JP2009113636A - Battery condition determination device and battery condition determination method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery condition determination device and a battery condition determination method, accurately performing determination of the condition of the battery according to a charging depth. <P>SOLUTION: In a memory part 11 of a power source control part 10, a relationship of a previously measured voltage of the battery 3 and a variation ratio of the voltage is memorized. After an engine 1 is stopped, the voltage of the battery 3 is detected by a voltage detection part 15, a power source control part 10 calculates the variation ratio of the voltage from the detection result, and the condition of the battery 3 is determined based on the relationship memorized in the memory part 11, the detected voltage, and the calculated variation ratio. According to the determination result, the power source control part 10 performs an ON/OFF control of a switch 21, and also a control of turing on/off of a warning lamp 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery state determination device and a battery state determination method for determining a state according to a charging depth (or battery capacity) of a battery mounted on a vehicle or the like.

  In recent years, from the viewpoints of vehicle safety, convenience, comfort, product power, and the like, the number of electrical devices mounted on vehicles has been increasing. For example, in addition to devices such as an electric brake and electric power steering that operate while the vehicle is running, devices such as a car navigation device that operates even when the vehicle is stopped, a remote locking and unlocking system, and a lamp are mounted on the vehicle. Electric equipment that operates while the vehicle is stopped is supplied with electric power from a battery mounted on the vehicle. However, the electric power that can be stored in the battery is limited, and so-called battery exhaustion is caused by using the electric device for a long time while the vehicle is stopped. As the number of electrical devices mounted on the vehicle increases, there is a problem that the possibility of battery exhaustion increases.

  In order to solve the above problem, there is a method in which time measurement by a timer is started after the vehicle engine is stopped, and supply of electric power from the battery is stopped after a predetermined time has elapsed. However, since it is necessary to consider a case where the SOC (State Of Charge) of the battery is already low when the engine is stopped, it is necessary to set a short time for the timer. Therefore, the user can use the electric device mounted on the vehicle only for a short period after the engine is stopped, and the convenience is reduced.

In Patent Document 1, the state of charge of a battery is detected, and the intermittent operation time for intermittent driving of the load in the automobile is calculated according to the operation guarantee period input by the user. An in-vehicle power management device that can prevent the battery from running out in a state has been proposed. In this in-vehicle power management device, the battery will not run out at least during the operation guarantee period input by the user.
JP 2006-188139 A

  However, the in-vehicle power management device described in Patent Document 1 is intermittent in a vehicle engine stop state, like a system that locks / unlocks a vehicle door by wireless communication with a small communication device carried by a user. It is intended to manage devices that operate in the same manner. Therefore, when the car navigation device or the audio device is continuously used after the engine is stopped, it cannot be guaranteed that the battery is not fully charged during the operation guarantee period.

  In addition, the in-vehicle power management device of Patent Document 1 measures the open-circuit voltage, regenerative current, and discharge current of a battery using a voltage sensor and a current sensor in order to detect the SOC of the battery, and further uses a temperature sensor. The battery temperature is being measured. Mounting these sensors causes an increase in the cost of the in-vehicle power management device and an increase in the cost of the vehicle.

  Therefore, in order to reduce costs, it is desirable to detect the SOC of the battery with a small number of sensors, for example, only with a voltage sensor. However, a difference in the voltage drop of the battery is caused by a difference in consumption current between devices connected to the battery and a difference in overall consumption current caused by a difference in operation status of each device after the engine is stopped. For this reason, when the battery voltage is simply measured by a voltage sensor and the battery SOC is detected, detection is not performed in consideration of the battery voltage drop, so there is a problem that the SOC detection error is large. .

  The present invention has been made in view of such circumstances. The object of the present invention is to previously store the relationship between the voltage and the rate of change of the voltage in accordance with the SOC of the battery and detect the voltage of the battery. A sensor for measuring the battery current, temperature, etc. by calculating the rate of change and determining the state of the battery based on the relationship stored in advance, the detected voltage and the calculated rate of change It is providing the battery state determination apparatus and battery state determination method which can perform the state determination according to SOC of a battery, without providing.

  Another object of the present invention is to store in advance a first relationship according to the first charge depth and a second relationship according to the second charge depth. Another object of the present invention is to provide a battery state determination device that can determine and classify battery states into more categories.

  Another object of the present invention is to obtain a first voltage and a second voltage corresponding to the calculated rate of change based on the first relationship and the second relationship, An object of the present invention is to provide a battery state determination device that can easily and reliably determine the state of the battery by comparing the detected voltage and determining the state of the battery.

  Another object of the present invention is to notify the user of a state in which the SOC of the battery has decreased by providing a warning when the detected battery voltage is lower than the first voltage. An object of the present invention is to provide a battery state determination device that can perform this.

  Another object of the present invention is that when the detected battery voltage is lower than the second voltage, the power supply from the battery is stopped so that the SOC of the battery is extremely reduced. It is an object of the present invention to provide a battery state determination device that can stop power supply and prevent further reduction in battery SOC.

  A battery state determination device according to a first aspect of the present invention is a battery state determination device that determines a state of a battery according to a charging depth, and a storage unit that stores in advance a relationship between a voltage and a voltage change rate according to the charging depth of the battery Detection means for detecting the voltage of the battery, calculation means for calculating a rate of change of the battery voltage based on the voltage detected by the detection means a plurality of times, and the relationship stored in advance in the storage means, And determining means for determining the state of the battery based on the voltage detected by the detecting means and the rate of change calculated by the calculating means.

  In the battery state determination device according to the second aspect of the present invention, the storage means includes a first relationship according to a first charging depth and a second charging depth that is lower than the first charging depth. The relationship between the two is stored in advance.

  In the battery state determination device according to a third aspect of the present invention, the determination unit acquires a first voltage corresponding to the rate of change calculated by the calculation unit based on the first relationship, and the second state Based on the relationship, the second voltage corresponding to the rate of change calculated by the calculation unit is obtained, the first voltage and the second voltage are compared with the voltage detected by the detection unit, It is characterized by determining the state of the battery.

  The battery state determination apparatus according to a fourth aspect of the present invention is further characterized by further comprising warning means for giving a warning when the voltage detected by the detection means is lower than the first voltage.

  The battery state determination device according to a fifth aspect of the present invention further includes stop means for stopping power supply of the battery when the voltage detected by the detection means is lower than the second voltage. .

  A battery state determination method according to a sixth aspect of the present invention is the battery state determination method for determining the state of the battery according to the charge depth. The relationship between the voltage according to the charge depth of the battery and the rate of change of the voltage is stored in advance. In addition, the battery voltage is detected, and the change rate of the battery voltage is calculated based on the voltage detected a plurality of times. Based on the relationship stored in advance, the detected voltage and the calculated change rate. And determining a state of the battery.

  In the present invention, the relationship between the voltage and the voltage change rate according to the SOC of the battery is previously measured and stored in the battery state determination device. For example, when the SOC of the battery is 70%, the current consumption from the battery is changed to change the voltage change rate, and the relationship between the voltage and the voltage change rate at this time is measured and stored. Two or more relationships may be stored. For example, the relationship may be measured and stored in advance when the SOC is 70% and when the SOC is 50%. The battery state determination device can calculate the rate of change of the battery voltage by performing battery voltage detection at least twice. The battery state determination device that has calculated the rate of change of voltage compares the detected voltage and the calculated rate of change with previously stored characteristics, so that, for example, the state of the battery at the time of measurement is close to a characteristic with an SOC of 70%. Or close to 50% characteristics. By using the voltage change rate for the state determination, it is possible to accurately determine the state of the battery without being affected by the current consumption and the operating state of each device to which the battery power is supplied. Further, the battery state determination device only needs to detect the voltage of the battery, and does not need to detect the current.

  In the present invention, the first relationship according to the first SOC and the second relationship according to the second SOC are measured and stored in advance (provided that the first SOC> the first relationship). 2 SOC). For example, the relationship when the SOC is 70% is stored as the first relationship, and the relationship when the SOC is 50% is stored as the second relationship. By storing the two types of relationships in this way, the current state of the battery is such that the SOC exceeds 70%, the SOC is less than 70% and exceeds 50%, or the SOC is 50 It can be determined that there are three states of% or less.

  In the present invention, the battery state determination device acquires the first voltage and the second voltage corresponding to the calculated change rate based on the first relationship and the second relationship stored in advance. The acquired first voltage and second voltage can be used as threshold values. By comparing the detected battery voltage with the first voltage and the second voltage, the battery state determination device determines the battery state. The above three states can be determined.

  In the present invention, the battery state determination device issues a warning when the detected battery voltage is lower than the first voltage. For example, when the relationship where the SOC is 70% is set as the first relationship, it can be determined whether the battery at the present time is in a state where the SOC exceeds 70%. When the current battery voltage is lower than the first voltage, the SOC of the battery is 70% or less. Therefore, by giving a warning at this stage, it is possible to prevent the user from running out of the battery by starting the engine or suppressing the use of the device mounted on the vehicle.

  In the present invention, when the detected battery voltage is lower than the second voltage, the battery state determination device stops the power supply of the battery. When the relationship where the SOC is 50% is set as the second relationship, it is possible to determine whether the current battery is in a state where the SOC exceeds 50%. When the current battery voltage is lower than the second voltage, the battery SOC is 50% or less. For example, if about 50% of the battery SOC is required to start the vehicle engine, there is a risk that the vehicle will not be able to run due to a further decrease in SOC. To prevent.

  In the case of the present invention, the rate of change is calculated by detecting the voltage of the battery, and the battery is based on the relationship between the voltage and the rate of change of the voltage corresponding to the SOC stored in advance and the detected voltage and the calculated rate of change. By determining the state of the battery, it is possible to accurately determine the state of the battery without being affected by the current consumption and the usage state of each device to which the battery power is supplied. Therefore, according to the determination result of the battery state, it is possible to accurately perform a warning to the user or control of the power supply of the battery, so that the battery can be prevented from running out. In addition, it is not necessary to detect the battery current to determine the state of the battery, and the determination can be made only by detecting the voltage. Therefore, it is not necessary to provide a sensor for detecting the current, and the battery state The cost of the determination device can be reduced.

  In the case of the present invention, the battery state is stored in the SOC by storing in advance the first relationship according to the first charge depth and the second relationship according to the second charge depth. Three states can be determined according to the condition. Therefore, the battery state determination device can perform warning or control of power supply suitable for each state, and can more reliably prevent the battery from running out.

  Further, in the case of the present invention, the first voltage and the second voltage corresponding to the calculated change rate are acquired based on the first relationship and the second relationship stored in advance, and the detected battery voltage and By comparing the first voltage and the second voltage to determine the state of the battery, it is possible to easily and reliably determine the state of the battery in three states without performing complicated arithmetic processing or the like. .

  Further, according to the present invention, when the detected battery voltage is lower than the first voltage, a warning is given to notify the user that the SOC of the battery has dropped below a predetermined value, and the engine is started or The use of equipment mounted on the vehicle can be suppressed. Therefore, the user can be prevented from running out of the battery, and the battery can be prevented from running out more reliably.

  Further, according to the present invention, when the detected voltage of the battery is lower than the second voltage, the power supply from the battery is stopped, so that the SOC of the battery is further lowered and the engine cannot be started. Prior to this, it is possible to reliably prevent the SOC from decreasing, and thus it is possible to more reliably prevent the battery from rising.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing a configuration of a battery state determination device according to the present invention. In FIG. 1, a power supply path is indicated by a solid line, a transmission path such as a control signal is indicated by a dashed arrow, and an information transmission path using a network such as a CAN (Controller Area Network) is indicated by a one-dot chain line. .

  In the figure, reference numeral 1 denotes an engine, which generates a driving force of the vehicle. The power generated by the engine 1 is transmitted to the alternator 2, and the alternator 2 converts the power into DC power and outputs it. The electric power output from the alternator 2 is supplied to various electrical devices such as a socket 4 and lamps 5 and 6 via a switch 21 and a door ECU (Electronic Control Unit) 22.

  The socket 4 is a so-called cigar socket capable of connecting an external device and supplying power. The lamp 5 is a lamp such as a room lamp or a map lamp. The lamp 6 is a so-called courtesy lamp that is provided on the door of the vehicle and is turned on / off in conjunction with the opening and closing of the door. The door ECU 22 controls lighting / extinguishing of the lamp 6, that is, control of power supply to the lamp 6.

  The electric power output from the alternator 2 is also supplied to the battery 3. The battery 3 is a storage battery that stores electric power. The battery 3 has two terminals. One terminal is connected to the alternator 2, the switch 21, the door ECU 22, and the like, and the other terminal is connected to the ground potential. The alternator 2 can charge the battery 3 when the engine 1 is operating. Further, when the engine 1 is not operating, the battery 3 supplies power to electrical devices such as the socket 4 and the lamps 5 and 6. A voltage detector 15 is connected between the two terminals of the battery 3, and the voltage detector 15 detects the voltage of the battery 3 and gives a detection result to the power supply controller 10.

  The power supply control unit 10 is configured by a microcomputer or the like, and includes a storage unit 11 and a communication unit 12. Based on the state of the IG (IGnition) switch 8 and the voltage of the battery 3 detected by the voltage detection unit 15, the power supply control unit 10 determines whether or not power can be supplied to the socket 4 and the lamps 5 and 6, etc. The power supply to is controlled. The power supply control unit 10 can determine whether or not the engine 1 is operating from the state of the IG switch 8.

  The switch 21 is a contact that can be electrically / mechanically controlled to be turned on / off. When it is determined that the supply of power is to be stopped, the switch 21 is turned off, whereby the power supply control unit 10 can be connected to the alternator 2 or the battery. The power supply from 3 to the socket 4 and the lamp 5 can be stopped.

  The power supply control unit 10 can communicate with the door ECU 22 via the CAN by the communication unit 12. When it is determined that the supply of power to the lamp 6 is stopped, the power supply control unit 10 gives a command to turn off the lamp 6 from the communication unit 12 to the door ECU 22 via CAN. The door ECU 22 stops the power supply to the lamp 6 and turns off the lamp 6 when a turn-off command is given from the power supply control unit 10. On the other hand, when it is determined that the supply of electric power to the lamp 6 is not stopped, the power supply control unit 10 gives the door ECU 22 permission to turn on the lamp 6. When the lighting permission is given from the power supply control unit 10, the door ECU 22 turns on / off the lamp 6 according to the opening / closing of the door.

  Further, the power supply control unit 10 controls the lighting / extinguishing of the warning lamp 7 according to the voltage of the battery 3 detected by the voltage detection unit 15 so as to warn the driver of the decrease in the SOC of the battery 3. is there. The warning light 7 is disposed in a place where it is easy for the driver to see, for example, an instrument panel of a vehicle. In FIG. 1, the power supply path from the alternator 2 and the battery 3 to the warning lamp 7 and the power supply control unit 10 is not shown.

  The control of power supply by the power control unit 10 and the control of the warning lamp 7 are based on the state of the IG switch 8 (whether the engine 1 is operating) and the detection result of the voltage of the battery 3 by the voltage detection unit 15. Done. At this time, when the engine 1 is operating, the power supply control unit 10 supplies power from the alternator 2 to the socket 4 and the lamps 5 and 6. That is, in this case, the power supply control unit 10 turns on the switch 21 and gives the door ECU 22 permission to turn on the lamp 6. In this case, the power control unit 10 does not light the warning lamp 7.

When the engine 1 is not operating, the power supply control unit 10 determines the state of the battery 3 from the detection result of the voltage detection unit 15. In the present embodiment, power supply control unit 10 determines which of the three states (shown below) the battery 3 is in accordance with the SOC.
1) Normal state: State where SOC exceeds 70% 2) Preventive state: State where SOC is 70% or less and exceeds 50% 3) Abnormal state: State where SOC is 50% or less Normal state is sufficient for battery 3 This is a state in which electric power is accumulated, and is a state in which electric power can be sufficiently supplied to an electric device mounted on the vehicle. The abnormal state is a state in which there is a possibility that it is difficult to start the engine 1 because the power stored in the battery 3 is very small. The preventive state is a state between a normal state and an abnormal state, and there is a possibility that the battery 3 will reach an abnormal state in the near future by continuing to use the power stored in the battery 3, and in a state where prevention is necessary. is there.

  When determining that the state of the battery 3 is normal, the power supply control unit 10 supplies power from the battery 3 to the socket 4 and the lamps 5 and 6. When it is determined that the state of the battery 3 is the prevention state, the power control unit 10 supplies power from the battery 3 to the socket 4 and the lamps 5, 6, etc. A warning is given to the driver. When it is determined that the state of the battery 3 is abnormal, the power supply control unit 10 turns off the switch 21 and gives an instruction to turn off the door ECU 22 to stop power supply from the battery 3 to the socket 4 and the lamps 5 and 6. I have to do it.

  Below, the method of the state determination of the battery 3 by the power supply control part 10 is demonstrated. The power supply control unit 10 stores the characteristics of the battery 3 measured in advance in the storage unit 11. The storage unit 11 includes a nonvolatile memory element such as a mask ROM (Read Only Memory) or an EEPROM (Electrically Erasable Programmable ROM), and the characteristics of the battery 3 in the manufacturing process or design stage of the power supply control unit 10 or the vehicle. Is stored in advance.

  FIG. 2 is a graph showing an example of the characteristics of the battery 3 stored in the storage unit 11. In the graph shown in FIG. 2, the vertical axis represents the voltage V of the battery 3, and the horizontal axis represents the rate of change dV / dt of the voltage of the battery 3. As characteristics of the battery 3, the storage unit 11 stores a relationship between the voltage and the rate of change when the SOC of the battery 3 is 70% (hereinafter referred to as a first relationship), and a voltage when the SOC of the battery 3 is 50%. And the rate of change (hereinafter referred to as the second relationship) are stored. For example, in the first relationship, the battery 3 is charged until the SOC reaches 70%, the current consumption from the battery is changed to change the voltage change rate, and the relationship between the voltage and the voltage change rate at this time is expressed as follows. It can be acquired in advance by measuring. The same applies to the second relationship.

  After the engine 1 is stopped, the power supply control unit 10 detects the voltage of the battery 3 by the voltage detection unit 15 at an arbitrary timing to acquire a detection result (voltage value V), and a predetermined time has elapsed from this voltage detection. At a later time (for example, after about 10 seconds have elapsed), voltage detection is performed again to obtain a detection result (voltage value V ′). Thereby, the power supply control part 10 can calculate the rate of change of the voltage of the battery 3. Based on the calculated change rate, the power supply control unit 10 acquires two corresponding voltage values from the first relationship and the second relationship stored in the storage unit 11. For example, when the calculated change rate is α, the power supply control unit 10 acquires the first relationship voltage V1 and the second relationship voltage V2 corresponding to the change rate α (see FIG. 2).

The power supply control unit 10 determines the state of the battery 3 by using the acquired two voltage values V1 and V2 as threshold values and comparing with the voltage of the battery 3 detected by the voltage detection unit 15. In addition, although the voltage detection of the battery 3 is performed twice as described above, the voltage value V ′ detected later is used as a voltage used for comparison for state determination. The power supply control unit 10 determines the state of the battery 3 as described below.
V ′> V1 → normal state V2 <V ′ ≦ V1 → prevention state V ′ ≦ V2 → abnormal state The power supply control unit 10 can perform power supply control and warning as described above based on the determination result. it can.

  FIG. 3 is a flowchart showing a procedure of processing performed by the battery state determination device according to the present invention. First, the power supply control unit 10 of the battery state determination device checks whether the engine 1 is turned off from the state of the IG switch 8 (step S1). When engine 1 is not turned off (S1: NO), power supply control unit 10 stands by until engine 1 is turned off. In this case, the power supply control unit 10 supplies power from the alternator 2 to the socket 4 and the lamps 5 and 6.

When the engine 1 is turned off (S1: YES), the power supply control unit 10 detects the voltage of the battery 3 by the voltage detection unit 15 (step S2) and waits for a predetermined time (step S3). After the predetermined time has elapsed, the power supply controller 10 detects the voltage of the battery 3 again (step S4), and changes in the voltage of the battery 3 based on the voltage detected in steps S2 and S3 and the predetermined time waited in step S3. The rate is calculated (step S5). When the detection result of step S2 is V, the detection result of step S4 is V ′, and the predetermined time of step S3 is T, the change rate α can be calculated by the following equation.
α = | V′−V | / T
Next, the power supply control unit 10 performs a process of determining the state of the battery 3 based on the voltage V ′ of the battery 3 detected in step S4 and the change rate α calculated in step S5 (step S6).

  FIG. 4 is a flowchart showing a procedure of state determination processing performed by the battery state determination device according to the present invention, and is processing performed in step S6 of the flowchart shown in FIG. In the state determination process, the power supply controller 10 determines the relationship between the voltage and the rate of change when the SOC stored in advance in the storage unit 11 is 70% based on the rate of change α calculated in step S5 (first relationship). The first voltage V1 corresponding to the rate of change α is acquired (step S21). Similarly, the power supply control unit 10 refers to the second relationship when the SOC stored in advance in the storage unit 11 is 50% based on the change rate α, and acquires the second voltage V2 corresponding to the change rate α. (Step S22).

  Next, the power supply controller 10 checks whether or not the voltage V ′ of the battery 3 detected in step S4 exceeds the first voltage V1 acquired in step S21 (step S23), and the voltage V ′ is the first voltage V ′. When the voltage V1 is exceeded (S23: YES), the battery 3 is determined to be in a normal state (step S24). When the voltage V ′ is equal to or lower than the first voltage (S23: NO), the power supply control unit 10 further checks whether or not the voltage V ′ exceeds the second voltage V2 acquired in step S22 (step S25). When the voltage V ′ exceeds the second voltage V2 (S25: YES), the power supply controller 10 determines that the state of the battery 3 is the prevention state (step S26), and when the voltage V ′ is equal to or lower than the second voltage V2 (step S26). S25: NO), the state of the battery 3 is determined to be an abnormal state (step S27). After determining the state of the battery 3 in step S24, S26 or S27, the power supply control unit 10 ends the state determination process and returns to the process shown in FIG.

  After the state determination process in step S6 ends, the power supply control unit 10 checks whether the state of the battery 3 is an abnormal state from the determination result (step S7). When the state of the battery 3 is an abnormal state (S7: YES), the power supply control unit 10 turns off the switch 21 and gives an instruction to turn off the door ECU 22 to supply power from the battery 3 to the socket 4 and the lamps 5 and 6. The supply is stopped (step S8), and the process proceeds to step S11. When the state of the battery 3 is not an abnormal state (S7: NO), the power supply control unit 10 further checks whether or not the state of the battery 3 is the prevention state (step S9). When the state of the battery 3 is the prevention state (S9: YES), the power supply control unit 10 turns on the warning lamp 7 to give a warning to the driver (step S10), and proceeds to step S11. When the state of the battery 3 is not the prevention state (S9: NO), that is, when the state of the battery 3 is a normal state, the power supply control unit 10 proceeds to step S11.

  Next, the battery state determination device checks whether or not the vehicle engine 1 is turned on from the state of the IG switch 8 (step S11). When the engine 1 is not turned on (S11: NO), the battery state determination device waits for a predetermined time (step S12), returns to step S2, and repeats steps S2 to S11 described above. When the engine 1 is turned on (S11: YES), the battery state determination device ends the process. As described above, the battery state determination device periodically determines the state of the battery 3 with the predetermined time in step S12 as a cycle, thereby reliably preventing the battery from running out.

  The battery state determination apparatus having the above configuration measures the relationship between the voltage and the rate of change according to the SOC of the battery 3 in advance and stores it in the storage unit 11, and uses the voltage of the battery 3 detected by the voltage detection unit 15. The power supply control unit 10 calculates the voltage change rate and determines the state of the battery 3 based on the relationship stored in the storage unit 11 in advance, the detected voltage, and the calculated change rate. The state of the battery 3 can be accurately determined without being affected by the current consumption, usage status, and the like of each device to which the electric power is supplied.

  In addition, by storing the first relationship when the SOC is 70% and the second relationship when the SOC is 50% in the storage unit 11, the state of the battery 3 is in the normal state, the preventive state, and the abnormal state. It is possible to make a determination by dividing into three states, and processing such as warning or stop of power supply can be performed according to each state. Therefore, processing such as a warning or stop of power supply can be performed with high accuracy according to the determination result of the state of the battery 3 with high accuracy, and the battery can be reliably prevented from running out. Further, the battery state determination device of the present invention only needs to detect the voltage of the battery 3 by the voltage detection unit 15 in order to determine the state of the battery 3, and it is necessary to detect the current value of the current flowing through the battery 3. Absent. Therefore, the cost of the battery state determination device can be reduced.

  In the present embodiment, the battery state determination device is configured to determine the state of the in-vehicle battery 3, but is not limited thereto, and is configured to determine the state of the battery 3 used for other purposes. It is good. In addition, the battery state determination device is configured to issue a warning by turning on the warning lamp 7 when it is determined that the battery 3 is in the prevention state. However, the present invention is not limited to this. For example, a warning message is displayed on the liquid crystal display. It is good also as a structure which performs warning by other methods, such as doing or warning by audio | voice output. Further, the battery state determination device is configured to issue a warning only when the battery 3 is in the prevention state, but is not limited thereto, and may be configured to issue a warning even in an abnormal state.

  Further, the battery state determination device is configured to determine whether or not the engine 1 is operating based on the state of the IG switch 8, but is not limited to this, for example, whether the engine 1 is rotating directly. It is good also as a structure which judges by other methods, such as judging by a sensor etc. or judging by the alternator 2 outputting electric power. Moreover, although the electric equipment which the electric power which the alternator 2 and the battery 3 supplies is the socket 4 and the lamps 5 and 6, it is an example and it does not restrict to this.

  Moreover, although the battery state determination apparatus was set as the structure which determines the state of the battery 3 in three states, a normal state, a prevention state, and an abnormal state, it is not restricted to this, About two or more states for determination It is good also as a structure to perform. In addition, in the case where the SOC is 70% and the case where the SOC is 50%, the relationship between the voltage and the rate of change is stored in the storage unit 11. However, the value of the SOC is an example and is not limited thereto. For example, when the SOC is 80% and 60%, the SOC value may be determined appropriately according to the characteristics of the battery 3 and the characteristics of the electrical equipment that supplies power. Further, the characteristics shown in FIG. 2 are merely examples, and the present invention is not limited to these.

It is a block diagram which shows the structure of the battery state determination apparatus which concerns on this invention. It is a graph which shows an example of the characteristic of the battery memorized by the storage part. It is a flowchart which shows the procedure of the process which the battery condition determination apparatus which concerns on this invention performs. It is a flowchart which shows the procedure of the state determination process which the battery state determination apparatus which concerns on this invention performs.

Explanation of symbols

1 Engine 2 Alternator 3 Battery 4 Socket 5, 6 Lamp 7 Warning light (Warning means)
8 IG switch 10 Power control unit (calculation means, determination means)
11 Storage unit (storage means)
12 communication unit 15 voltage detection unit (detection means)
21 Switch (stopping means)
22 Door ECU (stopping means)
V1 first voltage (first voltage)
V2 Second voltage (second voltage)

Claims (6)

In the battery state determination device that determines the state of the battery according to the charging depth,
Storage means for storing in advance the relationship between the voltage according to the charging depth of the battery and the voltage change rate;
Detecting means for detecting a voltage of the battery;
Calculation means for calculating a rate of change of the voltage of the battery based on the voltage detected by the detection means a plurality of times;
And a determination unit that determines the state of the battery based on the relationship stored in advance in the storage unit, the voltage detected by the detection unit, and the change rate calculated by the calculation unit. Battery state determination device. The storage means stores in advance a first relationship corresponding to a first charging depth and a second relationship corresponding to a second charging depth lower than the first charging depth. The battery state determination device according to claim 1. The determination means includes
Based on the first relationship, obtain a first voltage corresponding to the rate of change calculated by the calculating means,
Based on the second relationship, obtain a second voltage corresponding to the rate of change calculated by the calculating means,
The battery state determination according to claim 2, wherein the state of the battery is determined by comparing the first voltage and the second voltage with the voltage detected by the detection means. apparatus. The battery state determination device according to claim 3, further comprising warning means for giving a warning when the voltage detected by the detection means is lower than the first voltage. 5. The battery state determination according to claim 3, further comprising a stopping unit that stops power supply of the battery when the voltage detected by the detecting unit is lower than the second voltage. 6. apparatus. In the battery state determination method for determining the state of the battery according to the charging depth,
Pre-store the relationship between the voltage and the voltage change rate according to the charging depth of the battery,
Detecting the voltage of the battery;
Based on the voltage detected multiple times, calculate the rate of change of the battery voltage,
A battery state determination method, wherein the state of the battery is determined based on the relationship stored in advance, the detected voltage, and the calculated rate of change.

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