JP2014046715A - Vehicle battery monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle battery monitoring system that suppresses a decrease in a remaining battery capacity of a vehicle battery.SOLUTION: A vehicle battery monitoring system (a monitoring system 20) includes a monitoring unit 21 that monitors an electric state of a first battery 2 (a vehicle battery) with which a power plant 4 of a vehicle 100 can be started, and a power supply that is a second battery 23 which feeds power to the monitoring unit 21. The monitoring unit 21 determines whether the power plant 4 is stopped. If the power plant 4 is stopped, the monitoring unit 21 monitors the voltage V of the first battery 2 as the electric state.

Description

  The present invention relates to a system (vehicle battery monitoring system) for monitoring a battery provided in a vehicle.

  A vehicle such as an automobile includes electric components such as a head ride and a car security device, and these electric components can be operated by being supplied with electric power from a vehicle battery. For example, FIG. 2 of Patent Document 1 discloses a car security device 2, and according to the description of paragraph [0045] of Patent Document 1, the car security device 2 normally receives power from the main power supply 11 (vehicle battery). On the other hand, when the power from the main power supply 11 is not supplied, the power from the rechargeable battery 13 (auxiliary power supply) is supplied via the power supply switching unit 12.

JP 2008-279939 A

  The vehicle battery can start the vehicle prime mover and is therefore an important part. However, as described above, the vehicle battery can supply power to various electrical components, and the remaining amount of the vehicle battery is reduced depending on the operating status (usage status) of the electrical components. When the remaining amount of the vehicle battery is low, the vehicle prime mover cannot be started. In other words, the vehicle battery rises depending on the operating status (usage status) of the electrical component.

  One object of the present invention is to provide a vehicle battery monitoring system that suppresses a decrease in the remaining amount of the vehicle battery. Other objects of the present invention will become apparent to those skilled in the art by referring to the aspects and preferred embodiments exemplified below and the accompanying drawings.

  In the following, in order to easily understand the outline of the present invention, embodiments according to the present invention will be exemplified.

According to a first aspect of the present invention, a monitoring unit that monitors an electrical state of a first battery capable of starting a prime mover of a vehicle;
A power supply unit that is a second battery for supplying power to the monitoring unit;
With
The monitoring unit determines whether or not the prime mover is stopped,
When the prime mover is stopped, the monitoring unit monitors the voltage of the first battery as the electrical state, and is related to a vehicle battery monitoring system.

  When the prime mover is stopped, the monitoring unit can monitor the voltage of the first battery capable of starting the prime mover of the vehicle. Since the voltage of the first battery also decreases when the remaining amount of the first battery decreases, the monitoring unit can monitor the remaining amount of the first battery via the voltage of the first battery. In other words, the monitoring unit can monitor, for example, whether or not the motor of the vehicle can be started with the current remaining amount of the first battery. In addition, the monitoring unit that monitors the remaining amount of the first battery operates by being supplied with electric power from a second battery different from the first battery that can start the prime mover of the vehicle. Therefore, when monitoring the remaining amount of the first battery, the second battery can suppress a decrease in the remaining amount of the first battery.

  In the first aspect, the monitoring unit may predict a time when the voltage of the first battery is lower than the first voltage.

  Since the monitoring unit predicts the time when the voltage of the first battery falls below the first voltage, the monitoring unit can allow the voltage of the first battery to decrease until that time.

In the first aspect, the vehicle battery monitoring system includes:
A switching unit capable of connecting the first battery and the second battery in parallel;
When the prime mover is stopped, the monitoring unit controls the switching unit such that the first battery and the second battery are connected in parallel, and the second battery You may supply the said electric power from a 2nd battery to the electrical component with which the electric power from the said 1st battery was supplied.

  Since the electric power from the second battery is supplied to the electrical component, the second battery can suppress a decrease in the remaining amount of the first battery.

  In the first aspect, after the prime mover stops, until the voltage of the first battery falls below a second voltage that is higher than the first voltage, the monitoring unit The switching unit may be controlled so that the battery and the second battery are disconnected.

  During the period from when the prime mover stops until the voltage of the first battery falls below the second voltage, in other words, when the remaining amount of the first battery is large, the switching unit The supply to the product can be continued.

In the first aspect, the vehicle battery monitoring system includes:
You may further provide the alerting | reporting part which alert | reports the monitoring result of the said monitoring part to a user.

  Since the notification unit can notify the user of the remaining amount of the first battery, the user can recover the remaining amount of the first battery before the remaining amount of the first battery decreases. . Alternatively, the user can use the first battery without worrying about the remaining amount of the first battery until the remaining amount of the first battery decreases.

In the first aspect, the vehicle battery monitoring system includes:
A vibration sensor for detecting vibration of the prime mover,
The monitoring unit may determine whether or not the prime mover is stopped by the vibration sensor.

  The monitoring unit can determine whether or not the prime mover is stopped by a vibration sensor instead of the ignition switch.

  Those skilled in the art will readily understand that the illustrated embodiments according to the present invention can be further modified without departing from the spirit of the present invention.

The structural example of the vehicle battery monitoring system according to this invention is shown. 1 shows an example of a schematic functional block diagram of a monitoring device according to the present invention. An example of the explanatory view of the relation between the remaining amount of the vehicle battery and the voltage is shown. An example of the time change of the remaining amount of the vehicle battery is shown.

  The preferred embodiments described below are used to facilitate an understanding of the present invention. Accordingly, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below.

  FIG. 1 shows a configuration example of a vehicle battery monitoring system according to the present invention. In the example of FIG. 1, the vehicle battery monitoring system monitors a first battery 2 (vehicle battery) provided in the vehicle 100 and includes, for example, a monitoring device 20. In other words, the vehicle battery monitoring system includes at least the monitoring device 20 and can also include, for example, the first battery 2. The vehicle battery monitoring system may further include electrical components such as the headlight 11.

  In the example of FIG. 1, the monitoring device 20 is installed at the node P2 on the constant power supply line + B. However, the monitoring device 20 can be set at any node on the constant power supply line + B. You may install in the node P1 near the base of + terminal (positive electrode) of 1 battery 2. As will be described later, the monitoring device 20 or the vehicle battery monitoring system constantly monitors the electrical state on the power supply line + B, that is, the electrical state of the first battery 2.

  In the example of FIG. 1, a vehicle 100 is, for example, an automobile, and the automobile has an engine room that stores a prime mover 4 that is an internal combustion engine such as a gasoline engine, and a room that stores a driver's seat, for example. The first battery 2 is disposed on the engine room side, and the negative terminal (negative electrode) of the first battery 2 is grounded to the vehicle body 1. The + terminal (positive electrode) of the first battery 2 constitutes the starting point of the constant power supply line + B, and is connected or wired to, for example, the main fuse box 6 via the node P1 on the constant power supply line + B. The constant power supply line + B branches off before the main fuse box 6 and is connected to, for example, an ACG (alternating current generator) 3. The ACG 3 can generate alternating current with the operation or rotation of the prime mover 4, and can charge the first battery 2 with direct current converted from the alternating current.

  The main fuse box 6 has a main fuse (not shown) connected to the node P1 on the constant power supply line + B. The constant power supply line + B branches in the main fuse box 6 and a plurality of branched constant power supplies Each of the lines + B is connected to electrical components such as the headlight 11 and the starter 5 through a sub fuse (not shown) in the main fuse box 6. The main fuse box 6 has a relay (not shown) that always connects or disconnects the power supply line + B to the electrical component via the sub fuse. For example, the headlight 11 is turned on when the switch 8 is ON, while the switch 8 In the OFF state, the headlight 11 is turned off. Further, the constant power supply line + B from the main fuse box is directly connected to the indoor fuse box 10 disposed on the indoor side, and is connected to the indoor fuse box 10 via the ignition switch 9.

  The indoor fuse box 10 has a plurality of fuses (not shown), and the constant power line + B is branched in the indoor fuse box 10, and each of the branched constant power lines + B is in the indoor fuse box 10. And connected to an electrical component such as the monitoring device 20 via a fuse. The constant power line + B from the main fuse box is converted into the accessory power line ACC by the ignition switch 9, and the accessory power line ACC branches in the indoor fuse box 10, and each of the branched accessory power lines ACC is The indoor fuse box 10 is connected to an electrical component such as an audio device (not shown) via a fuse. For example, an audio device connected to the accessory power supply line ACC is activated when the ignition switch 9 is in an ON state or an ACC state, while the operation of the audio device is stopped when the ignition switch 9 is in an OFF state.

  In addition, the starter 5 operates in the START state of the ignition switch 9, the prime mover 4 starts, and thereafter, the prime mover 4 operates or rotates as long as the ignition switch 9 is maintained in the ON state. When the remaining amount of the first battery 2 is small, the first battery 2 cannot start the prime mover 4 of the vehicle 100 with the starter 5. In other words, for example, when the prime mover 4 is stopped and the ACG 3 does not generate power, the first battery 2 is raised by continuous lighting of the headlight 11.

  FIG. 2 shows an example of a schematic functional block diagram of the monitoring device 20 according to the present invention. In the example of FIG. 2, the monitoring device 20 configuring the vehicle battery monitoring system includes a monitoring unit 21 that constantly monitors the electrical state on the power supply line + B, that is, the electrical state of the first battery 2. The monitoring device 20 or the vehicle battery monitoring system includes not only the monitoring unit 21 but also a power supply unit. This power supply unit is not the first battery 2 (vehicle battery) in FIG. 1 but the second battery 23 in FIG. (Spare battery). The power supply unit that is the second battery 23 can supply power to the monitoring unit 21. Therefore, when the monitoring unit 21 monitors the electrical state of the first battery 2, the second battery 23 can suppress a decrease in the remaining amount of the first battery 2.

  The monitoring unit 21 monitors the voltage V of the first battery 2 (for example, the node P2 on the constant power supply line + B) as the electrical state of the first battery 2. In particular, when the prime mover 4 is stopped, the voltage V or remaining amount of the first battery 2 is determined by the receiver of the keyless entry system (not shown), the electronic control unit (not shown) for controlling the prime mover 4, etc. It is reduced by the dark current of the electrical equipment. The monitoring unit 21 can monitor whether or not the prime mover 4 can be started with the current voltage V or the remaining amount of the first battery 2. At this time, the monitoring unit 21 can grasp the accurate remaining amount of the first battery 2 by using the stable voltage V of the first battery 2 after the prime mover 4 is stopped. An operation example of the monitoring unit 21 will be described later.

  The monitoring device 20 or the vehicle battery monitoring system includes a switching unit 22 that can connect the first battery 2 and the second battery 23 in parallel, a notification unit 24 that notifies a user of a monitoring result of the monitoring unit 21, and a prime mover. 4, and a vibration sensor 25 that detects the vibration 4. Examples of operations of the switching unit 22, the notification unit 24, and the vibration sensor 25 will be described later. The power supply unit that is the second battery 23 can supply power to the switching unit 22, the notification unit 24, and the vibration sensor 25. Therefore, when the switching unit 22, the notification unit 24, and the vibration sensor 25 are activated, the second battery 23 can suppress a decrease in the remaining amount of the first battery 2.

  FIG. 3 shows an example of an explanatory diagram of the relationship between the remaining amount of the vehicle battery and the voltage. In the example of FIG. 3, the vehicle battery is, for example, a lead storage battery, and when the remaining amount (initial capacity) of the vehicle battery is 100 [%], the voltage of the vehicle battery indicates, for example, 12.5 [V]. Since the voltage of the vehicle battery decreases when the remaining amount of the vehicle battery decreases, when the remaining amount of the vehicle battery is 90, 83, 75 and 60 [%], the voltage of the vehicle battery is, for example, 12.2 respectively. 12.0, 11.5, 11.0 [V]. Further, when the remaining amount of the vehicle battery falls below, for example, 75 [%], the deterioration of the vehicle battery increases, and the capacity of the vehicle battery (capacity at full charge) decreases. In addition, when the remaining amount of the vehicle battery falls below 60%, for example, the engine cannot be started. Considering such characteristics of the vehicle battery, it is preferable that the remaining amount or voltage of the vehicle battery does not decrease. In particular, the remaining amount or voltage of the vehicle battery is less than 60 [%] or 11.0 [V]. Preferably not.

  In the example of FIG. 1, the wiring between the positive terminal (positive electrode) of the first battery 2 (vehicle battery) and the node P1 on the constant power supply line + B is composed only of a thick (for example, 5 [sq]) short electric wire. Therefore, the electric resistance of the wiring can be almost ignored. On the other hand, the wiring between the node P1 and the node P2 on the constant power supply line + B is thin between the main fuse box 6, the indoor fuse box 10, and between the main fuse box 6 and the indoor fuse box 10 (for example, 0.5 [sq ]) Since it is composed of a long electric wire, the electrical resistance of the wiring cannot be ignored. In other words, when the voltage V of the first battery 2 is always measured at the node P2 on the power supply line + B, the voltage V decreases due to the voltage drop. What is necessary is just to convert quantity (capacity). In addition, the heat resistance and water resistance of the monitoring device 20 installed on the indoor side such as the node P2 on the constant power line + B are compared with the resistance when installed on the engine room side such as the node P1. Therefore, the manufacturing cost of the monitoring device 20 installed indoors can be reduced.

  FIG. 4 shows an example of a temporal change in the remaining amount of the vehicle battery. In the example of FIG. 4, time zero is when the prime mover 4 is stopped, and the remaining amount of the vehicle battery (first battery 2) at time zero exceeds, for example, 100 [%]. In other words, since the ACG 3 is generating power before the prime mover 4 is stopped, the voltage of the first battery 2 immediately after the prime mover 4 is stopped is highly measured due to the influence of the ACG 3. The monitoring unit 21 of FIG. 2 stores the characteristics of the first battery 2 (relationship between the remaining amount of the vehicle battery and the voltage) such as a table as shown in FIG. From the characteristics, the measured voltage V of the first battery 2 can be converted into the remaining amount of the first battery 2. When the prime mover 4 is stopped, specifically, in the example of FIG. 4, the monitoring unit 21 continues to monitor the voltage V of the first battery 2 from time zero to time t4.

  Since the voltage of the first battery 2 after the prime mover 4 stops is reduced by the dark current of the electrical components, the prime mover 4 can be started with the current measured voltage V of the first battery 2. Whether or not is important. Next, it is also important whether or not the deterioration of the first battery 2 becomes large at the current measured voltage V of the first battery 2. Therefore, it is important to monitor the voltage V of the first battery 2, in other words, to monitor the remaining amount of the first battery 2.

  In the example of FIG. 2, the monitoring unit 21 can notify the user of the current measured voltage V or remaining amount of the first battery 2 via the notification unit 4 as a monitoring result. Here, the notification unit 4 is configured with, for example, a display, a speaker, and the like, and can transmit a monitoring result to an indoor user (occupant). Preferably, the notification unit 4 includes, for example, a 3G communication module, LTE ( Long term evolution (transmission module), WiFi (wireless fidelity) communication module, etc., and the result of monitoring (for example, current measurement of the first battery 2) to an outdoor or indoor user or a portable terminal (not shown) Can be transmitted in a transmission format such as e-mail. In response to this, the user operates the vehicle 100 or charges the first battery 2 with a dedicated charger (not shown) before the voltage V or the remaining amount of the first battery 2 decreases. In some cases, a booster cable (not shown) can be connected to the first battery 2 or the remaining amount of the first battery 2 can be recovered. Alternatively, the user can use the first battery 2 or electrical components without worrying about the remaining amount of the first battery 2 until the voltage V or the remaining amount of the first battery 2 decreases.

  The monitoring unit 21 can first determine whether or not the prime mover 4 is stopped. In the example of FIG. 2, the monitoring unit 21 can determine whether or not the prime mover 4 is stopped by a sensor 25 such as a vibration sensor. The vibration sensor can be constituted by, for example, a triaxial acceleration sensor. When the triaxial acceleration sensor does not detect vibration due to the operation of the prime mover 4, the monitoring unit 21 determines or monitors that the prime mover 4 is stopped. can do. For example, the monitoring unit 21 may determine whether or not the prime mover 4 is stopped in the OFF state of the ignition switch 9. In this case, the ignition switch 9 and the monitoring unit 21 (monitoring device 20) can be wired so that the monitoring unit 21 can capture the signal from the ignition switch 9.

  Note that the sensor 25 or the vibration sensor may detect a vibration having only a frequency lower than the vibration frequency due to the operation of the prime mover 4 (low frequency vibration). In this case, the monitoring unit 21 stops the prime mover 4. In this case, it may be determined or monitored whether or not the vehicle 100 has been stolen by detecting only low-frequency vibrations by the vibration sensor. In other words, the monitoring device 20 may be a security device, and the monitoring device 20 or the monitoring unit 21 that is the security device may be configured such that the current measured voltage V or the remaining voltage of the first battery 2 after the prime mover 4 is stopped. Not only the amount but also the presence or absence of theft of the vehicle 100 can be monitored.

  In the example of FIG. 4, the monitoring unit 21 waits until the influence of the ACG 3 on the first battery 2 is almost eliminated, that is, until 30 minutes elapse from the time zero, for example, a predetermined interval such as an interval of 1 minute. Thus, the voltage V or remaining amount of the first battery 2 can be measured or monitored, and the measured value can be stored. The monitoring unit 21 obtains the attenuation characteristic of the voltage V or the remaining amount of the first battery 2 based on the plurality of stored measurement values, and the future voltage V of the first battery 2 corresponds to, for example, the remaining amount 60 [%]. The time that falls below the first voltage can be predicted or monitored. Here, for example, if the voltage dropped from the positive terminal of the first battery 2 to the node P2 is 1.5 [V], the first voltage corresponding to the remaining amount 60 [%] is, for example, 9.5. [V] (= 11.0 [V] −1.5 [V]).

  In addition, the monitoring unit 21 may indicate, for example, “Vehicle battery voltage is less than the first voltage in the remaining XX hours”, “Vehicle battery remaining amount is 60% in the remaining OO time. The estimated time such as “The engine cannot be started in the remaining XX time” can be notified to the user via the notification unit 4. Here, the first voltage is set to a reference (remaining amount 60 [%]) indicating whether or not the prime mover 4 can be started. For example, is the deterioration of the first battery 2 large? It may be set as a reference indicating a failure (remaining amount 75 [%]). In this case, the monitoring unit 21 indicates, for example, “the remaining amount of the vehicle battery is less than 75 [%] in the remaining XX time” as the monitoring result, and “the vehicle battery deteriorates in the remaining XX time. The predicted time such as “” can be notified to the user via the notification unit 4.

  In addition, every time the prime mover 4 stops, that is, every time the operation of the vehicle 100 ends, the monitoring unit 21 keeps the first battery 2 in an interval of, for example, 1 minute from the time zero until 30 minutes elapse. Measure the voltage V or remaining amount and save. The monitoring unit 21 can obtain a comparison value such as an average value or a median value of the past attenuation characteristics of the voltage V or the remaining amount of the first battery 2, and the current value from the time zero until, for example, 30 minutes elapses. And a comparison value indicating a past attenuation characteristic can be compared or monitored. The monitoring unit 21 forgets to turn off the electrical components such as the headlight 11 when the current attenuation characteristic is larger than the past attenuation characteristic and the current voltage V or the remaining amount of the first battery 2 is decreasing rapidly. Predict or monitor and notify the monitoring unit 4 of the monitoring result (for example, “the headlight is lit. Please return to the car”, “Did you forget to turn off any electrical components?”, Etc.) The user can be notified.

  The monitoring unit 21 can determine or monitor whether or not the current voltage V of the first battery 2 is lower than the second voltage, and in the example of FIG. 4, the first battery 2 at the time t1 is monitored. The voltage V is lower than a second voltage corresponding to the remaining amount 83 [%], for example. The second voltage can be set higher than the first voltage, and the monitoring unit 21 delays the future voltage V of the first battery 2 from reaching the first voltage after time t1. Can be made. When the first voltage is set to a reference (remaining amount 60 [%]) indicating whether or not the prime mover 4 can be started, the second voltage is not the remaining amount 83 [%]. The reference (remaining amount 75 [%]) indicating whether or not the deterioration of the first battery 2 becomes large may be set.

  In the example of FIG. 4, from time zero to time t1, the monitoring unit 21 controls the switching unit 22 so that the first battery 2 and the second battery 23 are disconnected, and monitoring is performed after time t1. The unit 21 can control the switching unit 22 so that the first battery 2 and the second battery 23 are connected in parallel. After time t1, the second battery 23 can supply the electric power from the second battery 23 to the electrical component to which the electric power from the first battery 2 has been supplied. A decrease in the remaining amount of the first battery 2 can be suppressed.

  The voltage between the positive terminal (positive electrode) of the second battery 23 and the negative terminal (negative electrode) of the second battery 23 is, for example, 12.5 corresponding to the remaining amount 100 [%] of the first battery 2. It can be set to 12.8 [V] which is higher than [V]. The second battery 23 is, for example, a lithium ion storage battery. The second battery 23 is charged from 0 [%] to 100 [%], for example, with a remaining current of the second battery 23 (for example, an initial capacity of 2000 [mAh]) with a charging current of 2 [A] for one hour, for example. It consists of a battery that can be charged quickly. The voltage of the second battery 23, which is a battery that can be rapidly charged, can be maintained at, for example, 12.8 [V] regardless of the remaining amount of the second battery 23.

  In the example of FIG. 4, since the electric power from the second battery 23 is supplied to the electrical component from time t1 to time t3, the voltage V of the first battery 2 is shown by a solid line in FIG. Furthermore, the second voltage corresponding to a constant value, that is, the remaining amount 83 [%] of the first battery 2 is maintained. If the first battery 2 and the second battery 23 are not connected in parallel at time t1, as shown by the dotted line in FIG. 4, the voltage V of the first battery 2 or after time t1 The remaining amount is reduced by the dark current of the electrical component.

  As described above, the monitoring unit 21 can predict the time when the future voltage V of the first battery 2 falls below the first voltage corresponding to, for example, the remaining amount 60 [%]. As shown in FIG. 4 (time t1 to time t3), when the power of the second battery 23 is supplied to the electrical component, the monitoring unit 21 also considers the remaining amount% of the second battery 23, The time when the future voltage V of the first battery 2 falls below the first voltage, for example, can be predicted. In other words, if the electric power of the second battery 23 is not supplied to the electrical component, the monitoring unit 21 does not consider the remaining amount% of the second battery 23, and the first battery follows the dotted line in FIG. The time when the future voltage V of the first battery 2 falls below, for example, the first voltage may be predicted with the voltage V of 2 or the attenuation characteristic of the remaining amount.

  By the way, the monitoring unit 21 can store a plurality of basic characteristics that can be compared with the voltage V or remaining amount attenuation characteristics of the first battery 2, and the monitoring unit 21 has a plurality of basic characteristics that have a current attenuation characteristic. It can be determined or monitored which of the basic characteristics matches. Here, the basic characteristic correlates with the dark current of the electrical component (excluding the monitoring device 20 to which power from the second battery 23 is supplied), and the monitoring unit 21 has the current attenuation characteristic or the matching basic characteristic. Based on this, the dark current of the electrical component can be predicted or monitored. The monitoring unit 21 can use the second battery 23 based on the predicted dark current of the electrical component, the dark current (consumption current) of the monitoring device 20 itself, and the remaining amount% of the second battery 23 (time). t1 to time t3) can be predicted or monitored, and the time t4 when the future voltage V of the first battery 2 falls below the first voltage, for example, can be predicted or monitored.

  In the example of FIG. 2, the monitoring unit 21 can measure or monitor the current A (discharge current from the second battery 23) that always flows from the second battery 23 to the power supply line + B or the electrical component. The monitoring unit 21 controls the switching unit 22 so that the first battery 2 and the second battery 23 are connected in parallel at time t1, and at this time, the electrical component is supplied from the second battery 23. Since electric power is supplied, the discharge current from the second battery 23 may be measured. In this case, the monitoring unit 21 determines the dark current (discharge current from the second battery 23) measured by the electrical component, the dark current (consumption current) of the monitoring device 20 itself, and the remaining amount% of the second battery 23. Based on the above, the usable time (time t1 to time t3) of the second battery 23 may be predicted or monitored. In addition, the monitoring unit 21 corrects the current attenuation characteristic of the voltage V or the remaining amount of the first battery 2 in consideration of the dark current measured by the electrical component (discharge current from the second battery 23). May be.

  In the example of FIG. 2, the second battery 23 has a communication terminal (gauge) other than the + terminal (positive electrode) and the − terminal (negative electrode), and the monitoring unit 21 is connected to the communication terminal of the second battery 23. The remaining amount% of the second battery 23 can be measured or monitored. The monitoring unit 21 can monitor the remaining amount% of the second battery 23 at any time such as time zero and time t1. When the prime mover 4 is operating, the monitoring unit 21 can control the switching unit 22 so as to charge the second battery 23. Here, the switching unit 22 is always connected to the first power line + B from the first power line + B. The current A flowing through the second battery 23 (the charging current to the second battery 23) may be limited or adjusted.

  It is preferable that the second battery 23 is replaceable or detachable from the monitoring device 20. For example, when a problem occurs in the remaining amount% of the second battery 23 at time zero, the monitoring unit 21 determines the monitoring result. (For example, “the remaining amount of the spare battery is low. Please replace the spare battery”, “please charge the spare battery with the dedicated charger”, etc.) is notified to the user via the notification unit 4. can do.

  The monitoring unit 21 can determine or monitor whether or not the current remaining amount% of the second battery 23 is lower than the first remaining amount (for example, 10 [%]). In the example of FIG. The remaining amount% of the second battery 23 at t2 is lower than the first remaining amount, for example, 10% remaining amount. When the monitoring device 20 is a security device, the monitoring unit 21 may stop monitoring theft of the vehicle 100 and may reduce the dark current (current consumption) of the monitoring device 20 itself.

  The monitoring unit 21 can determine or monitor whether or not the current remaining amount% of the second battery 23 is lower than a first remaining amount (for example, 2 [%]) lower than the first remaining amount. In the example of FIG. 4, the remaining amount% of the second battery 23 at time t3 is lower than the second remaining amount, for example, 2 [%]. After time t3, the monitoring unit 21 can control the switching unit 22 so that the first battery 2 and the second battery 23 are disconnected. Thereby, the fall of the remaining amount% of the second battery 23 is suppressed, and the monitoring unit 21 that operates with the power from the second battery 23 continues to monitor the voltage V of the first battery 2 after time t3. can do.

  The monitoring unit 21 can determine or monitor whether or not the current voltage V of the first battery 2 is lower than the first voltage. In the example of FIG. 4, the monitoring unit 21 detects the first battery 2 at time t4. The voltage V is lower than a first voltage corresponding to, for example, a remaining amount of 60 [%]. In addition, the monitoring unit 21 may indicate, for example, “the vehicle battery voltage has fallen below the first voltage”, “the engine can no longer be started”, or “please charge the vehicle battery.” Or the like can be notified to the user via the notification unit 4. After time t4, the monitoring unit 21 can stop monitoring the voltage V or the remaining amount of the first battery 2.

  As described above, the monitoring unit 21 can measure or monitor the voltage V or the remaining amount of the first battery 2 at a predetermined interval such as a one-minute interval, for example, until 30 minutes elapse from time zero. it can. For example, after 30 minutes have elapsed after the prime mover 4 is stopped, the monitoring unit 21 can increase the predetermined interval for monitoring the voltage V or the remaining amount of the first battery 2. For example, after 30 minutes have elapsed since time zero, the monitoring unit 21 can change the predetermined interval from, for example, 1 minute to, for example, 1 hour. For example, after time t3, the monitoring unit 21 can measure or monitor the voltage V or the remaining amount of the first battery 2 at intervals of, for example, 5 hours. Thereby, the fall of the residual amount% of the 2nd battery 23 can be suppressed.

  The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent included in the claims. .

  DESCRIPTION OF SYMBOLS 1 ... Vehicle body, 2 ... 1st battery (vehicle battery), 3 ... ACG, 4 ... prime mover, 5 ... starter, 6 ... main fuse box, 8 ... switch , 9 ... Ignition switch, 10 ... Indoor fuse box, 11 ... Headlight (electrical component), 20 ... Monitoring device (vehicle battery monitoring system), 21 ... Monitoring unit, 22 ... Switching unit, 23 ... second battery (spare battery), 24 ... notification unit, 25 ... sensor, 100 ... vehicle, ACC ... accessory power line, + B ... always power line.

Claims (6)

A monitoring unit that monitors the electrical state of the first battery capable of starting the prime mover of the vehicle;
A power supply unit that is a second battery for supplying power to the monitoring unit;
With
The monitoring unit determines whether or not the prime mover is stopped,
When the prime mover is stopped, the monitoring unit monitors the voltage of the first battery as the electrical state.   The vehicle monitoring system according to claim 1, wherein the monitoring unit predicts a time when the voltage of the first battery falls below a first voltage. A switching unit capable of connecting the first battery and the second battery in parallel;
When the prime mover is stopped, the monitoring unit controls the switching unit such that the first battery and the second battery are connected in parallel, and the second battery The vehicle battery monitoring system according to claim 1 or 2, wherein the electric power from the second battery is supplied to an electrical component to which the electric power from the first battery has been supplied.   After the prime mover stops, the monitoring unit is configured to monitor the first battery and the second battery until the voltage of the first battery falls below a second voltage higher than the first voltage. The vehicle battery monitoring system according to claim 3, which is dependent on claim 2, wherein the switching unit is controlled so that the battery is disconnected. The vehicle battery monitoring system according to any one of claims 1 to 4, further comprising a notification unit that notifies a user of a monitoring result of the monitoring unit. A vibration sensor for detecting the vibration of the prime mover;
The vehicle battery monitoring system according to claim 1, wherein the monitoring unit determines whether or not the prime mover is stopped by the vibration sensor.

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