JPH10319101A - Device and method for detecting degree of deterioration of battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the replacement period of a rechargeable battery from scattering and to obtain its stable usage period by providing an arithmetic operator for calculating the degree of deterioration of the rechargeable battery from the ratio of the amount of integration of a discharge current by a current integrator to a rechargeable battery standard. SOLUTION: A rechargeable battery 6 is placed to the detection position of a device 1 for detecting the degree of deterioration and a switch 7 is closed and the rechargeable battery 6 is fully charged. At this time, the charging of the rechargeable battery 6 is controlled by a charger 6. Charging is completed when the charger 6 is fully charged and the switch 7 is opened. Then, a switch 9 opened and a discharge current is integrated while discharging the rechargeable battery 6. In this case, the amount of integrated current is measured by a current integrator 4. Current is discharged to a discharge end voltage V that is prescribed by the rechargeable battery 6 by a discharger 3. When the discharge is completed, the switch 9 is opened. Then, the degree of deterioration of the rechargeable battery 6 is detected from the ratio of the amount of integration of the discharge current to a charger rating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus and a method for detecting the degree of deterioration of a rechargeable battery used for detecting the degree of deterioration of a rechargeable battery.

[0002]

2. Description of the Related Art In general, it is known that a rechargeable battery has a characteristic that the amount of energy that can be discharged gradually decreases due to repeated use or aging after manufacture. The state in which the performance of the rechargeable battery has deteriorated due to these characteristics and has been degraded to a predetermined performance is defined as "life of the rechargeable battery", and the number of times of charge / discharge n until reaching this state is called "cycle life n".

[0003] Normally, the charge and discharge of about 300 times, the initial capacity of 6
The performance deteriorates to 0%, which is defined as the life. In this case, the cycle life is about 300 times. By the way, it is convenient for the user to detect the degree of deterioration of the rechargeable battery and to know the life of the rechargeable battery in advance so as to reliably know the time of replacement (replacement) of the rechargeable battery.

Conventionally, a device for detecting the degree of deterioration of a rechargeable battery of this type includes, for example, "NICD"
As the "rechargeable battery pack", the one disclosed as "rechargeable battery pack" in JP-A-5-011033 is employed.

[0005] This is based on the battery characteristic that the discharge capacity is gradually reduced by repeatedly charging the rechargeable battery.
This is to detect the degree of deterioration of the rechargeable battery by the number of times of charging instead of the discharge capacity that cannot be directly measured. For example, the discharge capacity is reduced to about 60% of the battery rated capacity after about 300 to 500 charge / discharge cycles.

[0006]

However, in the conventional apparatus for detecting the degree of deterioration of a rechargeable battery, the degree of deterioration of the rechargeable battery is detected by the number of times of charging, so that the degree of deterioration of the rechargeable battery is accurately detected. I couldn't do that.

That is, the deterioration characteristic of the rechargeable battery is determined by the number of times of use,
This is because the degree of deterioration of the rechargeable battery is different depending on various factors such as a use environment, a discharge method, a battery storage method, and a secular change after manufacturing due to temperature and humidity.

[0008] For example, in a cordless telephone or the like, since it is constantly being charged when not in use, it is not possible to define what makes "one charge", and it is temporarily possible to use "up to 300 charges". ", The predetermined discharge capacity cannot be obtained even if the number of times is less than 300 depending on the usage environment.

[0009] As a result, there is a problem that variations occur in the replacement time of the rechargeable battery, and a stable use period of the rechargeable battery cannot be obtained.

[0010] The present invention has been made in view of such circumstances, and it is possible to prevent the occurrence of variations at the time of replacing the rechargeable battery, and to thereby obtain a stable rechargeable battery usage period. It is an object of the present invention to provide a degree detecting device and a method thereof.

[0011]

According to a first aspect of the present invention, there is provided a rechargeable battery deterioration detection apparatus for charging a rechargeable battery as a deterioration degree detection target. A discharger that discharges the rechargeable battery charged by the charger, a current integrator that integrates the discharge current of the rechargeable battery by the discharger, and a ratio of the integrated amount of discharge current by the current integrator to the rechargeable battery rating. And a calculator for calculating the degree of deterioration of the rechargeable battery.

According to a second aspect of the present invention, in the rechargeable battery deterioration degree detecting device according to the first aspect, a display device for displaying a calculation result of the deterioration degree is connected to the arithmetic unit.

According to a third aspect of the present invention, there is provided a method for detecting the degree of deterioration of a rechargeable battery, wherein the rechargeable battery to be subjected to the degree of deterioration detection is fully charged, and the discharge current is integrated while discharging the rechargeable battery. This is a method of detecting the degree of deterioration of the rechargeable battery from the ratio between the integrated amount of the discharge current and the rating of the rechargeable battery.

According to a fourth aspect of the present invention, there is provided the method for detecting the degree of deterioration of a rechargeable battery according to the third aspect, wherein the rechargeable batteries are a plurality of rechargeable batteries, and the degrees of deterioration of the rechargeable batteries are simultaneously detected.

According to a fifth aspect of the present invention, in the method for detecting the degree of deterioration of a rechargeable battery according to the third aspect, the rechargeable batteries are a plurality of rechargeable batteries, and the degree of deterioration of the rechargeable batteries is sequentially detected.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a block diagram showing an apparatus for detecting the degree of deterioration of a rechargeable battery according to the first embodiment of the present invention. In the figure, a deterioration degree detection device denoted by reference numeral 1 includes a charger 2, a discharger 3, a current integrator 4, and a calculator (not shown).
And a display device 5. Thereby, the deterioration degree of the rechargeable battery 6 as the deterioration degree detection target is detected.

The charger 2 charges and releases the rechargeable battery 6 by opening and closing the switch 7. That is, the rechargeable battery 6
It is charged when the switch 7 is closed and released when the switch 7 is open.

The discharger 3 discharges and releases the rechargeable battery 6 charged by the charger 2 by opening and closing a switch 8. That is, the rechargeable battery 6 is discharged when the switch 8 is closed and released when the switch 8 is open.

The current integrator 4 integrates and stops the integration of the discharge current of the rechargeable battery 6 by the discharger 3 by opening and closing the switch 9. That is, the discharge current is integrated while the rechargeable battery 6 discharges when the switch 9 is closed. Also,
When the switch 9 is open, both the discharging and the current integration are stopped.

The arithmetic unit (not shown) is built in a controller (not shown). Thereby, the current integrator 4
Of discharge current (ymAH) and rechargeable battery rating (x
mAH), the degree of deterioration of the rechargeable battery 6 is calculated.

The display device 5 includes a controller (not shown)
It is connected to the. Thus, the degree of deterioration of the rechargeable battery 6 is determined by the integrated current value (ymAH) with respect to the rechargeable battery rating (xmAH).
Is displayed as the ratio (%) of In addition, each switch 7-9
Is controlled by a controller (not shown).

Next, a method for detecting the degree of deterioration of a rechargeable battery according to the first embodiment of the present invention will be described with reference to FIG. First, the rechargeable battery 6 is attached to the detection position of the deterioration degree detecting device 1, and the switch 7 is closed to fully charge the rechargeable battery 6. At this time, charging of the rechargeable battery 6 is controlled by the charger 2. When the rechargeable battery 6 is fully charged, the charging ends, and the switch 7 is opened. Further, the switches 8 and 9 remain open.

Next, the switch 9 is closed and the rechargeable battery 6 is closed.
, And integrate this discharge current. At this time, the discharge current from the rechargeable battery 6 is supplied to the current integrator 4, the discharger 3
Is consumed by flowing. In this case, the current integrator 4 measures the amount of integrated current as the integral of the portion shown by hatching in FIG. Further, in the discharger 3, the discharge of the rechargeable battery 6 is performed up to the discharge end voltage V0 defined by the rechargeable battery 6 as shown in FIG. When this discharge is completed, the switch 9 is opened.

Thereafter, the integrated amount of discharge current (ymAH)
The degree of deterioration of the rechargeable battery 6 is detected from the ratio of the rechargeable battery 6 and the rechargeable battery rating (xmAH). At this time, the ratio of the current integration amount to the rechargeable battery rating is calculated by a calculator (not shown), and the degree of deterioration is displayed on the display device 5 from the calculation result. Thus, the degree of deterioration of the rechargeable battery can be detected.

Although the present embodiment has been described with respect to an example used for detecting the degree of deterioration of the rechargeable battery 6, the present invention is not limited to this. When charging the rechargeable battery 6 (1), simply charging the rechargeable battery 6 (2), or using NiCd or Ni
It can also be used in the case of simply charging / discharging (discharge is forced discharge) a rechargeable battery having a memory effect such as an MH rechargeable battery (discharge is forced discharge) (3), and detecting the degree of deterioration and charging / discharging (4). .

First, the cases (1) and (2) (second embodiment) will be described with reference to FIG. FIG. 3 is a block diagram showing a rechargeable battery deterioration degree detecting device according to a second embodiment of the present invention. In FIG. 3, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, a deterioration detection device indicated by reference numeral 31 includes the deterioration detection device 1, and includes a display device 32 and an operation switch 33. The display device 32 displays three states: charging, completion of charging, and detection of the degree of deterioration.

The operation switch 33 has a switch 33a and a switch 33b. As a result, "only charge" or "charge while detecting deterioration degree" is selected. That is, when "only charging" is performed, the a side of the switch 33a is closed,
In the case of "charging while detecting the degree of deterioration", the switch 33a is closed and the switch 33b is closed.

After detecting the degree of deterioration of the rechargeable battery 6 in the first embodiment, the switch 7 is closed to charge the battery.

Next, the cases (3) and (4) (third embodiment) will be described with reference to FIG. In the figure, in the case of simply charging / discharging the rechargeable battery 6 (3), after the switch 8 is closed and forcedly discharged, the switch 8 is opened and the switch 7 is closed to charge.

In FIG. 3, when the degree of deterioration of the rechargeable battery 6 is detected and charging / discharging is performed (4), the switch 8 is first closed and forced discharge is performed, and then the switch 8 is opened and the first operation is performed. The degree of deterioration of the rechargeable battery 6 in the embodiment is detected (the switch 9 is closed), and then the switch 9 is opened and the switch 7 is closed to charge again.

Further, in each of the embodiments, the case where the deterioration degree detection is performed on a single rechargeable battery 6 has been described. However, the present invention is not limited to this, and the deterioration degree detection apparatus shown in FIG. By using 41 (fourth embodiment), it can be performed for a plurality of rechargeable batteries 6. in this case,
By using a plurality of deterioration degree detection devices 1, deterioration degree detection of each rechargeable battery 6 is performed simultaneously or sequentially.

[0032]

As described above, according to the present invention, a charger for charging a rechargeable battery as a deterioration degree detection target, a discharger for discharging the rechargeable battery charged by the charger,
A current integrator for integrating the discharge current of the rechargeable battery by the discharger, and a calculator for calculating the degree of deterioration of the rechargeable battery from the ratio of the integrated amount of the discharge current by the current integrator to the rechargeable battery rating. In addition, an accurate degree of deterioration of the rechargeable battery is detected.

Therefore, it is possible to prevent the occurrence of variation at the time of replacing the rechargeable battery, so that a stable use period of the rechargeable battery can be obtained.

In addition, the fact that the degree of deterioration of the rechargeable battery is accurately detected does not mean that the rechargeable battery is discarded in a usable state, so that the rechargeable battery can be used effectively.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a rechargeable battery deterioration degree detecting device according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams showing discharge characteristics of a rechargeable battery.

FIG. 3 is a block diagram for explaining a rechargeable battery deterioration degree detecting device according to a second embodiment and a third embodiment of the present invention.

FIG. 4 is a block diagram schematically illustrating a rechargeable battery deterioration degree detection device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deterioration detection device 2 Charger 3 Discharger 4 Current integrator 5 Display device 6 Rechargeable battery

Claims (5)

[Claims] 1. A charger for charging a rechargeable battery as a deterioration degree detection target, a discharger for discharging a rechargeable battery charged by the charger, and a current for integrating a discharge current of the rechargeable battery by the discharger An apparatus for detecting the degree of deterioration of a rechargeable battery, comprising: an integrator; and a calculator for calculating the degree of deterioration of the rechargeable battery from a ratio between the integrated amount of discharge current by the current integrator and the rating of the rechargeable battery. 2. The rechargeable battery deterioration degree detecting device according to claim 1, wherein a display device for displaying a deterioration degree calculation result is connected to the arithmetic unit. 3. A full charge of a rechargeable battery as a deterioration detection target, and then integrating the discharge current while discharging the rechargeable battery, and then a ratio of the integrated amount of the discharge current to the rechargeable battery rating. Detecting the degree of deterioration of the rechargeable battery from the following. 4. The method for detecting the degree of deterioration of a rechargeable battery according to claim 3, wherein the rechargeable batteries are a plurality of rechargeable batteries, and the degrees of deterioration of the rechargeable batteries are simultaneously detected. 5. The method for detecting the degree of deterioration of a rechargeable battery according to claim 3, wherein the rechargeable batteries are a plurality of rechargeable batteries, and the degrees of deterioration of the rechargeable batteries are sequentially detected.