JP5369499B2 - Vehicle power supply - Google Patents

Description

  The present invention includes an in-vehicle generator and an in-vehicle battery that is charged by electric power generated by the in-vehicle generator. When the accessory switch is on, the charge / discharge current value of the in-vehicle battery is integrated and the integrated current amount The present invention relates to a vehicle power supply device that calculates a state of charge (SOC) of a vehicle-mounted battery.

The remaining capacity of the in-vehicle battery of the vehicle power supply device is not easy to detect because there is a polarization phenomenon associated with charging / discharging of the battery. In the method of calculating the remaining capacity of the in-vehicle battery based on the charge / discharge current value of the in-vehicle battery accumulated from the full charge state of the in-vehicle battery, the measurement error due to the current sensor that detects the charge / discharge current value accumulates and is true. There is a problem that the error with the value increases.
Therefore, from the correspondence between the open-circuit voltage of the in-vehicle battery and the remaining capacity, the open-circuit voltage of the in-vehicle battery acquired before the accessory switch was turned on and the period during which the accessory switch was turned on (during vehicle travel) were integrated. A method of calculating the remaining capacity of the in-vehicle battery while the vehicle is traveling is considered based on the charge / discharge current of the in-vehicle battery.

  The power generation voltage of the alternator of the vehicle power supply device is about 14V, and the output voltage of the in-vehicle battery is about 12.8V. The power supply voltage varies depending on the current consumption of the electric load. Recently, based on the speed value of the vehicle, each vehicle state of idling, acceleration travel, steady travel and deceleration travel is determined, and in accordance with the determined vehicle state, for example, power is generated in a power generation mode as shown in FIG. There are an increasing number of vehicle power supply devices that perform charge control for controlling charging of an in-vehicle battery.

  The power generation mode in this charging control is to reduce the power generation voltage when the engine load is large, such as in acceleration travel, and to stop charging the in-vehicle battery, and to generate power when the engine load is small, such as in deceleration travel. It is stipulated that the on-board battery is charged by increasing the voltage. In addition, during idling, the generated voltage is set to an intermediate value, and when the capacity of the in-vehicle battery decreases, the generated voltage is increased to charge the in-vehicle battery. This reduces the load on the engine and improves the fuel efficiency of the vehicle.

Patent Document 1 discloses a prediction method for predicting the remaining capacity and / or afterimage life of a battery. In this prediction method, the first step for obtaining the relationship between the voltage at 0 A (0 ampere) and the no-load discharge voltage in advance, energizing the target battery for a certain period of time, measuring the amount of electricity Q, and before and after that at the time of 0 A A second step for obtaining the voltages V01 and V02 and a third step for obtaining the corresponding no-load leaving voltages Vna and Vnb by applying the voltages V01 and V02 at 0A obtained in the second step to the relationship of the first step. Have. In addition, in relation to the no-load discharge voltage with respect to the dischargeable amount of electricity obtained for each deterioration state of the same model as the target battery, the amount of electricity Q obtained in the second step and the amount before and after energization obtained in the third step The remaining capacity and / or afterimage life is predicted by applying the load discharge voltages Vna and Vnb.
JP 2003-28940 A

  In the method of calculating the remaining capacity of the in-vehicle battery based on the above-described open-circuit voltage value of the in-vehicle battery and the integrated charge / discharge current value of the in-vehicle battery, the measurement error caused by the current sensor that detects the discharge current value is an accessory switch. It is reset whenever is turned off and turned on. However, as shown in FIG. 14, it is generally known that the remaining capacity of the battery (battery) and the open-circuit voltage value are in a substantially linear relationship. As shown in the part, there is a case where the correlation in the vicinity of the full charge may change, and there is a problem that when the remaining capacity is estimated based on the open-circuit voltage value, an error from the true value may be increased.

  The present invention has been made in view of the circumstances as described above, and even if the remaining capacity of the in-vehicle battery is calculated based on the open-circuit voltage value of the in-vehicle battery and the accumulated charge / discharge current value of the in-vehicle battery, the error may occur. An object of the present invention is to provide a vehicular power supply device that does not increase.

The vehicular power supply device according to the first aspect of the present invention provides an in-vehicle generator, an in-vehicle battery charged with electric power generated by the in-vehicle generator, and a charge / discharge current value of the in-vehicle battery when an accessory switch is on. In a vehicle power supply device comprising: means for detecting; means for integrating the charge / discharge current value detected by the means; and a calculating means for calculating the remaining capacity of the in-vehicle battery based on the amount of current accumulated by the means The first relationship between the remaining capacity of the in-vehicle battery and the open voltage value obtained in advance, and the second relationship between the discharge depth and the open voltage value at full charge when the battery of the discharge depth is fully charged are stored. memory means for said and a voltage value acquiring means for accessory switch to obtain a voltage value of the vehicle battery before turned on, the storage means stores the voltage value acquiring voltage value acquiring unit acquires , Acquires a voltage value by the voltage value acquiring unit has acquired, includes a first determination hand stage equal to or smaller than a first open circuit voltage value corresponding to the remaining capacity of 70% of the first relationship, the calculation And a means for calculating a remaining start-time capacity corresponding to the acquired voltage value based on the first relationship when the first determining means determines that the acquired voltage value is equal to or less than the first open-circuit voltage value. and the calculated start remaining capacity, and based on the current amount, the configured to calculate the remaining capacity of the battery tare is, the first determination unit, the acquisition voltage value the first open-circuit voltage value When it is determined that the remaining capacity is exceeded, the remaining capacity corresponding to the lowest value of the acquired voltage value stored in the storage unit is calculated based on the first relationship, and corresponds to the discharge depth converted from the calculated remaining capacity. Calculate the open-circuit voltage value at full charge based on the second relationship Then, based on the calculated full-charge open-circuit voltage value, a portion where the remaining capacity of the first relationship exceeds 70% is corrected, and on the basis of the corrected portion, the remaining start time corresponding to the acquired voltage value is corrected. wherein the configuration tare Rukoto to calculate the volume.

In this vehicle power supply device, it includes an in-vehicle generator and an in-vehicle battery that is charged by the electric power generated by the in-vehicle generator, and when the accessory switch is on, detects the charge / discharge current value of the in-vehicle battery, The detected charge / discharge current values are integrated, and the remaining capacity of the in-vehicle battery is calculated based on the integrated current amount.
The first relationship between the open-circuit voltage value of the in-vehicle battery and the remaining capacity obtained in advance is stored in the storage means. The voltage value acquisition means acquires the voltage value of the in-vehicle battery before the accessory switch is turned on, and the first determination means has the first acquired voltage value corresponding to 70% of the remaining capacity of the first relationship. It is determined whether or not it is less than the open circuit voltage value. When the first determination unit determines that the acquired voltage value is equal to or less than the first open-circuit voltage value, the calculation unit calculates the start remaining capacity corresponding to the acquired voltage value based on the first relationship, and the calculated start The remaining capacity of the in-vehicle battery is calculated based on the remaining time capacity and the accumulated current amount.
The discharge depth refers to the ratio of the discharge capacity to the full charge capacity of the battery.
In this vehicle power supply device, the storage means stores the second relationship between the discharge depth and the fully charged open-circuit voltage value, and the acquired voltage value. When the first determination unit determines that the acquired voltage value exceeds the first open-circuit voltage value, the calculation unit calculates a remaining capacity corresponding to the lowest value of the acquired voltage value based on the first relationship, and the remaining capacity Is obtained by subtracting from 100%, and the full-charge open-circuit voltage value corresponding to the discharge depth is calculated based on the second relationship. The calculation means corrects a portion where the remaining capacity of the first relationship exceeds 70% based on the full-charge open-circuit voltage value, and calculates a starting remaining capacity corresponding to the acquired voltage value based on the corrected portion. calculate. And a calculation means calculates the remaining capacity of a vehicle-mounted battery based on the said remaining capacity at the time of start and the integrated electric current amount.

  According to a second aspect of the present invention, there is provided a vehicular power supply apparatus according to the first aspect, wherein the power generation voltage control means for controlling the power generation voltage value of the in-vehicle generator to a high level and the remaining capacity calculated by the calculation means exceed 70%. And a second determination means for determining whether or not the generated voltage control means prohibits charging of the in-vehicle battery when the second determination means determines that the remaining capacity exceeds 70%. For this purpose, the power generation voltage is set low.

  In this vehicle power supply device, the generated voltage control means controls the generated voltage value of the on-vehicle generator to be high and low, and the second determining means determines whether or not the remaining capacity calculated by the calculating means exceeds 70%. To do. When the second determination means determines that it exceeds 70%, the generated voltage control means sets the generated voltage low in order to prohibit charging of the in-vehicle battery.

According to a third aspect of the present invention, in the first or second aspect of the invention, the second relationship is obtained for three or more discharge depths.

  In this vehicle power supply device, it is possible to further reduce the error of the full-charge open-circuit voltage value corresponding to the discharge depth of the in-vehicle battery, and to correct the portion of the first relationship better.

The fourth invention for a vehicle power supply device according to, in any one of the first through third aspects, wherein the second relation, the discharge depth is characterized in that, calculated in regard to the case of more than 10%.

Until the discharge depth reaches 10%, the open-circuit voltage value at the time of full charge hardly changes.
In this vehicle power supply device, since the second relationship is obtained when the discharge depth exceeds 10%, it is possible to further reduce the error of the full-charge open-circuit voltage value corresponding to the discharge depth of the battery. It is possible to correct the one-related portion better.

According to the vehicle power supply device of the present invention, when calculating the remaining capacity of the in-vehicle battery based on the open-circuit voltage value of the in-vehicle battery and the integrated charge / discharge current value of the in-vehicle battery, the remaining capacity at the start is within 70% Therefore, it is possible to realize a vehicular power supply device in which an error in the remaining capacity is reduced.

According to the vehicle power supply device of the present invention, when the acquired voltage value exceeds the first open-circuit voltage value, the start remaining capacity is obtained after correcting the portion where the remaining capacity of the first relationship exceeds 70%. Therefore, it is possible to realize a vehicular power supply device in which an error in the current remaining capacity calculated based on the starting remaining capacity is reduced.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
Embodiment 1 FIG.
Figure 1 is a block diagram showing the schematic configuration of a vehicle power supply device according to Embodiment 1 of implementation.
In this vehicular power supply device, an alternator (on-vehicle generator, AC generator) 1 generates power in conjunction with the engine 15. The generated voltage is controlled at a constant voltage by a regulator (generated voltage control means) 2 attached to the alternator 1 by adjusting the field current of the alternator 1 and is also controlled in a step-up / step-down manner.

  The electric power generated by the alternator 1 is rectified in the alternator 1 and then charged to the in-vehicle battery 4 through the fuse F0 in the relay box 11 and the contact 16a of the accessory switch 16. The current detector 3 detects the charge / discharge current value of the in-vehicle battery 4 and gives it to a charge control ECU (Electronic Control Unit) (power generation voltage control means) 12. The voltage value acquisition means 5 in the charge control ECU 12 The input / output voltage value of the battery 4 is acquired. An on / off signal of the accessory switch 16 is given to the charging control ECU 12.

The charging control ECU 12 is given a vehicle speed signal from the vehicle running system, and determines each vehicle state of idling, acceleration running, steady running and deceleration running based on the given speed signal. Next, charge control is performed to control the regulator 2 and the alternator 1 so that power is generated in the power generation mode corresponding to the determined vehicle state.
In the power generation mode, as shown in FIG. 13, when the load on the engine 15 is large as in acceleration traveling, the power generation voltage is lowered to stop charging the in-vehicle battery 4, and the engine 15 is decelerated in deceleration traveling. When the load is small, the in-vehicle battery 4 is charged by increasing the generated voltage. During idling, the power generation voltage is set to an intermediate value, and when the capacity of the in-vehicle battery 4 decreases, the power generation voltage is increased to charge the in-vehicle battery. This reduces the load on the engine and improves the fuel efficiency of the vehicle.

  The charge control ECU 12 includes a storage unit 14, and the storage unit 14 stores a first map (first) obtained by obtaining a relationship between a remaining capacity (SOC) of the in-vehicle battery 4 and an open-circuit voltage value. (Relationship) 18 is stored. FIG. 4 is a graph showing the first map 18. The first map 18 is data indicating a substantially linear relationship between the open-circuit voltage value of the in-vehicle battery and the remaining capacity obtained by actual measurement or calculation, and the remaining capacity is linear that exceeds 70% as indicated by a D portion in FIG. Parts that are out of the relationship have been deleted.

  The output voltage of the in-vehicle battery 4 is applied, for example, to the electric load 8 through the contact of the fuse F1 and the relay 6, to the electric load 9 through the contact of the fuse F2 and the relay 7, and to the electric load 10 through the contact of the fuse F3 and the relay 13, respectively. Is done. The output voltage of the in-vehicle battery 4 is also applied to other electric loads through the respective fuses and switches. Relays 6, 7 and 13 are turned on / off by switches SW1, SW2 and SW3.

The operation of the vehicular power supply apparatus having such a configuration will be described below with reference to the flowcharts shown in FIGS.
Before the accessory switch 16 is turned on (S3), the charging control ECU 12 reads the voltage value V of the in-vehicle battery (battery) 4 by the voltage value acquisition means 5 and updates the storage (S1).
When the accessory switch 16 is turned on (S3: YES), the charging control ECU 12 determines that the voltage value V stored and updated immediately before that is a predetermined voltage value (first open-circuit voltage value: the remaining capacity 70 of the in-vehicle battery 70 in the first map 18). It is determined whether or not it is equal to or less than the open circuit voltage value corresponding to% (S5). Next, if the voltage value V is equal to or less than a predetermined voltage value, the remaining voltage at start (SOC) is calculated from the voltage value V with reference to the first map 18 with the voltage value V as an open-circuit voltage value (S7). ). The charging control ECU 12 obtains the starting SOC corresponding to the voltage value V based on the graph of FIG.

  Next, the charge control ECU 12 reads the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 (S9), and integrates the charge / discharge current value after the accessory switch 16 is turned on (S3: YES). (S11). Next, the current SOC of the in-vehicle battery 4 is calculated based on the calculated start SOC (S7) and the integrated current amount (S11) (S13).

Next, the charging control ECU 12 determines whether or not the calculated SOC (S13) exceeds 70% (S15), and if it exceeds 70% (S15: YES), the power generation mode (see FIG. 13). ) Is set to Lo, and charging from the alternator 1 to the in-vehicle battery 4 is prohibited (S19). Next, the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 is read (S9).
If the calculated SOC (S13) does not exceed 70% (S15: NO), the charging control ECU 12 sets the power generation mode (see FIG. 13) to Hi and charges the in-vehicle battery 4 from the alternator 1 ( S17). Next, the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 is read (S9).

If the voltage value V is not less than or equal to the predetermined voltage value (S5: NO), the charging control ECU 12 assumes that the remaining capacity (SOC) corresponding to the open circuit voltage value V is 70% (S21).
Next, the charge control ECU 12 reads the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 (S23), and integrates the charge / discharge current value after the accessory switch 16 is turned on (S3: YES). (S25). Next, based on the assumed SOC 70% (S21) and the integrated current value (S25), the current SOC of the in-vehicle battery 4 is temporarily calculated (S27).

Next, the charging control ECU 12 determines whether or not the calculated SOC (S27) is 40% or more (S29), and if it is 40% or more (S29: YES), the power generation mode (see FIG. 13). ) Is set to Lo, and charging from the alternator 1 to the in-vehicle battery 4 is prohibited (S33). Next, the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 is read (S23).
If the calculated SOC (S27) is not 40% or more (S29: NO), the charging control ECU 12 sets the power generation mode (see FIG. 13) to Hi and charges the in-vehicle battery 4 from the alternator 1 ( S31). Next, the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 is read (S23).

Here, the assumed SOC 70% (S21) is actually estimated to be 70% <SOC ≦ 100%, and the SOC (S27) temporarily calculated based on the assumed SOC 70% (S21) is less than 40%. Then, in practice, 40% <SOC ≦ 70%.
Therefore, when the SOC is 40% or more (S29), by prohibiting charging of the in-vehicle battery 4 (S33), when the accessory switch 16 is turned on next time (S3), the open circuit voltage value V is There is a high possibility that the open-circuit voltage value corresponding to the remaining capacity of 70% or less (S5: YES). As a result, the SOC of the in-vehicle battery 4 can be maintained at 70% or less, and the SOC error of the in-vehicle battery 4 does not increase.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing a schematic configuration of the vehicle power supply device according to Embodiment 2 of the present invention. In the figure, the same parts as those in FIG.
In addition to the first map 18, the storage unit 14 of the charging control ECU 12 of the vehicle power supply device according to the present embodiment obtains the relationship between the discharge depth of the in-vehicle battery 4 and the fully charged open circuit voltage value. The obtained second map 19 (see FIG. 11) is stored.

The operation of the vehicular power supply apparatus having such a configuration will be described below with reference to the flowcharts shown in FIGS.
Before the accessory switch 16 is turned on (S43), the charging control ECU 12 reads the voltage value V of the in-vehicle battery 4 by the voltage value acquisition means 5 and updates the storage (S41). A voltage value V read immediately before the accessory switch 16 is turned on, which will be described later, is stored in the storage unit 14. Alternatively, the minimum value of the voltage value V may be stored and updated.
When the accessory switch 16 is turned on (S43: YES), the charging control ECU 12 determines whether or not the voltage value V (open voltage value) stored and updated immediately before is less than or equal to the predetermined voltage value (first open voltage value). Is determined (S45).
When the charge control ECU 12 determines that the voltage value V is equal to or less than the predetermined voltage value (S45: YES), the charge control ECU 12 reads the first map 18 from the storage unit 14, and sets the start SOC corresponding to the voltage value V to the first value. Calculation is made based on the map 18 (S47).

  Next, the charge control ECU 12 reads the charge / discharge current value of the in-vehicle battery 4 detected by the current detector 3 (S49), and the charge / discharge current value from when the accessory switch 16 is turned on (S43: YES) to the present time. (S51). Next, the current SOC of the in-vehicle battery 4 is calculated based on the calculated start SOC (S47) and the accumulated current amount (S51) (S53).

Next, the charging control ECU 12 determines whether or not the calculated SOC (S53) exceeds 70% (S55). If it is determined that the calculated SOC (S53) exceeds 70% (S55: YES), the power generation mode ( 13) is set to Lo, charging from the alternator 1 to the in-vehicle battery 4 is prohibited (S59), and the process returns to step S49.
When it is determined that the calculated SOC (S53) does not exceed 70% (S55: NO), the charging control ECU 12 sets the power generation mode (see FIG. 13) to Hi, and from the alternator 1 to the in-vehicle battery 4 The battery is charged (S57), and the process returns to step S49.

  When it is determined that the voltage value V is not less than or equal to the predetermined voltage value (S45: NO), the charging control ECU 12 obtains the lowest value of the voltage value V stored so far from the storage unit 14 (S61). The charge control ECU 12 reads the first map 18 from the storage unit 14, and calculates the SOC corresponding to the lowest value based on the first map 18 (S63).

  Then, the charging control ECU 12 obtains a discharge depth (corresponding to the maximum value of the past discharge depth) by subtracting the SOC from 100%, reads the second map 19 from the storage unit 14, and the second map 19 Based on the above, a full-charge open-circuit voltage value corresponding to the discharge depth is calculated (S65).

Hereinafter, a method for creating the second map 19 will be described.
First, when the discharge depth (DOD) of the in-vehicle battery 4 was changed to 10%, 30%, 50%, and 100%, the relationship between the discharge capacity and the open-circuit voltage value was examined. 8, FIG. 9, and FIG. 10 are graphs showing the results of examining the relationship between the discharge capacity and the open-circuit voltage value when the DOD is 10%, 30%, and 50%. 8, 9, and 10, ◇ indicates initial data of the in-vehicle battery 4, and ○ indicates data of the in-vehicle battery 4 of each DOD.
8, 9, and 10, when the DOD is 10%, the open-circuit voltage value at full charge does not change between the initial in-vehicle battery 4 and the in-vehicle battery 4 after discharging to DOD 10%. Is 30% and 50%, the fully-charged open-circuit voltage value of the in-vehicle battery 4 after discharging to DOD 30% and 50% may be larger than the initial fully-charged open-circuit voltage value of the in-vehicle battery 4 I understand. This amount of change is larger at DOD 30%.

FIG. 11 is a graph showing the relationship between the discharge depth obtained as described above and the full-charge open-circuit voltage value. In the figure, a broken line indicates measurement data, and a solid line indicates an approximate curve (linear approximation) of the measurement data. Here, the approximate curve may be obtained by logarithmic approximation. Further, since the open-circuit voltage value at the time of full charge does not change much at the discharge depth of 0 to 10%, the approximate curve may be obtained without using the measurement data in the range of the discharge depth of 0 to 10%. .
The approximate curve obtained as described above is stored in the storage unit 14 as the second map 19.

The charging control ECU 12 corrects the first map 18 based on the fully charged open-circuit voltage value obtained using the second map 19 (S67).
FIG. 12 is a graph showing the corrected first map 18.
The case where the full-charge open-circuit voltage value corresponding to the maximum value of the past discharge depth of the in-vehicle battery 4 is 13.0V will be described as an example. The charging control ECU 12 connects the point on the graph when the SOC is 70% and the point where the SOC is 100% and the full-charge open circuit voltage value is 13.0 V by a straight line, A portion where the SOC is 70% to 100% is corrected. As described above, the minimum value of the voltage value V stored in the storage unit 14 is updated, and the maximum value of the discharge depth in the in-vehicle battery 4 is updated. Therefore, when it is determined in step S45 that the voltage value V exceeds the predetermined voltage value (S45: NO) and the discharge depth is updated, the first map 18 is also updated.

  The charging control ECU 12 calculates the starting SOC corresponding to the voltage value V using the corrected first map 18 (S69), advances the process to step S49, and performs the subsequent processes.

As described above, in the present embodiment, when the voltage value V exceeds the predetermined voltage value, the SOC at the start is obtained after correcting the portion where the remaining capacity of the first map 18 exceeds 70%. The error of the current SOC calculated using the starting SOC is reduced.
In the present embodiment, in step S55, it is determined whether or not the SOC calculated in step S53 exceeds 70%, and the generated voltage is controlled. However, steps S55, 57, and 59 are used. This processing may not be performed. However, it is preferable to perform the processes in steps S55, 57, and 59 because the SOC can be reduced to 70% or less and the SOC can be calculated more accurately.

Is a block diagram showing the schematic configuration of a vehicle power supply device according to Embodiment 1 of implementation. Is a flowchart showing an operation example of the vehicle power supply device according to Embodiment 1 of implementation. Is a flowchart showing an operation example of the vehicle power supply device according to Embodiment 1 of implementation. It is a graph which shows the 1st map obtained by calculating | requiring the relationship between the remaining capacity of a battery, and an open circuit voltage value. It is a block diagram which shows schematic structure of the vehicle power supply device which concerns on Embodiment 2 of this invention. It is a flowchart which shows the operation example of the vehicle power supply device which concerns on Embodiment 2 of this invention. It is a flowchart which shows the operation example of the vehicle power supply device which concerns on Embodiment 2 of this invention. It is a graph which shows the result of having investigated the relationship between discharge capacity and an open circuit voltage value when DOD is 10%. It is a graph which shows the result of having investigated the relationship between discharge capacity and an open circuit voltage value when DOD is 30%. It is a graph which shows the result of having investigated the relationship between discharge capacity and an open circuit voltage value when DOD is 50%. It is the graph which showed the relationship between discharge depth and the open circuit voltage value at the time of a full charge. It is a graph which shows the corrected 1st map. It is explanatory drawing which shows the example of charge control of the power supply device for vehicles. It is a characteristic view which shows the example of the correlation of the open circuit voltage value and remaining capacity of a vehicle-mounted battery.

Explanation of symbols

1 Alternator (on-vehicle generator, AC generator)
2 Regulator (Power generation voltage control means)
3 Current detector (means to detect charge / discharge current value)
4 vehicle-mounted battery 5 voltage value acquisition means 6, 7, 13 relay 8, 9, 10 electric load 11 relay box 12 charge control ECU (power generation voltage control means, first, second, third determination means, calculation means, integration means)
14 storage unit 15 engine 16 accessory switch 18 first map 19 second map SW1, SW2, SW3 switch

Claims (4)

An in-vehicle generator, an in-vehicle battery charged with electric power generated by the in-vehicle generator, a means for detecting a charge / discharge current value of the in-vehicle battery when the accessory switch is on, and a charge detected by the means In the vehicle power supply device comprising: means for integrating the discharge current value; and calculation means for calculating the remaining capacity of the in-vehicle battery based on the amount of current accumulated by the means.
The first relationship between the remaining capacity of the in-vehicle battery and the open voltage value obtained in advance, and the second relationship between the discharge depth and the open voltage value at full charge when the battery of the discharge depth is fully charged are stored. Storage means;
Voltage value acquisition means for acquiring a voltage value of the in-vehicle battery before the accessory switch is turned on ;
With
The storage means stores the acquired voltage value acquired by the voltage value acquisition means,
Acquiring a voltage value by the voltage value acquiring unit has acquired, includes a first determination hand stage equal to or smaller than a first open circuit voltage value corresponding to the remaining capacity of 70% of the first relation,
The calculating means includes
When the first determination unit determines that the acquired voltage value is equal to or less than the first open-circuit voltage value, a starting remaining capacity corresponding to the acquired voltage value is calculated based on the first relationship,
Calculated start remaining capacity, and based on the current amount, Ri configured tear to calculate the remaining capacity of the vehicle battery,
When the first determination unit determines that the acquired voltage value exceeds the first open-circuit voltage value, the remaining capacity corresponding to the minimum value of the acquired voltage value stored in the storage unit is based on the first relationship. Calculated,
Calculating a full-charge open-circuit voltage value corresponding to the discharge depth converted from the calculated remaining capacity based on the second relationship;
Based on the calculated full-charge open-circuit voltage value, correct the portion where the remaining capacity of the first relationship exceeds 70%,
Based on the corrected said portion, the vehicle power supply device according to claim configured tare Rukoto to calculate the start time of remaining capacity corresponding to the acquired voltage value. Power generation voltage control means for controlling the power generation voltage value of the in-vehicle generator to high or low;
A second determination means for determining whether or not the remaining capacity calculated by the calculation means exceeds 70%;
When the second determination means determines that the remaining capacity exceeds 70%, the generated voltage control means is configured to set the generated voltage low in order to prohibit charging of the in-vehicle battery. The vehicle power supply device according to claim 1. The second relationship is a vehicle power supply device according to claim 1 or 2, calculated in regard to three or more discharge depth. The vehicular power supply device according to any one of claims 1 to 3 , wherein the second relationship is obtained when the discharge depth exceeds 10%.

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