JPH04229030A - Charge controller for vehicle - Google Patents

Abstract

PURPOSE:To prevent overcharge by setting a target for battery charge based on comparison result between a first battery capacity at the time of starting an engine and a second battery capacity based on an accumulated value of battery current. CONSTITUTION:A discharge characteristic operating section 9e functions as means for detecting a first battery 1 capacity at the time of starting an engine. A battery capacity monitoring section 9g functions as means for adding an accumulated value of charge/discharge current to a first battery capacity thus detecting a second battery capacity. The battery 1 is then charged at a target value being set based on comparison between a currently detected first battery capacity and a second battery capacity detected immediately before detection of the first battery capacity. According to the constitution, the battery is protected against overcharge and the service life thereof is prevented from shortening.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle charging control device which sets a target charging value for a battery based on the state of the vehicle's battery and charges the battery to this target value during driving.

0002

2. Description of the Related Art Conventionally, as a means for detecting the capacity of an on-vehicle battery, for example, as shown in Japanese Unexamined Patent Publication No. 53-127646, the capacity determined from the discharge characteristics at the time of starting a starter is combined with the subsequent charge/discharge current of the battery. There is one that integrates.

[0003] When a decrease in battery capacity is detected by this battery capacity detection means, it is possible to take measures such as cutting off a predetermined electrical load to prevent the battery from running out. Further, methods are being considered to control the amount of power generated by a generator by taking into account the capacity of the battery and the state of the vehicle.

0004

Batteries generally have charging characteristics as shown in FIG. In other words, when the battery is new, as shown by the solid line, when the capacity of the battery is approximately 80% or less of the actual capacity, the rate of increase in capacity relative to charging current (hereinafter referred to as charging efficiency) is approximately 100%. be. However, when the capacity of the battery becomes approximately 80% or more of the actual capacity due to charging, the voltage of the electrode increases as the battery is charged and its capacity increases, and this electrode voltage exceeds a predetermined value. As the charging current increases, the charging efficiency gradually decreases due to a phenomenon in which the water in the battery liquid is electrolyzed by the charging current. As the battery deteriorates, the timing at which gassing begins, that is, the timing at which charging efficiency begins to decline, gradually becomes earlier, the charging efficiency declines more rapidly, and the capacity that can be charged to the battery decreases. (hereinafter referred to as "maximum capacity") decreases, and the capacity may not increase to the actual capacity (=maximum capacity when new). In other words, the charging characteristics of a battery are different when it is new and when it is deteriorated. The broken line in FIG. 5 indicates an example of charging characteristics of a deteriorated battery.

[0005] The capacity of a battery also decreases due to discharging. Therefore, in conventional battery state detection, even if a decrease in battery capacity can be detected, it is not possible to detect whether the decrease is due to discharge or deterioration.

As mentioned above, it is necessary to charge the battery as much as possible in order to control the amount of power generated by the generator in consideration of the vehicle condition, but if the battery is deteriorated, a large amount of charging current is used. It is used for gassing, and the battery fluid decreases by that amount, which affects the life of the battery. Further, if charging is continued despite the fact that the maximum capacity has decreased and the capacity does not increase even if charging current is continued to be supplied, problems such as further increase in the amount of battery fluid loss due to gassing occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle charging control device that can charge a battery in such a manner that the amount of gassing is suppressed as much as possible, taking into consideration the charging characteristics of the battery.

[0008]

[Means for Solving the Problems] In order to achieve the above object, there is provided a starter that is driven by an on-vehicle battery and starts an engine, a vehicular generator that is driven by the engine and that charges the battery, and a generator that is driven by the engine and charges the battery. a battery current detecting means for detecting a charging/discharging current; a battery voltage detecting means for detecting a terminal voltage of the battery; and a battery current integrating means for integrating the charging/discharging current of the battery detected by the battery current detecting means; a first battery capacity detection means for detecting the capacity of the battery at the time of starting the engine; and a first battery capacity detected by the first battery detection means; a second battery capacity detecting means that adds the battery current integrated value since the first battery capacity detection and detects it as a second battery capacity after starting the engine; and the first battery capacity detected this time; target value setting means for setting a charging target value for the battery after starting the engine based on a comparison result of the first battery capacity with a second battery capacity immediately before detecting the first battery capacity; To the target value set,
A vehicle charging control device is provided, comprising: power generation control means for controlling the amount of power generated by the vehicle generator so as to charge the battery.

[0009]

[Operations and Effects of the Invention] According to the vehicle charging control device described above, the amount of gassing is first detected by comparing the first battery capacity and the second battery capacity. Then, since a target charge value for the battery is set based on this amount of gassing, the battery is charged so as to suppress gassing as much as possible. As a result, it is possible to prevent overcharging of the battery, thereby preventing shortening of the battery life. Further, the difference between the first and second battery capacities during comparison is controlled to be small, and the first and second battery capacities obtained by different detection means show similar values, that is, These first and second battery capacities are accurate battery capacities. Therefore, the capacity of the battery can be known more accurately.

0010

[First Embodiment] A first embodiment of the vehicle charging control device of the present invention will be described below. In FIG. 1, 1 is an on-vehicle battery, 2 is an engine for driving the vehicle, 3 is a starter for starting the engine, and 4 is a starter switch for starting the starter.As is well known, when the starter switch 4 is turned on, power from the battery 1 is By supplying this to the starter 3, the starter 3 rotates and the engine 2 starts.

5 is a generator driven by the engine 2 via a belt and a pulley (not shown) to charge the battery 1 and supply electric power to electric loads 8 such as lamps, blower motors, defoggers, etc.; 6 is a generator for the battery 1; 7 is a temperature detector that detects the temperature of the battery 1; 9 is a temperature detector that detects the state of the engine 2, the voltage, current, and temperature of the battery 1; This is a control circuit using a microcomputer that controls the power generation of the generator 5, and also detects the battery life and displays it on the display 10. Below, regarding the control within the control circuit 9, (I
) Detection of battery capacity, (II) Setting of target battery charging value, and (III) Battery charging control during driving will be explained in this order.

(I) Battery Capacity Detection FIG. 2 is a block diagram showing the processing functions in the control circuit 9, and FIG.
is a flowchart showing the control within this control circuit 9, and the explanation will be based on these.

First, in the flowchart shown in FIG. 3, in step 20, the starter switch 4 is turned on to start the starter 3. Next, in step 30, the discharge characteristics at the time of starting the starter are measured, and this is determined according to FIG.
This will be explained below.

At step 302, the discharge current IB1 of the battery 1 detected by the current detector 6 is detected by the current detector 9.
Read from a. In step 303, when the discharge current IB1 becomes 100 [A] or more, starting of the starter 3 is confirmed. In step 304, for example, 50 [m
s] Wait. This is because immediately after starting the starter 3, a large current flows rapidly and generates noise, so that the starter 3 is not affected by this noise. After eliminating the influence of noise in step 304, the discharge current IB1 of the battery 1 is read from the current detection unit 9a in step 305.

[0015] Then, in step 306, step 3
The discharge current IB1 read in 05 is 60 [A]
to 250 [A], it is determined that the starter 3 is in operation. If it is determined in this step 306 that the starter 3 is starting, the voltage VB1 of the battery 1 is detected by the voltage detection unit 9c in step 307.
Load from. Here, the range of the discharge current mentioned above was set based on the judgment that a current of 60 [A] to 250 [A] will flow through the starter 3 when the starter 3 is operating and the engine 2 has not yet started. However, there is no need to specifically limit it to this range.

Next, in step 308, the above-mentioned discharge current IB1, voltage VB1, and time t of the battery 1 are calculated by the discharge characteristic calculation section 9, which functions as a first battery capacity detection means.
Store in e. Step 309 is 3 [
Steps 305 to 30 are performed when the above steps 305 to 30 are completed.
This is to stop the operation of starter 8, and after starting starter 3,
s] has not elapsed, the process returns to step 305 again. At this time, the operation of steps 305 to 309, that is, reading and storing the discharge current IB1 and voltage VB1 when the starter 3 is activated, is repeated at 25 [ms] intervals, and the discharge current IB1 corresponding to the time t at that time, Voltage VB
I remember 1. Note that the discharge characteristic calculation section 9e always stores 10 new pieces of data.

[0017] Then, in step 306, when it is determined that the discharge current is 60 [A] or less and the engine 2 has started, the operation except for steps 307 and 308 is repeated, and 3 [s] have passed since the starter was started. After the elapse of time, the process moves to step 310 in step 309. In step 310, from the data stored in step 308, the maximum value IBmax of the discharge current IB1 of the battery 1 and the voltage VB read simultaneously with this maximum value IBmax are determined.
1 and time t as VImax and tImax, respectively, and in the next step 311, conversely, the minimum value IBmin of the discharge current IB1 and this minimum value IBm
The voltage VB1 and time t read at the same time as in are calculated as VImin and tImin, respectively. Based on these, in step 312, the horizontal axis is the discharge current IB1,
Step 3 on the graph with the vertical axis set as voltage VB1.
The coordinates determined by the maximum value IBmax of the discharge current calculated in steps 10 and 311 and the voltage VImax at that time, and the coordinates determined by the minimum value IBmin of the discharge current and the voltage VImin at that time are plotted, respectively, and these are plotted as a straight line. Draw a characteristic diagram connected by . Next, from this characteristic diagram, the voltage VB1 when the discharge current IB1 is 150 [A] is calculated as the first capacitance detection voltage VBd1. Also, from the start of the starter, the above voltage VBd1
The time t until detection is determined by averaging tImax and tImin calculated in steps 310 and 311, and this is defined as the capacitance detection time td. However, the first
The discharge current I for determining the capacitance detection voltage VBd1 of
The value of B1 does not need to be particularly limited to 150 [A].

The first capacitance detection voltage V thus detected
Bd1 is corrected as shown in FIG. 9 for the following reasons. That is, the battery voltage when the battery 1 is discharged decreases with time, and reaches a stable voltage value after about 5 seconds have passed from the start of discharge. On the other hand, starting the engine 2 by driving the starter 3 is normally done within one second as described above, and the measured value of the voltage of the battery 1 when the starter is driven, that is, the voltage measured as described above, is The capacitance detection voltage VBd1 of 1 indicates a value higher than the voltage when stable. Therefore, the relationship between the battery characteristic discharge time and voltage is determined in advance, and in step 402, the first capacity detection voltage VBd1 determined based on the discharge current during starter drive is determined.
The deviation ΔV between this and the stable value obtained 5 seconds after the starter 3 starts is corrected by subtracting it from the first capacitance detection voltage VBd1. By correcting in this way, battery 1 becomes 1
More accurate battery 1 when discharging at 50 [A]
A voltage of V
Let it be Bd2.

Furthermore, since the battery voltage has temperature characteristics, in step 403, the battery temperature detector 7
The battery temperature TB detected by is input to the battery temperature detection section 9b, and in step 404, the second capacity detection voltage VBd2 is corrected according to the battery temperature TB. Through this correction, it is possible to obtain a more accurate voltage of the battery 1, which is then applied to the third capacity detection voltage VBd3.
shall be.

Next, in step 405, the first battery capacity VI1 during starter drive is determined from this third capacity detection voltage VBd3, which will be explained below. The solid line in FIG. 4 is a characteristic diagram showing the relationship between battery voltage and battery capacity when the battery 1 is discharged at a predetermined current for a predetermined time and there is no stratification of the battery liquid specific gravity or occurrence of polarization immediately after charging. It shows. As shown in the figure, when the battery capacity is small, the battery voltage becomes small. This characteristic is stored in the discharge characteristic calculating section 9e.

Based on this characteristic diagram, in step 405,
Third capacitance detection voltage VBd3 obtained as described above
Using this, the capacity VI1 of the battery 1 when the starter 3 is driven (hereinafter referred to as the first battery capacity) is determined.

[0022]Here, if the capacity of the battery 1 is unknown because the previous run was the first run, or because the battery 1 was replaced before the last run although it was not the first run, the function of the initial capacity setting means is performed. The battery capacity monitor section 9g sets the first battery capacity VI1 as the initial capacity. The current integrating section 9d integrates the charging/discharging current of the battery 1 after the engine 2 is started, which is detected by the current detector 6 and read into the battery current detecting section 9a, and also functions as a second battery detecting means. The battery capacity monitor section 9g adds the integrated value of the charging and discharging currents to the initial capacity to detect the second battery capacity VI2 during driving. and,
The battery capacity monitor section 9g detects the second battery capacity VI.
2, that is, the value when the engine is stopped, is stored as the third battery capacity VI3.

In this run, the third battery capacity VI
3 is stored in the battery capacity monitor section 9g. At step 50 in FIG.
This third battery capacity VI3 is read out. In step 60, the battery capacity monitor unit 9g detects the first battery capacity VI1 detected when the starter 3 is driven and the third battery capacity VI3 (that is, the second battery capacity VI1 immediately before detecting the first battery capacity VI1). battery capacity)
The smaller value is considered as the true value, and the initial capacity V
Set as I4. Normally, if the battery 1 is in good condition, the first and third battery capacities VI1 and V
I3 has approximately the same value, so these first and third
Either value of battery capacity VI1 or VI3 may be adopted. However, the following cases occur, so the first,
The smaller of the third battery capacities VI1 and VI3 is adopted.

The first case is when the first battery capacity VI1 is larger than the third battery capacity VI3 by a predetermined value. In battery 1, when the specific gravity of the battery fluid becomes stratified or a phenomenon in which the concentration of battery fluid near the electrodes increases immediately after charging (hereinafter referred to as "polarization"), the voltage characteristics with respect to the capacity change as shown in Figure 4. It looks like a broken line. In other words, when stratification or polarization occurs, the battery voltage becomes higher than normal. Therefore, if stratification or polarization occurs during first battery capacity detection, the capacity detection voltage will be detected to be higher than normal, and the first battery capacity V
I1 becomes larger than the true capacity and the third battery capacity VI3. Therefore, the third battery capacity VI3 is determined to be close to the true capacity and is set as the initial capacity.

The second case is that the third battery capacity VI3 is larger than the first battery capacity VI1 by a predetermined value. This is a case where gassing occurs as described above. When gassing occurs, the integrated value of the battery charging/discharging current, which is the basis for detecting the second battery capacity VI2, is a value integrated including the charging current used for gassing, and the second battery capacity VI2 is detected larger than the true capacity. Therefore, the third battery capacity VI3, which is the final value of the second battery capacity VI2 that has been determined to be large, is the true capacity and the first battery capacity V
It becomes larger than I1. Furthermore, when the battery is deteriorated, the charging efficiency decreases more quickly, so the third battery capacity VI3 becomes even larger than when it is new. Therefore, in this case, the first battery capacity VI1 is determined to be close to the true capacity and is set as the initial capacity.

In contrast to the above-mentioned stratification, gassing occurs when air bubbles are generated from the electrodes and the battery fluid is stirred by these air bubbles, so that it is difficult for stratification and gassing to occur at the same time. Therefore, the first and third battery capacities VI1,
Since both VI3 do not increase, the accurate capacity can be determined by adopting the smaller value as described above.

(II) Setting the Target Charging Value of the Battery Next, in step 70 shown in FIG. Determine.

For example, when the first battery capacity VI1 is larger than the third battery capacity VI3, the third battery capacity VI3 is set as the initial capacity as described above, and the upper limit capacity VI0 is set as shown in Equation 1.

[0029]

[Equation 1] VI0 = VI3 +A Here, the actual capacity of the battery 1 used in the present invention is 2
7 [Ah], and as shown in Figure 7, when the capacity is less than 9 [Ah], it is in a dangerous state, and when it is 9 [Ah] or more, it is 1
When it is less than 8 [Ah], it is in a bad state, and when it is 18 [Ah] or more, it is 25.
The state of the battery 1 is divided into four zones: a good state when it is less than [Ah], and a fully charged state when it is more than 25 [Ah]. Then, the capacity increment value A is the initial capacity V
Settings are made as shown in Table 1 depending on which zone I4 is in.

[0030]

[Table 1] The basis for setting the capacity increment value A as shown in Table 1 above is as follows. When battery 1 is in a dangerous state, we want to charge it as much as possible to increase its capacity in order to control the generator taking into consideration the vehicle state etc. as described above (this also applies to battery 1 in the other three states). ). but,
It is also possible that the capacity has decreased because the battery 1 has deteriorated, so the amount of gassing also needs to be taken into consideration. Therefore, at least 50% of the actual capacity, or 13.5A
h] is set to, for example, 15 [Ah] to ensure the capacity. When the battery 1 is in a defective state, it is also in a dangerous state; for example, when the initial capacity is the lowest 9 [A
The capacity is set to 10 [Ah] so that even if the capacity is 10 [Ah], the condition can be recovered to a good state. When the battery 1 is in a good state and in a fully charged state, it is set to 5 [Ah] and 2 [Ah], respectively, for the above-mentioned generator control.

[0031] When the third battery capacity VI3 is larger than the first battery capacity VI1, the first battery capacity VI1 is set as the initial capacity, but in this case, it is considered that gassing has occurred as described above. , the upper limit capacitance VI0 is corrected using a correction value B as shown in Equations 2 to 4 according to the amount of gassing.

[0032]

[Math 2] VI0 = VI1 +A-B

[0033]

[Math 3] B=α(VI3-VI1)

[0034]

[Equation 4] α=0.8 The correction value B is based on the difference between the third battery capacity VI3 and the first battery capacity VI1, that is, the amount of gassing during the previous run, and the correction value B is 80% of this gassing amount. ] is set to reduce the incremental value of the total battery capacity. Therefore, the capacity of battery 1 is charged so that it increases from the capacity when driving the starter to the upper limit value VI0, and the upper limit value VI0 increases each time driving is repeated, but if battery 1 has deteriorated, the predetermined amount Gushing begins to occur, and the increase in the upper limit value VI0 decreases. When the increase in the upper limit value VI0 decreases, the amount of gassing also decreases, so the upper limit value VI0 increases again. These steps are then repeated as the vehicle travels to charge the battery 1 while suppressing gassing.

Here, in order to minimize the increase in the upper limit value VI0 and further suppress the amount of gassing, for example, means for storing the correction value B is provided, so that the third battery capacity VI3 is the same as that of the first battery. If a state in which the capacitance is larger than VI1 continues, the previous correction value B0 and the current correction value B1 may be compared and the larger one may be adopted as the current correction value B.

(III) Charging control of the battery while driving In step 80, the charging/discharging current IB of the battery 1 while driving is
2. Read the voltage VB2 and the temperature TB2, and based on these, in step 90, the current integration unit 9d integrates the charge/discharge current IB2, and in addition to the initial capacity obtained in step 60, the current battery capacity while driving is calculated. , the aforementioned second battery capacity VI2 is determined, and the battery capacity monitor section 9g
to be memorized. In other words, the second battery capacity VI2, which changes moment by moment, is constantly detected. Next, step 100
Then, charging/discharging current IB2, voltage VB2, temperature TB2, second battery capacity VI2, upper limit capacity VI of battery 1
The generator 5 is controlled based on the information of 0 and the information of the engine 2, and based on the following Tables 2 to 4, explanations will be given in the order of ■ normal running, ■ idling, ■ accelerating, and ■ decelerating. do.

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

Here, Table 2 is a table showing the control charging current IBC to the battery 1 according to the state (charging state) of the battery 1 and the vehicle mode, and Table 3 is a table showing the control charging current IBC to the battery 1 according to the state of the battery 1 and the battery temperature. Table 4 is a table showing changes in the settings for the normal control voltage VBC in Table 3, depending on the vehicle mode.

■Normal running As shown in FIG. 10, the generator 5 has an armature winding 5a, a field winding 5b, and a full-wave rectifier 5c.
f is a transistor 9f that controls the current of the field winding 5b;
1, a flywheel diode 9f2 connected to both ends of the field winding 5b, a conductivity control circuit 9f3 that controls the conductivity of the transistor 9f1, a control charging current IBC
A control charging current determining circuit 9f4 that determines the control voltage V
It consists of a control voltage determining circuit 9f5 that determines BC.

Next, the operation will be explained according to the flowchart shown in FIG. In step 100b, battery 1
The charging current IB2 is detected, and this charging current IB2 and
The control charging current IBC determined by the control charging current determining circuit 9f4 is compared. And charge/discharge current IB2
is larger, in step 100c, the currently stored ON time TON of the transistor 9f1 is set to Δβ.
It decreases by 2. Here, if the control charging current IBC is larger, in step 100d, the currently stored ON time TON of the transistor 9f1 is changed to Δβ1.
only increases.

In step 100e, the voltage V of battery 1 is
B2 is detected, and the voltage VB2 of the battery 1 is compared with the control voltage VBC determined by the control voltage determining circuit 9f5. If the voltage VB2 of the battery 1 is larger, the transistor 9f1 is
The power generation of the generator 5 is stopped by setting the ON time TON to 0,
To prevent overcharging of the battery 1 or to prevent problems to the electric load caused by the voltage of the battery 1 becoming too high.

On the other hand, if the voltage VB2 of the battery 1 is smaller, the transistor 9f1 is turned on for the time TON determined in the previous step 100c or 100d. Then, the control loop (
Steps 80, 90, 100, 110, 120) are managed in step 170 with a calculation cycle of 10 [ms]. Therefore, the ON time is a certain time (Δβ1 or Δ
β2) is repeatedly set to increase or decrease every 10 [ms], and the control charging current IBC is set at a predetermined speed.
The charging current of the battery 1 is adjusted so as to approach the (predetermined current). (The control up to this point is performed by the battery current adjustment means and is shown as being included in the control by the conductivity control circuit 9f3.) Here, assuming that the above-mentioned initial capacity is within the good zone of FIG. , the upper limit capacity VI0 is set to VI3+5 [Ah] from Table 1. It is assumed that this upper limit capacity VI0 is also within the good zone. At this time, the second battery capacity VI2 is in a good state, so the control charging current determining circuit 9f4 sets the control charging current IBC to 5 [A] as shown in Table 2, and the control voltage determining circuit 9f5 sets the control charging current IBC to 5 [A] as shown in Table 3. As shown, the control voltage VBC
is set according to the temperature TB2 of the battery 1. and,
Control is performed so that the battery is always charged with a controlled charging current of 5 [A].

The control charging current IBC causes battery 1 to
is charged and the second battery capacity VI2 begins to increase,
When the upper limit capacity VI0 is reached, the control charging current IBC and the control voltage VBC are determined by the control charging current determining circuit 9f4 and the control voltage determining circuit 9f5 so that the controlled charging current IBC=0 [A] in the full charge zone shown in Table 1, respectively.
, the control voltage VBC is set to 12.8 [V] to stop charging the battery 1 and stop increasing the second battery capacity VI2.

Since the battery 1 is not charged after that, it is discharged and the second battery capacity VI2 becomes the upper limit capacity VI0.
When the voltage decreases by a predetermined value, the control charging current IBC and control voltage VBC are set in accordance with the state of the battery 1 at that time. In this example, as mentioned above, the upper limit capacity VI0
Since it is assumed that is in the good zone, the control charging current IBC = 5 [A] and the control voltage VBC = 14.0 [
V], start charging battery 1 again, and
The aim is to restore the battery capacity VI2. After that, the above-mentioned state is repeatedly controlled.

[0047] Also, during the control during normal driving,
The electric load 8 is large and the second battery capacity VI2
is in the good zone, the charging current to battery 1 is set to zero (control charging current IBC=
0), and load control is performed in which current from the generator 5 is supplied only to the electrical load 8, thereby reducing the power generated by the generator 5 and improving fuel efficiency. At this time, the battery 1 is gradually discharged, and when the second battery capacity VI2 decreases by a predetermined amount, the load control is canceled and the battery 1 is charged again.

Furthermore, for the above control, the upper limit capacity VI
0 is in the full charge zone, when the second battery capacity VI2 enters the full charge zone, the control charging current IBC and control voltage VB in the full charge zone
Controlled by C. Since this control is a control that does not charge the battery 1, overcharging can be prevented. On the other hand, when the discharge decreases to the good zone, the control is changed to the good zone, and when it enters the full charge zone, the control is changed again to the full charge zone.

[0049] Therefore, the upper limit capacity V
If I0 is set large, the battery will not be charged up to this upper limit capacity VI0 during normal driving. In the deceleration control described later, the control is changed to allow charging up to this upper limit capacity VI0.

[0050] Also, the second battery capacity VI during use
2. The above load control is performed only when the battery is in the fully charged zone or good zone. ■When idling (when the engine is running at a predetermined rotation speed or lower) second battery capacity VI2
is outside the danger zone and is idle,
When a large electrical load 8 is applied from a small electrical load 8, the power generation of the generator 5 is delayed in response to this change. Therefore, at this time, if the battery 1 is being charged by the generator, the charging current for the battery 1 is supplied to the electrical load 8, so the charging current suddenly decreases temporarily, and if the battery 1 is not being charged, the battery Since current is supplied from 1 to the electric machine load 8, the discharge current temporarily increases rapidly. By detecting these sudden changes in the current of the battery 1 with the current detector 6, the application of a large electrical load is detected.

Conversely, when the engine 2 is idle,
A state in which the electric load 8 is applied (for example, the field winding 5
If the electrical load 8 is interrupted (if the DUTY of the field current applied to b is 80% or more), the current supplied from the generator 5 to the interrupted electrical load 8 will temporarily Since the charging current is supplied to the battery 1 at the same time, the charging current increases rapidly. By detecting this sudden increase in the charging current with the current detector 6, a sudden decrease in the large electrical load 8 is detected.

Control when the load suddenly increases or decreases as described above (hereinafter referred to as sudden load change control) will be explained with reference to the flowchart shown in FIG. First, in step 100j, it is detected whether or not sudden load change control is currently being performed. Since this is cleared when the IG switch (not shown) is turned on, in the next step 100k, the charging current or discharging current of battery 1 is detected. The difference between IB2 and control charging current IBC is detected.

As described above, the charging current or discharging current IB2 of the battery 1 is controlled to approach the control charging current IBC at a predetermined speed, and even when the electrical load 8 is turned on or off, it continues at a predetermined speed. Because it is controlled,
The generator 5 does not respond immediately to changes in the electrical load 8, resulting in a time delay. Therefore, when the electrical load 8 increases, current is supplied from the battery 1 to the electrical load 8.
When IB decreases, charging current is supplied from the generator 5 to the battery 1, so the difference between the current IB2 of the battery 1 and the control charging current IBC increases. Therefore, the discharging current is shown with a different sign from the charging current, and if the absolute value of the difference between the current of the battery 1 and the control charging current IBC is smaller than a predetermined value I0 (for example, 15 [A]), it is assumed that there is no sudden change in the load. , normal control is entered in step 100l. (As mentioned above, the electrical load 8 is detected by the electrical load detecting means, and in this embodiment, the conductivity control circuit 9f3 is shown as including this electrical load detecting means.) This normal control is performed as described above. This control is the same as the control in the normal driving state, so the explanation will be omitted.

Next, to explain the case where the electric load 8 suddenly changes, in step 100k from the normal control state, the absolute value of the difference between the charging current or discharging current IB2 of the battery 1 and the control charging current IBC reaches the predetermined value I0. If it is detected that the load is larger than that, the load sudden change control is entered in step 100n, and at that time, it is stored that the load sudden change control is in progress. In step 100o, the battery 1 current IB2 calculated in the previous step 100k and the control charging current IB
For example, if the sign of the charging current is (+), it is determined that the electrical load 8 has increased rapidly when IB2-IBC<0, and in step 100p, the ON time TON of the transistor 9f1 is changed to the one during normal running. Δα smaller than Δβ1
Increase by 1.

Here, when IB2-IBC>0, it is determined that the electrical load 8 has suddenly decreased, and in step 100q, the ON time TON of the transistor 9f1 is changed to Δ during normal running.
It decreases by Δα2 which is smaller than β2. Furthermore, at this time, the control charging current IBC is set to 30 [A] as shown in Table 2, and the control voltage VBC is set to 0.5 [V] as shown in Table 4.
] is set to increase the amount of charge to the battery 1.

Thereafter, in step 100r, the voltage VB2 of the battery 1 and the control voltage VB
The power generation of the generator 5 is stopped only when the voltage VB2 of the battery 1 is higher than the voltage VB2 of the battery 1. This control is performed every 10 [ms] as in normal driving.

Next, since it is remembered that sudden load change control is being performed during the previous calculation, the process moves from step 100j to step 100m, and the charging current IB2 of the battery 1 and the control charging current IBC are compared. If both have the same value,
After the charging current gradually increases or decreases due to sudden load change control, it is determined that the control charging current IBC has been reached, and in step 100l, normal control is entered, and at this time, it is stored that normal control is in progress. In the comparison between the charging current IB2 of the battery 1 and the control charging current IBC at step 100m, if the two are not equal, the sudden load change control is entered again at step 100n. In step 100m, the normal control may be entered when the absolute value of the difference between the charging current IB2 of the battery 1 and the control charging current IBC is a predetermined value.

As mentioned above, if the electric load 8 is turned on during idle, this is reliably detected, and from this point on, the field current is gradually increased to gradually increase the power generation amount of the generator 5, and the engine By preventing the load on the engine 2 from rapidly increasing, it is possible to prevent problems such as engine stalling that occur due to a sudden increase in the load on the engine 2.

On the other hand, if the electrical load 8 is cut off during idle, this is reliably detected, and from this point on, the amount of power generated by the generator 5 is gradually reduced, and during that time, the charging current to the battery 1 is increased. By preventing the load on the engine 2 from suddenly decreasing, it is possible to prevent problems such as an increase in the rotational speed that would occur due to the sudden decrease in the load on the engine 2.

Here, if the electric load 8 is turned on when the DUTY of the field current flowing through the field winding 5b of the generator 5 is 90% or more, the field current is gradually increased. There's no need.

■When accelerating When accelerating while driving, this is detected from the rise in fuel intake pressure, and as shown in Tables 2 and 4 above, the second battery capacity VI2 is fully charged while driving. Or, if it is in the good zone, set the control voltage VBC to 2 [V] lower than the control voltage VBC that was set before acceleration, and set the control charging current IBC to 0 [A]. Improves acceleration by reducing the amount of power generated.

On the other hand, if the battery 1 is in a bad or dangerous state, it is necessary to continue charging, so even during acceleration, the control voltage VBC that was set before acceleration is
and continues control using the control charging current IBC.

■During deceleration When the vehicle decelerates while driving or when it goes downhill, the control charging current IBC is set to 30 [A] and the second 2.2 [V] if the battery capacity VI2 is in the full charge zone, 1.0 [V] if it is in the good zone, and 0.5 [V] if it is in the bad zone. , in addition to the control voltage VBC that was set before deceleration, the control voltage VBC
is set to 15 [V], and the upper limit capacity VI0 of the second battery capacity VI2 during running is changed to a value to which a correction value C (for example, 5 [Ah]) is added. In this way, the amount of power generated by the generator 5 is increased to charge the battery 1, the engine brake is increased to assist deceleration, and the energy during deceleration is regenerated to charge the battery 1.

On the other hand, if the second battery capacity VI2 is in the danger zone, setting the control charging current IBC and control voltage VBC above those shown in Tables 2 and 3 will have an adverse effect on the electrical load 8. Do not change these settings as it may cause adverse effects.

The control during acceleration and deceleration described above will be explained below with reference to FIG. First, in step 501, an engine status signal is input. The engine status signal is, for example, a throttle position sensor, an intake pressure sensor of an engine intake manifold, or the like, and may be a signal that can detect acceleration, deceleration, and downhill conditions of the vehicle. Next, in step 502, it is determined whether the vehicle is in an acceleration state. When it is determined that the vehicle is in an accelerating state, it is determined in step 503 whether the second battery capacity VI2 during running is fully charged or in the good zone. When it is determined that the battery is fully charged or in the good zone, in step 504,
As shown in Table 4 above, the control voltage VBC is lowered by 2 [V], and the control charging current IBC is reduced to 0 in step 505.
Set to [A].

On the other hand, if it is determined in step 502 that the vehicle is not in an accelerating state, then in step 506 it is determined whether the vehicle is in a decelerating state or in a downhill state. When it is determined that the vehicle is in a deceleration state or a downhill state, the second battery capacity VI2 is determined in step 507.
Determine whether or not the area is a danger zone. Second battery capacity V
When it is determined that I2 is not in the danger zone, the control voltage VBC is set to 15 [V] in step 508, and the control charging current IBC is set to 30 [A] in step 509. Next, in step 510, the upper limit capacity VI0 of the second battery capacity VI2 is increased by 5 [Ah].

If the above conditions are not met, the control charging current IBC, control voltage VBC, and upper limit capacity VI0 are adjusted in steps 511 to 513, respectively.
Set to normal value. Further, in order to prevent the battery 1 from being overcharged, the period for increasing the upper limit capacity VI0 during deceleration may be limited to a certain period of time from the start of deceleration.

As described above, when the vehicle is decelerating or descending a slope, the control voltage and control charging current are set high to the extent that they do not adversely affect the electrical load, and the upper limit capacity of the battery detected at the start of running is increased. To increase the price depending on the condition,
It is possible to obtain a regeneration effect that takes into account the state of the battery.

Next, returning to FIG. 3, in this embodiment, in step 110, if the second battery capacity VI2 falls below the set value of the danger zone, the alarm section 9i issues a warning that the battery is dead. Step 170 is as described above.
The calculation cycle is set to 10 [ms]. and,
If it is determined in step 120 that the key switch has been turned off, the last value of the second battery capacity VI2 is stored in the battery capacity monitor section 9g as the third battery capacity VI3 in step 130, and the value is stored in the battery capacity monitor section 9g as the third battery capacity VI3. Be prepared.

[0070]

[Second Embodiment] In the first embodiment, when gassing is detected, a capacity increase amount A set for each zone to which the initial capacity of the battery belongs is added to the initial capacity, and a correction value corresponding to the amount of gassing is added to the initial capacity. (For example, the amount of gassing x 0.8) was subtracted to set the upper limit capacity. However, in the second embodiment, the amount of gassing detected this time is calculated from the maximum value of the second battery capacity VI2 during the previous run. The subtracted value is taken as the optimum value of the battery capacity, and this is taken as the upper limit capacity explained in the first embodiment.

The second embodiment will be explained below with reference to FIGS. 14 to 18.
The explanation will be based on. 14 is a flowchart showing the control within the control circuit 9, FIG. 15 is a flowchart showing details of the process of step 70 in the flowchart shown in FIG. 13, and FIG. FIG. 17 is a characteristic diagram that approximates the characteristics of battery charging efficiency, and FIG. 18 is a characteristic diagram that shows actual battery charging efficiency.

In FIG. 14, steps 20 to 60 are the same as those in FIG. 3 shown in the first embodiment, and therefore their explanation will be omitted. Step 70 is to calculate the maximum capacity TSOC of the battery 1. To explain in detail with reference to FIG. 15, in step 700, the maximum value PSOC of the second battery capacity VI2 during the previous run is
It is determined whether B and the optimum value TSOCB calculated during the previous run (both stored in the battery capacity monitor section 9g) have been invalidated due to a power backup failure or the like. If it is determined that these data PSOCB and TSOCB are invalid, in step 707, the current value of TSOC is set to the rated capacity. This is because the cause of backup failure is often due to replacement of the battery 1. However, if it is set to a value higher than the actual maximum capacity of the battery 1, it may cause negative effects such as overcharging, so it may be set to about 50% of the rated capacity.

[0073] If it is determined in step 700 that the backup data is valid, in step 701 the gassing amount (hereinafter referred to as "invalid charging capacity") GSOC
Calculate.

An explanation will be given based on the change in battery capacity shown in FIG. 16. In the figure, g is the initial capacity VI4 during the previous run. As mentioned above, this initial capacity VI4 (
The subsequent charging and discharging currents are integrated in g) to determine the second battery capacity VI2 (e) during running. This is performed by the process of step 90 in FIG. 3 shown in the first embodiment. f is the actual change in battery capacity with charging efficiency taken into consideration; as shown in Figure 17, when the optimal value TSOC (d) of battery 1 is exceeded, the charging efficiency becomes 0%.
Therefore, battery 1 is not charged. Here, since the charging characteristics of the battery 1 are approximated, the maximum capacity=optimum value TSOC. On the other hand, since the second battery capacity VI2 (e) does not take charging efficiency into consideration, even if it exceeds the optimal value TSOC (d), the charging efficiency will decrease by 10%.
Continuing to integrate with 0%, the resulting capacity becomes the maximum capacity TSOC (
d) It is calculated as above. In other words, the optimal value TSOC(d)
The amount accumulated above is the invalid charging capacity GSOC. b
is the third battery capacity VI3, which is the final value of the second battery capacity VI2 (e) which has been integrated too much, including the invalid charge capacity GSOC during the previous run. On the other hand, the initial capacity VI4 during the current run should match the final value (a) of the previous change in actual battery capacity (f). As a result, the invalid charge capacity GS in the previous run
OC is the third battery capacity VI3 (b) and the actual battery capacity (=initial capacity VI4 during the current run) (a)
It can be seen that h corresponds to the difference between . Therefore, in step 701, the difference between the third battery capacity VI3 and the initial capacity VI4 during the current run is set as the invalid charge capacity GSOC during the previous run.

In step 702, the invalid charge capacity GSO
It is determined whether or not C is 0, and if it is determined that the invalid charging capacity GSOC is not 0, the optimum value TSOC is determined in step 704.
is calculated. Note that the invalid charge capacity GSOC becomes 0 when charging and discharging during the previous run was performed in a region where there was no decrease in charging efficiency and gassing did not occur. Here, the invalid charging capacity GSOC during the previous run is a value h3 that is the sum of h1 and h2 shown in FIG. 16. This is the invalid charging capacity GSOC no matter what pattern of charging and discharging.
is the maximum value PSOC(
c) and the optimum value TSOC(d). The invalid charge capacity GSOC during the previous run is calculated in step 701 as described above, and the invalid charge capacity GSOC determined by these two methods is equal. Therefore, the optimal value TSOC of battery 1 is the value obtained by subtracting the invalid charge capacity GSOC obtained in step 701 from the maximum value PSOCB of the second battery capacity VI2 during the previous run, and the optimal value TSOC is calculated in step 704. Ru.

On the other hand, in step 701, the invalid charge capacity G
If the SOC is determined to be 0, then in step 703, the optimal value TSOCB calculated during the previous run is compared with the maximum value PSOCB of the second battery capacity VI2 during the previous run. If it is determined that PSOCB≧TSOCB, it means that gassing did not occur even though the battery was charged to the optimal value TSOC calculated during the previous run.In other words, the battery was not charged in the region where the charging efficiency was 100%. This means that it has been charged. Therefore, it can be determined that the optimum value TSOCB calculated during the previous run was less than the actual optimum value. Therefore, in step 706, the current optimum value TSOC is changed to the previous optimum value TSOC.
It is revised upward to OCB+γ. This correction value γ is 1 [
A fixed value such as Ah] or a value calculated according to the state of charge may be used.

The optimal value TSOC calculated as described above is
As described in the first embodiment, the upper limit capacity is VI0,
When the vehicle is running, the battery 1 is
is charged. Here, also in the second embodiment, the first
As described in the embodiment, when the second battery capacity VI2 reaches the optimum value TSOC (in the second embodiment, the upper limit capacity VI0), the charging current to the battery 1 is reduced to zero.
Since it is assumed that the control is performed as follows, the optimum value TSOC is corrected as described above. However, for example, if the configuration is such that the second battery capacity VI2 can still be charged even if it reaches the optimum value TSOC, then the second battery capacity VI2 at the time of the previous run
2 exceeds the previously determined optimal value TSOCB, and the current calculated invalid charge capacity GSOC is 0. In this case, it can be determined that the optimum value TSOCB calculated during the previous run was smaller than the actual optimum value, so the current optimum value TSOC is set to, for example, the maximum value PSOCB of the second battery capacity VI2 during the previous run, or PSOCB+γ ' may be corrected to replace it with '.

On the other hand, in step 703, PSOCB<T
If SOCB is determined, the current optimum value TSOC is set to the previous optimum value TSOCB. The device of this embodiment is configured to calculate the optimal value independently each time when the invalid charging capacity GSOC due to gassing is detected, but since there are measurement errors etc. in an actual vehicle, It is also effective to use a method such as weighting and averaging the optimal value TSOCB.

Up to this point, the description has been made based on an approximation of the charging efficiency characteristics of the battery as shown in FIG. However, in reality, as shown in FIG. 18, the charging efficiency gradually decreases from near the maximum capacity of the battery (about 80% of the maximum capacity). Therefore, book 2
According to the embodiment, the calculated optimal value TSOC is a value between the battery capacity at the point (L or L') where the charging efficiency begins to decrease and the maximum capacity. However, the difference between the battery capacity at the point where charging efficiency begins to decrease (L or L') and each maximum capacity is 20% (4 to 6%) of the rated capacity.
[Ah]). Therefore, if this is taken into consideration, the maximum capacity can be easily calculated.

[0080] The second battery capacity VI2 is the optimum value TS
In the control to prevent OC from being exceeded, if the optimum value TSOC is repeatedly calculated as the vehicle repeatedly travels, the optimum value TSOC will be determined at the point where no gassing occurs (charging efficiency is 100%). It converges to a certain point (point L or point L' in FIG. 18). In other words, the optimal value TSOC is
This indicates the maximum capacity at which the battery can be charged at 100% charging efficiency. Therefore, the battery capacity is set to the optimal value TS
When the battery is below the OC, gassing does not occur when charging the battery, and the second battery capacity calculated from the integrated value of the battery's charging and discharging current is accurate without including errors due to gassing. This method has the advantage of being able to calculate the battery capacity. In addition, even if control is performed to charge the battery above the optimum value TSOC, it is known that the efficiency decreases in the region above the optimum value TSOC. If the configuration is configured to perform this, it is possible to maintain the integration accuracy without deteriorating it.

As described above, when the upper limit capacity VI0 is calculated in step 70, the initial values of each variable are set in step 150. Here, the initial capacity VI4 obtained in step 60 is changed to the second battery capacity VI4 during driving.
2 and substituted as the initial value of the maximum value PSOC.

Steps 80 to 120 showing control during running are the same as shown in the first embodiment, and their explanation will be omitted. However, in the second embodiment, the second battery capacity VI2 of the battery 1 during running is the optimum value T.
When the SOC is reached, the battery is not charged because the control charging current IBC and the control voltage VBC are set to those shown in Tables 2 and 3 at the time of full charge. Therefore,
Battery 1 is always charged in the region where the charging efficiency is 100%, so gassing does not occur, and the integrated value of charging current does not include invalid charging capacity.
Capacity detection accuracy is greatly improved. Also, step 11
The dead battery warning at 0 can also be issued when the optimum value TSOC drops to a certain value (for example, 30% of the rated capacity).

Step 160 is to store the maximum value of the second battery capacity VI2 during driving as PSOC in the battery capacity monitor section 9g, and the maximum value PSOC of the second battery capacity VI2 that changes every moment. is always remembered. Step 170 has a calculation period of 10 [m
s].

When it is determined in step 120 that the key switch is turned off, in step 130, the final value of the second battery capacity VI2 and the second battery capacity VI2 are determined.
The maximum value PSOC and the optimal value TSOC of
Third battery capacity VI3, PSOCB and TS
It is stored in the battery capacity monitor section 9g as OCB in preparation for the next run.

As described above, in the second embodiment of the device of the present invention, since the maximum capacity of the battery is always known, overcharging is prevented by not charging beyond the maximum capacity, and Battery deterioration and lifespan can be easily determined. Furthermore, since the optimal value is calculated as the limit capacity where the charging efficiency is 100%, the battery will not be charged in the region where the charging efficiency decreases, and the accurate battery capacity can be calculated using the integrated value of the battery charging and discharging current. I can do it.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing first and second embodiments of a vehicle charging control device using a battery state detection device of the present invention.

FIG. 2 is a block diagram showing processing functions of a control circuit in each of the above embodiments.

FIG. 3 is a flowchart showing processing within the control circuit in the first embodiment.

FIG. 4 is a characteristic diagram showing the characteristics of battery voltage with respect to battery capacity when the battery is discharged.

FIG. 5 is a characteristic diagram showing the characteristics of charging efficiency with respect to battery capacity when charging a battery.

FIG. 6 is a characteristic diagram showing the integrated amount of battery charging current with respect to the battery capacity when charging the battery.

FIG. 7 is a battery state indication diagram showing battery states divided into four categories according to their capacities.

FIG. 8 is a flowchart showing step 30 of FIG. 3 in detail.

FIG. 9 is a flowchart showing step 40 of FIG. 3 in detail.

10 is a configuration diagram showing in detail the generator 5 shown in FIG. 1 and the power generation control section 9f shown in FIG. 2. FIG.

FIG. 11 is a flowchart showing processing by the conductivity control circuit 9f3 during normal running.

FIG. 12 is a flowchart showing processing by the conduction rate control circuit 9f3 during idling.

FIG. 13 is a flowchart showing processing by the control circuit 9 during acceleration, deceleration, and downhill.

FIG. 14 is a flowchart showing processing within the control circuit in the second embodiment.

FIG. 15 is a flowchart showing step 70 of FIG. 13 in detail.

FIG. 16 is a characteristic diagram showing changes in battery capacity.

FIG. 17 is an approximate characteristic diagram that approximates the characteristics of charging efficiency with respect to battery capacity when charging a battery.

FIG. 18 is a characteristic diagram of charging efficiency versus battery capacity when charging a battery.

[Explanation of symbols]

1 Battery 2 Engine 3 Starter 4 Starter switch 5 Generator 6 Current detector 7 Temperature detector 9 Control circuit

Claims (8)

[Claims] 1. A starter driven by an on-vehicle battery to start an engine, a vehicle generator driven by the engine to charge the battery, and a battery current detection means for detecting charging/discharging current of the battery. A battery voltage detection means for detecting a terminal voltage of the battery, a battery current integration means for integrating charging and discharging current of the battery detected by the battery current detection means, and a capacity of the battery at the time of starting the engine. a first battery capacity detection means, and the first battery capacity detected by the first battery detection means is added to the battery current integration after the first battery capacity detection, which is detected by the battery current integration means. a second battery capacity detecting means which adds a value to detect the second battery capacity after starting the engine; the first battery capacity detected this time; and the second battery capacity immediately before detecting the first battery capacity; target value setting means for setting a charging target value for the battery after starting the engine based on a comparison result with a battery capacity of the battery; A vehicle charging control device comprising: power generation control means for controlling the amount of power generated by the vehicle generator. 2. A starter driven by an on-vehicle battery to start the engine, a vehicle generator driven by the engine to charge the battery, and a battery current detection means for detecting charging/discharging current of the battery. battery voltage detection means for detecting the terminal voltage of the battery; battery current integration means for integrating the charge/discharge current of the battery detected by the battery current detection means; and the starter drive detected by the battery current detection means. When the discharge current of the battery is a predetermined value,
a first battery capacity detection means for detecting a first battery capacity at the time of starting the engine based on the voltage of the battery detected by the battery voltage detection means; initial capacity setting means for setting an initial capacity of the battery based on the first battery capacity determined by the first battery; a second battery capacity detection means that adds the battery current integrated value after the capacity detection and detects it as a second battery capacity after the engine starts;
The initial capacity setting means includes a first capacity setting means detected this time.
The battery capacity of the first battery is compared with the second battery capacity immediately before detecting the first battery capacity, and the smaller value is set as the initial capacity. target value setting means for setting a charging target value of the battery after starting the engine according to a set initial capacity; and charging the battery to the target value set by the target value setting means. A vehicle charging control device comprising: power generation control means for controlling the amount of power generated by the vehicle generator. 3. The vehicle charging control device according to claim 2, wherein the target value setting means adds a capacity increment value set according to the initial capacity to the initial capacity to obtain the target value. 4. A starter driven by an on-vehicle battery to start the engine, a vehicle generator driven by the engine to charge the battery, and a battery current detection means for detecting charging/discharging current of the battery. A battery voltage detection means for detecting a terminal voltage of the battery, a battery current integration means for integrating charging and discharging current of the battery detected by the battery current detection means, and a capacity of the battery at the time of starting the engine. a first battery capacity detection means, and a first battery capacity detected by the first battery capacity detection means, and a battery current detected by the battery current integration means after the first battery capacity detection. a second battery capacity detection means which adds an integrated value and detects it as a second battery capacity after starting the engine; the first battery capacity detected this time; and the second battery capacity detected immediately before detecting the first battery capacity As a result of comparing the second battery capacity with the second battery capacity, when it is determined that the second battery capacity is larger, the value of the difference between the first and second battery capacities is detected as an invalid charging capacity, and this invalid charging capacity is detected. target value setting means for setting a target charging value of the battery after starting the engine according to the charging capacity;
A vehicle charging control device comprising: generator control means for controlling the amount of power generated by the vehicle generator so as to charge the battery to a target value set by the target value setting means. 5. A starter driven by an on-vehicle battery to start the engine, a vehicle generator driven by the engine to charge the battery, and a battery current detection means for detecting charging/discharging current of the battery. battery voltage detection means for detecting the terminal voltage of the battery; battery current integration means for integrating the charge/discharge current of the battery detected by the battery current detection means; and the starter drive detected by the battery current detection means. When the discharge current of the battery is a predetermined value,
a first battery capacity detection means for detecting a first battery capacity at the time of starting the engine based on the voltage of the battery detected by the battery voltage detection means; initial capacity setting means for setting an initial capacity of the battery based on the first battery capacity determined by the first battery; a second battery capacity detection means that adds the battery current integrated value after the capacity detection and detects it as a second battery capacity after the engine starts;
The initial capacity setting means includes a first capacity setting means detected this time.
The battery capacity of the first battery is compared with the second battery capacity immediately before detecting the first battery capacity, the smaller value is set as the initial capacity, and the first and second battery capacities are compared. When the second battery capacity has a larger value, the difference between the first and second battery capacities is detected as an invalid charge capacity, and the charge capacity is determined after the engine is started according to this invalid charge capacity. a target value setting means for setting a charging target value of the battery; and a target value setting means for charging the battery to the target value set by the target value setting means.
A vehicle charging control device comprising: generator control means for controlling the amount of power generated by the vehicle generator. 6. The target value setting means sets the target value by subtracting the invalid charge capacity from the maximum value of the second battery capacity immediately before detecting the first battery capacity. Item 5. The vehicle charging control device according to item 5. 7. The target value setting means, when detecting that the invalid charge capacity is zero, sets the previously set target value as the current target value. The vehicle charging control device described above. 8. The target value setting means is configured such that the invalid charge capacity is zero and the maximum value of the second battery capacity immediately before detecting the first battery capacity is a previously set target value. 6. The vehicle charging control device according to claim 5, wherein when a larger value is detected, a predetermined value is added to the previously set target value to obtain the target value.