JPH0884437A - Battery life judging device - Google Patents

Abstract

PURPOSE: To easily judge the life of a battery by retaining a specific constant- voltage current for discharging and at the same time calulating the discharging capacity of a chargecable storage battery and reporting the discharging capacity based on a measurement time until the voltage to be detected reaches a dischaging end voltage and a specific constant-current value. CONSTITUTION: A fully charged storage battery is discharged by a specific current using a constant-current discharging means 5 and at the same time a discharging voltage is detected by a voltage detection means 3. The time until the voltage reaches an end voltage is measured by a clocking means 11 and discharging is stopped by a discharging stop means 7 when the end voltage is reached. The discharging capacity is calculated by a discharging capacity operation means 8 according to the measurement time and the capacity value, the ratio to a value stored by a nominal capacity storage means 15 in advance is calculated by a ratio operation means 9 and is reported by a ratio reporting means 19, thus easily judging the life of a storage battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery life judging device for a rechargeable storage battery, and more particularly to a battery life judging device for detecting a decrease in discharge capacity.

[0002]

2. Description of the Related Art Today, NiCd batteries are known as rechargeable storage batteries used in electric tools and the like. N
The iCd battery is configured by connecting a plurality of 1.2 V cells, and the discharge capacity of each cell is 1300 mAh, 17
A nominal capacity such as 00 mAh is defined.

NiCd batteries become inactive when they are repeatedly charged and discharged with a certain amount of capacity remaining,
There is a temporary decline in battery capacity or battery voltage.

If charging and discharging are repeated a number of times, the battery capacity will decrease and eventually the battery life will be exhausted, and it will be possible to charge only a discharge capacity smaller than the standard discharge capacity, or the above-mentioned cells. A cell short circuit may occur in which the electromotive force of the cell itself is lost due to the deterioration of the performance of the organic material such as the separator or the electrode plate that constitutes the cell.

As described above, when a rechargeable storage battery that is charged with a discharge capacity smaller than the standard discharge capacity is used, the device can be used only for a short time due to the decrease in discharge capacity. In addition, due to the voltage drop, the driving speed and the driving torque may become insufficient, and the control system device may malfunction.

For the rechargeable storage battery in which these problems have occurred, the operator has used his experience or the like to make a judgment as to whether or not the life has expired. Therefore, it is not easy to determine the battery life of the rechargeable storage battery.

An object of the present invention is to solve the above problems and to provide a battery life determining device for a rechargeable storage battery, in which the battery life of the rechargeable storage battery can be easily determined.

[0008]

According to another aspect of the present invention, there is provided a battery life determining apparatus for a rechargeable storage battery, wherein a fully charged rechargeable storage battery is discharged while maintaining a discharge current at a predetermined constant current value. Rechargeable storage battery discharging means for obtaining a measurement time until the discharge voltage to be detected reaches the discharge end voltage,
Discharge capacity calculation means for calculating the discharge capacity of the rechargeable storage battery based on the measurement time and the predetermined constant current value,
A discharge capacity informing unit for informing the discharge capacity calculated by the discharge capacity calculating unit is provided.

In the battery life determining apparatus for a rechargeable storage battery according to a second aspect of the present invention, the fully charged rechargeable storage battery is discharged by holding the discharge current at a predetermined constant current value, and the discharge voltage to be detected is discharged. Rechargeable storage battery discharging means for obtaining the measurement time until reaching the cutoff voltage, discharge capacity calculation means for calculating the discharge capacity of the rechargeable storage battery based on the measurement time and the predetermined constant current value, nominal of the rechargeable storage battery Nominal battery capacity storage means for storing a battery capacity, ratio calculation means for calculating a ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity stored in the nominal battery capacity storage means, calculated by the ratio calculation means And a ratio notifying unit for notifying the ratio.

In the battery life determining apparatus for a rechargeable storage battery according to a third aspect of the present invention, the fully charged rechargeable storage battery is discharged by holding the discharge current at a predetermined constant current value and the discharge voltage detected is discharged. Rechargeable storage battery discharging means for obtaining a measurement time until reaching the cutoff voltage, standard time storage means for storing a standard battery capacity of the rechargeable storage battery and a standard time calculated based on the predetermined constant current value, for the standard time By calculating the ratio of the measurement time,
It is characterized by further comprising: a ratio calculating means for calculating a ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity; and a ratio notifying means for notifying a ratio calculated by the ratio calculating means.

According to another aspect of the battery life determining apparatus of the present invention,
The ratio notifying unit is characterized by having a battery life display section for displaying a visual change according to the ratio of the discharge capacity to the nominal battery capacity.

In the battery life determining device of claim 5,
A limit ratio storage unit for storing a limit ratio in the ratio of the discharge capacity to the nominal battery capacity, wherein the ratio notification unit, when the ratio of the discharge capacity to the nominal battery capacity is lower than the limit ratio, The present invention is characterized by having a limit ratio alarm unit for issuing an alarm.

In the battery life determining apparatus according to claim 6, A) the rechargeable battery discharging means is provided with the following a1), a2), and a3), and a1) discharge current is set to a predetermined constant current value. Constant current discharging means for discharging the rechargeable storage battery while holding at, a2) voltage detection means for detecting the discharge voltage of the rechargeable storage battery, a3) obtaining the measurement time until the discharge voltage reaches the discharge end voltage Time measuring means, B), further comprising voltage notifying means for notifying the voltage of the rechargeable storage battery detected by the voltage detecting means at the start of discharging.

In the battery life determining apparatus according to claim 7, A) the rechargeable storage battery discharging means is provided with the following a1), a2) and a3), and a1) the discharge current to a predetermined constant current value. Constant current discharging means for discharging the rechargeable storage battery while holding, a2) Voltage detecting means for detecting the discharge voltage of the rechargeable storage battery, a3) Timekeeping for obtaining the measurement time until the discharge voltage reaches the discharge end voltage Means, B) Further, comparing the nominal voltage of the rechargeable storage battery with the detection voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharging, and if the detection voltage is lower than the nominal voltage, It is characterized in that a voltage warning means for warning is provided.

According to another aspect of the battery life determining apparatus of the present invention,
The rechargeable storage battery discharging means has a discharge stopping means for stopping the discharge in the constant current discharging means when the voltage of the rechargeable storage battery to be detected reaches a preset discharge stop voltage. .

[0016]

In the battery life determining device for the rechargeable storage battery according to the first aspect of the present invention, the rechargeable storage battery discharging means holds the discharge current of the fully charged rechargeable storage battery at a predetermined constant current value and performs discharge. , The measurement time until the detected discharge voltage reaches the discharge end voltage is obtained. The discharge capacity calculation means is based on the measurement time and the predetermined constant current value,
The discharge capacity of the rechargeable storage battery is calculated. The discharge capacity notifying means notifies the calculated discharge capacity.

In this way, the battery life of the fully charged rechargeable storage battery can be determined based on the actual discharge capacity until the discharge end voltage is reduced. Since the discharge is performed with a constant current, the measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant.

In the battery life determining apparatus for a rechargeable storage battery according to a second aspect of the present invention, the rechargeable storage battery discharging means discharges the fully charged rechargeable storage battery while maintaining the discharge current at a predetermined constant current value. , The measurement time until the detected discharge voltage reaches the discharge end voltage is obtained. The discharge capacity calculation means calculates the discharge capacity of the rechargeable storage battery based on the measurement time and the predetermined constant current value. The ratio calculation means calculates a ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity stored in the nominal battery capacity storage means. The ratio notification means notifies the ratio calculated by the ratio calculation means.

In this way, based on the ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity,
The battery life of a fully charged rechargeable storage battery can be determined. Therefore, the operator can judge the life without comparing the discharge capacity with the nominal discharge capacity. Since the discharge is performed with a constant current, the measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant.

In the battery life determining apparatus for the rechargeable storage battery according to the third aspect, the standard time storage means stores the standard battery capacity of the rechargeable storage battery and the standard time calculated based on the predetermined constant current value. The rechargeable storage battery discharging means discharges the fully charged rechargeable storage battery while maintaining the discharge current at a predetermined constant current value and obtains a measurement time until the detected discharge voltage reaches the discharge end voltage. The ratio calculation means calculates the ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity by calculating the ratio of the measurement time to the standard time. The ratio notification means notifies the ratio calculated by the ratio calculation means. Therefore, the operator can determine the battery life of the fully charged rechargeable storage battery based on the ratio of the measurement time to the standard time without comparing the discharge capacity with the nominal discharge capacity. Since the discharge is performed with a constant current, the measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant.

In the battery life determining device according to claim 4,
The battery life display section provides a display that visually changes according to the ratio of the discharge capacity to the nominal battery capacity. Therefore, the operator can visually and easily make the life judgment.

In the battery life determining device of claim 5,
The limit ratio alarm unit warns when the ratio of the discharge capacity to the nominal battery capacity is lower than the limit ratio.
Therefore, the operator can judge the life by the alarm.

In the battery life determining device according to claim 6,
The voltage notification means notifies the voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharging. Therefore, for a fully charged rechargeable storage battery,
It is possible to determine whether a cell short circuit or the like has occurred.

In the battery life judging device according to claim 7,
The voltage alarm means compares the nominal voltage of the rechargeable storage battery with the detection voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharge, and when the detected voltage is lower than the nominal voltage, an alarm is issued. To do. Therefore, the operator can judge the life due to the cell short circuit by the alarm.

In the battery life judging device according to claim 8,
The discharge stopping means stops the discharge in the constant current discharging means when the voltage of the rechargeable storage battery to be detected reaches a preset discharge stopping voltage. In this way, the discharge is continued until the discharge stop voltage is reached even after the discharge end voltage is reached. Therefore, the rechargeable storage battery can be discharged to a discharge stop voltage lower than the discharge end voltage.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 9, the battery life determination device 1
The terminal T _A for mounting a rechargeable battery B, T _B, the constant current discharge circuit 32, a microcomputer 33, the operation and informing panel 35 and the buzzer 36. When the rechargeable storage battery B, which is fully charged by the charging device (not shown), is attached to the terminals T _A and T _B , the battery life determining device 1 discharges at a constant current value as described later and discharge capacity. To inform. Thereby, the battery life can be objectively determined.

The function of the battery life determining device 1 will be described. As shown in FIG. 1, the battery life determining device 1 includes a rechargeable storage battery discharging means 2, a voltage warning means 14, and a voltage notification means 1.
8, a discharge capacity calculation means 8, a ratio calculation means 9, a ratio notification means 19, a nominal battery capacity storage means 15, a limit ratio storage means 17, and a nominal voltage storage means 13.

The rechargeable storage battery discharging means 2 has a voltage detecting means 3, a constant current discharging means 5, a discharge stopping means 7, and a clocking means 11. The constant current discharging means 5 discharges the rechargeable storage battery while maintaining the discharge current at a predetermined constant current value. The voltage detection means 3 detects the discharge voltage of the rechargeable storage battery. The time measuring means 11 obtains a measurement time until the discharge voltage reaches the discharge end voltage. The discharge stopping means 7 is
When the voltage of the rechargeable storage battery to be detected reaches a preset discharge stop voltage, the discharge in the constant current discharge means is stopped. Therefore, the rechargeable storage battery discharging means 2 discharges the fully charged rechargeable storage battery while maintaining the discharge current at a predetermined constant current value, and the measured time until the discharge voltage to be detected reaches the discharge end voltage. Can be asked.

The discharge capacity calculating means 8 calculates the discharge capacity of the rechargeable storage battery based on the measured time and the predetermined constant current value. The ratio calculation means 9 calculates the ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity stored in the nominal battery capacity storage means 15. The ratio notification means 19 calculates the ratio calculated by the ratio calculation means 9. To inform. In this way, the ratio of the discharge capacity to the nominal battery capacity can be obtained.

The limit ratio storage means 17 stores the limit ratio of the ratio of the discharge capacity to the nominal battery capacity, and the ratio informing means 19 has a limit ratio alarm unit for issuing an alarm. The limit ratio alarm unit warns when the ratio of the discharge capacity to the nominal battery capacity is lower than the limit ratio.

Further, the voltage notifying means 18 notifies the voltage of the rechargeable storage battery detected by the voltage detecting means 3 at the start of discharging. The nominal voltage storage means 13 stores the nominal voltage of the rechargeable storage battery, and the voltage alarm means 14 detects the nominal voltage of the rechargeable storage battery and the rechargeable storage battery detected by the voltage detection means 3 at the start of discharging. The detection voltage is compared, and an alarm is issued if the detection voltage is lower than the nominal voltage.

In this way, the ratio of the installed rechargeable storage battery to the nominal battery capacity and the discharge voltage at the start of discharge can be obtained.

The ratio notifying means 19 may be provided with a battery life display section for visually displaying the battery life in accordance with the ratio of the discharge capacity to the nominal battery capacity.

Further, in this embodiment, the ratio calculating means 9 calculates the ratio of the discharge capacity to the nominal battery capacity. However, the discharge capacity calculated by the discharge capacity calculating means 8 may be notified without performing such calculation. In this case, the ratio calculating means 9 is not necessary, and instead of the ratio notifying means 19, a discharge capacity notifying means for notifying the calculated discharge capacity may be provided.

A standard time storage means for storing a standard time calculated based on the nominal battery capacity and the predetermined constant current value is provided, and the ratio calculation means calculates a ratio of the measured time to the standard time. By calculating,
You may make it calculate the ratio of the said discharge capacity of the said rechargeable storage battery with respect to the said nominal battery capacity.

FIG. 2 shows an example of a hardware configuration in which the battery life determining apparatus 1 is realized by using a CPU. The battery life determining device 1 includes a CPU 23, a ROM 25, a RAM 27,
A liquid crystal display 34, a clock 29, a constant current discharge circuit 32, a buzzer 36, a changeover switch 38 and a bus line 30 are provided. The clock 29 is connected to the CPU 23, and the constant current discharge circuit 32, the buzzer 36, and the changeover switch 38 are connected to the CPU via the I / O port 31.
It is connected to 23.

The ROM 25 stores a control program for the CPU 23 and the like. The CPU 23 controls each unit via the bus line 30 according to this control program. The RAM 27 stores the nominal battery capacity, the nominal voltage, the calculation result, and the like. The measured discharge capacity, voltage, and battery life are displayed on the liquid crystal display 34. The buzzer 36 is one of the notification means, and when the set rechargeable storage battery can charge only a predetermined discharge capacity, the buzzer 36 determines that the battery has reached the end of its life and notifies it. The changeover switch 38 switches the nominal battery capacity. The clock 29 outputs a clock signal by a ceramic oscillator in order to obtain the measurement time.

The liquid crystal display 34 will be described with reference to FIG. In the liquid crystal display 34, the segments 41 and 42 display the voltage of the rechargeable storage battery at the time of full charge (at the start of discharge). When the cell short circuit occurs, the voltage life display section 43 lights up. In segments 51 to 54, the discharge capacity of the rechargeable storage battery to be inspected is displayed. When the discharge capacity is smaller than the predetermined value, the discharge capacity life display unit 55 lights up.

In this embodiment, a slide switch 61 functioning as a changeover switch 38 is provided adjacent to the liquid crystal display 34. The slide switch 61 switches the nominal battery capacity of the rechargeable storage battery to be set.

The constant current discharge circuit 32 will be described with reference to FIG. The constant current discharge circuit 32 discharges while keeping the discharge current constant as follows. Terminal T _A and terminal T _B
When the rechargeable storage battery B is set in the meantime, the voltage of the rechargeable storage battery B is divided by the resistors R1 and R2 connected in parallel. When receiving the divided voltage, the CPU 23 determines that the storage battery is attached and sends a closing signal to the relay contact SW. When the relay contact SW is closed, the rechargeable storage battery B starts to be discharged.

The regulator Reg functions to keep the value of the discharge current I _o constant. Specifically, the regulator Reg includes an internal reference voltage V _REF and a current detection resistor R3.
Voltage V _R3 across both ends of When the voltage V _R3 is higher than the reference voltage V _REF , the anode-cathode voltage V _AK
(That is, the base voltage of the transistor Tr) is reduced to reduce the discharge current. On the contrary, when the voltage V _R3 is smaller than the reference voltage V _REF , the anode-cathode voltage V _AK is reduced and the discharge current is increased. Therefore, the discharge current I _o is kept at V _REF / R3. In this example, μpc1093 manufactured by NEC Corporation was used as the regulator Reg.

In the constant current discharge circuit 32, R
1:40 kΩ, R2: 10 kΩ, R3: 1.2 kΩ, R
It was set to 4: 1.2Ω and R5: 100Ω.

Next, a battery life determining method in this apparatus will be described with reference to FIGS. Prior to battery life determination, the operator first sets the changeover switch shown in FIG. 3 to the nominal battery capacity of the rechargeable storage battery to be determined. The nominal battery capacity set by this is RA
It is stored in M27. Then, the fully charged rechargeable storage battery is mounted on the constant current discharging circuit 32 shown in FIG.

The CPU 23 controls the voltage V _R2 across the resistor _R2.
To detect. The voltage V _R2 is “0” when the rechargeable storage battery is not attached, and when the rechargeable storage battery is attached, the voltage V _R2 has a divided voltage value according to the voltage of the rechargeable storage battery. That is, the CPU 23 determines whether or not the rechargeable storage battery is attached by detecting this partial pressure value (step ST1 in FIG. 5). When the rechargeable storage battery is mounted, the CPU 23 calculates the voltage of the mounted rechargeable storage battery at the start of discharging, based on the divided voltage (step ST2). In this example, R1: 4
Since it is 0 kΩ and R2: 10 kΩ, the voltage at the start of the discharge can be obtained by multiplying the voltage V _R2 by 5.

Next, the CPU 23 displays the calculated voltage value at the start of discharge on the segments 41 and 42 of the liquid crystal display shown in FIG. Furthermore, with this voltage value,
The nominal voltage of the rechargeable storage battery to be judged, which is stored in advance in the RAM 27 by an input means (not shown), is compared, and if the nominal voltage is larger, step ST1
3, the voltage life display section 43 is turned on, and a signal is further output to the buzzer 36 shown in FIG.
Sounds. Thereby, the operator can determine that the attached rechargeable storage battery has the cells destroyed.

On the other hand, if the nominal voltage is smaller in step ST3 in FIG. 5, the process proceeds to step ST4, and the CPU 23 sends a closing signal to the relay contact SW (see FIG. 4). As a result, discharge is started. CPU
At the same time as this discharge, 23 starts measuring the clock signal given from the clock 29 (step ST in FIG. 5).
5).

The CPU 23 monitors the divided voltage and continues this monitoring until it matches the discharge end voltage (step ST6). When the divided voltage and the discharge end voltage match, it is determined that the discharge has ended, and the CPU 23 ends the clock signal measurement (step ST7). In addition,
The discharge end voltage is generally 1.0 V / cell.
In this example, since the rechargeable storage battery having a nominal voltage of 12V was used, the discharge end voltage was 10V.

The CPU 23, based on the measured clock signal and the constant discharge current value in the constant current circuit 32,
The discharge capacity is calculated, and the obtained discharge capacity is set to the segment 51 to
It is displayed on 54 (step ST9). Next, CPU2
3 indicates that the discharge capacity calculated in step ST9 is RAM
What percentage (proportion) of the nominal battery capacity stored in 27 is calculated (step ST21 in FIG. 6). CPU
23, the discharge capacity calculated in step ST9 is RA
It is determined whether or not it is 50% or more of the nominal battery capacity stored in M27 (step ST22), and if it is less than 50%, the process proceeds to step ST23. In step ST23, the CPU 23 lights the discharge capacity life display portion 55 of the liquid crystal display 34, outputs a signal to the buzzer 36 shown in FIG. 2, and sounds the buzzer 36. This allows the operator to determine that the rechargeable storage battery has reached the end of its life. If the ratio obtained in step ST22 is 50% or more, the process ends. Thus, in this embodiment, the limit ratio is set to 50%,
The battery life was judged.

The CPU 23 then proceeds to step ST24.
At, it is determined whether the discharge voltage of the rechargeable storage battery B has reached the discharge stop voltage, and when the discharge voltage of the rechargeable storage battery B becomes equal to the discharge stop voltage, the process proceeds to step ST25. In step ST25, the CPU 23 turns off the relay contact SW (step ST8). This ends the discharge. The discharge stop voltage is set to a voltage at which the rechargeable storage battery B is not over-discharged, and in this embodiment, it is set to 6V which is 50% of the nominal voltage.

As described above, by obtaining the measurement time until the discharge voltage of the rechargeable storage battery B matches the discharge end voltage, the discharge capacity of the rechargeable storage battery to be measured can be obtained.

Further, in this embodiment, even if the discharge voltage of the rechargeable storage battery B coincides with the discharge end voltage, the discharge of the rechargeable storage battery B is continued only by ending the measurement of the measurement time. Therefore, the rechargeable storage battery B is in a state of being discharged to a voltage lower than the final discharge voltage. As a result, with respect to the rechargeable storage battery whose capacity is temporarily reduced, if it is recharged by the charging device and judged again by this device, it returns to the normal state. On the other hand, when the life is exhausted, the same result is obtained even if the judgment is performed again. This makes it possible to easily determine the life.

Such determination will be described in detail with reference to FIG. FIG. 10 is a diagram showing the relationship between time and discharge voltage when the device discharges at a constant current. When the rechargeable storage battery to be determined is normal, as shown by the characteristic curve 100, measurement is performed until time t ₀₂ , and discharge is performed at time t _01.
Is done until. In the present embodiment, the discharge current was set to 2 A, so the discharge capacity was 2 × t ₀ . On the contrary,
As shown by the characteristic curve 102, when the measurement is performed only until the time t ₁ , the discharge capacity becomes 2 × t ₁ . When this is less than 50% of the nominal battery capacity, the discharge capacity life display section 55 lights up, and it can be determined that this rechargeable storage battery has reached the end of life.

As shown by the characteristic curve 104, even when the capacity is temporarily reduced, the measurement is performed only until time t ₃ , and the discharge capacity is displayed as 2 × t ₃ . However, in this device, the discharge is performed until time t ₀₁ when the discharge stop voltage is reached. Therefore, the battery is completely refreshed (discharged to the discharge end voltage or lower), and the normal state is restored when the battery is charged again by the charging device. The same applies when the memory effect causes a further decrease in capacity as shown by the characteristic curve 106.

As described above, the normal rechargeable storage battery is OK in the first determination, and the rechargeable storage battery having the temporary capacity decrease can be determined by the determination again. That is, with respect to those that are not a temporary capacity decrease, almost the same discharge capacity is notified even in the second determination.

When the voltage at the start of discharge is lower than the nominal voltage, a characteristic curve 109 is shown.

Although the voltage life display section 43 or the discharge capacity life display section 55 is turned on in this embodiment, it may be turned on or off. In that case, you may make it change a blinking interval according to the calculated ratio.

In this embodiment, the liquid crystal display 34 is used as the informing means, but any device can be used as long as it can inform the operator of the life. That is, in this embodiment, the discharge capacity or voltage of the rechargeable storage battery at the time of full charge is displayed, and the life is displayed if the discharge capacity or voltage is less than the predetermined value. However, without being limited to this, instead of displaying the discharge capacity or voltage of the rechargeable storage battery to be determined, only the ratio of the rechargeable storage battery to the nominal battery capacity or voltage may be displayed. With this, the operator does not have to calculate the ratio by himself.
The life of the rechargeable storage battery can be intuitively determined. For example, as shown in FIG. 7, the LEDs 71 to 74 may notify the discharge capacity, and the LED 77 may notify the cell short circuit or the like. In this case, if the discharge capacity of the fully charged rechargeable storage battery is less than 50%, only the LED 71 is turned on. If the discharge capacity is less than 50% to 70%, the LEDs 71 and 72 are turned on and 70% to less than 90%. If so, the LED 71,
72, 73 are turned on, and if 90% or more, LED7
It suffices to turn on 1 to 74. Furthermore, LE
D71 to 74 having different emission colors may be used. In this way, the operator can more easily make a judgment by arranging such that the display visually changing according to the ratio of the discharge capacity to the nominal battery capacity is performed.

The flow chart in this case is shown in FIG.
This will be described using 1. In this case, the same applies to the flowchart of FIG. In step ST31 of FIG. 11, the CPU 23 determines the discharge capacity calculated in step ST9 of FIG.
The percentage (proportion) of the nominal battery capacity stored in M27 is calculated.

Next, the CPU 23 determines that the calculated discharge capacity is 50% of the nominal battery capacity stored in the RAM 27.
It is determined whether or not it is above (step ST32), and 50%
If it is less than, it proceeds to step ST33. Step ST
In 33, the CPU 23 turns on the LED 71, outputs a signal to the buzzer 36 shown in FIG. 2, and sounds the buzzer 36. This allows the operator to determine that the rechargeable storage battery has reached the end of its life.

The ratio obtained in step ST32 is 50%
If it is more than the above, the process proceeds to step ST34 and the LED 7
Turn on 2. Next, the CPU 23 determines whether the calculated discharge capacity is 70% or more of the nominal battery capacity (step ST35), and if less than 70%,
finish. On the other hand, if 70% or more, step ST3
Proceed to step 6 and turn on the LED 73. Next, CPU2
3 is the calculated discharge capacity is 9 of the nominal battery capacity.
It is judged whether it is 0% or more (step ST37), 9
If it is less than 0%, the process ends. On the other hand, if it is 90% or more, the process proceeds to step ST38 and the LED 74 is turned on.

As shown in FIG. 8, LEDs 81 to 8
The discharge capacity may be indicated by 4 and the cell short circuit or the like may be indicated by the LED 87.

Further, in FIG. 7 and FIG. 8, four LEDs are used to inform the discharge capacity, but four LEDs are not always necessary, and
For example, it is possible to make a notification with one LED. In this case, for example, if it is 90% or more, the LED is continuously turned on, and if it is less than 90%, the ratio of the LED lighting time and the extinguishing time is changed or the blinking ratio is changed according to the ratio. It is also possible to give some kind of display change, such as changing the absolute time in continuous flashing.

It should be noted that, in addition to ordinary LEDs, multicolor light emitting LEDs
May be used.

Further, in the present embodiment, the slide switch is used as the changeover switch, but any other changeover switch may be adopted. For example, a rotary switch as shown in FIG. 8 may be adopted, or
Any method such as displaying and selecting a preset value with a selection button (not shown) may be adopted.

The CPU 23 outputs a signal to the buzzer 36 when the discharge capacity ratio or the voltage is below a predetermined value. That is, the buzzer 36 is sounded only when the battery life is reached, but the buzzer 36 may be sounded even when the battery life is not exhausted. In this case, the sound quality or the sound volume may be changed according to the ratio of the discharge capacity or the voltage.

Further, although the constant current discharge circuit is used in this embodiment, any discharge circuit may be adopted as long as the discharge time does not become long. In the case of a circuit that does not discharge with a constant current, the discharge capacity can be obtained by integrating the discharged current.

In this embodiment, the discharge capacity is calculated based on the discharge current value and the measurement time until the discharge end voltage is reached, and the ratio to the nominal discharge capacity is calculated. However, without being limited to this, the nominal discharge capacity is divided by the discharge current value, the standard time is obtained and stored in advance, and the ratio of the measurement time until the discharge end voltage is reached to the standard time, You may ask.

In this embodiment, the case of using the NiCd battery as the rechargeable storage battery has been described, but any rechargeable storage battery may be used, for example, a nickel hydrogen battery or the like. .

In the above embodiment, even if the discharge voltage of the rechargeable storage battery to be judged becomes the discharge end voltage and the measurement is completed, the discharge is performed up to the discharge stop voltage. However, the present invention is not limited to this, and the discharge may be terminated at the discharge end voltage. Even in this case, it is possible to perform the refresh for discharging up to the discharge end voltage.

If there is no problem of over-discharge of the rechargeable storage battery to be judged, the discharge stopping means may be omitted. Further, the discharge stopping means may stop the discharge at a voltage other than the detected voltage. For example, the discharge may be stopped after a lapse of a predetermined time from the time when the discharge cutoff voltage is reached.

In the case of a temporary capacity decrease, FIG.
As shown in, the battery is discharged for a while near the discharge cutoff voltage. Therefore, when such a state is detected, it may be notified that the capacity is temporarily reduced.
This makes the determination of battery life more reliable.

[0072]

According to the battery life determining apparatus for a rechargeable storage battery of claim 1, the fully charged rechargeable storage battery is:
Rechargeable storage battery discharging means for obtaining a measurement time until the discharge voltage to be detected reaches the discharge end voltage while performing discharge while maintaining the discharge current at a predetermined constant current value, the measurement time and the predetermined constant current value. On the basis of the above, a discharge capacity calculating means for calculating the discharge capacity of the rechargeable storage battery and a discharge capacity notifying means for notifying the discharge capacity calculated by the discharge capacity calculating means are provided.

Therefore, the battery life of the fully charged rechargeable storage battery can be determined based on the discharge capacity until the discharge voltage matches the discharge end voltage. Since the discharge is performed with a constant current, the measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant. Accordingly, it is possible to provide a battery life determination device for a rechargeable storage battery that can easily determine the battery life of the rechargeable storage battery.

In the battery life determining apparatus for a rechargeable storage battery according to a second aspect of the present invention, the fully charged rechargeable storage battery is discharged by holding the discharge current at a predetermined constant current value and the discharge voltage to be detected is discharged. Rechargeable storage battery discharging means for obtaining the measurement time until reaching the cutoff voltage, discharge capacity calculation means for calculating the discharge capacity of the rechargeable storage battery based on the measurement time and the predetermined constant current value, nominal of the rechargeable storage battery Nominal battery capacity storage means for storing a battery capacity, ratio calculation means for calculating a ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity stored in the nominal battery capacity storage means, calculated by the ratio calculation means A ratio notifying unit for notifying a different ratio is provided.

Therefore, the battery life of the fully charged rechargeable storage battery can be determined based on the ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity. Therefore, the operator can judge the life without comparing the discharge capacity with the nominal discharge capacity. In addition,
Since the discharge is performed with a constant current, the measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant.

That is, it is possible to provide a battery life determining device for a rechargeable storage battery which can easily determine the battery life of the rechargeable storage battery.

In the battery life determining apparatus for a rechargeable storage battery according to a third aspect of the present invention, the fully charged rechargeable storage battery is discharged while the discharge current is maintained at a predetermined constant current value, and the detected discharge voltage is discharged. Rechargeable storage battery discharging means for obtaining a measurement time until reaching the cutoff voltage, standard time storage means for storing a standard battery capacity of the rechargeable storage battery and a standard time calculated based on the predetermined constant current value, for the standard time By calculating the ratio of the measurement time,
A ratio calculation unit for calculating a ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity, and a ratio notification unit for notifying a ratio calculated by the ratio calculation unit are provided.

Therefore, the battery life of the fully charged rechargeable storage battery can be determined based on the ratio of the measurement time to the standard time without the operator himself comparing the discharge capacity with the nominal discharge capacity.

Since the discharge is performed with a constant current,
The measurement time can be shortened as a whole, and there is no problem such as heating because the current to the circuit is constant.

That is, it is possible to provide a battery life determining device for a rechargeable storage battery, which can easily determine the battery life of the rechargeable storage battery.

In the battery life determining apparatus according to claim 4,
The ratio notifying unit has a battery life display unit that visually displays a change according to the ratio of the discharge capacity to the nominal battery capacity. Therefore, the operator can visually and easily make the life judgment. Accordingly, it is possible to provide a battery life determination device for a rechargeable storage battery that can easily determine the battery life of the rechargeable storage battery.

In the battery life determining apparatus according to claim 5,
A limit ratio storage unit for storing a limit ratio in the ratio of the discharge capacity to the nominal battery capacity is provided, and the ratio informing unit gives an alarm when the ratio of the discharge capacity to the nominal battery capacity is lower than the limit ratio. It has a limit ratio warning unit. Therefore, the operator can judge the life by the alarm. Accordingly, it is possible to provide a battery life determination device for a rechargeable storage battery that can easily determine the battery life of the rechargeable storage battery.

In the battery life judging device of claim 6,
The rechargeable storage battery discharging means is a1) a constant current discharging means for discharging the rechargeable storage battery while holding the discharge current at a predetermined constant current value, a2) a voltage detecting means for detecting the discharge voltage of the rechargeable storage battery. And a3) provided with a time measuring means for obtaining a measurement time until the discharge voltage reaches the discharge end voltage,
Further, B) voltage notification means for notifying the voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharging is provided. Therefore, it is possible to determine whether or not a cell short circuit or the like has occurred in the fully charged rechargeable storage battery. Accordingly, it is possible to provide a battery life determination device for a rechargeable storage battery that can easily determine the battery life of the rechargeable storage battery.

In the battery life determining device according to claim 7,
The rechargeable storage battery discharging means is a1) a constant current discharging means for discharging the rechargeable storage battery while holding the discharge current at a predetermined constant current value, a2) a voltage detecting means for detecting the discharge voltage of the rechargeable storage battery. And a3) provided with a time measuring means for obtaining a measurement time until the discharge voltage reaches the discharge end voltage,
Further, B) the nominal voltage of the rechargeable storage battery is compared with the detection voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharging, and an alarm is issued when the detection voltage is lower than the nominal voltage. Equipped with voltage warning means. Therefore, the operator can determine whether or not a cell short circuit or the like has occurred in the rechargeable storage battery that has been fully charged by the alarm. Accordingly, it is possible to provide a battery life determination device for a rechargeable storage battery that can easily determine the battery life of the rechargeable storage battery.

In the battery life determining device according to claim 8,
The rechargeable storage battery discharging means has a discharge stopping means for stopping the discharge in the constant current discharging means when the detected voltage of the rechargeable storage battery reaches a preset discharge stop voltage. In this way, the discharge is continued until the discharge stop voltage is reached even after the discharge end voltage is reached.
Therefore, the rechargeable storage battery can be discharged to a discharge stop voltage lower than the discharge end voltage. Thus, it is possible to provide a battery life determination device for a rechargeable storage battery, which can determine the battery life by discharging the rechargeable storage battery to the discharge end voltage or lower without causing over-discharge.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a battery life determination device 1 according to the present invention.

FIG. 2 is a diagram showing a hardware configuration using a CPU of the battery life determining apparatus 1.

FIG. 3 is a diagram of a liquid crystal panel 34 of the battery life determining apparatus 1.

FIG. 4 is a diagram showing a constant current discharge circuit 32.

5 is an operation flowchart of the battery life determination device 1. FIG.

FIG. 6 is an operation flowchart of the battery life determination device 1.

FIG. 7 is a diagram showing another example of notifying the battery life.

FIG. 8 is a diagram showing another embodiment for notifying the battery life.

FIG. 9 is an overall configuration diagram of a battery life determination device 1.

FIG. 10 is a diagram for explaining a measurement result in the battery life determining apparatus 1.

11 is an operation flowchart of the embodiment shown in FIG.

[Explanation of symbols]

 2 ... Rechargeable battery discharging means 3 ... Voltage detecting means 5 ... Constant current discharging means 7 ... Discharge stopping means 8 ...・ ・ ・ ・ ・ Discharge capacity calculation means 9 ・ ・ ・ ・ ・ Ratio calculation means 11 ・ ・ ・ ・ ・ ・ Timekeeping means 13 ・ ・ ・ ・ ・ ・ Nominal voltage storage means 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Nominal battery capacity Storage means 17 ... Limit limit storage means 19 .. Ratio notification means

Claims (8)

[Claims] 1. A rechargeable storage battery for fully charged rechargeable storage battery, in which the discharge current is held at a predetermined constant current value for discharging and a measurement time until the detected discharge voltage reaches the discharge end voltage is obtained. Discharging means, based on the measurement time and the predetermined constant current value, a discharge capacity calculating means for calculating the discharge capacity of the rechargeable storage battery, a discharge capacity notifying means for notifying the discharge capacity calculated by the discharge capacity calculating means, A battery life determining device comprising: 2. A rechargeable storage battery for fully charged rechargeable storage battery, in which the discharge current is held at a predetermined constant current value for discharging, and a measurement time until the discharge voltage to be detected reaches the discharge end voltage is obtained. Discharging means, discharge capacity calculating means for calculating the discharge capacity of the rechargeable storage battery based on the measurement time and the predetermined constant current value, nominal battery capacity storage means for storing the nominal battery capacity of the rechargeable storage battery, the nominal Ratio calculating means for calculating the ratio of the discharge capacity of the rechargeable storage battery to the nominal battery capacity stored in the battery capacity storing means, ratio notifying means for notifying the ratio calculated by the ratio calculating means, Battery life determination device characterized by. 3. A rechargeable storage battery for fully charged rechargeable storage battery, in which the discharge current is held at a predetermined constant current value for discharging, and the measured time until the discharge voltage to be detected reaches the discharge end voltage is obtained. Discharging means, a standard time storage means for storing a standard battery capacity of a rechargeable storage battery and a standard time calculated based on the predetermined constant current value, the nominal time by calculating a ratio of the measurement time to the standard time, A battery life determining device comprising: a ratio calculation unit that calculates a ratio of the discharge capacity of the rechargeable storage battery to a battery capacity; and a ratio notification unit that notifies the ratio calculated by the ratio calculation unit. 4. The battery life determining apparatus according to claim 2 or 3, wherein the ratio notifying unit visually displays a change according to the ratio of the discharge capacity to the nominal battery capacity. A battery life determining device having a battery life display unit. 5. The battery life determination device according to claim 2, 3, or 4, further comprising: a limit ratio storage unit that stores a limit ratio of a ratio of the discharge capacity to the nominal battery capacity. A means for battery life determination, characterized in that the means has a limit ratio alarm unit for issuing an alarm when the ratio of the discharge capacity to the nominal battery capacity is lower than the limit ratio. 6. Claim 1, claim 2, claim 3, claim 4
Alternatively, in the battery life determining apparatus according to claim 5, A) the rechargeable storage battery discharging means includes the following a1), a2), and a3), and a1) holds the discharge current at a predetermined constant current value. While, constant current discharging means for discharging the rechargeable storage battery, a2) voltage detection means for detecting the discharge voltage of the rechargeable storage battery, a3) time measuring means for determining the measurement time until the discharge voltage reaches the discharge end voltage, B) A battery life determining device, further comprising a voltage notifying unit for notifying the voltage of the rechargeable storage battery detected by the voltage detecting unit at the start of discharging. 7. Claim 1, claim 2, claim 3, claim 4
Alternatively, in the battery life determining apparatus according to claim 5, A) the rechargeable storage battery discharging means includes the following a1), a2) and a3), and a1) while maintaining the discharge current at a predetermined constant current value. A constant current discharging means for discharging the rechargeable storage battery, a2) voltage detection means for detecting the discharge voltage of the rechargeable storage battery, a3) time measuring means for obtaining a measurement time until the discharge voltage reaches the discharge end voltage, B ) Furthermore, the nominal voltage of the rechargeable storage battery is compared with the detection voltage of the rechargeable storage battery detected by the voltage detection means at the start of discharge, and when the detected voltage is lower than the nominal voltage, an alarm voltage is issued. A battery life determining device characterized by comprising an alarm means. 8. The battery life determining device according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6 or claim 7, wherein the rechargeable storage battery discharging means detects a charge. A battery life determining device comprising: a discharge stopping means for stopping the discharge in the constant current discharging means when the voltage of the storage battery reaches a preset discharge stopping voltage.