instructions to measure cell voltage at predetermined time intervals; Instructions for calculating the cell voltage slope for each time segment determined based on the predetermined time interval; and Based on the cell voltage slope and the cumulative cell voltage slope variation pattern for each time period, determine whether to initiate an instruction to perform one or more cell diagnostic procedures when the cell voltage is stable.

9. The device for diagnosing batteries according to claim 8, wherein, The instructions for determining whether to initiate the diagnostic procedure for one or more cells include: An instruction to determine whether the cell voltage slope decreases within a predetermined number or more consecutive time intervals; and An instruction to determine whether the cell voltage slope is below a threshold in the last time segment.

10. The device for diagnosing batteries according to claim 9, wherein, The instruction for determining whether to initiate the one or more cell diagnostic procedures also includes: If the cell voltage slope decreases during the predetermined number or more consecutive time intervals and the cell voltage slope in the last time interval is below the threshold, then an instruction to initiate the cell diagnostic procedure is determined.

11. The device for diagnosing batteries according to claim 8, wherein, The one or more cell diagnostic procedures performed under the stable cell voltage state include diagnostics for detecting the occurrence of micro-short circuits within the cell.

12. The device for diagnosing batteries according to claim 8, wherein, The instruction to measure the cell voltage at predetermined time intervals includes: The instruction to initiate cell voltage measurement is received upon receiving a signal indicating that the operation of the load connected to the battery has been terminated.

13. The device for diagnosing batteries according to claim 12, wherein, The signal indicating the termination of operation of the load connected to the battery includes a signal indicating the termination of operation of a vehicle equipped with the battery.

14. The device for diagnosing batteries according to claim 11, wherein, The diagnostics used to detect the occurrence of micro-short circuits within the battery cell include relaxation difference voltage diagnostics.

15. A computer-readable medium having a program recorded thereon for performing on a computer the method for diagnosing a battery according to any one of claims 1 to 7.

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