System and method for detecting a soft short in a battery

Abstract

Systems and methods for detecting soft shorts in a battery are provided. Systems, vehicles, and methods for detecting soft shorts in a battery utilize one or both of a first algorithm and a second algorithm to measure the impedance of the battery at Nz frequency points and at one or more voltages (e.g., by using electrochemical impedance spectroscopy); calculating one or more errors; determining a number of occurrences that one of the calculated errors is greater than a threshold error; and if the number of occurrences is greater than a threshold, identifying the battery as having a soft short circuit.

Description

Technical Field

[0001] This disclosure relates to systems and methods for detecting soft short circuits in batteries (e.g., battery cells or groups of battery cells within a battery module or battery pack). Background Technology

[0002] In battery-powered devices, such as automobiles, predicting battery health plays a crucial role in battery management. Electrochemical impedance spectroscopy (EIS) is a feasible method for monitoring battery health. EIS can be used to stimulate the battery and measure voltage changes, which then allows for impedance analysis.

[0003] However, there is a lack of clarity regarding impedance data (e.g., effective frequency range, etc.) and the follow-up processing required to detect abnormal battery health (e.g., soft short circuit). Summary of the Invention

[0004] According to one embodiment, a method for detecting a soft short circuit in a battery includes: (i) N in a frequency range z The impedance of the battery is measured at several frequency points and at selected voltages below a predetermined voltage level, thereby generating N values, each with a corresponding real component. z (ii) Calculate N by comparing the corresponding real component of each measured impedance with the corresponding reference impedance representing a healthy battery. z The corresponding error of each impedance in the measured impedance, thus generating N z (iii) Determine N corresponding calculation errors; z The number of times one of the calculation errors is greater than the threshold error; and (iv) if the number of occurrences is greater than the threshold, the battery is identified as having a soft short circuit.

[0005] N z Impedance measurements at individual frequency points can be performed using electrochemical impedance spectroscopy, and the frequency range can be approximately 0.01 to 1 Hz.

[0006] Each reference impedance can be: (i) the average real impedance component acting as a proxy for a healthy battery; or (ii) a corresponding member of the set of real impedance components representing a healthy battery. The average real impedance component can be obtained by averaging the corresponding real components of the corresponding impedances from two or more other batteries configured for use with the battery being measured at a selected voltage and frequency range. Each corresponding member of the set of real impedance components can correspond to N. z One of the corresponding frequency points out of a set of frequency points.

[0007] Each reference impedance can be obtained from a lookup table, and each measured impedance can have a corresponding imaginary component.

[0008] A predetermined voltage level can be defined as a voltage level at which, within a frequency range, the real component of the measured impedance of a soft-short-circuited battery differs significantly from the real component of the reference impedance of a healthy battery.

[0009] At approximately the same temperature, in N z The impedance of the battery is measured at several frequency points.

[0010] The battery can be a lithium-ion battery, with a predetermined voltage level of approximately 3.5 volts.

[0011] According to another embodiment, a method for detecting a soft short circuit in a battery includes: (i) N in the frequency range z At each frequency point and at the corresponding main voltage and alternative voltage, the battery impedance is measured. Each main voltage and alternative voltage is higher than a predetermined voltage level, thus generating N. z For the corresponding measured principal impedance and alternative impedance, each principal impedance and alternative impedance has a corresponding real component; (ii) N is calculated by comparing the corresponding real component of the corresponding measured principal impedance with the corresponding real component of the corresponding measured alternative impedance. z The corresponding measurement impedance error for each pair is calculated, thus generating the corresponding measurement impedance error; (iii) N is calculated by comparing the corresponding real component of the corresponding main reference impedance corresponding to the main voltage with the corresponding real component of the corresponding alternative reference impedance corresponding to the alternative voltage. z The corresponding reference impedance error for each pair is calculated, thus generating N. z (iv) Calculate N by dividing the difference between the corresponding measured impedance error and the corresponding reference impedance error by the corresponding reference impedance error. z The corresponding error for each pair of errors, thus generating an error of N. z (v) Determine the N corresponding error; z The number of times one of the errors exceeds the maximum permissible error; and (vi) if the number of occurrences exceeds the threshold, the battery is identified as having a soft short circuit.

[0012] In this embodiment, in N z Impedance measurements at individual frequency points can be performed using electrochemical impedance spectroscopy, and the frequency range can be approximately 0.1 to 10 Hz.

[0013] At least one of the primary reference impedance and the alternative reference impedance can be: (i) the average real impedance component acting as a proxy for the healthy battery; or (ii) a corresponding member of the set of real impedance components representing the healthy battery. The average real impedance component can be obtained by averaging the corresponding real components of the corresponding impedances from two or more other batteries within the battery, and each corresponding member of the set of real impedance components can correspond to N. zOne of the corresponding frequency points out of a set of frequency points.

[0014] A predetermined voltage level can be defined as a voltage level at which, within a frequency range, the real component of the measured impedance of a soft-short-circuited battery differs significantly from the real component of the reference impedance of a healthy battery.

[0015] The primary impedance and the alternative impedance can be measured at approximately the same temperature, and the battery can be a lithium-ion battery with a predetermined voltage level of approximately 3.5 volts.

[0016] According to another embodiment, a vehicle with onboard capability for detecting soft short circuits in a battery includes a body operatively supporting a propulsion system, an electrical system, a battery, and an electrochemical impedance spectroscopy (EIS) system, wherein the propulsion system, the battery, and the EIS system are all operatively connected to the electrical system, and wherein the EIS system is configured to execute at least one of a first algorithm and a second algorithm. The first algorithm includes: (i) using the EIS system in the frequency range N z The impedance of the battery is measured at a frequency point and at a first voltage below a predetermined voltage level, thereby generating N. z (ii) Calculate N by comparing the corresponding real component of each measured first impedance with the corresponding first reference impedance representing a healthy battery. z The corresponding principal error of each of the first impedance measurements, thus generating N z (iii) Determine N corresponding principal errors; z The second algorithm includes: (v) using the EIS system in the frequency range N z The impedance of the battery is measured at several frequency points and at corresponding second and third voltages, both above a predetermined voltage level, thereby generating N. z For the corresponding measured second and third impedances, each impedance has a corresponding real component; (vi) calculate N by comparing the corresponding real component of the corresponding measured second impedance with the corresponding real component of the corresponding measured third impedance. z The corresponding measured impedance error for each pair is calculated, resulting in N. z (vii) Calculate N by comparing the corresponding real component of the corresponding second reference impedance corresponding to the second voltage with the corresponding real component of the corresponding third reference impedance corresponding to the third voltage. z The corresponding reference impedance error for each pair is calculated, thus generating N. z(viii) Calculate N by dividing the difference between the corresponding measured impedance error and the corresponding reference impedance error by the corresponding reference impedance error. z The corresponding error for each pair of errors, thus generating an error of N. z One corresponding error; (ix) determine the N of the error. z The number of times one of the errors is greater than the maximum permissible error; and (x) if the number of occurrences is greater than the threshold, the battery is identified as having a soft short circuit.

[0017] The following solutions are provided:

[0018] 1. A method for detecting a soft short circuit in a battery, comprising:

[0019] N in the frequency range z The impedance of the battery is measured at several frequency points and at selected voltages below a predetermined voltage level, thereby generating N values, each with a corresponding real component. z Each corresponding measured impedance;

[0020] N is calculated by comparing the corresponding real component of each measured impedance with the corresponding reference impedance representing a healthy battery. z The corresponding error of each impedance in the measured impedance, thus generating N z One corresponding calculation error;

[0021] Determine N z The number of times that one of the calculation errors exceeds the threshold error; and

[0022] If the number of occurrences exceeds the threshold, the battery will be identified as having a soft short circuit.

[0023] 2. The method according to Scheme 1, wherein N z Impedance measurements at each frequency point were performed using electrochemical impedance spectroscopy.

[0024] 3. The method according to Scheme 1, wherein the frequency range is approximately 0.01 to 1 Hz.

[0025] 4. According to the method described in Scheme 1, each reference impedance is:

[0026] The average real impedance component acting as a proxy for a healthy battery; or

[0027] The corresponding members of the set representing the real impedance components of a healthy battery.

[0028] 5. The method according to Scheme 4, wherein the average real impedance component is obtained from the average of the corresponding real components of the corresponding impedances from two or more other cells, which are configured for use with the cell measured at a selected voltage and frequency range.

[0029] 6. The method according to Scheme 4, wherein each corresponding member of the set of real impedance components corresponds to N. z One of the corresponding frequency points out of a set of frequency points.

[0030] 7. The method according to Scheme 1, wherein each reference impedance is obtained from a lookup table.

[0031] 8. The method according to Scheme 1, wherein each measured impedance has a corresponding imaginary component.

[0032] 9. The method according to Scheme 1, wherein the predetermined voltage level is defined as a voltage level below which, within a frequency range, the real component of the measured impedance of the soft-short-circuited battery is significantly different from the real component of the reference impedance of the healthy battery.

[0033] 10. The method according to Scheme 1, wherein at approximately the same temperature, N z The impedance of the battery is measured at several frequency points.

[0034] 11. The method according to Scheme 1, wherein the battery is a lithium-ion battery and wherein the predetermined voltage level is approximately 3.5 volts.

[0035] 12. A method for detecting a soft short circuit in a battery, comprising:

[0036] N in the frequency range z At each frequency point and at the corresponding main voltage and alternative voltage, the battery impedance is measured. Each main voltage and alternative voltage is higher than a predetermined voltage level, thus generating N. z For the corresponding measured primary impedance and alternative impedance, each primary impedance and alternative impedance has a corresponding real component;

[0037] N is calculated by comparing the corresponding real component of the measured principal impedance with the corresponding real component of the measured alternative impedance. z The corresponding measured impedance error for each pair is calculated, resulting in N. z Each corresponding measured impedance error;

[0038] N is calculated by comparing the corresponding real component of the corresponding main reference impedance corresponding to the main voltage with the corresponding real component of the corresponding alternative reference impedance corresponding to the alternative voltage. z The corresponding reference impedance error for each pair is calculated, thus generating N. z One corresponding reference impedance error;

[0039] N is calculated by dividing the difference between the corresponding measured impedance error and the corresponding reference impedance error by the corresponding reference impedance error. zThe corresponding error for each pair of errors, thus generating an error of N. z One corresponding error;

[0040] Determine the error N z The number of times that one of the errors exceeds the maximum allowable error; and

[0041] If the number of occurrences exceeds the threshold, the battery will be identified as having a soft short circuit.

[0042] 13. The method according to scheme 12, wherein in N z Impedance measurements at each frequency point were performed using electrochemical impedance spectroscopy.

[0043] 14. The method according to Scheme 12, wherein the frequency range is approximately 0.01 to 10 Hz.

[0044] 15. The method according to Scheme 12, wherein at least one of the primary reference impedance and the alternative reference impedance is:

[0045] The average real impedance component acting as a proxy for a healthy battery; or

[0046] The corresponding members of the set representing the real impedance components of a healthy battery.

[0047] 16. The method according to claim 15, wherein the average real impedance component is obtained from the average of the corresponding real components of the corresponding impedances from two or more other cells configured for use with the battery, and wherein each corresponding member of the set of real impedance components corresponds to N. z One of the corresponding frequency points out of a set of frequency points.

[0048] 17. The method according to Scheme 12, wherein the predetermined voltage level is defined as a voltage level below which, within a frequency range, the real component of the measured impedance of the soft-short-circuit battery is significantly different from the real component of the reference impedance of the healthy battery.

[0049] 18. The method according to Scheme 12, wherein the primary impedance and the alternative impedance are measured at approximately the same temperature.

[0050] 19. The method according to claim 12, wherein the battery is a lithium-ion battery and wherein the predetermined voltage level is approximately 3.5 volts.

[0051] 20. A vehicle having onboard capability for detecting soft short circuits in a battery, comprising:

[0052] A vehicle body operably supports a propulsion system, an electrical system, a battery, and an electrochemical impedance spectroscopy (EIS) system, wherein the propulsion system, the battery, and the EIS system are all operably connected to the electrical system, and wherein the EIS system is configured to execute at least one of a first algorithm and a second algorithm;

[0053] The first algorithm includes:

[0054] Using the EIS system in the frequency range N z The impedance of the battery is measured at a frequency point and at a first voltage below a predetermined voltage level, thereby generating N. z Each first impedance is measured in a corresponding manner, and each first impedance has a corresponding real component.

[0055] N is calculated by comparing the corresponding real component of the first impedance for each measurement with the corresponding first reference impedance representing a healthy battery. z The corresponding principal error of each of the first impedance measurements, thus generating N z One corresponding principal error;

[0056] Determine N z The number of times that one of the main errors is greater than the threshold error; and

[0057] If the number of occurrences exceeds a threshold, the battery will be identified as having a soft short circuit; and

[0058] The second algorithm includes:

[0059] Using the EIS system in the frequency range N z The impedance of the battery is measured at several frequency points and at corresponding second and third voltages, both above a predetermined voltage level, thereby generating N. z For the corresponding measured second and third impedances, each impedance has a corresponding real component;

[0060] N is calculated by comparing the corresponding real component of the measured second impedance with the corresponding real component of the measured third impedance. z The corresponding measured impedance error for each pair is calculated, resulting in N. z Each corresponding measured impedance error;

[0061] N is calculated by comparing the corresponding real component of the corresponding second reference impedance corresponding to the second voltage with the corresponding real component of the corresponding third reference impedance corresponding to the third voltage. z The corresponding reference impedance error for each pair is calculated, thus generating N. z A corresponding reference impedance error; N is calculated by dividing the difference between the corresponding measured impedance error and the corresponding reference impedance error by the corresponding reference impedance error. zThe corresponding error for each pair of errors, thus generating an error of N. z One corresponding error;

[0062] Determine the error N z The number of times that one of the errors exceeds the maximum allowable error; and

[0063] If the number of occurrences exceeds the threshold, the battery will be identified as having a soft short circuit.

[0064] The foregoing features and advantages, as well as other features and advantages, of this teaching will become apparent when considered in conjunction with the accompanying drawings, from the following detailed description of some of the best modes and other embodiments for carrying out this teaching as defined in the appended claims. Attached Figure Description

[0065] Figure 1 This is a block diagram of a system that can be operatively connected to a vehicle for detecting soft short circuits in a battery.

[0066] Figure 2 This is a block diagram of a vehicle with onboard capability to detect soft short circuits in the battery.

[0067] Figure 3 It is a graph showing multiple voltage levels.

[0068] Figure 4 It is a block diagram of the battery impedance at three voltage levels and its corresponding real and imaginary components.

[0069] Figure 5 It is a block diagram of the battery impedance at the first voltage, including its real and imaginary components.

[0070] Figure 6 It is a block diagram of the battery's impedance at the main voltage and the alternative voltage, and its corresponding real and imaginary components.

[0071] Figure 7 It is a block diagram of the battery's impedance at the first voltage, the second voltage, and the third voltage, and its corresponding real and imaginary components.

[0072] Figure 8 It is a graph showing the imaginary component of impedance relative to the real component of impedance for multiple frequencies and voltage levels.

[0073] Figure 9 It is a graph of the imaginary component of impedance relative to the real component of impedance relative to voltage at a single frequency for multiple voltage levels.

[0074] Figure 10 It is a graph showing the imaginary component of impedance relative to the real component of impedance relative to voltage for multiple frequencies and voltage levels.

[0075] Figure 11 It is a graph of the frequency relative to the real component of the impedance for multiple voltages in the low to medium voltage range.

[0076] Figure 12 It is a graph of the frequency versus the real component of the impedance at a given voltage in the low-voltage region for healthy batteries and soft-short-circuit batteries.

[0077] Figure 13A Is for Figure 12 The graph shows the error between the real components of the impedance of a healthy battery and a soft-short-circuited battery relative to frequency, with the real component of the impedance of the healthy battery used as a baseline.

[0078] Figure 13B yes Figure 13A The percentage error plot of the curve shown has the real component of the impedance of the healthy battery used as the baseline.

[0079] Figure 14 It is a graph showing the imaginary component of impedance relative to the real component of impedance for multiple voltages in the medium to high voltage range.

[0080] Figure 15 It is a graph of the frequency relative to the real component of the impedance for multiple voltages in the medium to high voltage range.

[0081] Figure 16A This is a graph showing the difference between the real component of the impedance measured at a main voltage of 3.6V and the real component of the impedance measured at an alternative voltage of 4.0V for a healthy battery and two soft-short-circuited (500Ω and 1000Ω) batteries, relative to frequency.

[0082] Figure 16B This is a graph showing the error between the measured impedance error and the reference impedance error relative to the frequency for a healthy battery and two soft-short-circuited (500Ω and 1000Ω) batteries.

[0083] Figure 16C yes Figure 16B The curve shown is a percentage error plot, where the reference impedance error is used as the baseline.

[0084] Figure 17A -C corresponds to respectively Figure 16A The graph for component -C is shown, but using a main voltage of 3.6V and an alternative voltage of 3.8V.

[0085] Figure 18A -C corresponds to respectively Figure 16A The graph for component -C is shown, but using a mains voltage of 3.8V and an alternative voltage of 4.0V.

[0086] Figure 19This is a flowchart of a first method for detecting soft short circuits in a battery.

[0087] Figure 20 For N z A table showing the measured impedance of the battery at several frequency points and at the first voltage, along with their corresponding real and imaginary components.

[0088] Figure 21 This is a block diagram illustrating the error calculation of the first method.

[0089] Figure 22 For N z A table of reference impedances and their corresponding real and imaginary components at each frequency point and at the first voltage, main voltage, and alternative voltage.

[0090] Figure 23 This is a block diagram showing the impedance of a healthy battery and its real and imaginary components.

[0091] Figure 24 It is N z A member table of the set of real impedance components at each frequency point.

[0092] Figure 25 It is a block diagram of several other batteries and their corresponding impedances and corresponding real and imaginary components.

[0093] Figure 26 This is a flowchart illustrating the calculation of the occurrence count of the first method.

[0094] Figure 27 This is a block diagram showing how to determine whether the number of occurrences exceeds a threshold for the first, second, and third methods.

[0095] Figure 28 It is a block diagram of the impedance of a soft short-circuit battery and its real and imaginary components.

[0096] Figure 29 This is a flowchart of a second method for detecting soft short circuits in a battery.

[0097] Figure 30 For N z A table showing the measured impedance of the battery and its corresponding real and imaginary components at each frequency point and at the main voltage and alternative voltage.

[0098] Figure 31 This is a block diagram illustrating the measurement impedance error calculation for the second method.

[0099] Figure 32 This is a block diagram illustrating the calculation of the reference impedance error using the second method.

[0100] Figure 33 This is a block diagram illustrating the error calculation for the second and third methods.

[0101] Figure 34 This is a flowchart illustrating the calculation of the occurrence count for the second method.

[0102] Figure 35 This is a flowchart of a first method for detecting soft short circuits in a battery.

[0103] Figure 36 For N z A table showing the measured impedance of the battery and its corresponding real and imaginary components at several frequency points and at the first, second, and third voltages.

[0104] Figure 37 For N z A table showing the reference impedance and its corresponding real and imaginary components at each frequency point and at the first, second, and third voltages.

[0105] Figure 38 This is a block diagram illustrating the main error calculation for the third method.

[0106] Figure 39 This is a block diagram illustrating the calculation of the first occurrence count using the third method.

[0107] Figure 40 This is a block diagram illustrating the measurement impedance error calculation using the third method.

[0108] Figure 41 This is a block diagram illustrating the calculation of the reference impedance error using the third method.

[0109] Figure 42 This is a logic flowchart based on the first algorithm used to detect soft short circuits in the battery.

[0110] Figure 43 This is a logic flowchart based on the second algorithm used to detect soft short circuits in the battery. Detailed Implementation

[0111] Referring now to the accompanying drawings, in which the same numbers in several views denote the same parts, methods 100, 200, 300 for detecting a soft short circuit SS in battery B, a system 10 for detecting a soft short circuit SS in battery B, and various embodiments of a vehicle VEH having onboard capability for detecting a soft short circuit SS in battery B are shown and described herein.

[0112] Figure 1A block diagram of a system 10 for detecting a soft short circuit SS in battery B, operatively connected to a vehicle VEH, is shown. The vehicle VEH includes an electrical system ES, a propulsion system PS, an electric auxiliary system AS, and battery B connected to the electrical system ES. System 10 includes an electrochemical impedance spectroscopy (EIS) system EIS configured to be electrically connected to battery B, and may also include an input system 20 (e.g., a keyboard, mouse, barcode scanner, RFID scanner, etc.) and an output system 30 (e.g., a display monitor, register address / flag, etc.). The EIS system EIS and optional input / output systems 20, 30 may be connected to a controller or control system 40, which may include a processor 50, a memory 60 configured to contain instructions 70 (e.g., control codes), and a lookup table LUT. In the illustrated arrangement, the vehicle VEH may be temporarily connected to system 10 to detect whether battery B in the vehicle VEH has a soft short circuit SS.

[0113] Figure 2 A block diagram of a vehicle VEH with onboard capability for detecting a soft short circuit SS in the vehicle battery B is shown. Here, the vehicle VEH includes the body VB, which supports, carries, and / or accommodates components similar to... Figure 1 The vehicle system 10 is shown. Here, the vehicle system 10 includes an EIS system (EIS), an input system 20, an output system 40, and a controller / control system 40. The controller / control system 40 includes a processor 50 and a memory 60 configured to store instructions 70 and lookup tables (LUTs). The vehicle body VB also supports, carries, and / or houses the electrical system ES, the propulsion system PS, the electric auxiliary system AS, and the battery B, which is connected to the electrical system ES. In this arrangement, the battery B can be permanently connected to the EIS system (e.g., in a continuous monitoring arrangement), or intermittently / temporarily connected to the EIS system whenever it is desired to determine whether the battery B may have a soft short circuit SS. Furthermore, the vehicle VEH can be a motor vehicle, such as a car, truck, boat, aircraft, etc.

[0114] exist Figure 1-2 In any one or both of the arrangements shown, instruction 70 may include control code for causing processor 50 and EIS system EIS to execute one or more of first algorithm or method 100, second algorithm or method 200 and third algorithm or method 300 for detecting soft short circuit SS in battery B.

[0115] Generally, the first algorithm or method 100 is applicable to low to medium voltage regions or voltage levels, while the second algorithm or method 200 is applicable to medium to high voltage regions or voltage levels. However, in some arrangements involving battery type, battery chemistry, operating conditions, temperature range, etc., either algorithm / method 100 or 200 can be applied to any voltage region or voltage level. lev Therefore, in this paper, the concept of a given voltage region or voltage level V is discussed. lev Any statement that may apply to one algorithm / method or another should not be construed as a requirement or limitation. For example, Figure 3 The diagram shows various voltage levels V ranging from zero volts (0V) to the first voltage V1, the second voltage V2, and the third voltage V3. lev The predetermined voltage level V pre This is shown between the first and second voltages V1 and V2. In some cases, the first algorithm or method 100 may be more suitable than the second algorithm or method 200 for voltage levels below a predetermined voltage level V. pre voltage level V lev (For example, at a first voltage V1), while the second algorithm or method 200 may be more suitable than the first algorithm or method 100 for voltage levels equal to or greater than a predetermined voltage level V. pre voltage level V lev (For example, at the second and third voltage levels V2 and V3).

[0116] Figure 4 The diagram shows battery B at three different voltage levels V. lev (that is, at the first or selected voltage V1, at the second or main voltage V2, V...) m And in the third voltage or alternative voltage V3, V a The block diagram of the impedance Z and its corresponding real and imaginary components ReZ, ImZ. (As used here, the second and main voltages V2, V...) m They can be equal to each other, but they are given different names to distinguish their use in the first and second algorithms / methods 100 and 200, respectively. Similarly, the third and alternative voltages V3 and V... a They can be equal to each other, but they are given different names to distinguish their use in the first and second algorithms / methods 100 and 200, respectively. At the first voltage V1, a first measuring impedance Z1 can be measured, which has a real component ReZ1 and an imaginary component ImZ1. At the second or main voltage V2, V... m At this location, the second or primary measuring impedance Z2, Z can be measured. m It has real components ReZ2 and ReZ. m and imaginary components ImZ2, ImZ m And in the third or alternative voltage V3, Va It can measure the third or alternative measurement impedance Z3, Z a It has real components ReZ3 and ReZ a And imaginary components ImZ3, ImZ a In any case, it can be noted that the impedance Z of battery B is generally a function of battery chemistry, voltage V, temperature T, and sometimes other factors, and each impedance Z has a modulus—sometimes denoted as "ModZ" (but not shown in the figure)—where ModZ = sqrt[(ReZ)]. 2 +(ImZ) 2 (Therefore, any calculation involving the modulus ModZ of impedance Z will inherently involve the real component ReZ of impedance Z.)

[0117] Figure 5 A block diagram showing the impedance of battery B at the first voltage V1 and the first frequency F1, along with its real and imaginary components, is presented here (and below). Figure 6-7 (in Chinese), already used Figure 4 The impedance and component names shown are prefixed with "1" to indicate that these specific impedances and components are associated with the first frequency point F1. As can be seen throughout the rest of this specification and the accompanying drawings, additional subscripts may be appended to indicate impedances and components associated with other frequency points F, such as at the second frequency point F2 (with a "2" subscript), at the Nth frequency point F1. z Frequency point F Nz (with the subscript "Nz"), etc. Therefore, as Figure 5 As shown, at the first voltage V1 and the first frequency point F1, battery B can have a first impedance Z. 1,1 It has real component ReZ 1,1 imaginary component ImZ 1,1 (Here, the first "1" subscript indicates the first voltage V1, and the second "1" subscript indicates the first frequency point F1.) As explained further below, here... Figure 5 The subscripts and naming conventions shown refer to a first algorithm or method 100, and a third algorithm or method 300 that utilizes elements of the first algorithm or method 100.

[0118] Figure 6 Battery B is at the first frequency point F1 with the main voltage V m and alternative voltage V a A block diagram of the impedance and its corresponding real and imaginary components. Here, at the main voltage V... m Battery B can have a main impedance Z m,1 It has real component ReZ m,1 imaginary component ImZ m,1 (Here, the first "m" subscript indicates the main voltage V.)m And the second subscript "1" indicates the first frequency point F1. And in the alternative voltage V a Under these conditions, battery B can have a substitute impedance Z. a,1 It has real component ReZ a,1 imaginary component ImZ a,1 (Here, the first "a" subscript indicates the alternative voltage V.) a And the second subscript "1" indicates the first frequency point F1. As explained further below, here... Figure 6 The subscripts and naming conventions shown refer to the second algorithm or method 200.

[0119] Figure 7 This is a block diagram showing the impedance of battery B at the first frequency point F1 under the first voltage V1, the second voltage V2, and the third voltage V3, along with their corresponding real and imaginary components. Here, at the first voltage V1, battery B can have a first impedance Z. 1,1 It has real component ReZ 1,1 imaginary component ImZ 1,1 (Here, the first "1" subscript indicates the first voltage V1, and the second "1" subscript indicates the first frequency point F1.) At the second voltage V2, battery B can have a second impedance Z. 2,1 It has real component ReZ 2,1 imaginary component ImZ 2,1 (Here, the first subscript "2" indicates the second voltage V2, and the second subscript "1" indicates the first frequency point F1.) And at the third voltage V3, battery B can have a third impedance Z. 3,1 It has real component ReZ 3,1 imaginary component ImZ 3,1 (Here, the first subscript "3" indicates the third voltage V3, and the second subscript "1" indicates the first frequency point F1). As explained further below, here... Figure 7 The subscripts and naming conventions shown refer to a third algorithm or method 300 that utilizes elements of the first algorithm or method 100 and the second algorithm or method 200.

[0120] The following Figure 8-18C Various impedance, voltage, and frequency curves that can be measured on battery B via the EIS system are shown. More specifically, the battery B measured in these curves is a lithium-ion battery LIB configured for use in an electric motor vehicle under normal operating temperature and nominal charge conditions.

[0121] Figure 8This diagram shows graphs of the negative imaginary component of impedance, ImZ, versus the real component of impedance, ReZ (both measured in ohms), for multiple frequencies (measured in Hertz (Hz)) and voltages (measured in Volts (V)). Note that in this view, the curves for multiple frequencies and voltages appear to overlap somewhat. However, Figure 9-10 It shows the relationship with Figure 8 Similar information, but with the addition of an extra or third dimension (i.e., voltage), which allows for a clearer view of these curves. Specifically, Figure 9 The diagram shows the negative imaginary component of the impedance, -ImZ, relative to the real component of the impedance, ReZ, relative to the voltage for eight discrete voltages and a single cell B. Figure 10 It shows the relationship with Figure 9 Same view, but for multiple batteries B.

[0122] Figure 11 The graphs shown depict the real component ReZ of frequency (Freq) versus impedance for multiple voltages in the low to medium voltage range, which may be applicable, for example, to the first algorithm or method 100. These graphs show values ​​from 10... -2 Hz to approximately 3x10 3 The Hz range, but note how these curves change at voltages below approximately 3.4V (e.g., 3.3V and lower). -2 Up to 10 0 The impedance extends further within the frequency range FR (i.e., 0.01 to 1 Hz). In other words, for a given battery temperature and state of charge, the impedance of this lithium-ion battery LIB exhibits a wide range of values ​​in the low voltage region, less than approximately 3.4 to 3.5 V.

[0123] Figure 12 This is a graph showing the frequency versus the real component ReZ of the impedance at 3.3V for both a healthy battery HB (i.e., a battery without a soft short circuit SS) and a soft short circuit battery SSB (at 1000Ω). Similar to... Figure 11 The curve here is shown as starting from 10. - 2 Hz to approximately 3×10 3 Hz, but note how the HB and SSB curves differ around 10 Hz. 0 Hz (i.e., 1Hz) begins to separate from each other, and further separates from each other downwards to 10. -2 Hz (0.01Hz), therefore at approximately 10 -2 Up to 10 0 The frequency range FR extends separately in Hz (i.e., approximately 0.01 to 1 Hz). If the examination is similar to Figure 12The curve shows a certain trend, but for voltages greater than the 3.3V measured here, such as 3.4 to 3.5V and higher, you will see a curve at 10. -2 Up to 10 0 At frequencies within the Hz range (FR), the HB and SSB curves do not diverge as much as they do at voltages less than approximately 3.4 to 3.5 V. This approximately 3.4 to 3.5 V voltage level can be defined as the predetermined voltage level V. pre Below the predetermined voltage level, the real component of the measured impedance of the soft-short-circuit battery SSB deviates significantly from and differs from the real component of the reference impedance of the healthy battery HB within the frequency range FR.

[0124] Figure 13A It is for healthy batteries HB and Figure 12 The error Er between the real component ReZ of the impedance of the soft short-circuited battery SSB and the frequency is plotted, with the real component ReZ of the impedance of the healthy battery HB used as the baseline. Figure 13A It also includes a horizontal dashed line, which shows the threshold error Er. c This will be explained further below. Relatedly, Figure 13B It shows Figure 13A The graph shown represents the percentage error of the curves, where the real component ReZ of the impedance of the healthy battery HB is used as the baseline (i.e., the error Er of the SSB curve divided by the amount of the HB curve). Similar to... Figure 13A , Figure 13B This also includes horizontal dashed lines, which can optionally be used as thresholds, as described further below.

[0125] Figure 14 The graph shows the negative imaginary component of impedance, -ImZ, versus the real component, ReZ, for multiple voltages in the medium to high voltage range. Figure 15 The graph shows the real component ReZ of the frequency versus the impedance for multiple voltages in the medium to high voltage range.

[0126] Figure 16A The diagram shows the main voltage V at 3.6V for a healthy battery HB (denoted as "NoSS" in the attached diagram, indicating "no soft short circuit") and two soft-short-circuited batteries SSB (at 500Ω and 1000Ω). m The real component ReZ of the impedance measured at the point and the alternative voltage V at 4.0V. a A graph showing the difference between the real components Re and Z of the measured impedance versus frequency. Relatedly, Figure 16B The measured impedance error Er is shown for a healthy battery HB and two soft-short-circuited batteries SSB (at 500Ω and 1000Ω). meas and reference impedance error Er ref Error Er betweenerr A graph relative to frequency, and Figure 16C It shows Figure 16B The graph shown represents the percentage error of the reference impedance Er. ref It was used as a baseline.

[0127] Figure 17A -C corresponds to respectively Figure 16A -C shows the component's graph, but using a mains voltage of 3.6V. m and the alternative voltage V of 3.8V a ,and Figure 18A -C also corresponds to Figure 16A -C shows the component's graph, but using a mains voltage of 3.8V. m and the alternative voltage V of 4.0V a .

[0128] With the foregoing background, the algorithms or methods 100, 200, 300, system 10, and vehicle VEH according to this disclosure will now be described in detail.

[0129] Figure 19 A flowchart of the first algorithm or method 100 is shown. At block 110, N within the frequency range FR... z At a frequency point and below a predetermined voltage level V pre The impedance Z of battery B is measured at the selected or first voltage V1 (e.g., using an EIS system, EIS), thereby generating N. z Each measured impedance Z1 has a corresponding real component ReZ1 and a corresponding imaginary component ImZ1. For example, if ten specific frequency points F (i.e., N) are selected from the frequency range FR... z =10), then the first frequency point F can be designated as F1, the second frequency point F can be designated as F2, and the tenth or Nth frequency point F can be designated as F1. z Frequency point F can be specified as F Nz In this example, box 110 will produce ten measured impedances Z1 (because N z =10), which will include ten real components ReZ1 and ten imaginary components ImZ1. For example, see Figure 20 The table shown illustrates N z A frequency point F (i.e., F1, F2, ... F) Nz N measured at the first voltage V1 z The measured impedance Z1 (i.e., Z) 1,1 Z 1,2 , ...Z 1,Nz ), and N z The corresponding real component ReZ1 of the measured impedance Z1 (i.e., ReZ)1,1 ReZ 1,2 ...ReZ 1,Nz ) and the imaginary component ImZ1 (i.e., ImZ 1,1 ImZ 1,2 , ...ImZ 1,Nz ).

[0130] Now back Figure 19 In box 120, the corresponding real component ReZ1 of each measured impedance Z1 is compared with the corresponding reference impedance Z representing the healthy battery HB. ref Compare to N z Each of the measured impedances Z1 is used to calculate the corresponding error Er, thereby generating N. z The corresponding calculation error Er. In Figure 21 block diagram and Figure 22 The first four columns of the table further illustrate box 120. Figure 21 The diagram shows the frequency points from the first frequency point F1, the second frequency point F2, up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first measured impedance Z... 1,1 The real component ReZ 1,1 The first instance Z with reference impedance ref,1 The real component ReZ ref,1 This comparison (e.g., subtraction) produces the first calculation error Er1. Similarly, for the second frequency point F2, the second measured impedance Z is... 1,2 The real component ReZ 1,2 The second instance Z with reference impedance ref,2 The real component ReZ ref,2 Comparing (e.g., subtracting from it) produces a second calculation error Er2, and for the Nth... z Frequency point F Nz , will the Nth z Measured impedance Z 1,Nz The real component ReZ 1,Nz The Nth reference impedance z Example Z ref,Nz The real component ReZ ref,Nz Comparing (e.g., subtracting from), this produces the Nth... z Calculation error Er Nz .

[0131] exist Figure 22 In the table, the first four columns relate to the reference impedance Z. ref Various examples of this can be used in conjunction with a first algorithm or method 100 utilizing a first voltage V1. For a first frequency point F1, a first example of a reference impedance Z... ref,1 Having the first real component ReZref,1 (and the corresponding imaginary component not shown). Similarly, for the second frequency point F2, the second instance Z of the reference impedance. ref,2 Having a second real component ReZ ref,2 (and the corresponding imaginary components not shown), and for the Nth z Frequency point F Nz The Nth reference impedance z Example Z ref,Nz Having the Nth z Real component ReZ ref,Nz (and the corresponding imaginary components not shown).

[0132] Figure 23-24 The reference impedance Z is further clarified. ref As mentioned above, the reference impedance Z ref HB represents a healthy battery, such as Figure 23 As shown. The healthy battery HB has a reference impedance Z. ref It has real component ReZ ref imaginary component ImZ ref Note that, although Figure 23 Only a single reference impedance Z is shown. ref However, this is only for the sake of simplicity, because in reality, a healthy HB battery can have N... z A single reference impedance Z ref N z Each of the frequency points F has a reference impedance Z. ref In addition, note that Figure 23 Only the real component ReZ at each frequency point F is shown. ref (i.e., the imaginary component ImZ) ref (Not shown).

[0133] Reference impedance Z ref This could be an actual measurement of the healthy battery HB at various frequency points F and a first voltage V1 at a given temperature. Alternatively, as... Figure 23-24 As shown, the reference impedance Z ref It can be: (i) the average real impedance component ReZ used as a proxy for the healthy battery HB avg ; or (ii) the corresponding members M of the set S representing the real impedance components of the healthy battery HB (i.e., M1, M2, ... M Nz ), where each corresponding member M of the set S of real impedance components ReZ can correspond to N. z The corresponding frequency point among the frequency points. Note the average real impedance component ReZ. avg It can be a single value that can be used for all frequency points F, or it can be an array of values ​​(e.g., with a corresponding unique value assigned to each frequency point F).

[0134] Figure 25 A block diagram showing several other battery OBs and their corresponding impedances and corresponding real and imaginary components is illustrated. These other battery OBs can be additional batteries or other batteries besides the main battery B being evaluated, such as other batteries in a battery pack with the main battery B and configured to be used with battery B. The diagram shows the first other battery OB1, the second other battery OB2, and so on up to the Jth other battery OB. J Having a corresponding impedance Z determined at a first voltage V1 and a first frequency point F1. OB1,1 Z OB2,1 , ...Z OBJ,1 and the corresponding real component ReZ OB1,1 ReZ OB2,1 ...ReZ OBJ,1 imaginary component ImZ OB1,1 ImZ OB2,1 , ...ImZ OBJ,1 Average real impedance component ReZ avg These real components ReZ OB1,1 ReZ OB2,1 ...ReZ OBJ,1 The average value is obtained from the average value. As mentioned above, the average real impedance component ReZ avg It can be a single value available for all frequency points F, or it can be an array of values ​​with a corresponding unique value / average value determined for each frequency point F. In either case, each reference impedance Z ref Optionally, it can be stored in a lookup table (LUT) and obtained from the lookup table.

[0135] Back to Figure 19 In box 130, when N z Any one of the calculated errors Er is greater than the threshold error Er c When, determine the number of occurrences N. occ .exist Figure 26 The block diagram further illustrates this block 130, which shows the first frequency point F1, the second frequency point F2, and so on up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first calculation error Er1 is compared with the threshold error Er. c Comparison: If the first calculation error Er1 is not greater than the threshold error Er c If the first calculation error Er1 is greater than the threshold error Er, then zero (0) is generated, or if the first calculation error Er1 is greater than the threshold error Er1, then zero (0) is generated. c Then, a (1) is generated. Similarly, for the second frequency point F2, the second calculation error Er2 is compared with the threshold error Er. c If the second calculation error Er2 is not greater than the threshold error Er, then...c If the second calculation error Er2 is greater than the threshold error Er, then zero (0) is generated, or if the second calculation error Er2 is greater than the threshold error Er c Then a (1) is generated, and for the Nth z Frequency point F Nz , will the Nth z Calculation error Er Nz With threshold error Er c Compare, if the Nth z Calculation error Er Nz Not greater than the threshold error Er c If , then zero (0) is produced, or if the Nth z Calculation error Er Nz Error greater than threshold Er c Then, a (1) is generated. The number of occurrences N occ It's the sum of all these 0s and 1s.

[0136] Finally, in box 140, and as Figure 27 As shown in the flowchart, if the number of occurrences N occ Greater than threshold N c Then battery B is identified as having a soft short circuit SS. As shown in the figure, if the number of occurrences N occ Greater than threshold N c If a soft short circuit SS is detected, it can be indicated by setting a flag in memory 60, by inverting or changing a value in a register (e.g., from 0 to 1), by activating an indicator light or audible alarm, etc. However, if the number of occurrences is N... occ Not greater than threshold N c If the condition is met, it is determined that there is no soft short circuit SS; this can be indicated by a flag set in memory 60, by inverting or changing a value in a register (e.g., from 1 to 0), by turning an indicator light or an audible alarm on or off, etc.

[0137] The frequency range FR can be approximately 0.01 to 1 Hz, and the impedance Z of battery B can be approximately the same at temperature T in N. z Measurements were taken at each frequency point.

[0138] Figure 28 The impedance Z of a soft-short-circuit battery SSB with a soft short-circuit SS is shown. SS Together with the real and imaginary components of the impedance ReZ SS ImZ SS The block diagram above. Figure 12 As stated, and also as Figure 28 As shown, the predetermined voltage level V pre It can be defined as voltage level V lev At this voltage level V levBelow is the real component (i.e., ReZ) of the measured impedance of the soft short-circuit battery SSB. SS The real component of the reference impedance of the healthy battery HB (i.e., ReZ) ref The differences are significant within the frequency range FR. For example... Figure 28 As shown, in ReZ SS and ReZ ref They are compared to each other to determine whether they differ from each other by more than a difference threshold Δ. thr Optionally, battery B can be a lithium-ion battery LIB, wherein a predetermined voltage level V is specified. pre It is approximately 3.5 volts.

[0139] Figure 29 A flowchart of the second algorithm or method 200 is shown. At block 210, N within the frequency range FR... z At each frequency point and at the corresponding main voltage and alternative voltage V m V a The impedance Z of battery B is measured at the location, along with the main voltage and the replacement voltage V. m V a All are higher than the predetermined voltage level V pre .like Figure 30 As shown in the table, this measurement produces N z For the corresponding measured principal impedance and alternative impedance Z m Z a Each impedance has a corresponding real component ReZ. m ReZ a and the corresponding imaginary component ImZ m ImZ a For example, at the first frequency point F1 within the frequency range FR, the first measured main impedance Z m,1 It has the corresponding first real component and imaginary component ReZ m,1 ImZ m,1 And the first measurement of the alternative impedance Z a,1 It has the corresponding first real component and imaginary component ReZ a,1 ImZ a,1 Similarly, at the second frequency point F2, the second measured main impedance Z m,2 It has corresponding second real and imaginary components ReZ m,2 ImZ m,2 And the second measurement substitute impedance Z a,2 It has corresponding second real and imaginary components ReZ a,2 ImZ a,2 And on the Nth z Frequency point F Nz , Nth z Measuring the principal impedance Z m,Nz Having the corresponding Nthz Real and imaginary components ReZ m,Nz ImZ m,Nz And the Nth z Measuring the alternative impedance Z a,Nz Having the corresponding Nth z Real and imaginary components ReZ a,Nz ImZ a,Nz .

[0140] In box 220, the corresponding measured principal impedance Z is... m The corresponding real component ReZ m With the corresponding measured alternative impedance Z a The corresponding real component ReZ a Compare to N z For each pair, calculate the corresponding measurement impedance error Er. meas Thus generating N z The corresponding measured impedance error Er meas The box 220 is in Figure 31 The block diagram further illustrates the conditions for the first frequency point F1, the second frequency point F2, and up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first measured main impedance Z. m,1 The real component ReZ m,1 With the first measured alternative impedance Z a,1 The real component ReZ a,1 Comparing (e.g., subtracting) produces the first measurement impedance error Er. meas,1 Similarly, for the second frequency point F2, the second measured main impedance Z... m,2 The real component ReZ m,2 With the second measured alternative impedance Z a,2 The real component ReZ a,2 Comparing (e.g., subtracting from it) produces a second measurement impedance error Er. meas,2 And for the Nth z Frequency point F Nz , will the Nth z Measuring the principal impedance Z m,Nz The real component ReZ m,Nz With the Nth z Measuring the alternative impedance Z a,Nz The real component ReZ a,Nz Comparisons (e.g., subtraction) produce the Nth... z Measurement impedance error Er meas,Nz .

[0141] In box 230, by corresponding to the main voltage V mThe corresponding main reference impedance Z m-ref The corresponding real component ReZ m-ref With the corresponding substitution voltage V a The corresponding alternative reference impedance Z a-ref The corresponding real component ReZ a-ref For comparison, N z Calculate the corresponding reference impedance error Er for each pair in the pair. ref Thus generating N z The corresponding reference impedance error Er ref .exist Figure 32 In the block diagram and in Figure 22 The first, second, and fifth through eighth columns of the table further illustrate box 230. Figure 32 The diagram shows the frequency points from the first frequency point F1, the second frequency point F2, up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first main reference impedance Z... m-ref,1 The real component ReZ m-ref,1 With the first alternative reference impedance Z a-ref,1 The real component ReZ a-ref,1 The comparison (e.g., subtraction) produces the first reference impedance error Er. ref,1 Similarly, for the second frequency point F2, the second primary reference impedance Z is... m-ref,2 The real component ReZ m-ref,2 With the second alternative reference impedance Z a-ref,2 The real component ReZ a-ref,2 This comparison (e.g., subtraction) produces a second reference impedance error Er. ref,2 And for the Nth z Frequency point F Nz , will the Nth z Main reference impedance Z m-ref,Nz The real component ReZ m-ref,Nz With the Nth z Alternate reference impedance Z a-ref,Nz The real component ReZ a-ref,Nz Comparisons (e.g., subtraction) produce the Nth... z Reference impedance error Er ref,Nz .

[0142] exist Figure 22 In the table, columns one, two, and five through eight relate to the reference impedance Z. ref It can be used with the main voltage and the alternative voltage V m V a The second algorithm or method 200 is used together. For the first frequency point F1, the first primary reference impedance Z m-ref,1 Having the first real component ReZm-ref,1 (and the corresponding imaginary component not shown), and the first alternative reference impedance Z a-ref,1 Having the first real component ReZ a-ref,1 (and the corresponding imaginary components not shown). Similarly, for the second frequency point F2, the second principal reference impedance Z m-ref,2 Having a second real component ReZ m-ref,2 (and the corresponding imaginary component not shown), and the second alternative reference impedance Z a-ref,2 Having a second real component ReZ a-ref,2 (and corresponding imaginary components not shown); and for the Nth... z Frequency point F Nz , Nth z Main reference impedance Z m-ref,Nz Having the Nth z Real component ReZ m-ref,Nz (and the corresponding imaginary components not shown), and the Nth z Alternate reference impedance Z a-ref,Nz Having the Nth z Real component ReZ a-ref,Nz (and the corresponding imaginary components not shown).

[0143] In box 240, the corresponding measured impedance error Er is... meas and the corresponding reference impedance error Er ref The difference between them divided by the corresponding reference impedance error Er ref , for N z The corresponding error Er for each pair of calculated errors in the pair err This results in an error of N. z Each corresponding error Er err .exist Figure 33 The block 240 is further illustrated, showing the first frequency point F1, the second frequency point F2, and so on up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first measured impedance error Er. meas,1 With the first reference impedance error Er ref,1 A comparison is made (e.g., subtracted from), which produces a first difference, diff1; this first difference, diff1, is then divided by the first reference impedance error, Er. ref,1 This generates the first error Er. err,1 Similarly, for the second frequency point F2, the second measured impedance error Er will be... meas,2 With the second reference impedance error Er ref,2 The comparison (e.g., subtraction) produces a second difference, diff2; this second difference, diff2, is then divided by the second reference impedance error, Er. ref,2This generates the second error Er. err,2 And for the Nth... z Frequency point F Nz , will the Nth z Measurement impedance error Er meas,Nz With the Nth z Reference impedance error Er ref,Nz Comparison (e.g., subtraction) yields the Nth... z diff Nz The Nth z diff Nz Then divide by the Nth z Reference impedance error Er ref,Nz This produces the Nth error z Error Er err,Nz .

[0144] In box 250, when the error N z Error Er err Any one greater than the maximum permissible error Er max When, determine the number of occurrences N. occ The box is 250 in Figure 34 The block diagram further illustrates the conditions for the first frequency point F1, the second frequency point F2, and up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first error Er is calculated. err,1 With the maximum permissible error Er max Compare, if the first error Er err,1 Not greater than the maximum permissible error Er max If the first error Er produces zero (0), then the error is zero (0), or if the first error Er err,1 Greater than the maximum permissible error Er max Then, a (1) is generated. Similarly, for the second frequency point F2, the second error Er of the error is... err,2 With the maximum permissible error Er max Compare, if the second error Er err,2 Not greater than the maximum permissible error Er max If the second error Er produces zero (0), then the error will be zero (0), or if the second error Er... err,2 Greater than the maximum permissible error Er max Then, a (1) is generated; and for the Nth... z Frequency point F Nz The Nth error z Error Er err,Nz With the maximum permissible error Er max Compare, if the Nth error z Error Ererr,Nz Not greater than the maximum permissible error Er max If the Nth error is zero (0), then zero (0) is produced, or if the Nth error is... z Error Er err,Nz Greater than the maximum permissible error Er max Then, a (1) is generated. The number of occurrences N occ It's the sum of all these 0s and 1s.

[0145] And finally, in box 260, and as Figure 27 As shown in the flowchart, if the number of occurrences N occ Greater than threshold N c If so, battery B is identified as having a soft short circuit SS.

[0146] In this second algorithm or method 200, the main impedance Z m It can be done at the main temperature T m Measure and replace impedance Z a It can be used at the alternative temperature T a Measurements, and in some cases, these impedances Z m Z a It can be measured at approximately the same temperature (i.e., T). m ≈T a ).

[0147] Figure 35 A flowchart of a third algorithm or method 300 is shown, which may utilize elements present in one or both of the first and second algorithms 100, 200. This third algorithm or method 300 may be executed by the system 10 or a vehicle VEH having the onboard capability to execute the third algorithm or method 300.

[0148] The third method 300 begins at “Start” in box 310 and, in box 320, makes an evaluation or decision to execute either the first algorithm 100 (via the branch marked “1”) or the second algorithm 200 (via the branch marked “2”).

[0149] The first algorithm 100 includes: (i) at block 330, using the EIS system EIS within the frequency range FR N... z At a frequency point and below a predetermined voltage level V pre The impedance Z of battery B is measured at the first voltage V1, thereby generating N. z (ii) In box 340, by comparing the corresponding real component ReZ1 of each measured first impedance Z1 with the corresponding first reference impedance Z representing the healthy battery HB. ref1 Compare and calculate N z The corresponding principal error Er of the first impedance Z1 measuredp Thus generating N z Each corresponding principal error Er p (iii) In box 350, determine N. z One principal error Er p One of them is greater than the threshold error Er c The number of times N occurs occ ; and (iv) in box 360, if the number of occurrences N occ Greater than threshold N c If so, battery B will be identified as having a soft short circuit (SS).

[0150] The second algorithm 200 includes: (v) in block 370, using the EIS system EIS within the frequency range FR N. z At each frequency point, and all are above the predetermined voltage level V. pre The impedance Z of battery B is measured at the second and third voltages V2 and V3, thereby generating N. z For the corresponding measured second and third impedances Z2 and Z3, each impedance has a corresponding real component ReZ2 and ReZ3; (vi) in box 380, N is calculated by comparing the corresponding real component ReZ2 of the corresponding measured second impedance Z2 with the corresponding real component ReZ3 of the corresponding measured third impedance Z3. z The corresponding measured impedance error Er for each pair in the pair meas Thus generating N z The corresponding measured impedance error Er meas (vii) In box 390, by passing the corresponding second reference impedance Z corresponding to the second voltage V2 ref2 The corresponding real component ReZ ref2 With the corresponding third reference impedance Z corresponding to the third voltage V3 ref3 The corresponding real component ReZ ref3 Compare and calculate N z The corresponding reference impedance error Er for each pair in the pair ref Thus generating N z The corresponding reference impedance error Er ref (viii) In box 400, by measuring the corresponding impedance error Er meas and the corresponding reference impedance error Er ref The difference between them divided by the corresponding reference impedance error Er ref To calculate N z The corresponding error Er for each pair of errors in the pair err This results in an error of N. z Each corresponding error Er err (ix) In box 410, determine the error N. z Error Er errOne of them is greater than the maximum permissible error Er max The number of times N occurs occ ; and (x) in box 420, if it occurs N times occ Greater than threshold N c If so, battery B will be identified as having a soft short circuit (SS).

[0151] In box 430, an evaluation or decision is made as to whether to repeat the soft short-circuit SS detection process; if yes (“Y”), the process returns to the point before box 320, but if no (“N”), the process proceeds to the “end” of box 440. Note that in this third method 300, the first and second algorithms 100, 200 may utilize the same frequency range FR, or they may utilize different corresponding frequency ranges FR.

[0152] Figure 36 A table showing various impedance measurements (and their corresponding real and imaginary components) that can be generated by the third algorithm or method 300 is provided, and Figure 37 A table showing reference impedances (and their corresponding real components) that can be used with the third algorithm or method 300 is provided. Various portions of these tables may be used during the execution of the third algorithm or method 300, depending on the logical flow. Figure 35 The left column (via the branch marked "1", corresponding to the first algorithm or method 100) or along Figure 35 The right column (via the branch marked "2", corresponding to the second algorithm or method 200).

[0153] If the logical flow of the third algorithm or method 300 follows Figure 35 If the left column is advanced (corresponding to the first algorithm or method 100), then in box 330, at Nz frequency points F (i.e., at F1, F2, ... Fz) Nz The impedance Z of battery B is measured using the first voltage V1, and the result is... Figure 36 The impedance values ​​are shown in the third, fourth, and fifth columns. For example, at a first voltage V1, at a first frequency point F1, the first measured impedance Z... 1,1 It has corresponding real and imaginary components ReZ 1,1 I m Z 1,1 At the second frequency point F2, the second measured impedance Z 1,2 It has corresponding real and imaginary components ReZ 1,2 I m Z 1,2 And in the Nth z Frequency point FNz, the Nth z Measured impedance Z 1,Nz It has corresponding real and imaginary components ReZ 1,Nz I mZ 1,Nz .

[0154] Next, in box 340, and as... Figure 38 As shown in the block diagram, by comparing the corresponding real component ReZ1 of each measured impedance Z1 with the corresponding first reference impedance Z representing the healthy battery HB ref1 For comparison, N z For each of the measured impedances Z1, the corresponding principal error Er is calculated. p Thus generating N z Each corresponding principal error Er p .

[0155] exist Figure 37 The first four columns in the table show the options available for N z The first reference impedance Z at frequency point F ref1 Various examples. For the first frequency point F1, the first example Z of the first reference impedance. ref1,1 Having the first real component ReZ ref1,1 (And the corresponding imaginary components not shown). Similarly, for the second frequency point F2, the second instance Z of the first reference impedance. ref1,2 Having a second real component ReZ ref1,2 (and the corresponding imaginary components not shown), and for the Nth z Frequency point F Nz The Nth reference impedance z Example Z ref1,Nz Having the Nth z Real component ReZ ref1,Nz (and the corresponding imaginary components not shown).

[0156] Back Figure 38 The diagram shows the values ​​for the first frequency point F1, the second frequency point F2, and the Nth frequency point. z Frequency point F NZ The calculation of box 340. For example, for the first frequency point F1, the first measured impedance Z is... 1,1 The real component ReZ 1,1 The first instance Z with the first reference impedance ref1,1 The real component ReZ ref1,1 Comparison (e.g., subtraction) produces the first principal error Er. p,1 Similarly, for the second frequency point F2, the second measured impedance Z... 1,2 The real component ReZ 1,2 The second instance Z with the first reference impedance ref1,2 The real component ReZ ref,2 Comparisons (e.g., subtraction) produce the second principal error Er. p,2 And for the Nth z Frequency point FNz , will the Nth z Measured impedance Z 1,Nz The real component ReZ 1,Nz The Nth impedance of the first reference impedance z Example Z ref1,Nz The real component ReZ ref1,Nz Comparisons (e.g., subtraction) produce the Nth... z Main error Er p,Nz .

[0157] Next, in box 350, determine N. z One principal error Er p One of them is greater than the threshold error Er c The number of times N occurs occ .exist Figure 39 The block diagram further illustrates this block 130, which shows the first frequency point F1, the second frequency point F2, and so on up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first principal error Er is... p,1 With threshold error Er c Comparison, if the first principal error Er p,1 Not greater than the threshold error Er c If the first principal error Er is zero (0), then zero (0) is produced, or if the first principal error Er is zero (0) ... produced. p,1 Error greater than threshold Er c Then, a (1) is generated. Similarly, for the second frequency point F2, the second principal error Er is... p,2 With threshold error Er c Comparison, if the second principal error Er p,2 Not greater than the threshold error Er c If the second principal error Er is zero (0), then zero (0) is produced, or if the second principal error Er is zero (0) ... produced. p,2 Error greater than threshold Er c Then, a (1) is generated; and for the Nth... z Frequency point F Nz , will the Nth z Main error Er p,Nz With threshold error Er c Compare, if the Nth z Main error Er p,Nz Not greater than the threshold error Er c If , then zero (0) is produced, or if the Nth z Main error Er p,Nz Error greater than threshold Er c Then, a (1) is generated. The number of occurrences N occ It's the sum of all these 0s and 1s.

[0158] Then, in box 360, and as Figure 27 As shown in the flowchart, if the number of occurrences N occ Greater than threshold N c If so, battery B is identified as having a soft short circuit SS.

[0159] On the other hand, if the logical flow of the third algorithm or method 300 follows Figure 35 If the right column advances (corresponding to the second algorithm or method 200), then in box 370, the EIS system EIS is used within the frequency range FR for N. z At several frequency points, the impedance Z of battery B is measured at the second and third voltages V2 and V3, thereby generating N. z The corresponding measurements are of the second and third impedances Z2 and Z3. These measurements are of the second and third impedances Z2 and Z3. Figure 36 It is shown in columns six through eleven. For example, at the second voltage V2 (i.e., columns six through eight), at the first frequency point F1, the first instance Z of the second measured impedance. 2,1 It has corresponding real and imaginary components ReZ 2,1 I m Z 2,1 At the second frequency point F2, the second instance Z of the second measured impedance. 2,2 It has corresponding real and imaginary components ReZ 2,2 I m Z 2,2 And in the Nth z Frequency point F Nz The Nth of the second measured impedance z Example Z 2,Nz It has corresponding real and imaginary components ReZ 2,Nz I m Z 2,Nz Similarly, at the third voltage V3 (i.e., columns nine through eleven), at the first frequency point F1, the first instance Z of the third measured impedance... 3,1 It has corresponding real and imaginary components ReZ 3,1 I m Z 3,1 At the second frequency point F2, the second instance Z of the third measured impedance. 3,2 It has corresponding real and imaginary components ReZ 3,2 I m Z 3,2 And in the Nth z Frequency point F Nz The Nth impedance measurement z Example Z 3,Nz It has corresponding real and imaginary components ReZ 3,Nz I m Z 3,Nz .

[0160] In box 380, the corresponding real component ReZ2 of the corresponding measured second impedance Z2 is compared with the corresponding real component ReZ3 of the corresponding measured third impedance Z3, for N. z The impedance error Er for each pair of measurements in the pair is... meas Thus generating N z The impedance error Er of each corresponding measurement meas .exist Figure 40 The block diagram further illustrates this block 380, which shows the first frequency point F1, the second frequency point F2, and so on up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first instance Z of the measured second impedance. 2,1 The real component ReZ 2,1 The first instance Z of the measured third impedance 3,1 The real component ReZ 3,1 Comparing (e.g., subtracting) produces the first measurement impedance error Er. meas,1 Similarly, for the second frequency point F2, the second instance Z of the measured second impedance will be... 2,2 The real component ReZ 2,2 The second instance Z of the measured third impedance 3,2 The real component ReZ 3,2 Comparing (e.g., subtracting) produces a second measurement impedance error Er. meas,2 And for the Nth z Frequency point F Nz The Nth impedance of the measured second impedance z Example Z 2,Nz The real component ReZ 2,Nz The Nth impedance of the measured third impedance z Example Z 3,Nz The real component ReZ 3,Nz Comparing (e.g., subtracting from), this produces the Nth... z Measurement impedance error Er meas,Nz .

[0161] In box 390, by passing the corresponding second reference impedance Z corresponding to the second voltage V2 ref2 The corresponding real component ReZ ref2 With the corresponding third reference impedance Z corresponding to the third voltage V3 ref3 The corresponding real component ReZ ref3 For comparison, N z Calculate the corresponding reference impedance error Er for each pair in the pair. ref Thus generating N z The corresponding reference impedance error Erref The box at 390 is... Figure 41 In the block diagram and in Figure 37 Further details are shown in columns one, two, and five through eight of the table. Figure 41 The diagram shows the frequency points from the first frequency point F1, the second frequency point F2, up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first instance Z of the second reference impedance. ref2,1 The real component ReZ ref2,1 The first instance Z with the third reference impedance ref3,1 The real component ReZ ref3,1 The comparison (e.g., subtraction) produces the first reference impedance error Er. ref,1 Similarly, for the second frequency point F2, the second instance Z of the second reference impedance is... ref2,2 The real component ReZ ref2,2 The second instance Z with the third reference impedance ref3,2 The real component ReZ ref3,2 Comparing (e.g., subtracting) produces a second reference impedance error Er. ref,2 And for the Nth z Frequency point F Nz The Nth reference impedance z Example Z ref2,Nz The real component ReZ ref2,Nz The Nth of the third reference impedance z Example Z ref3,Nz The real component ReZ ref3,Nz Comparing (e.g., subtracting from), this produces the Nth... z Reference impedance error Er ref,Nz .

[0162] exist Figure 37 In the table, columns one, two, and five through eight relate to the reference impedance Z corresponding to the second and third voltages V2 and V3. ref For the first frequency point F1, the first instance Z of the second reference impedance. ref2,1 Having the first real component ReZ ref2,1 (and the corresponding imaginary component not shown), and the first instance Z of the third reference impedance. ref3,1 Having the first real component ReZ ref3,1 (and the corresponding imaginary component not shown). Similarly, for the second frequency point F2, the second instance Z of the second reference impedance. ref2,2 Having a second real component ReZ ref2,2 (and the corresponding imaginary component not shown), and the second instance Z of the third reference impedance. ref3,2 Having a second real component ReZ ref3,2(and corresponding imaginary components not shown); and for the Nth... z Frequency point F Nz The Nth reference impedance z Example Z ref2,Nz Having the Nth z Real component ReZ ref2,Nz (and the corresponding imaginary components not shown), and the Nth of the third reference impedance z Example Z ref3,Nz Having the Nth z Real component ReZ ref3,Nz (and the corresponding imaginary components not shown).

[0163] In box 400, the corresponding measured impedance error Er is... meas and the corresponding reference impedance error Er ref The difference between them divided by the corresponding reference impedance error Er ref , for N z The corresponding error Er for each pair of calculated errors in the pair err This results in an error of N. z Each corresponding error Er err The box 400 is further in Figure 33 The diagram shows the values ​​for the first frequency point F1, the second frequency point F2, and up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first measured impedance error Er. meas,1 With the first reference impedance error Er ref,1 A comparison is made (e.g., subtracted from), which produces a first difference, diff1; this first difference, diff1, is then divided by the first reference impedance error, Er. ref,1 This generates the first error Er. err,1 Similarly, for the second frequency point F2, the second measured impedance error Er will be... meas,2 With the second reference impedance error Er ref,2 The comparison (e.g., subtraction) produces a second difference, diff2; this second difference, diff2, is then divided by the second reference impedance error, Er. ref,2 This generates the second error Er. err,2 And for the Nth... z Frequency point F Nz , will the Nth z Measurement impedance error Er meas,Nz With the Nth z Reference impedance error Er ref,Nz Comparison (e.g., subtraction) yields the Nth... z diff Nz The Nth zdiff Nz Then divide by the Nth z Reference impedance error Er ref,Nz This produces the Nth error z Error Er err,Nz .

[0164] In box 410, determine the error N. z Error Er err One of them is greater than the maximum permissible error Er max The number of times N occurs occ .exist Figure 34 The block diagram further illustrates block 410, which shows the values ​​for the first frequency point F1, the second frequency point F2, and up to the Nth frequency point. z Frequency point F NZ The calculation. For example, for the first frequency point F1, the first error Er is calculated. err,1 With the maximum permissible error Er max Compare, if the first error Er err,1 Not greater than the maximum permissible error Er max If the first error Er produces zero (0), then the error is zero (0), or if the first error Er err,1 Greater than the maximum permissible error Er max Then, a (1) is generated. Similarly, for the second frequency point F2, the second error Er of the error is... err,2 With the maximum permissible error Er max Compare, if the second error Er err,2 Not greater than the maximum permissible error Er max If the second error Er produces zero (0), then the error will be zero (0), or if the second error Er... err,2 Greater than the maximum permissible error Er max Then, a (1) is generated; and for the Nth... z Frequency point F Nz The Nth error z Error Er err,Nz With the maximum permissible error Er max Compare, if the Nth error z Error Er err,Nz Not greater than the maximum permissible error Er max If the Nth error is zero (0), then zero (0) is produced, or if the Nth error is... z Error Er err,Nz Greater than the maximum permissible error Er max Then, a (1) is generated. The number of occurrences N occ It's the sum of all these 0s and 1s.

[0165] Finally, in box 420, and as Figure 27 As shown in the flowchart, if the number of occurrences Nocc Greater than threshold N c If so, battery B is identified as having a soft short circuit SS.

[0166] Figures 42-43 Logic flowcharts are shown for detecting a soft short circuit SS in battery B according to first and second algorithms / methods 100 and 200, respectively. These diagrams can be used to design hardware, software, and / or control systems or subsystems having inputs, outputs, interconnections, sequences, and logic components for executing the first and second algorithms / methods 100 and 200.

[0167] exist Figure 42 In the first voltage V1 (e.g., lower than a predetermined voltage level V), pre At a given temperature T1, the impedance Z is sensed or accessed by the EIS system and optionally by a lookup table LUT, and the impedance Z is within the frequency range FR. z Measurements are taken at frequency point F. The real components Re of these impedances Z are then extracted—see ReZ|, which represents the set of current real components Re of these impedance measurements. V1,T1 crnt Array, and ReZ| representing the set of real components Re that are stored / retrieved. V1,T1 NoSS The arrays, where these real components Re represent healthy cells HB (i.e., "NoSS") without soft short circuits SS, are compared or subtracted from each other to produce N. z There are several different calculated errors Er. These calculated errors Er are then compared with the threshold error Er. c Compare and determine the number of occurrences N. occ N z How many of the calculated errors Er are greater than the threshold error Er? c If the occurrence occurs N times occ Greater than threshold N c If the condition is met, it is considered that a soft short circuit (SS) has been detected; otherwise, it is considered that the "no soft short circuit" (NoSS) condition has been detected.

[0168] exist Figure 43 In the middle, the second and third voltages V2 and V3 (for example, both are higher than the predetermined voltage level V) pre The corresponding second and third temperatures T2 and T3 are sensed or accessed by the corresponding EIS system (or optionally by a single EIS system), and also optionally by the corresponding lookup table (LUT), and within the frequency range FR, N z The corresponding impedance Z is measured at each frequency point F. Then, the real components Re of these impedances Z are extracted—see ReZ|. V2,T2 crnt and ReZ| V3,T3crnt Arrays representing the corresponding sets of the current real components Re of these impedance measurements at two voltages V1 and V2, and ReZ| V2,T2 NoSS and ReZ| V3,T3 NoSS Arrays, representing collections of real components Re representing the storage / retrieval of healthy cells HB (i.e., "NoSS") without soft short circuits SS. The real components Re from impedance measurements of the EIS system are compared or subtracted to produce N. z Different measured impedance errors Er meas And it compares or subtracts the real components Re retrieved from the lookup table LUT to produce N. z Different reference impedance errors Er ref The impedance errors Er measured in these measurements meas and reference impedance error Er ref Compare or subtract them, and divide the difference by the corresponding reference impedance error Er. ref N, which produces the error z Different errors Er err Then these errors Er err With the maximum permissible error Er max Compare and determine the error N. z Error Er err How many of them are greater than the maximum permissible error Er? max The number of times N occurs occ If the occurrence occurs N times occ Greater than threshold N c If the condition is met, it is considered that a soft short circuit (SS) has been detected; otherwise, it is considered that the "no soft short circuit" (NoSS) condition has been detected.

[0169] As those skilled in the art will understand, the system 10, vehicle VEH, and methods 100, 200, 300 of this disclosure can be presented or arranged in various different configurations and embodiments.

[0170] According to one embodiment, a method 100 for detecting a soft short circuit SS in battery B includes: (i) in block 110, N within the frequency range FR z At a frequency point and below a predetermined voltage level V pre The impedance Z of battery B is measured at the selected voltage V1, thereby generating N. z (ii) In box 120, by comparing the corresponding real component ReZ1 of each measured impedance Z1 with the corresponding reference impedance Z representing the healthy battery HB. ref Compare and calculate N zThe corresponding error Er for each impedance in the measured impedance Z1, thus generating N z (iii) In box 130, determine the corresponding calculation error Er; z One of the calculation errors Er is greater than the threshold error Er c The number of times N occurs occ ; and (iv) in box 140, if the number of occurrences N occ Greater than threshold N c If so, battery B will be identified as having a soft short circuit (SS).

[0171] N z The impedance Z at a given frequency point can be measured using electrochemical impedance spectroscopy, and the frequency range FR can be approximately 0.01 to 1 Hz.

[0172] Each reference impedance Z ref It could be: (i) the average real impedance component ReZ acting as a proxy for the healthy battery HB avg ; or (ii) the corresponding member M of the set S representing the real impedance components ReZ of a healthy battery HB. Average real impedance component ReZ avg This can be obtained from the average of the corresponding real components of the corresponding impedances configured for use with battery B, such that the corresponding impedances are measured within the selected voltage V1 and frequency range FR. Each corresponding member M of the set S of real impedance components ReZ can correspond to N. z One of the corresponding frequency points out of a set of frequency points.

[0173] Each reference impedance Z ref It can be obtained from the lookup table LUT, and each measured impedance Z1 can have a corresponding imaginary component ImZ1.

[0174] Predetermined voltage level V pre It can be defined as a voltage level below which, within the frequency range FR, the real component of the measured impedance of the soft-short-circuit battery SSB is significantly different from the real component of the reference impedance of the healthy battery HB.

[0175] At approximately the same temperature T in N z The impedance Z of battery B was measured at a frequency point.

[0176] Battery B can be a lithium-ion battery LIB, wherein a predetermined voltage level V is specified. pre It is approximately 3.5 volts.

[0177] According to another embodiment, a method 200 for detecting a soft short circuit SS in battery B includes: (i) in block 210, N within the frequency range FR z At each frequency point and at the corresponding main voltage and alternative voltage Vm V a The impedance Z of battery B is measured at the location, along with the main voltage and the replacement voltage V. m V a All are higher than the predetermined voltage level V pre Thus generating N z For the corresponding measured principal impedance and alternative impedance Z m Z a Each impedance has a corresponding real component ReZ. m ReZ a (ii) In box 220, by measuring the corresponding principal impedance Z m The corresponding real component ReZ m The corresponding measured alternative impedance Z a The corresponding real component ReZ a Compare and calculate N z The corresponding measured impedance error Er for each pair in the pair meas Thus generating N z The corresponding measured impedance error Er meas (iii) In box 230, by passing the main voltage V m The corresponding main reference impedance Z m-ref The corresponding real component ReZ m-ref With the corresponding substitution voltage V a The corresponding alternative reference impedance Z a-ref The corresponding real component ReZ a-ref Compare and calculate N z The corresponding reference impedance error Er for each pair in the pair ref Thus generating N z The corresponding reference impedance error Er ref (iv) In box 240, by measuring the corresponding impedance error Er meas and the corresponding reference impedance error Er ref The difference between them divided by the corresponding reference impedance error Er ref Calculate N z The corresponding error Er for each pair of errors in the pair err This results in an error of N. z Each corresponding error Er err (v) In box 250, determine the error N. z Error Er err One of them is greater than the maximum permissible error Er max The number of times N occurs occ ; and (vi) in box 260, if the number of occurrences N occ Greater than threshold N c If so, battery B will be identified as having a soft short circuit (SS).

[0178] In this embodiment, N z The impedance Z at a given frequency point can be measured using electrochemical impedance spectroscopy, and the frequency range FR can be approximately 0.1 to 10 Hz.

[0179] Main reference impedance Z m-ref and alternative reference impedance Z a-ref At least one of them can be: (i) the average real impedance component ReZ acting as a proxy for the healthy battery HB avg ; or (ii) the corresponding member M of the set S representing the real impedance components ReZ of a healthy battery HB. Average real impedance component ReZ avg It can be obtained from the average of the corresponding real components of the corresponding impedances from two or more other batteries OB configured for use with battery B, and each corresponding member M of the set S of real impedance components ReZ can correspond to N. z One of the corresponding frequency points out of a set of frequency points.

[0180] Predetermined voltage level V pre It can be defined as a voltage level below which, within the frequency range FR, the real component of the measured impedance of the soft-short-circuit battery SSB is significantly different from the real component of the reference impedance of the healthy battery HB.

[0181] At approximately the same temperature T m ≈T a Measure the principal impedance and the alternative impedance Z m Z a Furthermore, battery B can be a lithium-ion battery LIB, wherein a predetermined voltage level V pre It is approximately 3.5 volts.

[0182] According to another embodiment, a vehicle VEH having onboard capability for detecting a soft short circuit SS in battery B includes a body VB operably supporting a propulsion system PS, an electrical system ES, battery B, and an electrochemical impedance spectroscopy (EIS) system EIS, wherein the propulsion system PS, battery B, and EIS system EIS are all operably connected to the electrical system ES, and wherein the EIS system EIS is configured to perform at least one of a first algorithm 100 and a second algorithm 200. The first algorithm 100 includes: (i) at block 330, using the EIS system EIS within the frequency range FR N z At a frequency point and below a predetermined voltage level V pre The impedance Z of battery B is measured at the first voltage V1, thereby generating N. z(ii) In box 340, by comparing the corresponding real component ReZ1 of each measured first impedance Z1 with the corresponding first reference impedance Z representing the healthy battery HB. ref1 Compare and calculate N z The corresponding principal error Er of the first impedance Z1 measured p Thus generating N z Each corresponding principal error Er p (iii) In box 350, determine N. z One principal error Er p One of them is greater than the threshold error Er c The number of times N occurs occ ; and (iv) in box 360, if the number of occurrences N occ Greater than threshold N c Then battery B is identified as having a soft short circuit SS. The second algorithm 200 includes: (v) in block 370, using the EIS system EIS in the frequency range FR N. z At each frequency point, and all are above the predetermined voltage level V. pre The impedance Z of battery B is measured at the second and third voltages V2 and V3, thereby generating N. z For the corresponding measured second and third impedances Z2 and Z3, each impedance has a corresponding real component ReZ2 and ReZ3; (vi) in box 380, N is calculated by comparing the corresponding real component ReZ2 of the corresponding measured second impedance Z2 with the corresponding real component ReZ3 of the corresponding measured third impedance Z3. z The corresponding measured impedance error Er for each pair in the pair meas Thus generating N z The corresponding measured impedance error Er meas (vii) In box 390, by passing the corresponding second reference impedance Z corresponding to the second voltage V2 ref2 The corresponding real component ReZ ref2 With the corresponding third reference impedance Z corresponding to the third voltage V3 ref3 The corresponding real component ReZ ref3 Compare and calculate N z The corresponding reference impedance error Er for each pair in the pair ref Thus generating N z The corresponding reference impedance error Er ref (viii) In box 400, by measuring the corresponding impedance error Er meas and the corresponding reference impedance error Er ref The difference between them divided by the corresponding reference impedance error Er ref To calculate N zThe corresponding error Er for each pair of errors in the pair err This results in an error of N. z Each corresponding error Er err (ix) In box 410, determine the error N. z Error Er err One of them is greater than the maximum permissible error Er max The number of times N occurs occ ; and (x) in box 420, if it occurs N times occ Greater than threshold N c If so, battery B will be identified as having a soft short circuit (SS).

[0183] Although the various steps of methods 100, 200, and 300 have been described as separate boxes, and the various functions of system 10 and vehicle VEH have been described as separate modules or elements, it can be noted that two or more steps can be combined into fewer boxes, and two or more functions can be combined into fewer modules or elements. Similarly, some steps described as a single box can be divided into two or more boxes, and some functions described as a single module or element can be divided into two or more modules or elements. Furthermore, the order of the steps or boxes described herein can be rearranged in one or more different orders, and the arrangement of functions, modules, and elements can be rearranged into one or more different arrangements.

[0184] (As used herein, "module" can include hardware and / or software, including executable instructions for receiving one or more inputs, processing one or more inputs, and providing one or more corresponding outputs. It should also be noted that at some points throughout this disclosure, a single input, output, element, etc., may be referred to, while at other points, multiple / several inputs, outputs, elements, etc., may be referred to. Therefore, emphasis should not be placed on whether inputs, outputs, elements, etc., are used in the singular or plural form at any particular point in this disclosure, as the singular and plural use of such terms should be considered interchangeable unless the specific context indicates otherwise.)

[0185] The above description is intended to illustrate and not limit. While the dimensions and types of materials described herein are illustrative, they are by no means limiting, but rather exemplary embodiments. In the appended claims, the terms “first,” “second,” “top,” “bottom,” etc., are used merely as labelling and are not intended to impose numerical or positional requirements on their objects. As used herein, an element or step recited in the singular and preceded by the word “a” or “an” should be understood to not exclude a plurality of such elements or steps unless such exclusion is expressly stated. Furthermore, the phrases “at least one of A and B” and “A and / or B” should both be understood to mean “only A, only B, or both A and B.” Additionally, unless expressly stated to the contrary, embodiments that “comprise” or “have” one or more elements having a particular property may include additional such elements that do not have that property. Furthermore, when broad descriptive adverbs (such as “basically” and “usually”) are used in this text to modify adjectives, these adverbs mean “most,” “mainly,” “for most,” “significantly,” “to a large extent,” and / or “at least 51% to 99% of the 100% probability,” and do not necessarily mean “perfectly,” “completely,” “strictly,” “entirely,” or “100%.” Additionally, the word “close” can be used in this text to describe the position of an object or part thereof relative to another object or part thereof, and / or to describe the positional relationship between two objects or their respective parts relative to each other, and can mean “close to,” “adjacent,” “near,” “near,” “in close proximity,” “at,” etc.

[0186] According to this disclosure, the written description uses examples including best practices to enable those skilled in the art to manufacture and use apparatus, systems, and material compositions, and to perform methods. The appended claims (including equivalents) define the scope of this disclosure.

Claims

1. A method for detecting a soft short circuit in a battery, comprising: N in the frequency range z The impedance of the battery is measured at several frequency points and at selected voltages below a predetermined voltage level, thereby generating N values, each with a corresponding real component. z Each corresponding measured impedance; N is calculated by comparing the corresponding real component of each measured impedance with the corresponding reference impedance representing a healthy battery. z The corresponding error of each impedance in the measured impedance, thus generating N z One corresponding calculation error; Determine N z The number of times that one of the calculation errors is greater than the threshold error; as well as If the number of occurrences exceeds the threshold, the battery will be identified as having a soft short circuit.

2. The method according to claim 1, wherein N z Impedance measurements at each frequency point were performed using electrochemical impedance spectroscopy.

3. The method of claim 1, wherein the frequency range is approximately 0.01 to 1 Hz.

4. The method of claim 1, wherein each reference impedance is: The average real impedance component acting as a proxy for a healthy battery; or The corresponding members of the set representing the real impedance components of a healthy battery.

5. The method of claim 4, wherein the average real impedance component is obtained from the average of the corresponding real components of the corresponding impedances from two or more other cells configured for use with the cell measured at a selected voltage and frequency range.

6. The method of claim 4, wherein each corresponding member of the set of real impedance components corresponds to N. z One of the corresponding frequency points out of a set of frequency points.

7. The method of claim 1, wherein each reference impedance is obtained from a lookup table.

8. The method of claim 1, wherein each measured impedance has a corresponding imaginary component.

9. The method of claim 1, wherein the predetermined voltage level is defined as a voltage level below which, within a frequency range, the real component of the measured impedance of the soft-short-circuited battery is significantly different from the real component of the reference impedance of the healthy battery.

10. The method of claim 1, wherein the battery is a lithium-ion battery, and wherein the predetermined voltage level is approximately 3.5 volts.

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