Method for detecting states of battery and battery management system performing the method

Abstract

One embodiment provides a battery state measurement method and a battery management system for predicting the point in time when the battery's charging capacity decreases relatively rapidly. A battery state measurement method may include the step of monitoring a change in at least one precursor related to the charge capacity of the battery with respect to the number of charge cycles performed for the battery, and the step of predicting that a rapid decrease in the charge capacity of the battery is imminent if the change in the at least one precursor follows at least one pre-configuration pattern for the battery that has undergone a critical number of charge cycles.

Description

Technology Field

[0001] The technical concept of the present disclosure generally relates to a battery condition measurement method and a battery management system, and more specifically, to a battery condition measurement method and a battery management system capable of predicting a rapid decrease in the battery's charge capacity by monitoring the change pattern of at least one precursor with respect to the battery's charge capacity. Background Technology

[0002] Currently, there is a growing trend of using rechargeable batteries as a power source for an increasing number of electronic devices and electric vehicles. As rechargeable batteries are applied to many electronic devices and electric vehicles, their reliability can be critical. The phenomenon known as "sudden death" is known, in which the battery suddenly stops operating due to a rapid decrease in its charge capacity. This sudden death phenomenon can be a major cause of reduced reliability in rechargeable batteries.

[0003] As the use of electronic devices and electric vehicles increases, the number of charge-discharge cycles performed on the batteries of these devices and electric vehicles is also increasing. The charge capacity of a battery gradually decreases as charge-discharge cycles progress. The rate of decrease in battery charge capacity and the current charge capacity can be indicated using State of Health (SoH).

[0004] However, it is known that when a battery's charge capacity drops below a certain level, the battery's charge capacity decreases rapidly. Therefore, all batteries may exhibit a sudden death phenomenon due to a rapid decrease in charge capacity, which can interfere with the operation of electronic devices and electric vehicles.

[0005] Methods used to detect a rapid loss of battery charge capacity include SoH and RUL (Remaining Useful Life) prediction. When using SoH and RUL methods, it is highly likely that a rapid decrease in battery charge capacity will be detected only when the moment of the battery's 'sudden death' is approaching. Such methods may not provide the user with sufficient time to initiate corrective actions, such as modifying usage patterns or replacing the battery.

[0006] Detecting a rapid decrease in battery charge capacity well in advance of the moment of sudden death may require sophisticated battery analysis, extensive crunching, and specialized measurement methods. Such sophisticated analysis, crunching, and specialized measurement methods require significant power and computational capabilities. Therefore, detecting a rapid decrease in battery charge capacity online (in electronic devices or within electric vehicles) may not be practical. The problem to be solved

[0007] According to various embodiments of the present disclosure, a battery condition measurement method and a battery management system are provided for predicting the occurrence of a rapid decrease in the charging capacity of a battery provided in a device / vehicle sufficiently prior to a point in time when the battery may become inoperable.

[0008] According to various embodiments of the present disclosure, a battery condition measurement method and a battery management system are provided that predict a rapid decrease in the charge capacity of a battery and generate a warning signal indicating such decrease.

[0009] According to various embodiments of the present disclosure, the present invention aims to provide a battery status measurement method and a battery management system capable of predicting the occurrence of a sudden decrease in battery charge capacity based on real-time monitoring of the change pattern of a precursor regarding the battery charge capacity, thereby providing the user with sufficient time to take corrective measures to prevent a sudden death phenomenon of the battery. means of solving the problem

[0010] One embodiment is,

[0011] A battery condition measurement method is provided to predict the point at which the battery's charging capacity decreases relatively rapidly.

[0012] The battery state measurement method described above may include the steps of monitoring a change pattern of at least one precursor related to the charge capacity of the battery with respect to the number of charge cycles performed for the battery, and predicting that a rapid decrease in the charge capacity of the battery is imminent if the change pattern of the at least one precursor follows at least one pre-configured pattern for the battery that has undergone a critical number of charge cycles.

[0013] The above at least one precursor may include the first derivative and second derivative of the charge capacity of the battery with respect to the number of additional charge cycles performed for the battery after a reference number of charge cycles has been performed for the battery, and the effective life of the battery related to the number of charge cycles during which the battery can be maintained in an operable state.

[0014] In the step of predicting that a rapid decrease in the charging capacity of the battery is imminent, if the change pattern of at least one of the first derivative and the second derivative of the charging capacity of the battery follows at least one pre-configured pattern, it can be predicted that a rapid decrease in the charging capacity of the battery is imminent.

[0015] The at least one pre-configured pattern that follows at least one of the first derivative and second derivative change patterns may include a pattern of decreasing and then increasing.

[0016] In the step of predicting that a rapid decrease in the charging capacity of the battery is imminent, if the change pattern of the effective life of the battery follows at least one pre-configured pattern, it can be predicted that a rapid decrease in the charging capacity of the battery is imminent.

[0017] The at least one pre-configured pattern that follows the change pattern of the effective life of the battery may include a pattern that increases and then decreases.

[0018] The battery status measurement method described above may further include the step of generating at least one warning signal indicating that a rapid decrease in the charging capacity of the battery is imminent.

[0019] The step of generating the above warning signal may be achieved through at least one of displaying a warning message indicating that the battery is in an unreliable state and suggesting at least one corrective action to delay the initiation of a rapid decrease in the battery's charge capacity.

[0020] Another example is,

[0021] A battery state measurement method is provided, comprising the steps of: estimating the charge capacity of the battery using real-time charge / discharge data of the battery; calculating the first derivative of the estimated charge capacity of the battery; calculating the second derivative of the estimated charge capacity of the battery; calculating the effective life of the estimated charge capacity of the battery; monitoring a change pattern of at least one of the first derivative, the second derivative, and the effective life of the charge capacity of the battery; and generating a decision indicating a point in time when the charge capacity of the battery rapidly decreases based on the change pattern of at least one of the values.

[0022] Another example is,

[0023] A battery management system is provided that predicts the point at which the battery's charging capacity decreases relatively rapidly.

[0024] The above battery management system may include at least one battery and a processor for measuring the state of the battery.

[0025] The processor may be configured to monitor a change pattern of at least one precursor related to the charge capacity of the battery with respect to the number of charge cycles performed for the battery, and to predict that a rapid decrease in the charge capacity of the battery is imminent if the change of the at least one precursor follows at least one pre-configured pattern for the battery that has undergone a critical number of charge cycles.

[0026] The above at least one precursor may include the first derivative and second derivative of the charge capacity of the battery with respect to the number of additional charge cycles performed for the battery after a reference number of charge cycles has been performed for the battery, and the effective life of the battery related to the number of charge cycles during which the battery can be maintained in an operable state.

[0027] The processor can predict that a rapid decrease in the charge capacity of the battery is imminent if the change pattern of at least one of the first derivative and the second derivative of the charge capacity of the battery follows at least one pre-configured pattern.

[0028] The at least one pre-configured pattern that follows at least one of the first derivative and second derivative change patterns may include a pattern of decreasing and then increasing.

[0029] The processor can predict that a rapid decrease in the charging capacity of the battery is imminent if the change pattern of the effective life of the battery follows at least one pre-configured pattern.

[0030] The at least one pre-configured pattern that follows the change pattern of the effective life of the battery may include a pattern that increases and then decreases.

[0031] The processor may be configured to generate at least one warning signal indicating that a rapid decrease in the charge capacity of the battery is imminent.

[0032] The battery management system may further include a display that displays a message according to the warning signal generated by the processor.

[0033] The above message may include at least one of a warning message indicating that the battery is in an unreliable state and a message suggesting at least one corrective action to delay the initiation of a rapid decrease in the battery's charge capacity. Effects of the invention

[0034] According to various embodiments of the present disclosure, a battery condition measurement method and a battery management system can be provided to predict the occurrence of a rapid decrease in the charging capacity of a battery provided in a device / vehicle sufficiently prior to a point in time when the battery may become inoperable.

[0035] A battery state measurement method and system according to various embodiments of the present disclosure can predict the occurrence of a rapid decrease in the battery's charge capacity based on real-time monitoring of the change patterns of precursors, such as the first derivative and second derivative of the battery's charge capacity and the effective life of the battery.

[0036] In addition, the battery status measurement method and battery management system according to various embodiments of the present disclosure can provide the user with sufficient time to take corrective action before the sudden death phenomenon of the battery occurs by generating and displaying a warning signal indicating a rapid decrease in the battery's charging capacity. Brief explanation of the drawing

[0037] Figure 1 is a graph briefly illustrating an exemplary change pattern of the charging current delivered to the battery over time. Figure 2 is a graph briefly illustrating the exemplary change pattern of the battery's charging capacity according to the number of charging cycles after the i-th cycle performed on the battery. Figure 3 is a graph briefly illustrating the exemplary change pattern of the absolute value of the battery's charge capacity normalized to the first derivative of the battery's charge capacity with respect to the number of charge cycles after the i-th charge cycle performed on the battery. Figure 4 is a graph briefly illustrating the exemplary change pattern of the value normalized to the second derivative of the battery's charge capacity with respect to the number of charge cycles after the i-th charge cycle performed on the battery. Figure 5 is a graph briefly illustrating the exemplary change pattern of the effective life of a battery with respect to the number of charging cycles performed on the battery. FIG. 6 briefly illustrates an exemplary configuration of a battery management system configured to predict a rapid decrease in the charging capacity of a battery according to various embodiments of the present disclosure. FIG. 7 is a flowchart illustrating a method for predicting a rapid decrease in the charging capacity of a battery according to various embodiments of the present disclosure. Specific details for implementing the invention

[0038] Below, with reference to the attached drawings, embodiments of a battery condition measurement method and a battery management system are described in detail so that those skilled in the art can easily implement them. In the drawings, the same reference numerals refer to the same components, and the size or thickness of each component in the drawings may be exaggerated for clarity of explanation. Meanwhile, the various embodiments of the battery condition measurement method and system described below are exemplary, and the battery condition measurement method and system may be implemented in various different forms and are not limited to the embodiments described herein.

[0039] In the following, terms designated as "upper" or "upper" may include not only those directly above in contact but also those above non-contact. Singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0040] The use of the term "for example" and similar descriptive terms may be in both singular and plural. All examples or the use of exemplary terms are merely intended to describe the technical concept in detail and, unless limited by the claims, the scope is not limited by such examples or exemplary terms.

[0041] Various embodiments of the present disclosure may provide a battery condition measurement method and a battery management system for predicting a relatively rapid decrease in the charge capacity of a battery. A battery condition measurement method and a battery management system according to various embodiments of the present disclosure may predict the occurrence of a rapid decrease in the charge capacity of a battery sufficiently prior to the point in time when the battery may become inoperable. In addition, a battery condition measurement method and a battery management system according to various embodiments of the present disclosure may calculate the value of at least one precursor used to predict the occurrence of a rapid decrease in the charge capacity of a battery. At least one precursor may include the first derivative and the second derivative of the charge capacity of the battery with respect to the number of charge cycles and the effective life of the battery.

[0042] A battery state measurement method and a battery management system according to various embodiments of the present disclosure can perform real-time monitoring of the value of at least one precursor. The value of at least one precursor can be calculated after each charging cycle or discharging cycle performed on the battery.

[0043] A battery state measurement method and a battery management system according to various embodiments of the present disclosure can generate a warning signal indicating that a rapid decrease in the charge capacity of a battery is imminent. For example, the warning signal may be generated when it is detected that the change pattern of the value of at least one precursor follows at least one pre-configured pre-configuration pattern.

[0044] FIG. 1 is a graph briefly illustrating the exemplary change pattern of the charging current (Icharge) delivered to the battery over time. FIG. 2 is a graph briefly illustrating the exemplary change pattern of the battery's charging capacity according to the number of charging cycles after the i-th for the battery. FIG. 3 is a graph briefly illustrating the exemplary change pattern of the absolute value normalized by the first derivative of the battery's charging capacity according to the number of charging cycles after the i-th for the battery. FIG. 4 is a graph briefly illustrating the exemplary change pattern of the value normalized by the second derivative of the battery's charging capacity according to the number of charging cycles after the i-th for the battery. FIG. 5 is a graph briefly illustrating the exemplary change pattern of the battery's effective life according to the number of charging cycles for the battery.

[0045] Referring to FIG. 1, the charging current (I) delivered to the battery for battery charging charge ) may decrease as the battery is charged. This is the charging current (I) when charging of the battery begins. charge This may be because ) is sufficiently high. As the battery charge rate increases, the battery capacity and the voltage across the battery terminals may increase. Therefore, as the battery charge rate increases, the charging current (I charge ) can decrease. Charging current (I chargeThe relationship between ) and the battery's charging capacity is defined as follows (Equation 1).

[0046] (Equation 1)

[0047] Referring to Fig. 2, the initial charge capacity of the battery may be close to 3500 mAh. As the number of charge cycles increases due to battery usage, the charge capacity of the battery may begin to decrease. As more charge cycles are performed on the battery, the charge capacity of the battery may gradually decrease. The charge capacity of the battery immediately after the i-th charge cycle is C i It can be defined as follows. The charge capacity of the battery immediately after the i + Nth charge cycle is defined as follows (Equation 2) based on the i-th charge cycle.

[0048] (Equation 2)

[0049] In Equation (2) above, 'β' is a fitting parameter that defines the rate of decay of the battery's charge capacity. If the rate of decay of the battery's charge capacity decreases gradually, the fitting parameter β may decrease. On the other hand, if the rate of decay of the battery's charge capacity decreases rapidly, the fitting parameter β may increase. According to Equation (2) above, the decrease in the battery's charge capacity with respect to the number of charge cycles follows a decay exponential function pattern.

[0050] One of the precursors used to predict a rapid decrease in the battery's charge capacity may include the first derivative of the battery's charge capacity with respect to the number of charge cycles performed on the battery. After the i + Nth charge cycle has been performed, the first derivative of the battery's charge capacity with respect to the number of charge cycles is defined as follows in (Equation 3).

[0051] (Equation 3)

[0052] As shown in FIG. 3, the value of the first derivative of the battery's charge capacity with respect to the number of charge cycles is It can be calculated based on. Therefore, the absolute value of the value of the first derivative of the battery's charge capacity with respect to the number of charge cycles, normalized to the battery's charge capacity value, is defined as follows in (Equation 4).

[0053] (Equation 4)

[0054] Meanwhile, after the i + Nth charging cycle is completed, the second derivative of the battery's charge capacity with respect to the number of charging cycles is defined as follows (Equation 5).

[0055] (Equation 5)

[0056] As shown in FIG. 4, the value of the second derivative of the battery's charge capacity with respect to the number of charge cycles, normalized to the battery's charge capacity value, can be calculated based on the following (Equation 6).

[0057] (Equation 6)

[0058] The pattern of change in the effective life of the battery illustrated in FIG. 5 is the pattern of change in the total service life of the battery, that is, the period during which the battery can be continuously used (operable). The change in the total service life of the battery can be determined based on the following Equation (7).

[0059] (Equation 7)

[0060] Equation (7) above indicates that if the charge capacity of the battery after N charge cycles does not decrease to 80% of the initial charge capacity, the battery can be considered usable.

[0061] The decrease in battery charging capacity can be a self-limiting parameter. In other words, as the battery's charging capacity decreases, the rate of decrease in charging capacity may decrease. For example, consider a situation where the battery's charging capacity decreases from 100 charging units to 95 charging units. In this case, the rate of decrease in battery charging capacity may initially be high. Subsequently, as the decrease in battery charging capacity continues, the rate of decrease may decrease. This indicates that the rate of decrease in battery charging capacity when it decreases from 100 charging units to 99 charging units is higher than the rate of decrease when it decreases from 99 charging units to 98 charging units.

[0062] It can be assumed that the number of charging cycles performed to reduce the battery's charging capacity from 100 charging units to 95 charging units is 50. Conversely, the number of charging cycles to reduce the battery's charging capacity from 95 to 90 charging units is likely to be greater than 50. In other words, the battery's charging capacity does not decrease from 95 charging units to 90 charging units in 50 charging cycles. As such, when the battery's charging capacity decreases to a specific level, the rate of decrease in charging capacity relative to the number of charging cycles decreases.

[0063] As the number of charging cycles performed on the battery increases, the charging capacity of the battery decreases, and consequently, the phenomenon of the rate of decrease in the charging capacity of the battery decreasing is represented by the region indicating the negative slope of the graphs shown in FIGS. 3 and 4. A decrease in the rate of decrease in the charging capacity of the battery means a decrease in the values ​​of the first and second derivatives of the charging capacity of the battery with respect to the number of charging cycles. This may be due to a decrease in the fitting parameter β (see Equations 4 and 6). When the fitting parameter β is small, the charging capacity of the battery decreases gradually.

[0064] A gradual decrease in the rate of decrease of the battery's charge capacity can increase the time the battery remains in an operational state. This is indicated by the area representing the positive slope of the graph shown in Fig. 5. Referring to Fig. 5, the total service life of the battery decreases as the number of charge cycles performed on the battery increases. Therefore, as shown in Fig. 5, the area representing the positive slope of the graph, which signifies an 'increase' in the total service life of the battery, implies a decrease in the rate of decrease of the battery's charge capacity or a decrease in the fitting parameter β (see Equation 7).

[0065] When the charge capacity of a battery decreases below a certain level, a rapid decrease in the charge capacity of the battery may begin to occur, unlike the section where a gradual decrease in the charge capacity occurs, in which the rate of decrease in the charge capacity decreases as the charge capacity decreases. In the section where the charge capacity of the battery decreases rapidly, the battery is no longer considered reliable. The charge capacity level corresponds to the number of charge cycles performed on the battery. Referring to FIG. 2, when approximately 510 charge cycles have been performed on the battery, the charge capacity of the battery may begin to decrease suddenly. At this stage, the battery is expected to be unreliable. A battery state measurement method and a battery management system according to various embodiments of the present disclosure can predict a rapid decrease in the charge capacity of the battery sufficiently in advance of 510 charge cycles.

[0066] Considering the previous example, if the battery's charge capacity units decrease to 90, the rate of decrease in the battery's charge capacity may show a rapid change. Several charge cycles are performed on the battery, and as a result, the battery's charge capacity may decrease to 90 charge units. When the battery's charge capacity decreases to fewer than 90 charge units, the battery's charge capacity begins to decrease rapidly, which means that the battery is no longer stable in operation.

[0067] As illustrated in FIGS. 3 and 4, when approximately 400 charging cycles are performed on the battery, the values ​​of the first and second derivatives of the battery's charging capacity with respect to the number of charging cycles may have minimum values. This implies that if the number of charging cycles performed on the battery exceeds 400, the battery's charging capacity decreases rapidly, meaning that the rate of decrease in the battery's charging capacity is no longer gradual. As illustrated in FIGS. 3 and 4, when 400 charging cycles have been performed on the battery, the rate of change of the battery's charging capacity (first derivative) and the rate of change of the battery charging capacity (second derivative) have minimum values ​​(each 10 -4 and 10 -8 It can represent ).

[0068] After approximately 400 charge cycles have been performed on the battery, a rapid decrease in the battery's charge capacity may be imminent. As illustrated in FIGS. 3 and 4, the rate of change of the battery's charge capacity (first derivative) and the rate of change of the battery's charge capacity (second derivative) may begin to increase after approximately 400 charge cycles have been performed on the battery. The increase in the values ​​of the rate of change of the battery's charge capacity (first derivative) and the rate of change of the battery's charge capacity (second derivative) appears in the region with a positive slope of the graphs illustrated in FIGS. 3 and 4. In the region with a positive slope of the graphs illustrated in FIGS. 3 and 4, the value of the fitting parameter β increases. As the fitting parameter β increases, the values ​​of the first derivative and the second derivative of the battery's charge capacity increase (see Equations 4 and 6).

[0069] As shown in Fig. 5, the total effective life of the battery may reach a maximum value after approximately 400 charge cycles. This is because the fitting parameter β remains low when the rate of decrease in the battery's charge capacity is gradual. When the fitting parameter β is at its lowest, the total effective life of the battery reaches a maximum value (see Equation 7). After approximately 400 charge cycles for the battery, the fitting parameter β may begin to increase. This leads to a gradual decrease in the total effective life of the battery (indicated by the region with a negative slope in the graph shown in Fig. 5).

[0070] A battery state measurement method and battery management system according to various embodiments of the present disclosure may include a step of detecting a change pattern of precursor values ​​to predict a rapid loss of the battery's charge capacity. The change pattern of precursor values ​​may be pre-configured for the first derivative and second derivative of the battery's charge capacity with respect to the number of charge cycles and the total effective life of the battery. When the precursor values ​​are the first derivative and second derivative of the battery's charge capacity with respect to the number of charge cycles, the pre-configured change pattern of precursor values ​​may include a pattern in which the values ​​of the first derivative and second derivative decrease and then increase. Conversely, when the precursor values ​​are the battery's total effective life, the pre-configured change pattern of precursor values ​​may include a pattern in which the value of the battery's total effective life increases and then decreases. A battery state measurement method and battery management system according to various embodiments of the present disclosure may notify a user that a rapid decrease in battery capacity is imminent when a pre-configured pattern is detected.

[0071] FIG. 6 briefly illustrates an exemplary configuration of a battery management system (BMS) (200) configured to predict a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure. However, it is not limited thereto, and the battery management system (200) may include fewer or more components than those shown in FIG. 6. Additionally, the label or name of the unit of the battery management system (200) is used for illustrative purposes only and does not limit the scope of the various embodiments of the present disclosure. One or more components may be combined to perform the same or substantially similar functions within the battery management system (200).

[0072] According to one embodiment, the battery management system (200) and the battery (202) may be included in an electric vehicle. According to another embodiment, the battery management system (200) and the battery (202) may be included in various devices. As illustrated in FIG. 2, the battery management system (200) may include a power management integrated circuit (PMIC) (201). The power management integrated circuit (201) may include a processor (203) and a display (204).

[0073] Examples of various devices to which the battery management system (200) and battery (202) can be applied include smartphones, laptops, tablets, wearable devices, cameras, Internet of Things (IoT) devices, trimmers, robots, vacuum cleaners, vehicle infotainment systems, etc.

[0074] The processor (203) can determine the charge capacity of the battery (202) at the time when a charging cycle proceeding for the battery ends. The charge capacity of the battery (202) may decrease at the time when each charging cycle ends. The processor (203) can determine that the charge capacity of the battery (202) decreases gradually. The processor (203) can determine the pattern of decrease in the charge capacity of the battery (202). According to one embodiment, the pattern of decrease in the charge capacity of the battery (202) may follow a decay exponential function.

[0075] According to one embodiment, the charge capacity value of the battery (202) at the end of a charge cycle performed on the battery (when the 'i + N'th charge cycle has been performed on the battery (202)) is determined based on the charge capacity of the battery (202) at the end of a reference i-th charge cycle and a decay exponential function. For example, the parameter of the decay exponential function may be equal to the product of the number of charge cycles (N, i.e., i + Ni) performed on the battery (202) exceeding a reference number (i times) and a fitting parameter (β) (see Equation 2).

[0076] One of the natural phenomena occurring in the battery (202) is that the rate of decrease in the charging capacity of the battery (202) decreases as the charging capacity of the battery (202) decreases. For example, the number of charging cycles required to decrease the charging capacity of the battery (202) by the same amount increases as the charging capacity of the battery (202) decreases.

[0077] The processor (203) can calculate at least one precursor to predict the occurrence of a rapid decrease in the charge capacity of the battery (202). The at least one precursor may include a first derivative and a second derivative with respect to the number of charge cycles of the charge capacity of the battery (202). Additionally, the at least one precursor may include the effective life of the battery (202) related to the number of charge cycles while the battery (202) is in an operable state.

[0078] The processor (203) can determine a pattern of change in the first derivative of the charge capacity of the battery (202) with respect to the number of charge cycles (N) performed on the battery (202) after a reference number of charge cycles (i) performed on the battery (202). Additionally, the processor (203) can determine a pattern of change in the second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles (N) performed by the battery (202) after a reference number of charge cycles (i) performed on the battery (202). Furthermore, the processor (203) can determine a pattern of change in the effective life of the battery (202) related to the number of charge cycles during which the battery (202) can be maintained in an operable state.

[0079] The processor (203) can determine that as the number of charging cycles performed on the battery (202) increases, the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles decrease. As the number of charging cycles performed on the battery (202) increases, the rate of decrease of the charging capacity of the battery (202) decreases. In this stage, where the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles gradually decrease, the value of the fitting parameter β can be maintained at a relatively low level.

[0080] A decrease in the rate of decrease in the charge capacity of the battery (202) also increases the period during which the battery can operate. As the number of charge cycles performed on the battery (202) increases, the pattern of increasing duration (effective life of the battery (202)) follows a decreasing pattern of the first derivative and second derivative values ​​of the charge capacity of the battery (202) with respect to the number of charge cycles. As long as the rate of decrease in the charge capacity of the battery (202) decreases, the values ​​of the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles follow a decreasing pattern.

[0081] Another natural phenomenon occurring in the battery (202) is that when the charging capacity of the battery (202) drops below a certain level, the charging capacity of the battery (202) does not decrease gradually but begins to decrease rapidly. When the charging capacity of the battery (202) begins to decrease rapidly, the battery (202) is considered unreliable or inoperable. According to one embodiment, when the charging capacity of the battery (202) drops below 80% of the initial charging capacity of the battery (202), the battery (202) is more likely to become inoperable after a certain number of charging cycles. According to one embodiment, the charging capacity of the battery (202) may drop below 80% of the initial charging capacity of the battery (202) after approximately 510 charging cycles have been performed on the battery.

[0082] The charging capacity level at which the charging capacity of the battery (202) begins to decrease rapidly may vary depending on the usage pattern of the device or vehicle equipped with the battery (202). Additionally, the number of charging cycles at which the charging capacity of the battery (202) begins to decrease rapidly and the battery (202) is likely to become inoperable may vary depending on the usage pattern of the device or vehicle equipped with the battery (202).

[0083] After a critical number of charging cycles have been performed on the battery (202), the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles may each decrease to a minimum value. For example, after 400 charging cycles have been performed on the battery (202), the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles may each decrease to a minimum value. The total effective life of the battery (202) may reach a peak value when the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles decrease to a minimum value. In this case, the critical number of charging cycles performed on the battery (202) may be 400. After that, when additional charging cycles are performed on the battery (202) beyond 400 times, the values ​​of the first derivative and the second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles begin to increase (at the minimum value, respectively), and the total effective life of the battery (202) begins to decrease (at the peak value).

[0084] The processor (203) may be configured to monitor the change pattern of the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles and the total effective life value. If the processor (203) determines that the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles and the total effective life value follow a pre-configured pattern, it may interpret that a rapid decrease in the charge capacity of the battery (202) is imminent. The processor (203) may be pre-configured to detect the change pattern of the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles and the total effective life value to predict a rapid decrease in the charge capacity of the battery (202).

[0085] If the processor (203) detects that the values ​​of the first derivative and the second derivative of the charge capacity of the battery (202) follow a pattern of decreasing and then increasing, the processor (203) may determine that the battery (202) is likely to become unreliable and that a rapid decrease in the charge capacity of the battery (202) is imminent. Additionally, if the processor (203) detects that the value of the total effective life of the battery (202) follows a pattern of increasing and then decreasing, the processor (203) may determine that the battery (202) is likely to become unreliable and that a rapid decrease in the charge capacity of the battery is imminent.

[0086] The processor (203) may generate a warning signal indicating that a rapid decrease in the charge capacity of the battery (202) may begin when it is detected that the change pattern of the value of at least one precursor follows at least one pre-configured pattern. The warning signal of the processor (203) may be generated when it is detected that the first derivative and second derivative of the charge capacity of the battery (202) and the total effective life follow a pre-configured pattern. Detection of the fact that the first derivative and second derivative of the charge capacity of the battery (202) and the total effective life follow a pre-configured pattern may occur after a critical number of charge cycles have been performed on the battery (202). Accordingly, the processor (203) may generate a warning signal after a critical number of charge cycles have been performed on the battery (202).

[0087] According to one embodiment, the processor (203) may be configured to display a message on the display (204) in accordance with a warning signal. The content of the message in accordance with the warning signal may indicate that the battery (202) is no longer in a reliable state and is likely to fail to operate in the future. According to another embodiment, in accordance with a warning signal generated by the processor (203), a message may be displayed on the display (204) suggesting at least one corrective action to the user to delay the initiation of a rapid decrease in the charging capacity of the battery (202). The corrective action may include a change in the user's usage pattern or charging pattern for the battery (202).

[0088] FIG. 7 is a flowchart (300) illustrating a battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to various embodiments of the present disclosure.

[0089] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to one embodiment may include a first step (301) for determining a change in the charge capacity of the battery (202) with respect to the number of charge cycles performed on the battery (202). The charge capacity of the battery (202) decreases after each charge cycle is completed. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step for determining a decrease pattern in the charge capacity of the battery (202). According to one embodiment of the present disclosure, the decrease in the charge capacity of the battery (202) follows a decay exponential function. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a method for determining the charge capacity value of the battery (202) at the end of a charge cycle based on the charge capacity of the battery (202) at the end of a reference number of charge cycles and the decay exponential function. The parameters of the damping exponential function include the number of charging cycles (N) performed for the battery (202) that exceed the reference number of charging cycles performed for the battery (202), and the fitting parameter β.

[0090] A battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to one embodiment may include a second step (302) of calculating at least one precursor for predicting the occurrence of a rapid decrease in the charging capacity of the battery (202). The at least one precursor includes a first derivative and a second derivative of the charging capacity of the battery (202) with respect to the number of charging cycles performed for the battery (202) after a reference number of charging cycles has been performed for the battery (202), and an effective life of the battery (202) related to the number of charging cycles during which the battery (202) can remain in an operable state.

[0091] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles during which the battery (202) may remain in an operable state, and a change pattern of effective life. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles performed on the battery (202), and a change pattern of effective life.

[0092] A battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to one embodiment may include a third step (303) of monitoring a change pattern of at least one precursor used to predict the occurrence of a rapid decrease in the charging capacity of the battery (202).

[0093] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of monitoring a change pattern of the values ​​of the first derivative and second derivative of the charge capacity with respect to the number of charge cycles of the battery (202) and the total effective life. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining that the values ​​of the first derivative and second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles increase as the number of charge cycles performed on the battery (202) increases. As the number of charge cycles performed on the battery (202) increases, the rate of decrease in the charge capacity of the battery (202) decreases.

[0094] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining that the total effective life of the battery (202) increases as the rate of decrease in the charge capacity of the battery (202) decreases. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining that while the rate of decrease in the charge capacity of the battery (202) gradually decreases, the values ​​of the first derivative and the second derivative with respect to the number of charge cycles of the charge capacity of the battery (202) follow a decreasing pattern, and the value of the total effective life of the battery (202) follows an increasing pattern.

[0095] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of detecting that the values ​​of the first derivative and the second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles have decreased to their respective minimum values ​​as the charge capacity of the battery (202) gradually decreases. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining the charge capacity of the battery (202) and the number of charge cycles performed for the battery (202) when the values ​​of the first derivative and the second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles have decreased to their respective minimum values. A battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to various embodiments of the present disclosure may include the step of detecting that the total effective life of the battery (202) increases to a peak value when the values ​​of the first derivative and the second derivative with respect to the number of charging cycles of the battery (202) charging capacity decrease to their respective minimum values.

[0096] A battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to various embodiments of the present disclosure may include the step of storing the charging capacity of the battery (202) and the number of charging cycles performed for the battery (202) when the values ​​of the first derivative and the second derivative with respect to the number of charging cycles of the charging capacity of the battery (202) decrease to their respective minimum values ​​and the total effective life value of the battery (202) increases to a peak value. In the case where the values ​​of the first derivative and the second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles decrease to their respective minimum values ​​and the total effective life value of the battery (202) increases to a peak value, the charge capacity of the battery (202) and the number of charge cycles performed for the battery (202) can be defined as the 'critical capacity' and the 'critical number,' respectively. A battery state measurement method for predicting a rapid decrease in the charge capacity of the battery (202) according to various embodiments of the present disclosure may include the step of determining that when an additional number of charge cycles exceeding the critical number is performed for the battery (202), the values ​​of the first derivative and the second derivative of the charge capacity of the battery (202) with respect to the number of charge cycles begin to increase and the total effective life of the battery (202) begins to decrease.

[0097] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to one embodiment may include a fourth step (304) of predicting that a rapid decrease in the charge capacity of the battery (202) is imminent when the change pattern of at least one precursor follows at least one pre-configured pattern. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of configuring a pre-configured pattern for each of at least one precursor. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of detecting whether at least one value among the first derivative and second derivative with respect to the number of charge cycles of the charge capacity of the battery (202) and the total effective life follows each of at least one pre-configured pattern.

[0098] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining that the battery (202) is likely to become unreliable and that a rapid decrease in the charge capacity of the battery (202) is imminent when detecting that the values ​​of the first derivative and the second derivative with respect to the number of charge cycles of the charge capacity of the battery (202) follow a pattern of decreasing and then increasing. Additionally, a battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of determining that the battery (202) is likely to become unreliable and that a rapid decrease in the charge capacity of the battery is imminent when detecting that the value of the total effective life of the battery (202) follows a pattern of increasing and then decreasing.

[0099] A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to one embodiment may include a fifth step (305) of generating a warning signal indicating the possibility of initiation of a rapid decrease in the charge capacity of the battery (202) when a change in at least one precursor value follows at least one pre-configured pattern is detected. A battery state measurement method for predicting a rapid decrease in the charge capacity of a battery (202) according to various embodiments of the present disclosure may include a step of generating a warning signal when the values ​​of the first derivative and the second derivative with respect to the number of charge cycles of the charge capacity of the battery (202) decrease to their respective minimum values ​​and the total effective life value of the battery (202) increases to a peak value. This was devised based on the phenomenon that after a critical number of charging cycles have been performed on the battery (202), the change pattern of the first derivative and second derivative values ​​of the charging capacity of the battery (202) with respect to the number of charging cycles follows a pre-configured decreasing-to-increasing pattern, and the change pattern of the total effective life value of the battery (202) follows a pre-configured increasing-to-decreasing pattern.

[0100] According to one embodiment, a message indicating that the battery (202) is in an unreliable state according to a warning signal may be displayed. According to one embodiment, a message suggesting at least one corrective action to delay the onset of a rapid decrease in the charge capacity of the battery (202) may be displayed. For example, when the battery (202) is applied to a device, a battery condition measurement method for predicting a rapid decrease in the charge capacity of the battery (202) according to various embodiments of the present disclosure may suggest replacing the battery (202) first among the various components mounted on the device. Additionally, a battery condition measurement method for predicting a rapid decrease in the charge capacity of the battery (202) according to various embodiments of the present disclosure may use a conservative charging protocol as a corrective action to prevent rapid charging of the device (if the device supports rapid charging) and to pump a low current to the battery (202) to prevent degradation of the battery (202). In addition, a battery state measurement method for predicting a rapid decrease in the charging capacity of a battery (202) according to various embodiments of the present disclosure can block the operation of an application that may rapidly deplete the battery (202), and can block specific operations such as Bluetooth, near field communication (NFC), flashlight, etc.

[0101] When a battery (202) is applied to a vehicle, a battery condition measurement method for predicting a rapid decrease in the charging capacity of the battery (202) according to various embodiments of the present disclosure may suggest vehicle maintenance. A battery condition measurement method for predicting a rapid decrease in the charging capacity of the battery (202) according to various embodiments of the present disclosure may warn that the estimation of the range of distance the vehicle can travel (the range of distance the vehicle can travel based on the current charging state) is unreliable. A battery condition measurement method for predicting a rapid decrease in the charging capacity of the battery (202) according to various embodiments of the present disclosure may suggest redistributing the load without using a defective battery pack.

[0102] The various steps of the flowchart (300) illustrated in FIG. 7 may be performed in the order presented or in a different order, or at least some of the various steps of the flowchart (300) may be performed simultaneously. Additionally, in some embodiments, some steps of the flowchart (300) may be omitted.

[0103] Various embodiments of the present disclosure may be implemented through at least one software program that is executed on at least one hardware device and performs network management functions for controlling network elements. The network element illustrated in FIG. 6 includes a block that may be at least one of a hardware device or a combination of a hardware device and a software module.

[0104] Various embodiments of the present disclosure include a battery condition measurement method and a battery management system for predicting the point in time when the charge capacity of a battery in a device / vehicle equipped with a battery decreases rapidly, sufficiently prior to the battery becoming inoperable. Accordingly, the scope of protection of various embodiments of the present disclosure may extend to computer-readable storage means containing messages and such programs, such computer-readable storage means may implement one or more steps included in the battery condition measurement method according to various embodiments of the present disclosure and may include means of program code executed on a server, a mobile device, or a suitable programmable device. The battery condition measurement method according to various embodiments of the present disclosure may be implemented, for example, by a software program written in a very fast integrated circuit hardware description language (VHDL) or any other programming language, or by one or more VHDL or multiple software modules executed on at least one hardware device. The hardware device may be any type of portable device that is programmable.

[0105] For example, the device may include hardware (e.g., an Application-Specific Integrated Circuit (ASIC)) or a combination of hardware and software means (e.g., an ASIC and a Field Programmable Gate Array (FPGA), or at least one memory having one or more microprocessors and software modules).

[0106] A battery state measurement method for predicting the point at which the charge capacity of a battery rapidly decreases according to various embodiments of the present disclosure may be implemented in part by hardware and in part by software. Alternatively, a battery state measurement method for predicting the point at which the charge capacity of a battery rapidly decreases according to various embodiments of the present disclosure may be implemented, for example, by various hardware devices (e.g., a plurality of central processing units (CPUs)).

[0107] The battery condition measurement method and system described above have been explained with reference to the embodiments illustrated in the drawings for the sake of understanding, but this is merely illustrative and those skilled in the art will understand that various modifications and equivalent embodiments can be derived therefrom. Accordingly, the true technical scope of protection of the battery condition measurement method and system according to the present disclosure should be determined by the appended claims. Explanation of the symbols

[0108] 200: Battery Management System 201: Power Management Integrated Circuit 202: Battery 203: Processor 204: Display

Claims

Claim 1 A battery state measurement method of a battery management system for predicting a point in time when the charging capacity of a battery decreases relatively rapidly, comprising: a step of monitoring at least one of the first derivative and the second derivative of the charging capacity of the battery with respect to the number of charging cycles performed for the battery by a processor of the battery management system; and a step of predicting that a rapid decrease in the charging capacity of the battery is imminent by a processor of the battery management system if the change pattern of at least one of the first derivative and the second derivative follows at least one pre-configured pattern for the battery after a critical number of charging cycles has been performed; wherein, among the charging capacities of the battery with respect to the number of charging cycles, the charging capacity (C) of the battery immediately after the i+Nth charging cycle has been performed, after a reference number (i times) of charging cycles have been performed for the battery i+N ) is the battery charge capacity (C) immediately after the i-th charge cycle has been completed i Based on ), it is defined as Equation 2 below, and (Equation 2) Here, β is a fitting parameter defining the rate of decrease of the battery's charge capacity, the first derivative and the second derivative are calculated using Equation 2, and the at least one pre-configured pattern includes a pattern of decreasing and then increasing, a battery state measurement method. Claim 2 A battery condition measurement method according to claim 1, wherein the monitoring step further comprises the step of monitoring the effective life of the battery related to the number of charging cycles during which the battery can be maintained in an operable state. Claim 3 delete Claim 4 delete Claim 5 A battery state measurement method according to claim 1, further comprising the step of generating at least one warning signal by a processor of the battery management system indicating that a rapid decrease in the charge capacity of the battery is imminent. Claim 6 A battery condition measurement method according to claim 5, wherein the step of generating the warning signal is performed through at least one of displaying a warning message indicating that the battery is in an unreliable state and suggesting at least one corrective action to delay the initiation of a rapid decrease in the charge capacity of the battery. Claim 7 A battery state measurement method of a battery management system for predicting a point in time when the charging capacity of a battery decreases relatively rapidly, comprising: a step of estimating the charging capacity of a battery using real-time charge / discharge data of the battery by a processor of the battery management system; a step of calculating the first derivative of the estimated charging capacity of the battery by a processor of the battery management system; a step of calculating the second derivative of the estimated charging capacity of the battery by a processor of the battery management system; a step of calculating the effective life of the estimated charging capacity of the battery by a processor of the battery management system; a step of monitoring a change pattern of at least one of the first derivative, the second derivative, and the effective life of the charging capacity of the battery by a processor of the battery management system; and a step of generating a decision indicating a point in time when the charging capacity of the battery decreases rapidly based on the change pattern of at least one of the values ​​by a processor of the battery management system. ...including, among the charging capacities of the battery, the charging capacity of the battery immediately after the i+Nth charging cycle is performed, following a reference number (i times) of charging cycles for the battery. i+N ) is the battery charge capacity (C) immediately after the i-th charge cycle has been completed i Based on ), it is defined as Equation 2 below, and (Equation 2) Here, β is a fitting parameter defining the rate of decrease of the battery's charge capacity, and the first derivative and the second derivative are calculated using Equation 2. A battery state measurement method that determines that if at least one of the first derivative and the second derivative includes a pattern of decreasing followed by increasing, it indicates a point in time when the battery's charge capacity decreases rapidly. Claim 8 A battery management system for predicting a point in time when the charging capacity of a battery decreases relatively rapidly comprises: at least one battery; and a processor for measuring the state of said battery; wherein the processor monitors at least one change pattern among the first derivative and the second derivative of the charging capacity of said battery with respect to the number of charging cycles performed for said battery, and is configured to predict that a rapid decrease in the charging capacity of said battery is imminent if the change pattern among the first derivative and the second derivative follows at least one pre-configured pattern for said battery after a critical number of charging cycles has been performed, and among the charging capacity of said battery with respect to the number of charging cycles, the charging capacity (C) of the battery immediately after the i+Nth charging cycle has been performed, after a reference number (i times) of charging cycles has been performed for said battery. i+N ) is the battery charge capacity (C) immediately after the i-th charge cycle has been completed i Based on ), it is defined as Equation 2 below, and (Equation 2) Here, β is a fitting parameter defining the rate of decrease of the battery's charge capacity, the first derivative and the second derivative are calculated using Equation 2, and the battery management system includes at least one pre-configured pattern that decreases and then increases. Claim 9 In claim 8, the processor is a battery management system that further monitors the effective life of the battery in relation to the number of charging cycles during which the battery can be maintained in an operable state. Claim 10 delete Claim 11 delete Claim 12 In claim 8, the battery management system is configured such that the processor generates at least one warning signal indicating that a rapid decrease in the charging capacity of the battery is imminent. Claim 13 A battery management system according to claim 12, further comprising a display for displaying a message according to a warning signal generated by the processor, wherein the message comprises at least one of a warning message indicating that the battery is in an unreliable state and a message suggesting at least one corrective action to delay the initiation of a rapid decrease in the charge capacity of the battery.

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