JP2017187377A - Battery examination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery examination device that outputs a residual travelling distance serving as a rough indication by a battery exchange time.SOLUTION: A processor of a battery examination device is configured to: calculate an amount of change dRc from a measured resistance component Rc1 to a resistance component Rc2; calculate an amount of change dXc from a measured capacity component Xc1 to a capacity component Xc2; calculate a ratio (resistance ratio Rratio) of a difference between an amount of change dRe and an amount of change dRc to a difference between the amount of change dRe and an amount of change dRs; calculate a ratio (capacity ratio Xratio) of a difference between an amount of change dXe and an amount of change dXc to a difference between the amount of change dXe and an amount of change dXs; and let a smaller ratio between the resistance ratio Rratio and the capacity ratio Xratio be a residual life Yj, and calculate SK×Yj/(1.0-Yj) with respect to a travelling distance SK from a use start of a battery to a current time to output a calculation result as a residual travelling distance.SELECTED DRAWING: Figure 2

Description

  The present specification relates to a battery inspection device (battery inspection device) for supplying electric power to a traveling motor. In particular, the present invention relates to a battery inspection device that outputs a remaining travel distance that is a guide until battery replacement time. Hereinafter, in the present specification, the “battery that supplies power to the traveling motor” may be simply referred to as “battery”.

  The battery that supplies power to the motor for traveling frequently repeats charging and discharging. A battery deteriorates as it is repeatedly charged and discharged. It is desirable to replace the battery when the deterioration has progressed to a considerable extent. Since the degree of deterioration also changes depending on the battery usage status, the battery replacement timing may be determined in consideration of the battery usage status. Regarding the battery replacement time, it is convenient to obtain an indication of the distance traveled until the replacement time, and how long the battery will travel after reaching the replacement time. For example, Patent Literature 1 and Patent Literature 2 disclose a technique for calculating a travel distance that is a guideline for reaching the battery replacement time. Hereinafter, the travel distance that serves as a guideline until the battery replacement time is reached from now is referred to as the remaining travel distance.

JP 2012-074342 A JP 2014-041768 A

  In the technique of Patent Document 1, the temperature of a running battery is periodically measured, and the degree of deterioration and the remaining travel distance are calculated from the temporal data of the temperature. In the technique of Patent Document 2, the internal resistance of the battery is measured, and the remaining travel distance is calculated based on the increase rate from the initial value of the internal resistance to the current value. Since the temperature of the battery depends not only on the deterioration of the battery but also on other factors, the technique of Patent Document 1 does not have a high accuracy of the correlation between the remaining travel distance and the degree of deterioration of the battery. On the other hand, since the internal resistance of the battery is directly related to the degree of deterioration of the battery, the remaining travel distance by the technique of Patent Document 2 is excellent as a measure of the replacement time of the battery as compared with the technique of Patent Document 1. However, a technique capable of obtaining a more appropriate remaining travel distance is desired.

  The present specification provides a technique for obtaining a more appropriate value as the remaining travel distance that is a measure of battery replacement time, using the value of the internal impedance of the battery. The internal impedance has a capacitance component and a resistance component, both of which change as the battery deteriorates. Further, the change amount of the resistance component and the change amount of the capacity component according to the deterioration of the battery are not always the same, and may be different depending on the use state (that is, the running state) of the battery. Therefore, in the technology disclosed in this specification, the remaining life (postponement until the battery replacement time) is estimated for each of the capacity component and the resistance component, and the remaining travel distance is calculated based on the value of the component having the shorter remaining life. To do.

  The battery inspection apparatus which this specification discloses, a measurement means, a memory | storage means, and a processor are provided. The measuring means measures the resistance component Rc1 and the capacitance component Xc1 at a predetermined first frequency of the current internal impedance of the battery, and the resistance component Rc2 and the capacitance component Xc2 at a predetermined second frequency. The storage means stores the following data. That is, the storage means stores the initial resistance change amount dRs, the initial capacitance change amount dXs, the final resistance change amount dRe, and the final capacitance change amount dXe. Here, the initial resistance change amount dRs is a change amount from the resistance component Rs1 at the first frequency to the resistance component Rs2 at the second frequency of the internal impedance of the battery before use. The initial capacity change amount dXs is a change amount of the internal impedance of the battery before use from the capacity component Xs1 at the first frequency to the capacity component Xs2 at the second frequency. The terminal resistance change amount dRe is a change amount from the resistance component Re1 at the first frequency to the resistance component Re2 at the second frequency of the internal impedance of the battery at the time of replacement. The terminal capacity change amount dXe is a change amount from the capacity component Xe1 at the first frequency to the capacity component Xe2 at the second frequency of the internal impedance of the battery at the replacement time. These values are obtained in advance by experiments and simulations and are stored in the storage means. The processor can execute the following processing. The processor calculates a change amount (current resistance change amount dRc) from the measured resistance component Rc1 to the resistance component Rc2, and also measures a change amount (current capacity change amount dXc) from the measured capacitance component Xc1 to the capacitance component Xc2. Is calculated. The processor calculates a ratio (resistance ratio Rratio) of the difference between the final resistance change dRe and the current resistance change dRc with respect to the difference between the final resistance change dRe and the initial resistance change dRs. The processor calculates the ratio (capacity ratio Xratio) of the difference between the final capacity change amount dXe and the current capacity change quantity dXc with respect to the difference between the final capacity change amount dXe and the initial capacity change amount dXs. Then, the processor uses the smaller ratio of the resistance ratio Rratio and the capacity ratio Xratio as the remaining life Yj, and SK × Yj / (1.0−Yj) with respect to the travel distance SK from the start of use of the battery to the present. ) Is calculated and output as the remaining travel distance.

  The battery replacement time means when the battery has deteriorated so that it is better to replace it. There is a correlation between deterioration and the internal impedance of the battery. In other words, the magnitude of the internal impedance corresponding to the replacement time (final internal impedance) can be determined in advance. The internal impedance (initial internal impedance) before using the battery is also known. Therefore, depending on where the current internal impedance of the battery is located between the initial internal impedance and the final internal impedance, the degree of deterioration (in other words, the remaining life until the replacement time) can be estimated. it can.

  On the other hand, the internal impedance has a resistance component and a capacitance component, and the degree of change differs depending on the driving situation. Therefore, the battery inspection apparatus disclosed in this specification compares the current internal impedance (current internal impedance) with the initial / final internal impedance for each of the resistance component and the capacity component, and calculates the remaining life corresponding to the degree of deterioration. To do. The resistance ratio Rratio corresponds to the remaining life based on the resistance component, and the capacity ratio Xratio corresponds to the remaining life based on the capacity component. The smaller ratio of the resistance ratio Rratio and the capacity ratio Xratio is adopted as the remaining battery life. Finally, the remaining travel distance (travel distance from the present time until the replacement time is reached) is obtained from the travel distance up to the present and the remaining life. With the above procedure, the battery inspection device disclosed in the present specification can output a more appropriate value as the remaining travel distance that serves as an indication of the replacement time.

  The size of each component of the internal impedance depends on the temperature. Therefore, the technology disclosed in the present specification employs the amount of change in the value at the first frequency and the value at the second frequency for each component of the internal impedance. By adopting the amount of change in components at two frequencies, the influence of temperature can be reduced. Note that the first frequency and the second frequency are also predetermined. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the battery test | inspection apparatus of an Example. It is a flowchart of the process which a battery test | inspection apparatus performs. It is a graph which shows an example of the Nyquist plot of the internal impedance of the battery before use and replacement time. It is a graph which shows an example of the Nyquist plot of the internal impedance of the present battery. It is a graph explaining the temperature dependence of the Nyquist plot of the internal impedance of a battery.

  A battery inspection apparatus 10 according to an embodiment will be described with reference to the drawings. FIG. 1 shows a block diagram of the battery inspection apparatus 10. FIG. 1 also shows a battery 20 that is an inspection target of the battery inspection apparatus 10. The battery 20 is a lithium ion battery mounted on an electric vehicle or a hybrid vehicle, and is a battery for supplying electric power to a traveling motor. The battery 20 is removed from the mounted vehicle and connected to the battery inspection device 10. The batteries of electric vehicles and hybrid vehicles are frequently charged and discharged. A battery deteriorates as it is repeatedly charged and discharged. As deterioration progresses, performance decreases. Battery manufacturers recommend replacing a battery when it has deteriorated significantly. The battery inspection apparatus 10 is an apparatus that evaluates deterioration of the battery 20 and presents a situation regarding the replacement time of the battery 20. The battery inspection device 10 determines the degree of deterioration based on the internal impedance of the battery 20. Moreover, the battery test | inspection apparatus 10 shows the progress degree of deterioration with a remaining travel distance and remaining travel time. The remaining travel distance and the remaining travel time are numerical values that serve as an indication of how much the recommended replacement time (a time when deterioration has progressed enough to be replaced) when the vehicle is mounted with the battery 20. The magnitude of the change in internal impedance depends on the driving situation so far. The remaining traveling distance and remaining traveling time calculated by the battery inspection device 10 based on the internal impedance take into account the traveling state up to that time, and serve as an appropriate standard for the battery replacement time.

  Note that the replacement time recommended by the battery provider (the time when deterioration has progressed to the point of replacement) may be referred to as “battery life”. Further, the grace period until the replacement time recommended by the battery provider is sometimes referred to as “remaining life”. The remaining travel distance and remaining travel time described above correspond to the remaining life.

  The battery inspection apparatus 10 will be described with reference to the block diagram of FIG. The battery inspection device 10 includes an AC-IR device 14, an input device 15, an output device 16, a processor 12, and a nonvolatile memory 13. Specifically, the input device 15 is a keyboard or a card reader. Specifically, the output device 16 is a display or a printer. The AC-IR device 14 gives weak AC power between the positive electrode 20 a and the negative electrode 20 b of the battery 20 and measures the internal impedance of the battery 20. The AC-IR device 14 applies AC power while changing the frequency, and measures the frequency characteristics of the internal impedance of the battery 20. As is well known, there are a capacitance component and a resistance component in the impedance, and the AC-IR device 14 can measure the capacitance component and the resistance component at each frequency of the internal impedance of the battery 20. The AC-IR device 14 and the positive electrode 20a and the negative electrode 20b of the battery 20 are electrically connected by a cable 14a.

  The AC-IR device 14, the input device 15, the output device 16, the processor 12, and the nonvolatile memory 13 are connected by a data bus 17, and exchange data with each other.

  The nonvolatile memory 13 stores a program executed by the processor 12 and various data used for battery evaluation. The programs stored in the nonvolatile memory 13 include a remaining travel distance / remaining travel time calculation / output program 13a. Various data used for the battery inspection is stored in the data area 13b. The processor 12 reads the remaining travel distance / remaining travel time calculation / output program 13 a from the nonvolatile memory 13 and executes the program to check the deterioration degree of the battery 20. The processor 12 reads and uses various data from the data area 13b at the time of inspection. Various data stored in the data area 13b will be described later.

  Prior to inspecting the battery 20, the user of the battery inspection device 10 uses the input device 15 to determine the distance traveled and the travel time of the vehicle (hybrid vehicle or electric vehicle) on which the battery 20 is mounted. Enter. The travel distance and travel time of the vehicle on which the battery 20 is mounted are stored in the memory of the vehicle. The user of the battery inspection device 10 reads the travel distance and travel time from the car memory and inputs them using the input device 15. Alternatively, in the case where the memory of the automobile is a detachable memory card, the user of the battery inspection device 10 inserts the memory card into a card slot which is a kind of the input device 15 of the battery inspection device 10, and the data ( The travel distance and travel time) may be input to the battery inspection device 10. The input travel distance and travel time are also stored in the data area 13 b of the nonvolatile memory 13.

  In FIG. 2, the flowchart of the process which the battery test | inspection apparatus 10 performs is shown. The battery inspection apparatus 10 first measures the internal impedance of the battery 20. As described above, the AC-IR device 14 measures the internal impedance. The measurement data of the AC-IR device 14 is stored in the data area 13 b of the nonvolatile memory 13 via the data bus 17.

  The battery inspection device 10 measures the resistance component and the capacity component of the current internal impedance of the battery 20 using the AC-IR device 14 (S2). As described above, the AC-IR device 14 measures the internal impedance while changing the frequency of the supplied power. Here, the relationship between the frequency dependence of the resistance component and the capacity component of the internal impedance and the deterioration of the battery will be described.

  FIG. 3 shows a Nyquist plot of the internal impedance of the battery 20. The Nyquist plot is represented by a set (R, X) of a resistance component R and a capacitance component X on a coordinate axis with the resistance component R of the internal impedance on the horizontal axis and the capacitance component X of the internal impedance on the vertical axis. 6 is a graph depicting a trace of internal impedance (trajectory when the frequency is changed). The solid line graph in FIG. 3 shows the Nyquist plot Gs of the battery 20 before use. An arrow A in FIG. 3 indicates the moving direction of the locus of the Nyquist plot when the frequency is gradually lowered from the high frequency. The Nyquist plot of the battery 20 draws a curve in the high frequency band and becomes a straight line in the low frequency range. A point Ps1 (Rs1, Xs1) in FIG. 3 indicates the internal impedance at the first frequency F1 of the battery 20 before use, and a point Ps2 (Rs2, Xs2) indicates the second frequency F2 of the battery 20 before use. Shows the internal impedance. The first frequency F1 is higher than the second frequency F2. The Nyquist plot is sometimes called a Cole-Cole plot.

  As the battery 20 deteriorates, the internal impedance in the low frequency region changes. The dotted line in FIG. 4 shows the Nyquist plot Ge of the internal impedance at the time of replacement of the battery 20 recommended by the battery manufacturer (that is, the time when deterioration has progressed so as to be better). In other words, the graph Ge shows a Nyquist plot of the battery 20 at the replacement time.

  The solid line portion in FIG. 4 is also a part of the Nyquist plot Ge. That is, the Nyquist plot Ge at the replacement time has a shape (profile) obtained by extending the end point Ps2 of the Nyquist plot Gs before use of the battery. In other words, the Nyquist plot profile of the internal impedance is constant in a higher frequency range than the first frequency F1, regardless of the degree of deterioration. Conversely, in the low frequency range, the Nyquist plot profile of the internal impedance of the battery changes depending on the degree of deterioration. The first frequency F1 is selected in a frequency band in which the Nyquist plot profile does not change regardless of the degree of deterioration, and the second frequency F2 is selected in a frequency band in which the Nyquist plot profile changes in accordance with the degree of deterioration. .

  The resistance component Rs1 and the capacity component Xs1 in FIG. 3 respectively indicate the resistance component and the capacity component at the first frequency F1 of the internal impedance of the battery 20 before use. The resistance component Rs2 and the capacity component Xs2 respectively indicate the resistance component and the capacity component at the second frequency F2 of the internal impedance of the battery 20 before use.

  A resistance component Re1 and a capacity component Xe1 in FIG. 3 respectively indicate a resistance component and a capacity component at the first frequency F1 of the internal impedance of the battery 20 at the time of replacement. A resistance component Re2 and a capacity component Xe2 indicate a resistance component and a capacity component at the second frequency F2 of the internal impedance of the battery 20 at the time of replacement, respectively. The resistance components Rs1, Rs2, Re1, Re2, and the capacitance components Xs1, Xs2, Xe1, Xe2 are obtained in advance through experiments and simulations.

  When the resistance component Rc2 at the second frequency F2 of the battery 20 in use reaches Re2, or when the capacity component Xc2 reaches Xe2, the battery 20 is ready for replacement. On the other hand, the internal impedance in the low frequency range of the battery 20 is such that the resistance component Rc changes more rapidly than the capacity component Xc as the travel distance (or travel time) elapses depending on the battery usage status. The component Xc changes greatly faster than the resistance component Rc. In other words, the Nyquist plot in the low frequency range changes according to the driving situation. Therefore, the battery inspection apparatus 10 evaluates the deterioration of the battery by using the one having the larger change (that is, the one in which the deterioration proceeds faster) between the resistance component Rc2 and the capacitance component Xc2 at the second frequency F2.

  FIG. 4 shows an example Nyquist plot Gc for the current internal impedance of the battery 20. FIG. 4 is a diagram in which the Nyquist plot Gc of the current internal impedance of the battery 20 is added to the graph of FIG. 3 (Nyquist plots Gs, Ge). In the Nyquist plot Gc of FIG. 4, the resistance component Rc2 at the second frequency F2 of the current internal impedance of the battery 20 is the capacity component relative to the internal impedance Ps2 (Rs2, Xs2) of the battery 20 before use. It changes more greatly than Xc2. In the example in which the current internal impedance of the battery 20 is represented by the Nyquist plot Gc in FIG. 4, it is more appropriate to evaluate the deterioration of the battery 20 based on the resistance component Rc. The battery inspection apparatus 10 acquires data corresponding to the Nyquist plot Gc in FIG. 4 using the AC-IR apparatus 14 and stores it in the data area 13b.

  As described above, the Nyquist plot profile does not depend on the deterioration of the battery in a higher frequency range than the first frequency F1. Therefore, the internal impedance at the first frequency F1 is the same before use and at the time of replacement (point Ps1, point Pe1, and point Pc1 overlap).

  In the data area 13b of the nonvolatile memory 13, dRs, dXs, dRe, and dXe shown in FIG. 3 are stored. Here, dRs (initial resistance change amount dRs) is a change amount of the internal impedance of the battery 20 before use from the resistance component Rs1 at the first frequency F1 to the resistance component Rs2 at the second frequency F2. dXs (initial capacity change amount dXs) is a change amount of the internal impedance of the battery 20 before use from the capacity component Xs1 at the first frequency F1 to the capacity component Xs2 at the second frequency F2. dRe (final resistance change amount dRe) is a change amount of the internal impedance of the battery 20 at the time of replacement from the resistance component Re1 at the first frequency F1 to the resistance component Re2 at the second frequency F2. dXe (final capacity change amount dXe) is a change amount of the internal impedance of the battery 20 at the replacement time from the capacity component Xe1 at the first frequency F1 to the capacity component Xe2 at the second frequency F2. The battery inspection device 10 compares the data with the current amount of change of the battery 20 (current resistance change amount dRc, current capacity change amount dXc), and the degree of deterioration of the battery 20 (that is, the remaining travel distance and the remaining travel time). ) Is calculated.

  The battery inspection apparatus 10 uses the amount of change from the value at the first frequency F1 to the value at the second frequency F2, not the absolute magnitude of the internal impedance. This is because the internal impedance changes depending on the temperature, so that the influence of temperature on the deterioration evaluation is reduced. Note that the Nyquist plot profile (graph shape) of the internal impedance of the battery does not depend on temperature. The shape of the Nyquist plot graph is constant regardless of the temperature, but the position in the coordinate system with the resistance component and the capacitance component as axes changes depending on the temperature. For example, FIG. 5 shows a Nyquist plot G1 for internal impedance when the battery temperature is 10 ° C., a Nyquist plot G2 for 25 ° C., and a Nyquist plot G3 for 35 ° C. As shown in FIG. 5, the Nyquist plot profile of the battery 20 does not depend on the temperature, but the position on the coordinate system with the resistance component and the capacity component as axes changes according to the temperature.

  In FIGS. 3 to 5, the shape of the Nyquist plot is simplified for easy understanding.

  Returning to FIG. 2, the description of the processing of the battery inspection device 10 will be continued. The processor 12 of the battery inspection apparatus 10 loads and executes the remaining travel distance / remaining travel time calculation / output program 13 a stored in the nonvolatile memory 13. By the remaining travel distance / remaining travel time calculation / output program 13a, the processor 12 performs the processing after step S2 in FIG.

  After the AC-IR device 14 measures the current internal impedance of the battery 20, the processor 12 accesses the data area 13b of the nonvolatile memory 13, and the resistance component Rc1 and the capacitance component Xc1, at the first frequency F1 of the internal impedance, Then, the resistance component Rc2 and the capacitance component Xc2 at the second frequency F2 are specified (S3). Next, the processor 12 calculates the current resistance change amount dRc and the current capacitance change amount dXc using the specified measurement data Rc1, Rc2, Xc1, and Xc2 (S4). Note that the current resistance change amount dRc is a change amount from the resistance component Rc1 at the first frequency F1 to the resistance component Rc2 at the second frequency F2. The current capacitance change amount dXc is a change amount from the capacitance component Xc1 at the first frequency F1 to the capacitance component Xc2 at the second frequency F2. Next, the processor 12 accesses the data area 13b and reads the initial resistance change amount dRs, the initial capacitance change amount dXs, the final resistance change amount dRe, and the final capacitance change amount dXe (S5).

  Next, the processor 12 calculates a resistance ratio Rratio and a capacity ratio Xratio (S6). Here, the resistance ratio Rratio is the difference between the terminal resistance change amount dRe and the current resistance change amount dRc with respect to the difference between the terminal resistance change amount dRe and the initial resistance change amount dRs. The resistance ratio Rratio is obtained by the equation (dRe−dRc) / (dRe−dRs). The capacity ratio Xratio is the difference between the terminal capacity change amount dXe and the current capacity change amount dXc with respect to the difference between the terminal capacity change amount dXe and the initial capacity change amount dXs. The capacity ratio Xratio is obtained by the equation (dXe−dXc) / (dXe−dXs).

  The resistance ratio Rratio corresponds to the distance between the terminal resistance component Re2 and the current resistance component Rc2 at the second frequency F2 of the battery 20 in FIG. The distance between the terminal resistance component Re2 and the initial resistance component Rs2 corresponds to the life of the battery 20 (the length from the start of use to the replacement time), and the resistance ratio Rratio corresponds to the remaining life. The same applies to the capacity ratio Xratio. In the equation for obtaining the resistance ratio Rratio and the capacity ratio Xratio, the amount of change in the resistance component (capacitance component) at the first frequency F1 and the second frequency F2 is simply used without using the difference between the final resistance component Re2 and the initial resistance component Rs2. The reason why the initial resistance change amount dRs is used is to remove the influence of the temperature of the battery 20 in the coordinate system of the Nyquist plot.

  As described above, the speed of the change in the resistance component of the internal impedance and the speed of the change in the capacity component depend on the driving situation. Both the resistance ratio Rratio and the capacity ratio Xratio correspond to the remaining life. In other words, the resistance ratio Rratio is the remaining life calculated based on the resistance component, and the capacitance component ratio Xratio is the remaining life calculated based on the capacitance component. The battery inspection apparatus 10 employs the smaller remaining life as the remaining life of the battery 20 among the remaining life based on the resistance component (resistance ratio Rratio) and the remaining life based on the capacity component (capacity ratio Xratio). That is, the processor 12 substitutes the smaller one of the resistance ratio Rratio and the capacity ratio Xratio for the remaining life Yj (S7).

  Next, the processor 12 reads the travel distance SK and travel time ST from the start of use of the battery 20 to the present time from the data area 13b (S8), and the remaining travel distance ZSK and the remaining travel distance according to (Equation 1) and (Equation 2) below. The travel time ZST is calculated (S9). The travel distance SK from the start of use to the present and the travel time ST from the start of use to the present are input in advance by the user of the battery inspection apparatus 10 as described above.

ZSK = SK × Yj / (1.0−YJ) (Equation 1)
ZST = ST × YJ / (1.0−YJ) (Equation 2)

  The calculated remaining travel distance ZSK and remaining travel time ZST are presented to the user through the output device 16 such as a display (S9).

  The meanings of (Equation 1) and (Equation 2) will be described by exemplifying numerical values. Consider the case where the remaining life Yj is 0.2. The remaining life Yj = 0.2 means that 80% of the life until the replacement time has already passed and the remaining is 20%. For example, when the current travel distance SK is 80000 km and the current travel time is 8 years, if those values are substituted into (Equation 1), the remaining travel distance ZSK is 20000 km and the remaining travel time ZST is 2 years. . That is, in this case, the battery 20 has a life of 100000 km / 10 years, the remaining travel distance ZSK is 20000 km, and the remaining travel time ZST is 2 years.

  Even with the same battery and the same remaining life Yj, the travel distance SK and travel time ST up to now may be different. For example, when there are many long-distance drivings using an expressway, and when the driving is gentle and the load on the battery is small, the progress of deterioration is delayed compared to the traveling distance / traveling time. For example, it is assumed that even if the same battery has the same remaining life Yj = 0.2, the travel distance SK up to the present is 120,000 km and the travel time ST is 12 years. In this case, the remaining travel distance ZSK / remaining travel time ZST of the battery 20 is the remaining travel distance ZSK = 30000 km from (Equation 1) and (Equation 2), and the remaining travel time ZST is 3 years.

  The battery inspection apparatus 10 described above calculates the remaining life for each of the resistance component and the capacity component of the internal impedance of the battery, and adopts the smaller remaining life as the remaining life of the battery 20. The time-dependent change of the resistance component and the time-dependent change of the capacity component depend on how the battery is used, that is, the running situation. By adopting the shorter remaining life based on the resistance component and the remaining life based on the capacity component, the battery inspection device 10 can output an appropriate remaining travel distance / remaining travel time as a guideline until battery replacement.

  Points to be noted regarding the technology described in the embodiments will be described. The battery inspection apparatus 10 according to the embodiment calculates and outputs the remaining travel distance and the remaining travel time based on the internal impedance of the battery. The battery inspection device 10 may calculate and output only the remaining travel distance.

  The battery inspection apparatus disclosed in the present specification can be applied to the remaining life calculation of other chemical batteries that deteriorate while being repeatedly charged and discharged, such as nickel-metal hydride batteries, in addition to lithium ion batteries. The battery inspection device disclosed in this specification may be applied to an assembled battery including a plurality of battery packs.

  The battery inspection apparatus 10 of an Example is connected to the battery removed from the motor vehicle. The technology disclosed in the present specification may be incorporated in an automobile equipped with a traveling motor and a battery. In that case, the battery inspection apparatus may present the remaining traveling distance and the remaining traveling time periodically during traveling or in response to a request from the driver. The battery temperature changes during travel. The battery inspection apparatus that uses the resistance component change amount and the capacitance component change amount at the first frequency F1 and the second frequency F2 can reduce the influence of the temperature, and is therefore preferably incorporated in an automobile.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

10: Battery inspection device 12: Processor 13: Non-volatile memory 13a: Output program 13b: Data area 14: AC-IR device 14a: Cable 15: Input device 16: Output device 17: Data bus 20: Battery

Claims (1)

It is a battery inspection device that calculates the remaining travel distance until the replacement time of the battery that supplies power to the travel motor,
Measuring means for measuring the resistance component Rc1 and the capacitance component Xc1 at a predetermined first frequency of the current internal impedance of the battery, and the resistance component Rc2 and the capacitance component Xc2 at a predetermined second frequency;
A change amount (initial resistance change amount dRs) of the internal impedance of the battery before use from the resistance component Rs1 at the first frequency to the resistance component Rs2 at the second frequency, and the internal impedance of the battery before use. The amount of change from the capacity component Xs1 at one frequency to the capacity component Xs2 at the second frequency (initial capacity change amount dXs) and the resistance component Re1 at the first frequency of the internal impedance of the battery at the replacement time to the second frequency And the amount of change from the capacity component Xe1 at the first frequency to the capacity component Xe2 at the second frequency (the terminal capacity) of the internal impedance of the battery at the time of replacement. Storage means storing change amount dXe);
A processor;
And the processor is
A change amount (current resistance change amount dRc) from the measured resistance component Rc1 to the resistance component Rc2 is calculated, and a change amount (current capacity change amount dXc) from the measured capacitance component Xc1 to the capacitance component Xc2 is calculated. )
Calculating a ratio (resistance ratio Rratio) of the difference between the terminal resistance change amount dRe and the current resistance change amount dRc with respect to the difference between the terminal resistance change amount dRe and the initial resistance change amount dRs;
Calculating a ratio (capacity ratio Xratio) of the difference between the final capacity change dXe and the current capacity change dXc with respect to the difference between the final capacity change dXe and the initial capacity change dXs;
Of the resistance ratio Rratio and the capacity ratio Xratio, the smaller ratio is defined as the remaining life Yj, and SK × Yj / (1.0−Yj) with respect to the travel distance SK from the start of use of the battery to the present. Calculate and output as remaining mileage,
Battery inspection device.

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