JP6604478B2 - Vehicle and its battery state detection system - Google Patents

Description

  The present invention relates to a vehicle equipped with a lead battery and a battery state detection system thereof, and more particularly to a vehicle and a battery state detection system thereof that can accurately detect a dischargeable time depending on the battery state regardless of the amount of discharge.

  In recent years, vehicles equipped with automatic engine stop and restart (ISS: idle stop / start) functions have become widespread in order to cope with the reduction of exhaust gas generated by engine cars, and in-vehicle lead-acid batteries are kept in a state where idle stop is possible. Technology is desired.

  That is, in an automobile (vehicle) equipped with an ISS, loads such as an air conditioner and a car stereo while the engine is stopped are all covered by power from the lead battery. For this reason, the deep discharge of a lead battery increases compared with the past, and it exists in the tendency for the charge condition of a lead battery to fall.

  Since the output of the lead battery depends on its state of charge, if the state of charge of the lead battery drops while the engine is stopped, it will not be possible to obtain sufficient output to start the engine, making it impossible to restart after stopping the engine. There is.

  Therefore, in order to maintain a state where the engine can be restarted, the charge state of the lead battery (for example, SOC: State Of Charge) is calculated (estimated) and the presence or absence of output necessary for engine start is monitored. When there is an output required for starting, idling stop is permitted, but when there is no output necessary for starting the engine, idling stop is prohibited and a signal such as charging a lead battery is transmitted to the vehicle computer. There is a need.

  Patent Documents 1 and 2 disclose a technique for determining the state of charge of a lead battery by measuring its open circuit voltage (OCV). In this prior art, the state of charge is calculated by substituting the OCV measured when the vehicle is stopped into the linear equation using the fact that the relationship between the state of charge and the OCV is expressed by a linear equation.

  Patent Document 3 discloses a technique for estimating the state of charge by measuring the internal resistance R of a lead battery. In this prior art, the relationship between the state of charge and the internal resistance R is expressed by an approximate expression, and the state of charge is calculated by substituting R measured when the vehicle is stopped into this approximate expression.

JP-A-4-264371 JP 2009-241633 JP Japanese Patent No. 3687628

  The remaining capacity of batteries mounted on automobiles is generally evaluated as “amount of electricity that can be discharged by 5-hour rate charging”. In particular, lead batteries can be discharged by temperature as shown in FIG. It is known that not only the amount of electricity differs but also the amount of discharge varies depending on the magnitude of the discharge amount (discharge current amount or discharge power amount).

  For example, with a battery with a time rate of “12V / 30Ah (5HR)”, a current of 6A can be taken out over 5 hours from the fully charged state until the voltage reaches the discharge end voltage (10.5V). If the current consumption is 10A, the time can be taken out less than 3 hours of the proportional calculation value, and if the current consumption is 3A, the time taken out is longer than 10 hours of the proportional calculation value. be able to.

  As described above, in a lead battery mounted in an automobile, the amount of electricity that can be taken out decreases as the discharge amount increases, and the performance characteristics depend on the temperature and the health condition of the battery. It was not possible to make an accurate prediction using only proportional calculations. Therefore, if the discharge amount larger than expected continues, the remaining capacity of the battery decreases faster than expected, and there is a possibility that the use of electrical components or the like may be hindered.

  An object of the present invention is to solve the above technical problem and to provide a vehicle capable of accurately predicting a battery dischargeable time regardless of the amount of discharge, the level of temperature, or the state of health, and its battery state detection system. It is in.

  In order to achieve the above object, the present invention is characterized in that a battery state detection system for detecting a battery state while the engine is stopped has the following configuration.

  (1) means for measuring a battery health condition index value, means for measuring a battery temperature index value, means for measuring a battery charge condition index value, means for measuring a battery discharge amount index value, Means for managing the relationship between the battery discharge amount index value, the dischargeable time index value and the state of charge for each combination of the battery temperature and the health state index value, and each of the temperature index value, the discharge amount index value and the health state index value Means for obtaining a dischargeable time index value by applying the measurement result to the managing means.

  (2) means for measuring the SOC of the battery, means for measuring the discharge amount index value of the battery, means for managing the relationship between the discharge amount index value of the battery, the dischargeable time and the SOC as a first correspondence relationship; Means for managing the relationship between the discharge amount index value of the battery, the dischargeable time and the open circuit voltage as a second correspondence relationship; means for detecting a use request for the electrical component; Means for obtaining a virtual discharge amount when the electrical component is used based on the measurement result of the discharge amount index value, and applying the virtual discharge amount and SOC to the first correspondence relationship and the virtual discharge amount and dischargeable time Means for obtaining a relationship with the index value; and means for obtaining an open circuit voltage when the virtual discharge amount is consumed by applying the relationship between the virtual discharge amount and the dischargeable time index value to the second correspondence relationship; Comparison result between open circuit voltage and predetermined minimum operating voltage And means for permitting or prohibiting the use of the electrical component based on the above.

  (3) A priority is set for each on-board electrical component, and the priority of other electrical components is compared to the method of comparing the priority between the electrical component requested to be used and the other electrical component in use. If it is low, it has means for calculating an alternative virtual discharge amount when using the electrical component requested to be used instead of the other electrical component, and obtains the relationship between the virtual discharge amount and the dischargeable time index value The means applies the alternative virtual discharge amount and SOC to the first correspondence relationship, and the means for obtaining the open circuit voltage applies the relationship between the alternative virtual discharge amount and the dischargeable time index value to the second correspondence relationship. did.

  According to the present invention, the following effects are achieved.

  (1) The battery dischargeable time is determined not only by the battery charge state, health condition, and temperature T but also by considering the discharge amount (discharge current amount or discharge power amount). The battery dischargeable time can be accurately predicted regardless of the level of the battery or the health condition.

  (2) The relationship between the virtual discharge amount Iv and the dischargeable time Time can be obtained by applying the virtual discharge current Iv and SOC measurement results to the relationship between the discharge amount registered in advance and the dischargeable time Time and SOC. Furthermore, by applying this to the relationship between the discharge amount registered in advance and the dischargeable time Time and the battery voltage V, it is possible to accurately predict the battery voltage Vv when the virtual discharge amount Iv is assumed to be consumed. . Therefore, if the virtual discharge amount Iv when the stopped electrical component is operated is obtained, it is based on whether the virtual battery voltage Vv when the discharge amount Iv is consumed is lower than the minimum guaranteed voltage Vmim of the electrical component. Thus, it is possible to prevent the use of electrical components that may interfere with vehicle travel.

  (3) From the viewpoint of lowering battery voltage due to the use of electrical components, if the use of low-priority electrical components can be newly used by stopping the use of low-priority electrical components, Since the use of high-priority electrical components is permitted after the use is stopped, the use of low-priority electrical components can prevent the use of high-priority electrical components and prevent the vehicle from being disabled. become.

It is the functional block diagram which showed the structure of the principal part of the battery state detection system which concerns on one Embodiment of this invention. It is a functional block diagram of an embodiment which estimates dischargeable time Time according to current discharge current amount I based on temperature T, current I, SOH, and SOC of a lead battery. It is a functional block diagram of an embodiment which estimates dischargeable time Time according to current discharge current amount I based on temperature T, current I, SOH, and voltage V of a lead battery. It is a functional block diagram of an embodiment which estimates dischargeable time Time according to current discharge electric energy Q based on temperature T, current I, SOH, and SOC of a lead battery. FIG. 5 is a functional block diagram of an embodiment for estimating a dischargeable time Time according to the current discharge power amount Q based on the temperature T, current I, SOH, and voltage V of the lead battery. It is a flowchart of the function (the 1) which prevents the immobilization of the electric equipment system resulting from the fall of the battery voltage accompanying the increase in discharge amount, and the disabling of vehicle travel resulting from this. It is a flowchart of the function (the 2) which prevents the immobilization of the electric equipment system resulting from the fall of the battery voltage accompanying the increase in discharge amount, and the disabling of vehicle travel resulting from this. It is the figure which showed the example in which the relationship between a discharge current and a full charge capacity depends on temperature.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing a configuration of a main part of a battery state detection system 1 according to an embodiment of the present invention. Here, a gasoline engine vehicle equipped with a lead battery 12 having an ISS function is shown. Application will be described as an example.

  The battery state detection system 1 includes a temperature sensor 2 such as a thermistor for measuring the temperature of the lead battery 12, a voltage measuring unit 3 having a differential amplifier circuit or the like and connected to an external terminal of the lead battery 12, a hall element, and the like. A microcomputer (hereinafter referred to as a microcomputer) 10 that detects the battery state of the current sensor 4 and the lead battery 12 is a main component.

  The lead battery 12 has a substantially rectangular battery case serving as a battery container, and a total of six electrode plate groups are accommodated in the battery case. As the material of the battery case, for example, a polymer resin such as polyethylene (PE) can be used. Each electrode plate group is formed by laminating a plurality of negative plates and positive plates with a separator interposed therebetween, and the cell voltage is 2.0V. For this reason, the nominal voltage of the lead battery 12 is set to 12V. The upper part of the battery case is bonded or welded to an upper lid made of a polymer resin such as PE that seals the upper opening of the battery case. A rod-like positive electrode terminal and a negative electrode terminal for supplying electric power to the outside using the lead battery 12 as a power source are erected on the upper lid. In addition, the temperature sensor mentioned above is being fixed to the side part or bottom face part of a battery case.

  A positive terminal of the lead battery 12 is connected to a central terminal of an ignition switch (hereinafter, IGN) 5 through a current sensor 4. The IGN5 has an OFF terminal, ON / ACC terminal, and START terminal in addition to the central terminal, and the central terminal and any of the OFF, ON / ACC, and START terminals can be switched in a rotary manner. .

  The START terminal is connected to an engine starting cell motor (starter) 9. The cell motor 9 can transmit a rotational driving force to the rotating shaft of the engine 8 via a clutch mechanism (not shown). The ON / ACC terminal is used for the generator 7 that generates electric power by the rotation of the engine 8 through an auxiliary device (electrical equipment) 6 such as an air conditioner, a radio, a lamp, and a regulator including a rectifying element that allows a current flow in one direction. Connected to one end. That is, the anode side of the regulator is connected to one end of the generator 7, and the cathode side is connected to the ON / ACC terminal.

  The rotating shaft of the engine 8 can transmit power to the generator 7 via a clutch mechanism (not shown). For this reason, when the engine 8 is in a rotating state, the generator 7 is operated via the clutch mechanism, and the generated power is supplied (charged) to the auxiliary machine 6 and the lead battery 12. The OFF terminal is not connected to either.

  The output of the voltage measuring unit 3 is connected to an A / D converter built in the microcomputer 10. The outputs of the temperature sensor 2 and the current sensor 4 are connected to an A / D converter built in the microcomputer 10, respectively. For this reason, the microcomputer 10 can take in the voltage and temperature of the lead battery 12 and the current flowing through the lead battery 12 as digital values every predetermined time. The microcomputer 10 can communicate with the host vehicle control system 11 via the I / O.

  The microcomputer 10 functions as a CPU that functions as a central processing unit, a ROM that stores basic control programs for the battery state detection system 12, program data such as maps and mathematical formulas described later, and a work area for the CPU and temporarily stores the data. It is configured to include RAM to store, nonvolatile EEPROM, etc.

  The other end of the generator 7, the cell motor 9 and the auxiliary machine 6, the negative terminal of the lead battery 12, and the microcomputer 10 are each connected to the ground (the same potential as the chassis of the automobile). Note that the microcomputer 10 of the present embodiment samples the voltage, current, and temperature at predetermined time intervals (for example, the voltage and current are each 2 milliseconds and the temperature is 1 second), and the sampling result is stored in the RAM. . Further, regarding the current, the integrated values are calculated separately for the discharge current and the charge current.

  The CPU mounted on the microcomputer 10 determines the terminal position based on the voltage of the IGN 5, and further detects the engine state. If the IGN 5 is a type that outputs a signal representative of the terminal position, the engine state may be detected based on the signal or a signal from the vehicle control system 11. In general, in an automobile having an internal combustion engine such as a gasoline engine car or a diesel engine car, electric power is supplied from a lead battery and a cell motor is rotated to start the engine.

  When a predetermined time for eliminating the polarization reaction of the lead battery 12 elapses after the engine is stopped, the CPU takes in the terminal voltage of the lead battery 12 measured through the voltage measuring unit 3 as an open circuit voltage OCV. The OCV is repeatedly fetched by a timer interrupt at a cycle, and at other timings, only the timer is activated and the power saving mode is entered in which no control operation is performed.

  FIG. 2 is a functional block diagram of the first embodiment in which the microcomputer 10 estimates the dischargeable time Time according to the discharge amount based on the temperature T and current I of the lead battery 12, and the CPU of the microcomputer 10 This is realized by operating based on programs and data stored in advance in ROM or EEPROM.

  In this embodiment, for a large number of lead batteries having the same specifications as the in-vehicle lead battery 12, the relationship between the discharge amount, the dischargeable time and the charge state is obtained for each combination of the battery temperature and the health state, and these are obtained. Based on a map or function created by statistical processing, a dischargeable time Time when it is assumed that the current discharge amount continues is calculated.

  The database 100 shows the relationship between the discharge current I (x axis), which is the index value of the discharge amount, and the dischargeable time Time (y axis) constructed using SOC (State Of Charge) as the index value of the state of charge. A large number of first correspondence tables are registered for each combination of battery temperature T and health status. In this embodiment, SOH (State Of Health) is adopted as an index value of the health state.

  In the calculation unit 101, the SOH calculation unit 101a calculates the SOH of the lead battery 12. There are various methods for calculating the SOH of a lead battery. For example, an SOH that represents the relationship between the internal resistance R and SOH measured in advance in various health conditions (deteriorated conditions) of many lead batteries having the same specifications as this. It can be obtained by applying the measurement result of the internal resistance R to the map.

  The SOC calculation unit 101b calculates the SOC of the lead battery 12. The dischargeable time calculation unit 101c selects a corresponding first correspondence table from the database 100 based on the measurement results of the temperature T and the health state SOH, and measures and calculates the discharge current I and the charge state SOC in the table. Apply the result to obtain the dischargeable time Time. When there is no table corresponding to the measurement result, a plurality of tables with similar measurement values are selected, and the dischargeable time Time is estimated by interpolating or extrapolating those measurement results.

  In the above embodiment, the SOC is used as an index value representative of the state of charge of the battery, but the present invention is not limited to this, and the terminal voltage V of the battery is used as the index value. You may make it do.

  FIG. 3 is a functional block diagram of another embodiment of the present invention. In the database 200, the discharge current I (x axis) and the dischargeable time Time measured by using the terminal voltage V of the battery as an index value of the charge state are shown. A large number of second correspondence relationship tables indicating the relationship with (y-axis) are registered for each combination of temperature T and health state SOH.

  In the calculation unit 201, the SOH calculation unit 201a calculates the SOH of the lead battery 12. The dischargeable time calculation unit 201b selects a corresponding second correspondence table from the database 200 based on the measurement results of the temperature T and the health condition SOH, and each measurement result of the discharge current I and the terminal voltage V in the table. Is applied to estimate the dischargeable time Time.

  In each of the above embodiments, the discharge current I is described as an index value representative of the discharge amount. However, the present invention is not limited to this, as shown in FIG. The discharge power amount Q may be adopted.

  The database 300 includes a third correspondence relationship table showing the relationship between the electric energy Q (x axis), which is the index value of the discharge amount, and the dischargeable time Time (y axis), which is obtained by measuring the SOC as the index value of the state of charge. Are registered for each combination of temperature T and state of health SOH.

  In the calculation unit 301, the SOH calculation unit 301 a calculates the SOH of the lead battery 12. The SOC calculation unit 301b calculates the SOC of the lead battery 12. The power calculation unit 301c calculates power Q based on the voltage V and the current I. The dischargeable time calculation unit 301d selects a corresponding third correspondence table from the database 300 based on the measurement result of the temperature T and the health state SOH, and applies each measurement result of the SOC and the electric energy Q to the table. Thus, the dischargeable time Time is estimated.

  Alternatively, as shown in FIG. 5, the voltage V may be adopted as the state of charge index value instead of the SOC. In this case, the database 400 includes a fourth correspondence table indicating the relationship between the electric energy Q (x axis) and the dischargeable time Time (y axis) measured by using the voltage V as an index value of the charge state. A lot will be registered for each combination of health status and SOH.

  In the calculation unit 401, the SOH calculation unit 401a calculates the SOH of the lead battery 12. The power calculation unit 401b calculates the power amount Q based on the voltage V and the current I. The dischargeable time calculation unit 401c selects a corresponding fourth correspondence table from the database 400 based on the measurement results of the temperature T and the health state SOH, and stores the measurement results of the voltage V and the electric energy Q in the table. By applying it, the dischargeable time Time is estimated.

  As described above, according to each of the embodiments described above, the dischargeable time Time of the battery includes not only the battery charge state (SOC or voltage V), the health state SOH and the temperature T, but also the discharge amount (discharge current amount I or Since the amount of discharge electric power Q) is also estimated, the battery dischargeable time Time can be accurately estimated regardless of the amount of discharge.

  Next, in the above system, the function of preventing the immobilization of the electrical system due to the decrease in the battery voltage accompanying the increase in the discharge amount and the disabling of the vehicle traveling due to this will be described with reference to the flowchart of FIG. .

  When the in-vehicle battery charge state decreases, the degree of battery voltage drop increases as the amount of discharge increases, so if you start to use unused electrical equipment or vehicle auxiliary equipment, the battery voltage will become electrical equipment. The minimum operating voltage Vmin, etc., may not be guaranteed.

  If the minimum operating voltage Vmin of an electrical component such as an ECU (engine control unit) that is indispensable for vehicle travel is also lowered, the vehicle travel itself cannot be maintained. Therefore, in this embodiment, based on the relationship between the discharge current I of the in-vehicle battery, the dischargeable time T, and the voltage V, the use of electrical components that may interfere with vehicle travel is prohibited.

  In step S1, it is determined whether or not use of an electrical component in a stopped state is requested. When the use request is detected, the process proceeds to step S2, and the virtual discharge amount Iv (= Ic + I) is calculated by adding the requested rated current Ic of the requested electrical component and the current measured value of the discharge current I. The For example, if the current discharge current amount I is 20 A and the rated current Ic of the electrical component requested to be used is 10 A, the virtual discharge amount Iv is obtained as 30 A.

  In step S3, the relationship between the current SOC of the on-vehicle battery and the virtual discharge amount Iv is applied to the first correspondence table of the database 100 shown in FIG. 4 to enable discharge corresponding to the virtual discharge amount Iv. Time T is calculated. Further, by applying the relationship between the virtual discharge amount Iv and the dischargeable time T to the second correspondence table of the database 200 shown in FIG. 5, the battery voltage corresponding to the virtual discharge amount Iv is changed to the virtual battery. Estimated as voltage Vv.

  In step S4, the operation minimum voltage Vmin of each electrical component registered in advance and the virtual battery voltage Vv are compared, and if Vv> Vmin, the process proceeds to step S5 and the use of the requested electrical component is permitted. Is done. On the other hand, if Vv ≦ Vmin, the process proceeds to step S6, and the use of the requested electrical component is prohibited.

  As described above, according to the present embodiment, the virtual discharge amount Iv and the measurement result of the SOC are applied to the relationship between the discharge current I, the dischargeable time T, and the SOC registered in advance, so that the virtual corresponding to the SOC can be obtained. The relationship between the discharge amount Iv and the dischargeable time is obtained based on the accuracy. Furthermore, by applying this to the relationship between the pre-registered discharge current I, dischargeable time T and battery voltage V, it is possible to accurately predict the battery voltage Vv when the virtual discharge amount Iv is assumed to be consumed. .

  Therefore, if the virtual discharge amount Iv when using the currently stopped electrical component is obtained, it is based on whether the virtual battery voltage Vv at the virtual discharge amount Iv is lower than the minimum guaranteed voltage Vmim of the main electrical component. In addition, it is possible to prevent in advance the use of electrical components that may interfere with vehicle travel.

  On the other hand, electrical components include those that are not necessarily necessary for vehicle travel, such as air conditioners and car audios, in addition to those that are indispensable for vehicle travel or important to the same extent. It is undesirable to prohibit the use of more important electrical components.

  Therefore, in the embodiment described below, when a priority is set in advance for each electrical component, there is a possibility that the virtual battery voltage Vv may not be able to maintain the minimum guaranteed voltage Vmin due to the use of the newly requested electrical component. Inspects whether or not an electrical component with a lower priority than the relevant electrical component is used, and if an electrical component with a lower priority is in use, the use is stopped and the electrical component with a higher priority is used. You may make it switch.

  FIG. 7 is a flowchart showing the operation of the present embodiment. Since the operations in steps S1 to S3 are the same as those in the above embodiment, the description thereof is omitted.

  In step S4, the minimum operating voltage Vmin registered in advance and the virtual battery voltage Vv obtained in step S3 are compared. If Vv> Vmin, the process proceeds to step S20 and the requested electrical component is detected. Use is allowed.

  On the other hand, if Vv ≦ Vmin, the process proceeds to step S15, and it is determined whether or not an electrical component whose priority is lower than the requested electrical component is in use. If an electrical component with a low priority is not in use, the process proceeds to step S17, and the use of the requested electrical component is prohibited.

  On the other hand, if a low-priority electrical component is in use, the process proceeds to step S16, and the amount of discharge is reduced by stopping the use of the electrical component. In step S18, the virtual discharge amount Iv and the virtual battery voltage Vv reflecting the reduced discharge amount are recalculated.

  In step S19, the virtual battery voltage Vv and the operation guarantee lower limit voltage Vmin are compared. If Vv ≦ Vmin, the process returns to step S15 and the above-described procedures are repeated for the electrical component with the next lowest priority. As a result, if Vv> Vmin, the process proceeds to step S20, and the use of the requested electrical component is permitted.

  According to the present embodiment, from the viewpoint of battery voltage drop due to the use of electrical components, when the use of electrical components with high priority can be newly used by stopping the use of electrical components with low priority, Use of low-priority electrical components is permitted and use of high-priority electrical components is permitted, so use of low-priority electrical components prevents the use of high-priority electrical components and makes the vehicle unable to run You can prevent that.

  DESCRIPTION OF SYMBOLS 1 ... Battery state detection system, 2 ... Temperature sensor, 3 ... Voltage measuring part, 4 ... Current sensor, 5 ... IGN, 6 ... Auxiliary machine, 7 ... Generator, 8 ... Engine, 9 ... Cell motor for engine starting, 10 ... Microcomputer, 12 ... lead battery,

Claims (9)

In the battery state detection system that detects the battery state while the engine is stopped,
Means for measuring the health index value of the battery;
Means for measuring the temperature index value of the battery;
Means for measuring the state of charge index value of the battery;
Means for measuring a battery discharge amount index value;
Means for managing the relationship between the battery discharge amount index value, the dischargeable time index value and the state of charge for each combination of battery temperature and health condition index value;
A battery state detection system comprising: means for obtaining a dischargeable time index value by applying each measurement result of the temperature index value, discharge amount index value and health condition index value to the managing means.   The battery state detection system according to claim 1, wherein a charge state index value of the battery is SOC.   The battery state detection system according to claim 1, wherein the charge state index value of the battery is an open circuit voltage.   The battery state detection system according to any one of claims 1 to 3, wherein the discharge amount index value is a discharge current of the battery.   The battery state detection system according to claim 1, wherein the discharge amount index value is power consumption of the battery. In the battery state detection system that detects the battery state while the engine is stopped,
Means for measuring the SOC of the battery;
Means for measuring a battery discharge amount index value;
Means for managing the relationship between the battery discharge amount index value, the dischargeable time and the SOC as a first correspondence relationship;
Means for managing the relationship between the discharge amount index value of the battery, the dischargeable time and the open circuit voltage as a second correspondence relationship;
Means for detecting the use request of electrical components;
Means for obtaining a virtual discharge amount when the electrical component is used based on a measurement result of the current consumption amount registered and the discharge amount index value with respect to the electrical component;
Means for determining the relationship between the virtual discharge amount and the dischargeable time index value by applying the virtual discharge amount and the SOC to the first correspondence relationship;
Means for obtaining an open circuit voltage when the virtual discharge amount is consumed by applying the relationship between the virtual discharge amount and the dischargeable time index value to the second correspondence relationship;
A battery state detection system comprising: means for permitting or prohibiting use of the electrical component based on a comparison result between the open circuit voltage and a predetermined minimum operating voltage. Priorities are set for each on-board electrical component,
A means for comparing priorities between the requested electrical component and other electrical components in use;
If the priority of the other electrical component is lower, comprising means for calculating an alternative virtual discharge amount when using the electrical component requested to be used instead of the other electrical component,
The means for determining the relationship between the virtual discharge amount and the dischargeable time index value applies the alternative virtual discharge amount and SOC to the first correspondence relationship,
7. The battery state detection system according to claim 6, wherein the means for obtaining the open circuit voltage applies a relationship between the alternative virtual discharge amount and a dischargeable time index value to the second correspondence relationship. Means for measuring the health index value of the battery;
Means for measuring the temperature index value of the battery,
The first correspondence relationship and the second correspondence relationship are managed for each combination of battery temperature and health condition index value;
The means for obtaining the relationship between the virtual discharge amount and the dischargeable time index value employs a first correspondence according to the combination of the battery temperature and the health condition index value,
8. The battery state detection system according to claim 6, wherein the means for obtaining the open circuit voltage employs a second correspondence relationship according to a combination of a battery temperature and a health state index value. 9.   A vehicle characterized by detecting a state of an in-vehicle battery using the battery state detection system according to any one of claims 1 to 8.