JPH08106928A - Remaining capacity meter for automobile batteries - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to accurately display the remaining capacity even when the battery has deteriorated. [Structure] The amount of electricity consumed by the battery is obtained by accumulating the output of the ammeter in the amount of electricity calculation unit, and the amount of consumed electricity is subtracted from the fully charged capacity of the battery in the remaining capacity display control unit to obtain the remaining capacity. , Converted to the ratio to the capacity when fully charged,
The remaining capacity display section displays the remaining capacity of the battery as a ratio to the fully charged capacity. Then, at the time of this display, the deterioration degree calculation unit calculates the deterioration degree with respect to the output power when the battery is new, and the remaining capacity correction unit calculates the deterioration degree according to the battery deterioration degree.
The ratio of the remaining capacity to the capacity when the battery is fully charged is set to be small and given to the remaining capacity display control unit as a display correction. As a result, the remaining capacity display unit can display the remaining capacity in a small amount in accordance with the deterioration of the battery, and the accurate remaining capacity can be displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle battery residual capacity meter mounted in an electric vehicle.

[0002]

2. Description of the Related Art In recent years, the development of electric vehicles has been progressing at a rapid pace. However, electric vehicles are equipped with a large number of automobile batteries as a drive source, and their remaining capacity limits the mileage. Therefore, the remaining capacity meter of the vehicle battery mounted on the electric vehicle must accurately display the remaining capacity even when the battery has been used for a long period of time and has deteriorated.

[0003] Therefore, conventionally, the remaining amount of the electricity amount accumulating method is calculated by integrating the electricity consumption amount of the battery, subtracting the electricity consumption amount from the electricity storage amount at the time of initial charging, and displaying it as a ratio to the electricity storage amount at the time of full charge. The meter is being used. Then, a warning light that warns that the remaining capacity has decreased before the battery voltage drops and the vehicle cannot run is turned on to notify the driver that recharging is necessary.

[0004]

However, since the conventional vehicle battery remaining capacity meter does not have a function of correcting the remaining battery capacity even if the battery has been used for a long period of time and deteriorates, the following problem occurs. There was a problem.

As a general characteristic of a battery, when it is fully charged by recharging, the voltage is almost the same as that of a new battery, but the usable period becomes longer, and the amount of electricity that can be output decreases as the battery deteriorates. By the way, the remaining capacity meter of the electricity quantity integration method integrates the consumed electricity quantity of the battery as a remaining capacity meter, subtracts the consumed electricity quantity from the stored electricity quantity at the initial charging, and calculates it as a ratio to the stored electricity quantity at the full charge. I am trying to display it. Therefore, if the remaining capacity is determined by measuring only the amount of electricity consumed and subtracting it from the amount of electricity stored when fully charged, the amount of electricity consumed will be the same in the case of a deteriorated battery compared to a new battery. However, the remaining capacity is extremely low.

However, conventionally, the remaining capacity is determined on the basis of the fully charged electric quantity at the time of new article, and when the remaining capacity becomes less than the reference value, the warning light is turned on to prompt recharging. If the battery is deteriorating, the actual remaining capacity will be close to 0 when the warning light turns on, and you will not be able to drive to a service station or home with charging facilities. Sometimes it became impossible to run before was lit.

The present invention has been made in view of the above-mentioned problems of the related art, and the remaining capacity of a battery for an automobile that can accurately display the remaining capacity according to the deterioration of the battery progresses. The purpose is to provide a total.

[0008]

According to a first aspect of the present invention, there is provided a vehicle battery residual capacity meter, an ammeter for detecting a battery current, a voltmeter for detecting a battery voltage, and a battery residual capacity for the battery. The remaining capacity display section that displays the ratio to the capacity when fully charged, the electricity amount calculation section that integrates the output of the ammeter to obtain the electricity consumption amount, and the electricity consumption amount calculated by the electricity amount calculation section The remaining capacity is calculated by subtracting the remaining capacity from the remaining capacity, converted to a ratio to the capacity when fully charged, and the remaining capacity display control unit given to the remaining capacity display unit and the degree of deterioration with respect to the output power when the battery is new are calculated. Depending on the deterioration degree calculation unit and the deterioration degree of the battery calculated by the deterioration degree calculation unit, the ratio of the remaining capacity to the capacity when the battery is fully charged is set to a small value, and the remaining capacity display control unit displays It is obtained by a remaining capacity correction section that gives a.

According to a second aspect of the present invention, in the remaining capacity meter of the automobile battery according to the first aspect, the deterioration degree calculation unit reaches a predetermined discharge stop voltage based on the time change of the outputs of the voltmeter and the ammeter. It is provided with an outputtable power calculation unit for calculating the maximum outputtable power.

[0010]

In the remaining capacity meter for a battery for an automobile according to the first aspect of the invention, the amount of electricity consumed by the battery is obtained by accumulating the output of the ammeter in the electricity amount calculator, and the consumed electricity amount is calculated in the remaining capacity display controller. Calculate the remaining capacity by subtracting it from the fully charged capacity of the battery, convert it to the ratio to the fully charged capacity and give it to the remaining capacity display section.The remaining capacity display section shows the remaining capacity of the battery at the fully charged capacity. It is displayed as a ratio to.

Then, at the time of this display, the deterioration degree calculating section calculates the deterioration degree with respect to the output power of the new battery, and the remaining capacity correcting section calculates the deterioration degree of the battery according to the deterioration degree.
The ratio of the remaining capacity to the capacity when the battery is fully charged is set to be small and given to the remaining capacity display control unit as a display correction.

As a result, the remaining capacity display portion can display the remaining capacity to a small extent in accordance with the deterioration of the battery, and the accurate remaining capacity can be displayed.

According to a second aspect of the present invention, in the vehicle battery residual capacity meter according to the first aspect, the deterioration degree calculating section reaches a predetermined discharge stop voltage based on a temporal change in the outputs of the voltmeter and the ammeter. By providing the outputable power calculation unit that calculates the maximum power that can be output up to this point, it becomes possible to automatically correct the remaining capacity according to the deterioration degree regardless of the period of use of the battery.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a circuit configuration of a common embodiment of the inventions of claims 1 and 2. The vehicle battery residual capacity meter according to this embodiment includes an ammeter 2 that measures the current of the battery 1, a voltmeter 3 that measures the voltage, and an electric current consumed by the battery by accumulating the current measured by the ammeter 2. An electric quantity calculation unit 4 for calculating the amount and an outputable power calculation unit 5 for calculating the outputable power from the measured values of the ammeter 2 and the voltmeter 3 by the method described later are provided as the deterioration degree calculation unit.

The remaining capacity meter for a vehicle battery of this embodiment also obtains the remaining capacity by subtracting the consumed electricity amount calculated by the electricity amount calculation unit 4 from the fully charged capacity of the battery 1 to obtain the remaining capacity. The remaining capacity display control unit 6 that converts and outputs the ratio to the capacity, and the remaining capacity display control unit 6 from the time when the outputable power calculated by the outputable power calculation unit 5 is lower than the maximum outputable power of a new product. Remaining capacity display correction unit 7 which gives a correction command to the remaining capacity display to be output
Based on the instruction from the remaining capacity display control unit 6, the battery 1
The remaining capacity display unit 8 for displaying the remaining capacity of the battery as a ratio of the remaining capacity to the fully charged capacity of the battery.

Further, the remaining capacity meter of the automobile battery is
Since it is necessary to issue a warning for a recharge instruction when the remaining capacity becomes equal to or less than a predetermined value, the comparison reference setting unit 9 that sets the remaining capacity comparison reference, and the comparison reference provided by the comparison reference setting unit 9 Is compared with the deterioration-corrected remaining capacity output from the remaining capacity display control unit 6, and outputs a warning command when the remaining capacity falls below a comparison standard, and a warning command of the comparison unit 10. A warning light 11 is provided for displaying a warning accordingly.

Next, the operation of the remaining capacity meter of the automobile battery having the above structure will be described. First, the electric quantity calculation unit 4
Calculates the amount of electricity used by the battery 1 by integrating the measured values of the current output from the ammeter 2, and outputs this to the remaining capacity display control unit 6.

The remaining capacity display control unit 6 subtracts the consumed electricity amount calculated by the electricity amount calculation unit 4 from the fully charged capacity of the battery 1 to obtain the remaining capacity, which is converted into a ratio to the fully charged capacity. When the remaining capacity is reduced to the amount at which the remaining capacity is fully charged to F (full) and the battery 1 needs to be recharged, E is displayed.
Meter display as (empty).

FIG. 2 shows a decreasing pattern of the remaining capacity when the battery 1 is new and the battery 1 is used with a constant power. The remaining capacity decreases with the time of use, and the remaining capacity is A1. The setting is to turn on the warning lamp 11 at the time point t1 when the number of lights reaches the point. This is the comparison unit 10
2, the remaining capacity output value output by the remaining capacity display control unit 6 is compared with the comparison reference (line indicated by Lt in FIG. 2) set by the comparison reference setting unit 9, and if it is less than that, the warning lamp 11 It is realized by turning on.

A curve A shown by a full line in FIG. 3 shows a decrease pattern of the outputtable power when a new battery 1 is used in a constant amount. When the battery is new, the outputtable power is maintained until a certain use time. Is decreased as the usage time becomes longer, and the usage time t1 until the outputtable power becomes lower than the reference point Pr is the above-mentioned remaining capacity warning point Lt.
The warning lamp 11 is turned on at this point. However, if the battery characteristics deteriorate due to long-term use of the battery, the pattern changes to a pattern of a curve B as shown by a broken line in FIG. Therefore,
The output lowering point is accelerated from A2 to B2.

This outputtable power curve is obtained from the graph shown in FIG.
Calculated by The power line that can be output when new is P10
Assuming that 0 (100%), the battery voltage V and the battery current I do not fall on the line P100 when the battery 1 is new, and the output power line P
75 (75%), P50 (50%) or P25 (25%)
Will be on the line. Therefore, the available output power calculation unit 5 monitors changes in the current value and the voltage value measured by the ammeter 2 and the voltmeter 3, and registers P100 and P7 registered in advance.
Determine which of the power lines such as 5, P50, P25, etc., and output the corresponding maximum output power P100, P75, P50
Alternatively, it finds P25 and outputs it to the remaining capacity display correcting unit 7.

Therefore, the remaining capacity display correcting section 7 corrects the remaining capacity as shown in FIG. 5 with respect to the calculation result from the outputtable power calculating section 5. That is, the lowering point of the outputtable power of the battery 1 advances from A2 to B2, and the reference point Pr
The lowering point is from A1 to B1, and the operating time is shortened from t1 to t2. Therefore, it is determined that the remaining capacity becomes small by catching the operating time t3 at the point B2 where the outputtable power decreases, and the remaining capacity is determined. The decreasing pattern is changed from the new pattern α to β, and this is given to the remaining capacity display control unit 6.

Therefore, the remaining capacity display control unit 6 calculates the remaining capacity from the amount of electricity used up to that time based on the corrected remaining capacity pattern β, and causes the remaining capacity display unit 8 to display the remaining capacity in a meter. At the same time, the comparison unit 10 compares the corrected remaining capacity output from the remaining capacity display control unit 6 with the comparison reference provided by the comparison reference setting unit 9, and the remaining capacity is L.
The warning lamp 11 is turned on at the point B1 at which t is reached.

In this way, according to the remaining capacity meter for the automobile battery of this embodiment, when the deterioration of the battery progresses, the remaining capacity obtained by subtracting the used electricity quantity from the stored electricity quantity at full charge is obtained. Since it can be corrected so that it is displayed a little, even if the amount of electricity used is the same, the battery that has deteriorated will reach the warning light lighting level earlier, and when the warning light lights up, almost all the battery will be consumed. It is possible to avoid a situation in which the vehicle cannot run because it has been emptied or emptied before the warning light is turned on, and the reliability of the display of the remaining capacity meter can be improved.

Although the output power curve shown in FIG. 5 is used for the deterioration degree calculation in the above embodiment, the calculation of the deterioration degree of the battery is not limited to this, and for example, it may be performed in multiple stages according to the traveling distance of the vehicle. A method is also possible in which the degree of deterioration is set and the data is registered in a table format so that the remaining capacity correction amount is set for each degree of deterioration.

Further, the amount of electricity used in the battery is integrated from the time of new product until the battery life is reached, the deterioration degree is set in multiple stages according to the accumulated electricity amount, and the remaining capacity correction amount is set for each deterioration degree. A method of registering data in a table format so as to set is also possible.

[0027]

As described above, according to the invention of claim 1,
The amount of electricity consumed by the battery is calculated by integrating the output of the ammeter in the electricity quantity calculation unit, and the remaining capacity is calculated by subtracting this amount of electricity consumption from the fully charged capacity of the battery in the remaining capacity display control unit to obtain the remaining capacity It is converted to the ratio to the remaining capacity and given to the remaining capacity display section, and the remaining capacity display section displays the remaining capacity of the battery as a ratio to the fully charged capacity,
In this display, the deterioration degree calculation unit calculates the deterioration degree with respect to the output power when the battery is new, and the remaining capacity correction unit reduces the ratio of the remaining capacity to the fully charged capacity of the battery according to the deterioration degree of the battery. Since it is set to, and it is given as a display correction to the remaining capacity display control section, the remaining capacity display section can display the remaining capacity to a small extent according to the deterioration of the battery. , It is possible to display the accurate remaining capacity, and avoid the situation where the battery was almost empty when the warning light was lit as in the past, or the battery became empty before the warning light was lit and it became impossible to drive. Therefore, the reliability of the display of the remaining capacity meter can be improved.

According to the second aspect of the present invention, in the remaining capacity meter of the automobile battery according to the first aspect, the deterioration degree calculating section comprises:
Based on the time change of the output of the voltmeter and the ammeter, it is equipped with an outputable power calculation unit that calculates the maximum power that can be output before reaching the predetermined discharge stop voltage, so it can be automatically used regardless of the battery life. The remaining capacity can be accurately corrected according to the degree of deterioration, and the display reliability of the remaining capacity meter can be improved.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a common embodiment of the inventions of claims 1 and 2. FIG.

FIG. 2 is a graph showing a display example of remaining capacity of a new battery in the above embodiment.

FIG. 3 is a graph showing how the outputtable power changes in accordance with the degree of deterioration of the battery in the above embodiment.

FIG. 4 is a graph showing a display example of remaining capacity of a deteriorated battery in the above embodiment.

FIG. 5 is a graph showing changes in the outputtable power characteristics of a battery registered in the outputtable power calculation unit in the above embodiment.

[Explanation of symbols]

 1 Battery 2 Ammeter 3 Voltmeter 4 Electricity Calculation Unit 5 Outputtable Power Calculation Unit 6 Remaining Capacity Display Control Unit 7 Remaining Capacity Display Correction Unit 8 Remaining Capacity Display Unit 9 Comparison Reference Setting Unit 10 Comparison Unit 11 Warning Light

Claims (2)

[Claims] 1. An ammeter for detecting a battery current, a voltmeter for detecting the battery voltage, a remaining capacity display section for displaying the remaining capacity of the battery as a ratio to the fully charged capacity of the battery, An electricity amount calculation unit that calculates the amount of electricity consumed by accumulating the output of the ammeter, and an amount of electricity consumption calculated by the electricity amount calculation unit is subtracted from the capacity when the battery is fully charged to obtain the remaining capacity, and the battery is fully charged. The remaining capacity display control unit for converting the ratio to the remaining capacity and giving it to the remaining capacity display unit, the deterioration degree calculation unit for calculating the deterioration degree with respect to the outputtable power when the battery is new, and the deterioration degree calculation unit Depending on the degree of deterioration of the battery to be calculated, the ratio of the remaining capacity to the capacity when the battery is fully charged is set to a small value, and the remaining capacity compensation given to the remaining capacity display control unit as a display correction is set. A remaining capacity meter for an automobile battery, comprising: 2. The outputtable power calculator for calculating the maximum power that can be output before the discharge stop voltage reaches a predetermined level, based on the time change of the outputs of the voltmeter and the ammeter. The remaining capacity meter for an automobile battery according to claim 1, wherein the remaining capacity meter is provided.