JPH06342046A - Battery-residual-capacity display apparatus of electric car - Google Patents

Abstract

PURPOSE:To provide the battery-residual-capacity display apparatus, of an electric car, wherein, even when a battery becomes old, an operator can avoid mistakenly recognizing the battery capacity to be more sufficient than actual. CONSTITUTION:A charging device 11 with reference to a loaded battery 6 is provided. A charging-amount detection means 13 which detects a charging amount with the passage of time by the charging operation of the battery 6 and a discharge-amount detection means 15 which detects a discharge amount with the passage of time by the use of the battery 6 are provided. A display means 17 which displays a battery capacity in the ratio of a computed charging amount obtained by multiplying the total charging amount detected by the charging-amount detection means 13 by a prescribed correction factor to the capacity of the battery 6 as a new battery is installed. The display means is constituted so as to display an actual residual capacity in the ratio of a residual capacity subtracted from the computed charging amount to the capacity of the battery as the new battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery remaining capacity display device for an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, as a battery remaining capacity display device for an electric vehicle of this type, a battery terminal voltage is simply detected and a display corresponding to the terminal voltage is made based on the detection result. It was That is, the remaining capacity is displayed according to the degree of decrease in the voltage value between the battery terminals at the time of full charge.

[0003]

By the way, although the chargeable electric capacity decreases with age when the battery gets old as it is used for a long period of time, in the conventional one, the chargeable capacity decreases. Nevertheless, if the remaining battery capacity is displayed based on the voltage value between the terminals of the battery, even if it is displayed in a state close to full charge, due to the decrease in capacity, the battery terminals will relatively quickly There is a high possibility that the voltage will become low, and therefore, if the driver mistakenly recognizes that the battery capacity is sufficient by looking at the display device and then travels, the battery runs out and the vehicle cannot run. The present invention has been made in view of the above circumstances, and is an electric vehicle capable of avoiding the operator from erroneously recognizing that the battery capacity is more sufficient than it actually is, even if the battery is old. It is intended to provide a battery remaining capacity display device.

[0004]

In order to achieve the above object, a battery remaining capacity display device for an electric vehicle according to the present invention is provided with a charging device for an on-board battery, and is equipped with a charging device for charging the battery. A charge amount detecting means for detecting a charge amount and a discharge amount detecting means for detecting a discharge amount over time due to use of the battery are provided, and a predetermined correction coefficient is added to the total charge amount detected by the charge amount detecting means. By providing a display means for displaying the battery capacity by the ratio of the calculated charge amount obtained by multiplying the battery and the new capacity of the battery, further, by the ratio of the remaining capacity subtracted from the calculated charge amount and the new capacity. The display means is characterized in that the actual remaining capacity is displayed. The operation and effect of this characteristic configuration are as follows.

[0005]

In other words, the actual charge capacity corrected so as to be compared with the new capacity of the battery is calculated by multiplying the charge amount over time due to charging the battery by a predetermined correction coefficient,
The amount of charge is displayed based on the ratio of the calculated amount of charge and the capacity at the time of new product, and the actual remaining capacity is calculated by the ratio of the remaining capacity after subtracting the amount of discharge over time due to use from the calculated amount of charge and the capacity at new product. Is displayed, the actual charge amount according to the charging capacity of the battery is displayed, and the actual remaining capacity obtained by subtracting the discharge amount from the actual charge amount is displayed. The remaining electric capacity can be known almost accurately.

[0006]

Therefore, even if the battery capacity decreases over time, by obtaining the calculated charge amount corresponding to the degree of decrease, the actual discharge amount can be subtracted based on the calculated charge amount. Since the remaining capacity of the battery can be displayed in a state closer to the remaining capacity of the battery, the problem of notifying the operator of incorrect remaining battery capacity information as in the past can be solved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a small electric vehicle as an example of the electric vehicle. This small electric vehicle includes a battery 6, a steering wheel 1, a rear portion of a vehicle body frame 5 supported by a pair of left and right rear wheels 4 and 4 driven by an electric motor 3, and a battery 6 and a steering wheel 1 which are steerable by a steering wheel 1. A seat 7, a control device 8 and the like are installed and configured.

A display section 9 for displaying the electric capacity of the battery 6 is provided on the panel section of the steering handle 1 as shown in FIG. The display section 9 is formed by arranging a plurality of light emitting diodes 10 ... In a horizontal or vertical direction.
This shows that there is an electric capacity corresponding to the number of lights. Specifically, five light emitting diodes 10 ... Are arranged side by side, and when all the light emitting diodes 10 ... That is, the battery 6 has an electric capacity of about 80% of the fully charged state.

Next, the charging structure will be described. As shown in FIG. 1, a charging device 11 for charging the battery 6 is arranged near the battery 6. This charging device 11 is connected between terminals of the battery 6 via a charging current detecting resistor R1. A charge amount counter 1 that measures the voltage value between terminals of the charge current detecting resistor R1 with time and integrates and detects the charge amount after starting charging.
2 is provided. Here, the charging current detecting resistor R1 and the charging amount counter 12 constitute a charging amount detecting means 13. The information detected by the charge counter 12 is input to the control device 8. Further, in order to detect the discharge amount of the battery 6 by driving the electric motor 3, a discharge current detecting resistor R2 is provided in series with the electric motor 3. A discharge amount counter 14 is provided which measures the voltage value between the terminals of the discharge current detecting resistor R2 over time and integrates and detects the discharge amount after the start of discharge. Here, the discharge current detecting resistor R2 and the discharge amount counter 14 constitute a discharge amount detecting means 15. Information detected by the discharge amount counter 14 is also input to the control device 8. In FIG. 1, reference numeral 16 is a transistor as a control element for controlling the speed of the electric motor 3. When a drive command signal from the control device 8 is input to the base of the transistor 16, switching operation is performed. Drive current flows from the battery 6 to the electric motor 3.

The control device 8 comprises a microcomputer and comprises the charge amount counter 1
It is configured to output a signal for displaying the remaining capacity of the battery 6 to the display unit 9 based on the signals of 2 and the discharge amount counter 14. More specifically, the control device 8 includes an arithmetic unit 8a and a storage unit 8b, and the arithmetic unit 8a obtains the charge amount counter 12 from the start of charging by the charging device 11 to the end of charging. The stored integrated charge amount J (ampere × hour) is stored in the storage unit 8b, and is set in advance as the integrated charge amount according to a program stored in the storage unit 8b.
The calculated charge amount S is obtained by calculating the product with the predetermined correction coefficient K stored in the storage unit 8.
Store in b. That is, S = KJ Then, the calculation unit 8a divides the calculated charge amount S by the new capacity F of the battery 6 to obtain the new capacity F.
Then, the ratio P is calculated for how much the calculated charge amount S is.
That is, P = S / F and, for example, if the ratio P is 100%, it is determined that the battery is fully charged, and the five light emitting diodes 10 ...
, A display signal is output from the control device 8 so that all of the LEDs are turned on. If the ratio P is 80%, the light emitting diode 1
The control device 8 outputs to the display unit 9 the display signals of which only four lights 0. After that, when the battery 6 is discharged by using a small electric vehicle, the integrated discharge amount H from the start of the discharge is detected by the discharge amount counter 14, and the integrated discharge amount H is calculated as the calculated charge amount. By subtracting from S and further dividing by the new capacity F, the actual remaining capacity A of the battery 6 with respect to the new capacity F is obtained, and the remaining capacity signal is output to the display device 9. That is, A = (SH) / F Therefore, if the remaining capacity A is about 80% of the charging capacity F when it is new, as described above, the light emitting diodes 10 ...
If only the number of the light-emitting diodes 10 ... Is turned on and the remaining capacity A is about 60% of the charge capacity F of the new product, only three light-emitting diodes 10 ... Are turned on as described above. Here, the control device 8 and the display unit 9
Constitutes the display means 17.

The above-mentioned correction coefficient K is a coefficient preset in accordance with the accumulated charge amount for obtaining the charged amount actually charged in the battery 6 almost accurately corresponding to the value of the accumulated charge amount. , Stored in the storage unit 8b.

With the above structure, even the battery 6 that has been used for a long time is in a state closer to the actual remaining capacity as compared with the one in which the remaining capacity is displayed based on the voltage across the terminals of the battery 6. Since it is displayed with, it is possible to avoid erroneously recognizing the battery capacity.

The correction coefficient and the full charge capacity of a new battery may be stored in the storage unit at the time of factory shipment. Further, the correction coefficient set according to the years of use of the battery may be stored in advance and the calculated charge amount may be obtained by the control device judging according to the years of use of the mounted battery.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of a battery remaining capacity display device of an electric vehicle.

FIG. 2 is a plan view showing a steering handle.

FIG. 3 is an overall side view showing a small electric vehicle

[Explanation of symbols]

 6 Battery 11 Charging Device 13 Charge Amount Detecting Means 15 Discharge Amount Detecting Means 17 Display Means

Claims (1)

[Claims] 1. A charging device (11) for an on-board battery (6), and a charging amount detection means (13) for detecting a charging amount over time due to charging of the battery (6); 6) is provided with a discharge amount detection means (15) for detecting a discharge amount over time due to use,
Display means for displaying the battery capacity by the ratio of the calculated charge quantity obtained by multiplying the total charge quantity detected by the charge quantity detection means (13) by a predetermined correction coefficient and the new capacity of the battery (6). (17) is provided, and the battery means for an electric vehicle further comprising the display means (17) configured to display the actual remaining capacity by a ratio of the remaining capacity subtracted from the calculated charge amount and the new capacity. Remaining capacity display device.