JP2003111204A - Charge and discharge control method for hybrid car power source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate capacity variations without adversely affecting the running of the hybrid car or shortening the life of the battery. SOLUTION: The charge and discharge control method consists of dividing the driving secondary batteries 8 into a plurality of battery units, and at the same time controlling the charge and discharge of the driving secondary batteries 8 so that the relative residual capacities of the battery units of the driving secondary batteries 8 as a whole are in the charge and discharge permissible region. The charge and discharge permissible region has a normal mode region and a capacity difference eliminating mode region; the maximum value of the capacity difference eliminating mode region is 100% or less and larger than the maximum value of the normal mode region. The charge and discharge control method detects the difference in relative residual capacities of the plurality of battery units. When this difference exceeds the set value, the charge and discharge permissible region is changed from the normal mode region to the capacity difference eliminating mode region to perform charge and discharge, thereby reducing the difference in relative residual capacities of the battery units.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging / discharging control method for a power supply device mounted on a hybrid car that runs on both a motor and an engine.

[0002]

2. Description of the Related Art A hybrid car runs while rotating a generator with an installed engine to charge a drive secondary battery. The secondary battery for driving is discharged by supplying electric power to a motor and charged by a generator driven by an engine. The drive secondary battery is charged / discharged while controlling the relative remaining capacity within the charge / discharge allowable region. In the hybrid car, the charge / discharge allowable region is set to 30 to 70%, for example. The reason why charging and discharging are performed while controlling the relative remaining capacity within this range is to extend the life of the driving secondary battery as much as possible. The drive secondary battery charged and discharged within this range is prevented from overcharging and overdischarging, and is charged and discharged within a range in which deterioration of the battery can be minimized.

By the way, in a power supply device mounted on a hybrid car, a plurality of battery units are connected in series in order to increase the output. The battery units connected in series are charged and discharged with the same current. Therefore, in principle, the relative remaining capacities of the respective battery units should be the same. However, in reality, the relative remaining capacities of the battery units vary. This occurs because it is not possible to manufacture all the battery units to have exactly the same characteristics, and it is not possible to make the usage environment of the plurality of battery units, especially the ambient temperature, the same. When a large number of battery units are used and the relative remaining capacity varies, a battery unit with a large relative remaining capacity is in a state close to overcharge, and a battery unit with a small relative remaining capacity is in a state close to overdischarge. . The battery unit in this state is liable to deteriorate and shortens the battery life.

[0004]

In order to eliminate this adverse effect, the following three methods have been developed as control methods for eliminating the variation of each battery unit. The first method changes the charge / discharge current of each battery unit to make the relative remaining capacity uniform. In this method, for example, a bypass circuit is connected to a battery unit with a large capacity to reduce the charging current, or a discharge circuit is connected to a battery unit with a large capacity to discharge this battery unit. Reduce the capacity. This method
Since the charging / discharging current is controlled for each battery unit, the circuit becomes complicated and the charging / discharging control becomes complicated.

In the second method, the relative remaining capacity of the battery unit is reduced to 1 by charging until the relative remaining capacity exceeds 100%.
Align to 00%. This method has the biggest drawback that the battery life is shortened because the battery unit is overcharged.
The secondary battery for driving a hybrid car is extremely expensive because it is composed of an extremely large number of batteries. Therefore, it is extremely important how to use it for a long period of time. Therefore, the control for shortening the life is the most harmful effect to this type of battery control. Further, this method has a drawback that the battery becomes hot when the variation in capacity is reduced.

The third method, like the second method,
After charging to more than 100% to make the capacity of the battery unit uniform to 100%, the battery unit is forcibly discharged to reduce the capacity to, for example, about 60%. This method forcibly discharges and reduces the capacity to 60%, so charging of the battery is prohibited at this time. Therefore, there is an adverse effect of restricting the traveling of the hybrid car, such as being unable to decelerate by regenerative braking. Furthermore, this method charges all the battery units up to more than 100% and then forcibly discharges them until the capacity reaches 60%, so it takes time to eliminate the variation in capacity, and this time zone At
There is a drawback that the control that gives priority to the running of the hybrid car cannot be performed.

The present invention was developed for the purpose of solving such drawbacks. An important object of the present invention is to charge and discharge a drive secondary battery so that the hybrid car can be prioritized to run, so that the capacity variation of the hybrid car can be eliminated without adversely affecting the running of the hybrid car. Another object of the present invention is to provide a charge / discharge control method. Another important object of the present invention is to provide a charging / discharging control method for a power supply device of a hybrid car, which can eliminate the capacity variation while preventing overcharging of the battery and eliminate the capacity variation without shortening the battery life. To provide. Furthermore, another important object of the present invention is to reduce the temperature of the battery as compared with the method of overcharging and eliminating the capacity variation, and further, the output of the driving secondary battery after eliminating the capacity variation. It is an object of the present invention to provide a charging / discharging control method for a power supply device of a hybrid car capable of minimizing the deterioration. Further, there is provided a charge / discharge control method for a power supply device of a hybrid car, in which it is not necessary to individually control charge / discharge of a large number of battery units, and both a circuit and a control method for controlling charge / discharge can be simplified to reduce capacity variations. Especially.

[0008]

According to a charge / discharge control method for a power supply device of a hybrid car of the present invention, a plurality of batteries are connected in series to drive a traveling motor.
Is divided into a plurality of battery units, and the charging / discharging of the driving secondary battery 8 is controlled so that the relative remaining capacity of the battery unit or the entire driving secondary battery 8 falls within a preset charge / discharge allowable region. . Further, the charge / discharge control method of the present invention is provided with the normal mode region and the capacity difference elimination mode region as the charge / discharge allowable region. In the capacity difference elimination mode area, the maximum value is set to 100% or less and larger than the maximum value in the normal mode area. The charging / discharging control method detects a difference in relative remaining capacities of a plurality of battery units, and when the difference in relative remaining capacities of the battery units becomes larger than a set value, a charging / discharging control of the driving secondary battery 8 is performed. The discharge allowable area is changed from the normal mode area to the capacity difference elimination mode area for charging and discharging to reduce the difference between the relative remaining capacities of the battery units.

In the charge / discharge control method of the present invention, one battery module 1 in which a plurality of unit cells are connected in series can be used as one battery unit. Furthermore, in the charging / discharging control method, a plurality of battery modules 1 in which a plurality of unit cells are connected in series are made into one battery unit, or the unit cells constituting the battery module 1 are made into one battery unit. You can also

Furthermore, the charge / discharge control method of the present invention detects the relative remaining capacity of the entire drive secondary battery 8 so that the relative remaining capacity of the entire drive secondary battery 8 falls within the charge / discharge allowable range. The charging / discharging of the driving secondary battery 8 can be controlled. Further, the charge / discharge control method detects the relative remaining capacities of a plurality of battery units, and controls the charging / discharging of the drive secondary battery 8 so that the relative remaining capacities of all the battery units fall within the charge / discharge allowable region. You can also Furthermore, the charging / discharging control method calculates an average value of the detected relative residual capacities of the plurality of battery units, and charges the driving secondary battery 8 so that the calculated average relative residual capacity falls within the charge / discharge allowable region. The discharge can also be controlled.

The normal mode area has a minimum capacity of 20-40.
%, And the maximum capacity can be set to 60 to 80%.
In the capacity difference elimination mode area, the lowest value can be set to the highest value in the normal mode area.

Further, the charging / discharging control method detects the difference in the relative remaining capacities of the respective battery units, and when the difference in the relative remaining capacities becomes smaller than a set value, the charging / discharging for charging / discharging the drive secondary battery 8 is performed. The allowable area can be switched from the capacity difference elimination mode area to the normal mode area. Further, in the charging / discharging control method, the time for charging / discharging the drive secondary battery 8 can be set with a timer by setting the charging / discharging allowable region as the capacity difference elimination mode region.

Further, the charge / discharge control method detects the battery temperature, and only when the battery temperature is lower than the set temperature,
The charge / discharge allowable region can be switched from the normal mode region to the capacity difference elimination mode region. Furthermore, when the ignition switch of the hybrid car is turned on, the charge / discharge control method switches the charge / discharge allowable region from the normal mode region to the capacity difference elimination mode region to charge / discharge the drive secondary battery 8. You can also

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a charge / discharge control method for embodying the technical idea of the present invention, and the present invention does not specify the charge / discharge control method as the following method.

Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "claims" and "to solve the problems." It is added to the members shown in "Means column".
However, the members shown in the claims are not limited to the members of the embodiment.

FIG. 1 is a circuit diagram of a power supply device mounted on a hybrid car. This power supply device includes a drive secondary battery 8 for driving a motor that drives a hybrid car.
Equipped with. The drive secondary battery 8 has a plurality of battery modules 1 connected in series in order to increase the output voltage.
The battery module 1 has a plurality of unit cells connected in series. The unit cell is a nickel-hydrogen battery or a lithium ion secondary battery. However, a lead battery or a nickel-cadmium battery can also be used for this unit cell. In the power supply device shown in the figure, a plurality of battery modules 1 are connected in series to form a driving secondary battery 8.

In the charge / discharge control method of the present invention, the drive secondary battery 8 is divided into a plurality of battery units, and the charge / discharge is controlled so that the relative remaining capacities of the battery units are equalized.
One battery unit is composed of one or a plurality of unit cells. A battery unit composed of a plurality of unit cells is preferably one battery module 1. That is, one battery module 1 is used as one battery unit, and charging / discharging is performed so that the relative remaining capacities of the battery units are made uniform. However, it is also possible to control the plurality of battery modules as one battery unit so that the relative remaining capacities of the battery units are made uniform.

In the power supply device shown in the figure, one battery module 1 is used as one battery unit to detect the relative remaining capacity. The plurality of battery modules 1 connected in series are
Even if the charging and discharging currents are the same, the relative remaining capacities are not necessarily the same. This is because the temperature environment and the like used by the battery module 1 are different, and the maximum capacity that can be charged, the efficiency of charging and discharging, and the like change due to this. Although not shown, an apparatus using a plurality of battery modules as one battery unit detects the relative remaining capacity with the plurality of battery modules as one.

The power supply device shown in the figure is used for each battery module 1
A sensor (not shown) for detecting the voltage and the temperature in each battery module 1 in order to detect the relative remaining capacity of
And an arithmetic circuit 2 for detecting the relative remaining capacity.
The arithmetic circuit 2 transmits the detected voltage, temperature, and calculated relative remaining capacity to the control 3 via the communication bus 4. The arithmetic circuit 2 calculates the relative remaining capacity of each battery module 1 and transmits the calculated relative remaining capacity to the control 3 via the communication bus 4. The arithmetic circuit 2 calculates the relative remaining capacity from the charge capacity, the discharge capacity, and the maximum charge capacity, as shown by the following equation. Relative remaining capacity = (Charging capacity−Discharging capacity) × 100 / Maximum charging capacity The charging capacity is calculated by multiplying the integrated value of the charging current by the charging efficiency. The discharge capacity is calculated by multiplying the integrated value of the discharge current by the discharge efficiency. The maximum charge capacity is the maximum capacity that can be charged in the battery unit. The maximum charge capacity decreases as the battery unit deteriorates. Therefore, it is corrected by the number of times of charging / discharging or the elapsed time, or by the charging capacity from the lowest voltage to the highest voltage.

The arithmetic circuit 2 can also detect the voltage of the battery unit to detect the relative remaining capacity. Since the voltage decreases as the relative remaining capacity decreases, the voltage of the battery unit can be detected to calculate the relative remaining capacity. Further, as shown by the above-described calculation formula, the relative remaining capacity calculated from the charge capacity and the discharge capacity can be corrected when the predetermined voltage is reached, and the relative remaining capacity can be detected most accurately. Therefore, the charge / discharge control method of the present invention does not specify a method for detecting the relative remaining capacity of the battery unit. The relative remaining capacity of the battery unit can be detected by all the methods that are currently adopted, or can be detected by the method that will be developed.

The arithmetic circuit 2 converts the detected voltage and temperature and the calculated relative remaining capacity into a digital signal and outputs it on the communication bus 4. Therefore, it has a built-in A / D converter that converts voltage and temperature into digital signals. The A / D converter converts the detected analog signal into a digital signal and transmits it to the control 3. The arithmetic circuit 2 converts the detected signal into a digital signal to calculate the relative remaining capacity and transmits the calculated relative remaining capacity to the control 3 at a constant sampling cycle. The sampling period is preferably 100 msec. However, the sampling period may be set to 10 msec to 1 sec. The arithmetic circuit 2 does not have to detect the voltage or temperature at a constant sampling cycle. For example, it is possible to shorten the sampling cycle when the hybrid car is running and lengthen the sampling cycle when the hybrid car is not running to reduce unnecessary power consumption.

Since the battery modules 1 are connected in series, the flowing currents are the same. Therefore, the power supply device in the figure is provided with one current detection circuit 5. This current detection circuit 5 also has a built-in A / D converter. The detected current signal is converted into a digital signal and transmitted to the arithmetic circuit 2 and the control 3 via the communication bus 4. This A / D converter also converts the current signal into a digital signal at a predetermined sampling cycle. When the hybrid car is running, the current flowing in the battery is
It fluctuates greatly in a short time. Therefore, the current detection circuit 5 has a sampling period as short as possible, for example, 1
At a cycle of 00 msec, the current signal is converted into a digital signal and transmitted to the control 3. Furthermore, the sampling cycle can be shortened.

The control 3 shown in the drawing is a battery ECU 7
And a vehicle side control 6. The control 3 controls the charging / discharging of the driving secondary battery 8 so that the relative remaining capacity transmitted from each arithmetic circuit 2 is in the charging / discharging allowable region. The control 3 charges and discharges the drive secondary battery 8 in either the normal mode or the capacity difference elimination mode. The normal mode is a mode in which the hybrid car runs normally. The capacity difference elimination mode is a mode in which charging / discharging is performed when the difference between the relative remaining capacities of the battery units exceeds a predetermined value, and is a charging / discharging mode in which the difference between the relative remaining capacities of the battery units is reduced.

The control 3 changes the charge / discharge allowable area in the normal mode and the capacity difference elimination mode. Figure 2
Shows the normal mode area and the capacity difference elimination mode area. In this figure, the normal mode area is 30 to 70%, and the capacity difference elimination mode area is 70 to 100%. The control 3 for setting the charge / discharge allowable region to this range controls charge / discharge so that the relative remaining capacity is 30 to 70% in the normal mode, and the relative remaining capacity is 70 to 70% in the capacity difference elimination mode. The charge / discharge is controlled so that it becomes 100%. In the capacity difference elimination mode, the maximum value in the charge / discharge allowable area is set to be larger than the maximum value in the normal mode area in order to reduce the capacity difference. Further, in FIG. 2, the minimum value in the capacity difference elimination mode region is set as the maximum value in the normal mode region. By setting the capacity difference elimination mode region in this manner, the capacity difference can be eliminated promptly. However, the minimum value of the capacity difference elimination mode region can be made smaller than the maximum value of the normal mode region. When the capacity difference elimination mode area is set to this area, the capacity capable of substantially charging and discharging the drive secondary battery 8 in the capacity difference elimination mode can be increased.

The charging efficiency of the battery unit decreases as it is charged to nearly 100%. Therefore, 1
When the battery unit is charged to near 00%, the charging efficiency of the battery unit having a large relative remaining capacity becomes lower than the charging efficiency of the battery unit having a small relative remaining capacity. Therefore, as shown in FIG. 2, the capacity difference of the battery unit is reduced by charging and discharging in the capacity difference elimination mode region. Note that FIG.
Shows a change in the relative remaining capacity of the battery unit having a large relative remaining capacity with a solid line and a change in the relative remaining capacity of the battery unit with a small relative remaining capacity with a chain line.

FIG. 2 shows the capacity difference elimination mode areas 70-1.
Although set to 00%, the capacity difference elimination mode region has a maximum value of 100% or less, and can be set to be larger than the maximum value of the normal mode region to reduce the capacity difference. The maximum value is set to 100% or less in order to prevent deterioration of battery performance due to overcharge. Further, the reason why the maximum value is made larger than the maximum value in the normal mode area is to charge deeper and reduce the capacity difference. Further, in FIG. 2, the normal mode area is set to 30 to 70%, but the normal mode area has a minimum value of 20 to 40% and a maximum value of 60 to 8%.
It can be 0%. When the minimum value and the maximum value of the normal mode area are increased and the range is increased, the capacity capable of substantially charging and discharging the drive secondary battery 8 increases. However, widening this range shortens the life of the drive secondary battery 8. Therefore, the normal mode region is set to an optimum value in consideration of the life and discharge capacity of the driving secondary battery 8.

The control 3 detects the relative remaining capacity of the drive secondary battery 8 and controls charging / discharging so that the detected relative remaining capacity falls within the charge / discharge allowable range. At this time, the control 3 preferably detects the relative remaining capacities of the plurality of battery units separately, and the driving secondary battery 8 is set so that the relative remaining capacities of all the battery units are within the charge / discharge allowable region.
Control the charging and discharging of. In this control method, the relative remaining capacity of any battery unit does not go out of the charge / discharge allowable region. Therefore, the deterioration of the battery unit can be minimized. However, the charge / discharge control method of the present invention detects the relative remaining capacities of a plurality of battery units, calculates the average value of the relative remaining capacities of the detected battery units, and the calculated average relative remaining capacity is the charge / discharge allowable value. It is also possible to control the charging / discharging of the driving secondary battery 8 so as to be within the range. Further, the relative remaining capacity of the entire driving secondary battery 8 is detected so that the relative remaining capacity of the entire driving secondary battery 8 falls within the charge / discharge allowable region,
It is also possible to control the charging / discharging of the driving secondary battery 8.

The control 3 switches the charging / discharging mode from the normal mode to the capacity difference elimination mode when the capacity difference of the battery unit becomes larger than the set value. When charging / discharging is performed in the capacity difference elimination mode and the capacity difference of the battery unit becomes less than the set value, or when a predetermined time has elapsed, the capacity difference elimination mode is switched to the normal mode and the drive secondary battery 8 is operated in the normal state. Charge and discharge.

FIG. 3 shows a flowchart in which the control reduces the capacity difference of the battery units. This method reduces the capacity difference of the battery units as follows. [Step n = 1] The control 3 charges and discharges the driving secondary battery 8 in the normal mode. [Step n = 2] The control 3 determines whether or not the capacity difference between the battery units is larger than the set value. If the capacity difference is smaller than the set value, this step is looped. [Step n = 3] When the capacity difference of the battery unit becomes larger than the set value, the normal mode is switched to the capacity difference elimination mode in this step. [Steps of n = 4 to 5] The charge / discharge allowable region in the capacity difference elimination mode is larger than the normal mode region. Therefore,
In this step, the drive secondary battery 8 is charged,
The relative remaining capacity of each battery unit or the entire drive secondary battery 8 is set as the capacity difference elimination mode region. [Step n = 6] The drive secondary battery 8 is charged / discharged in the capacity difference elimination mode. In the battery unit charged and discharged in the capacity difference elimination mode, the capacity difference gradually decreases as shown by the solid line and the chain line in FIG. [Step n = 7] It is determined whether or not the battery unit capacity difference becomes smaller than a set value. The step of n = 6 is looped until the capacity difference of the battery unit becomes smaller than the set value. In this step, the capacity difference of the battery unit is detected and the capacity difference elimination mode is terminated, so that the capacity difference of the battery unit can be reliably reduced. However, in the present invention, the capacity difference elimination mode can be ended by a timer.
This timer is used to drive the secondary battery 8 in the capacity difference elimination mode.
The time to charge and discharge is stored. This method switches the capacity difference resolution mode to the normal mode when the timer is set up. [Step n = 8] When the capacity difference of the battery unit becomes smaller than the set value, the capacity difference elimination mode is switched to the normal mode. [Step of n = 9 to 10] Since the charge / discharge allowable area in the normal mode is smaller than that in the capacity difference elimination mode, the drive secondary battery 8 is discharged, and the battery unit or the drive secondary battery 8 as a whole is relatively discharged. The remaining capacity is set as the normal mode area. In other words, discharging is performed until the relative remaining capacity reaches the normal mode region.

[0030]

The charging / discharging control method of the present invention is characterized in that it can ideally eliminate the capacity variation of the driving secondary battery. That is, when the charging / discharging control method of the present invention divides the driving secondary battery into a plurality of battery units and detects a difference in relative remaining capacities of the plurality of battery units, the difference becomes larger than a set value. This is because the charge / discharge allowable area is changed from the normal mode area to the capacity difference elimination mode area for charging / discharging. In the charge / discharge control method of the present invention, the maximum value in the capacity difference elimination mode region is set to 100% or less and larger than the maximum value in the normal mode region. That is, the capacity difference elimination mode region is set to a region higher than the normal mode region. The battery unit has a characteristic that the charging efficiency decreases as it is charged to nearly 100%. Therefore, by charging in the capacity difference elimination mode area,
A battery unit with a large relative remaining capacity has a lower charging efficiency than a battery unit with a small relative remaining capacity, and the capacity difference between these battery units is small. As described above, the charge / discharge control method of the present invention can eliminate the capacity variation of a plurality of battery units by extremely simple control of changing the charge / discharge allowable area from the normal mode area to the capacity difference elimination mode area.

As described above, since the charge / discharge control method of the present invention can eliminate the variation in capacity without overcharging the battery, it does not adversely affect the running of the hybrid car, in other words, the running of the hybrid car. It has the feature that charge and discharge can be controlled while giving priority to. Further, since the charge / discharge control method of the present invention does not overcharge the battery, there is also a feature that the output temperature of the driving secondary battery after eliminating the capacity variation can be minimized without raising the battery temperature to a high temperature. . Furthermore, a battery that is not overcharged has the feature that the battery life can be extended. The ability to extend the battery life is extremely important for a secondary battery for driving a hybrid car, which is composed of an extremely large number of batteries.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a power supply device mounted on a hybrid car used in a charge / discharge control method according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state in which a battery unit is charged and discharged in a capacity difference elimination mode region.

FIG. 3 is a flowchart showing a process of reducing the difference in capacity between battery units.

[Explanation of symbols]

1 ... Battery module 2 ... Operation circuit 3 ... Control 4 ... communication bus 5 ... Current detection circuit 6 ... Car side control 7 ... Battery ECU 8 ... Drive secondary battery

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02J 7/00 H02J 7/00 302C 302 7/02 H 7/02 B60K 9/00 E (72) Inventor Atsushi Terachi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. F term (reference) 2G016 CA03 CB12 CC04 CC26 5G003 AA07 BA03 CA01 CA11 DA12 DA13 EA05 FA06 5H030 AA01 AS08 BB01 BB10 BB21 FF41 FF42 FF43 FF43 FF 5H115 PA08 PC06 PG04 PI14 PI16 PI22 QN03 SE06 TI01 TI05 TI06 TI10 TR19 TU20 TZ01

Claims (13)

[Claims] 1. A drive secondary battery (8) for driving a traveling motor, which is formed by connecting a plurality of batteries in series, is divided into a plurality of battery units, and the battery unit or the drive secondary battery (8) is also provided. In the charging / discharging control method of the hybrid car power supply device, which controls the charging / discharging of the driving secondary battery (8) so that the overall relative remaining capacity falls within the preset charging / discharging allowable range, , A normal mode area and a capacity difference resolution mode area are provided, and the maximum value of the capacity difference resolution mode area is
If the difference between the relative remaining capacities of a plurality of battery units is detected and the difference between the relative remaining capacities of a plurality of battery units becomes larger than the set value, the drive is set Charging / discharging allowable area for controlling charging / discharging of the secondary battery (8) is changed from the normal mode area to the capacity difference elimination mode area for charging / discharging to reduce the difference in relative remaining capacity of each battery unit. A charging / discharging control method for a power supply device of a hybrid car, comprising: 2. The charge / discharge control method for a power supply device of a hybrid car according to claim 1, wherein one battery module (1) in which a plurality of unit cells are connected in series is used as one battery unit. 3. The charge / discharge control method for a power supply device of a hybrid car according to claim 1, wherein a plurality of battery modules (1) in which a plurality of unit cells are connected in series are used as one battery unit. 4. The charging / discharging control method for a power supply device of a hybrid car according to claim 1, wherein the unit cells constituting the battery module (1) are one battery unit. 5. A secondary battery for driving, which detects a relative residual capacity of the entire secondary battery for driving (8) so that the relative residual capacity of the entire secondary battery (8) for driving falls within a charge / discharge allowable region. The charge / discharge control method for a power supply device of a hybrid car according to claim 1, wherein the charge / discharge of (8) is controlled. 6. The charging / discharging of the driving secondary battery (8) is controlled so that the relative remaining capacities of a plurality of battery units are detected and the relative remaining capacities of all the battery units fall within a charge / discharge allowable region. 1. A charge / discharge control method for a power supply device for a hybrid car according to 1. 7. A drive for detecting relative remaining capacities of a plurality of battery units, calculating an average value of the detected relative remaining capacities of the battery units, and driving the calculated average relative remaining capacities to fall within a charge / discharge allowable region. The charge / discharge control method for a power supply device for a hybrid car according to claim 1, wherein the charge / discharge of the secondary battery (8) is controlled. 8. The minimum capacity of the normal mode area is 20-40.
%, And the maximum capacity is 60-80%. The charge / discharge control method for a power supply device of a hybrid car according to claim 1. 9. The charge / discharge control method for a power supply device of a hybrid car according to claim 1, wherein the minimum value of the capacity difference elimination mode region is set to the maximum value of the normal mode region. 10. A charging / discharging permissible region for charging / discharging the driving secondary battery (8) is detected when a difference in relative remaining capacities of the respective battery units is detected, and when the difference in relative remaining capacities becomes smaller than a set value. The charge / discharge control method for a power supply device of a hybrid car according to claim 1, wherein the capacity difference elimination mode region is switched to the normal mode region. 11. The charging / discharging device for a hybrid car according to claim 1, wherein a time for charging / discharging the drive secondary battery (8) is set by using a charge / discharge allowable region as a capacity difference elimination mode region. Discharge control method. 12. The hybrid car according to claim 1, wherein the battery temperature is detected, and the charge / discharge allowable region is switched from the normal mode region to the capacity difference elimination mode region only when the battery temperature is lower than the set temperature. Charge / discharge control method for power supply device. 13. The charging / discharging allowable area is switched from the normal mode area to the capacity difference elimination mode area when the ignition switch of the hybrid car is turned on to charge / discharge the drive secondary battery (8). A charging / discharging control method for a power supply device of a hybrid car described in.