JPH06341954A - Battery electric capacity measuring method and its device - Google Patents

Abstract

PURPOSE:To enable the accurate and continuous measurement of specific gravity of electrolyte or electric capacity of a battery without being influenced by outside environment by irradiating battery electrolyte with infrared light to make it absorb infrared light and measuring intensity of its transmission light. CONSTITUTION:With light which contains infrared region component of wavelength of 690 to 2000nm, battery electrolyte (including battery electrolyte) is irradiated, and intensity of the light after it passes the battery electrolyte is received and measured. Specific gravity of electrolyte and electric capacity are in comparatively accurate correspondence relation, and there is also correlation between intensity of infrared transmission light and specific gravity of electrolyte. Therefore, if correlation between transmission intensity of infrared light and specific gravity or electric capacity of electrolyte is obtained in advance, it is possible to convert intensity of transmission light into specific gravity of electrolyte or electric capacity of battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for continuously and optically measuring the electric capacity of a storage battery.

[0002]

2. Description of the Related Art As a method for knowing the electric capacity of a storage battery (for example, a lead-sulfuric acid battery), an electric method for measuring the terminal voltage of the storage battery, a method for measuring the specific gravity of an electrolytic solution,
An optical refractive index method and the like are known. Among these, in the method of measuring the specific gravity of the electrolytic solution, a float type method in which the electrolytic solution is sucked up into a glass dropper containing a graduated float and the position of the float is read is the mainstream. The optical refractive index method is a method in which the storage battery electrolyte is placed in contact with the surface of optical elements such as optical fibers and prisms, and the intensity and position of light that passes through the optical elements is measured. This utilizes a phenomenon in which the refractive index of the liquid changes and the intensity and position of the light transmitted through the optical element in contact with the electrolytic solution also change at the same time.

[0003]

However, in the electric method for measuring the terminal voltage described above, when the storage battery is aged or the temperature is low, a large error occurs due to the degree of deterioration of the storage battery. It was difficult to know the electric capacity accurately. Moreover, with this electrical method, when a storage battery ages, it becomes exhausted in a short time and cannot be used.At this time, if the storage battery is recharged and all storage batteries are inspected, the terminal voltage will be fully charged. Since it shows the voltage at the time and the specific gravity of the electrolyte satisfies the specified value at the time of full charge, it is not easy to judge the degree of deterioration of the storage battery by an electrical method, and it is particularly difficult to detect the life at an early stage. .

Further, the method of measuring the specific gravity of the electrolytic solution allows the electric capacity of the storage battery to be known relatively accurately, but when the liquid temperature of the storage battery electrolyte changes from room temperature, the electric capacity of the storage battery can be accurately predicted. There was a flaw that I could not do. Even if the specific gravity is measured with the liquid temperature kept constant, the liquid with a high specific gravity sinks to the bottom of the battery, and the liquid with a low specific gravity floats on the liquid surface of the battery. Have to wait until they are sufficiently evenly mixed, and there is a time lag in the relationship between the specific gravity of the electrolyte to be measured and the electrical capacity of the storage battery. It was difficult to know the electric capacity of the storage battery. The float-type specific gravity measurement is weak against vibration and vertical movement of the liquid surface, and is not suitable for measuring the capacity of a storage battery installed in an electric vehicle.

In the optical refractive index method, since only the refractive index of the electrolytic solution in contact with the optical element can be measured, the specific gravity of the electrolytic solution is distributed inside the storage battery, the contact surface between the optical element and the electrolytic solution, and the like. When the liquid surface is disturbed or dirty, the error between the measured value and the actual value tends to increase. Further, since the accuracy of the contact surface is strictly required and the positional information of the incident light is also required, a sensor such as CCD is required, which complicates the configuration.

[0006]

In order to solve these problems, it was thought that the problem could be solved if the change in the storage battery electrolyte could be observed by a method other than the method described above. As a result of consideration, since the storage battery electrolyte is always in contact with the electrode substance and the electrode substance and the storage battery electrolyte react by an electrochemical reaction to release electric energy, the storage battery electrolyte contains no Some substances are ionized and melted. Usually, in order to know such eluted ions, it was noted that absorptiometric analysis is often performed.

Therefore, when the electrolyte solution before and after discharge of the storage battery was irradiated with light to be absorbed and the spectral spectrum of the transmitted light was measured, the characteristics as shown in FIG. 3 were obtained.
That is, in FIG. 3, the solid line is the absorption spectrum of the electrolytic solution before discharging the storage battery, and the dotted line is the absorption spectrum after discharging the storage battery. Comparing the solid line and the dotted line, it can be seen that the absorption spectrum in the wavelength range of about 1400 nm to about 1900 nm in the infrared region changes. And FIG.
Indicates the transmittance of the electrolytic solution, so that when the storage battery is discharged, the transmittance of about 1500 nm to about 1900 nm increases, and conversely, the transmittance of infrared rays of about 1400 nm to about 1500 nm decreases. I understand. Moreover, when the discharged storage battery is charged, the absorption spectrum of the dotted line portion of FIG. 3 returns to the absorption spectrum of the solid line portion. That is, the change in the transmitted light intensity in the infrared region at the above-mentioned wavelength is a reversible phenomenon. Therefore, it was considered that the electric capacity of the storage battery can be accurately known relatively easily by utilizing this phenomenon.

A method for measuring the electric capacity of a storage battery and a device therefor according to the present invention include a storage battery electrolytic solution (including a storage battery electrolyte).
Is irradiated with light containing an infrared region component (wavelength 690 nm to 2000 nm) to cause the substance constituting the storage battery electrolyte solution to absorb the light, and the light after passing through the storage battery electrolyte solution is measured and received. The light intensity is converted into an electric signal intensity and converted into a storage battery capacity.

As a method of converting the measured value into the storage battery capacity, the specific gravity of the electrolytic solution has a relatively accurate correspondence with the electric capacity (unless the storage battery is deteriorated), and Since there is a correlation between the infrared transmitted light intensity and the specific gravity of the same electrolytic solution, the correlation between the infrared light transmission intensity of the storage battery electrolytic solution and the specific gravity or the electric capacity is obtained in advance, and this relationship is used. There is a method of conversion. The relationship between the infrared light transmission intensity transmitted through the storage battery electrolyte and the specific gravity or the electric capacity is as shown in FIG. 4 or FIG. 5, for example. The electric capacity of the storage battery is determined by converting the light intensity obtained by the above measurement into the specific gravity or the electric capacity of the storage battery electrolyte using such a correlation.

In this method and apparatus, individual characteristics of the storage battery are experimentally measured in advance and once the correlation as shown in FIGS. 4 and 5 is obtained, thereafter, the correlation information will be obtained. Can be used to measure the electric capacity of the storage battery.
In addition, the relationship between infrared light transmission intensity and specific gravity or electric capacity is
It does not always have to be a straight line as shown in FIGS. 4 and 5. Furthermore, apart from the above, as a method of converting the measured value of the infrared light transmission intensity into the storage battery capacity, the infrared light transmission intensity of the storage battery electrolyte to be measured and the optical characteristics corresponding to the initial value of the storage battery electrolyte solution. There is a method of comparing the intensity of light transmitted through a standard sample having a value of or an electric signal value corresponding to the light intensity or its information.

Furthermore, each of the following embodiments is a desirable example of the method and apparatus for measuring the electric capacity of a storage battery according to the present invention. Measurement methods, such as wavelength-converting infrared light in the wavelength range for measurement, using electrical numerical values to control the charging and discharging states, and omitting procedures by automating some methods It is possible to implement with partial amendments and changes. In addition, the electrolyte constituting the battery such as the storage battery electrolyte may be a substance in any state such as liquid, solid, or gas as long as it is a substance that transmits light in the infrared region, and the electrolyte is a gel or solid battery. It is also possible to measure the electric capacity of. It should be noted that the light in the infrared region includes near-infrared light and far-infrared light, and FIG. 3 does not show the situation in which the absorption spectrum changes before and after discharge in the infrared region having a small wavelength. Will be described later.

[0012]

OPERATION FIG. 6 shows the state of charge / discharge reaction inside the storage battery. This reaction is the most typical reaction of a lead-sulfuric acid battery. From FIG. 6, the reaction in the reaction path a occurs during discharge, and the sulfuric acid of the storage battery electrolyte is consumed, and the lead oxide of the positive electrode 1 becomes lead sulfate, and the lead of the negative electrode 2 also becomes lead sulfate. Along with this, the concentration of sulfuric acid in the storage battery electrolyte decreases, and the specific gravity of the solution approaches that of water. Sulfuric acid is about 1400 in the infrared region
nm has an absorption peak at about 1900 nm, and compared with the absorption rate of water, the absorption rate of sulfuric acid is higher than that of water, so the transmitted light intensity of light in the infrared region at about 1500 nm to about 1900 nm is It increases as the battery discharges, that is, the specific gravity of the battery electrolyte decreases. This relationship is shown in FIG.

FIG. 4 shows the relationship between the light intensity transmitted through the storage battery electrolyte solution and the specific gravity of the storage battery electrolyte solution in the wavelength range of the infrared region. That is, it is shown that the transmitted light intensity increases as the specific gravity of the storage battery electrolyte decreases. Considering the specific gravity of the storage battery electrolyte as the electric capacity of the storage battery, the relationship as shown in FIG. 5 is established between the transmitted light intensity and the electric capacity. That is, the transmitted light intensity increases when the specific gravity of the storage battery electrolyte decreases due to discharge and the electricity amount of the storage battery decreases. At the time of charging, the reaction on the reaction path b in FIG. 6 occurs due to the electric energy input from the outside. That is, the lead sulfate of + electrode 1 becomes lead oxide, and the lead sulfate of − electrode 2 becomes lead.
As a result, the sulfuric acid that has been combined with the electrode substance is eluted as sulfuric acid ions in the storage battery electrolyte, and becomes sulfuric acid almost at the same time.
As a result, the concentration of sulfuric acid in the storage battery electrolyte solution increases, and conversely, the concentration of water decreases, so the transmitted light intensity of light in the infrared region decreases, and upon completion of charging, the transmitted light intensity before discharge is restored.

However, the above phenomenon may not return to the transmitted light intensity before discharge depending on the frequency of use of the storage battery and the degree of deterioration. In this case, it is either the case where the storage battery has deteriorated and has reached the end of its life, or the case where replenishment of water is necessary, and it can be determined by the intensity of the transmitted light of the infrared ray. In many cases, when the infrared light transmission intensity of the storage battery electrolyte after charging is higher than the initial value, the storage battery itself is in a state of deterioration, and conversely, the infrared light transmission intensity is higher than the initial value. If it is small, it is often necessary to replenish water. The opposite may occur depending on the state of the electrolyte, and in that case, the charge / discharge characteristics of the storage battery to be actually investigated must be investigated in advance by an electrical method and the method according to the present invention. In the conventional method, even when trying to know the life of the storage battery and the timing of replenishment of water, it was difficult because the specific gravity of the electrolytic solution did not change significantly when the storage battery was aged, but the measurement method according to the present invention was appropriate. Since the change in the state of the storage battery can be read, it is possible to easily determine the replacement time of the storage battery, the need for replenishing water, and the like.

Further, it is difficult to grasp the relationship between the amount of electricity of the storage battery and the specific gravity of the storage battery electrolyte by the terminal voltage of the storage battery, if it is a slight change, but in the measuring method of the present invention, the discharge is performed. Since the minute changes in the sulfuric acid concentration of the storage battery electrolyte can be continuously detected, the charging timing can be known early before the terminal voltage or the discharge current changes significantly. Further, since there is no need to correct the temperature of the storage battery electrolyte, the electric capacity of the storage battery can be effectively observed without being affected by the external environment.

[0016]

【Example】

Example 1 FIG. 1 is a flowchart showing a processing procedure of a measuring method according to Example 1. First, the infrared transmitted light intensity of the storage battery electrolyte used in the measured storage battery that has been charged is measured, and the specific gravity of the storage battery electrolyte is checked, and these are set as initial values (S1). Next, the measured storage battery is discharged at a current value calculated at a time rate of 10 hours or more. This discharge current value may be freely set as long as it does not affect the use and performance of the storage battery, but normally it is desirable to discharge at a current value calculated at a time rate of about 10 hours. During discharging, the specific gravity of the storage battery electrolyte and the infrared transmitted light intensity are continuously measured (S
2), the relationship corresponding to FIGS. 4 and 5 is obtained. A photoelectric conversion element such as a semiconductor or a photomultiplier tube may be used for measuring the light intensity. If the discharge stop condition is met, stop the discharge (S
3). The discharge stop condition is set to a value in which the specific gravity of the storage battery electrolyte is reduced by about 10% from the initial value. This value is a desirable value and is merely a guide, and may be a value other than this. Normally, the specific gravity of the storage battery electrolyte is 1.2
Since it is around 8, the specific gravity of the discharge stop condition is around 1.15. After the discharge is stopped, the specific gravity of the storage battery electrolyte and the infrared transmitted light intensity are measured again (S4).

A relationship corresponding to FIGS. 4 and 5 is obtained from the measured values of both of the above, and the relationship between the specific gravity of the storage battery electrolyte of the storage battery to be measured and the infrared transmitted light intensity is converted into a conversion formula (S5). In this way, once the conversion formula is once obtained by the first measurement, the infrared transmitted light intensity is only measured in the second and subsequent measurements performed after the storage battery to be measured is replaced or charged (S6). The specific gravity can be obtained by calculation using a conversion formula, and discharging and charging for normal use can be performed (S7 to S14). Considering that the specific gravity of the storage battery electrolyte is the electric capacity of the storage battery, it is possible to easily convert the consumption rate of the electric capacity. In addition, upon charging, if the specific gravity or the electric capacity of the storage battery electrolyte solution calculated by the above-mentioned conversion formula is restored to the initial value, then the charging completion condition is set.

Further, when the type of the storage battery or the storage battery itself is changed, it is desirable to change the above conversion formula, but it is effective unless the storage battery is changed, and if a slight error may be included. For example, the conversion formula may be used without being changed. Furthermore, the above process is usually performed by a measurement meter, but if the measurement is automated by adding a computer or electronic circuit means to the meter, it is possible to easily change the conversion formula. Therefore, the charge / discharge status of the storage battery can be managed very easily. The normal use in FIG. 1 indicates that this embodiment can be applied as a part of the measurement work performed every day. Further, when the storage batteries are replaced, even if there are variations in their performance, the variations can be corrected by performing the initial offset adjustment on the measurement meter side.

Second Embodiment FIG. 2 is a flow chart showing the processing procedure of the measuring method according to the second embodiment. In this embodiment, first, a standard sample having optical characteristics corresponding to the initial value of the storage battery electrolyte is set as a standard value, and the standard sample and a storage battery to be measured are prepared (S21), and infrared transmission of both of them is performed. By comparing and calculating the light intensities, the degree of consumption of the electric capacity of the storage battery to be measured and the specific gravity of the storage battery electrolyte can be converted by calculation, so that charging / discharging for normal use can be performed (S22 to S29). The standard sample corresponding to the initial value does not have to be the storage battery electrolyte, but may be made of other materials. Further, an electric signal value set electronically or information stored in a computer or the like can be used. Also,
If the characteristics of the standard sample are known, some deviations in the values can be corrected by calculation.
For example, when temperature characteristics are seen in the infrared light transmission intensity of the storage battery electrolyte, a standard sample having a similar relationship to the temperature characteristics of the storage battery electrolyte may be adopted for the optical characteristics of the standard sample. In this case, the standard sample Even if there is an offset of some value in, the offset can be corrected by calculation. Also, when the type of storage battery or the storage battery itself is changed, it can be dealt with by changing the standard sample.

In this way, the electric capacity of the storage battery and the specific gravity of the storage battery electrolyte can be converted by calculation simply by comparing the measured value of the transmitted light intensity of the storage battery to be measured with the value of the standard sample. The normal use in FIG. 2 indicates that the present embodiment can be applied as a part of the measurement work performed every day. The discharge stop condition in FIG. 2 is that the difference in infrared light transmission intensity between the standard sample and the storage battery electrolyte is 10%.
The discharge may be stopped at the time when it changes back and forth, but this numerical value is merely a guide and may be another value. The charging completion condition may be set to a time when the difference in infrared light transmission intensity between the standard sample and the storage battery electrolyte becomes zero.
As in the case of the first embodiment described above, if the series of procedures described above is automated by using a computer or electronic circuit means, it is possible to manage the charge / discharge status of the storage battery extremely easily.

The above-mentioned FIG. 3 did not show the fluctuation of the absorption spectrum before and after the discharge in the infrared wavelength region shorter than around 1300 nm, which has a low absorptance to the electrolyte solution, but in FIG. 7, the red of 1100 nm to 1300 nm is not shown. The state in the outer wavelength range and the absorption spectrum of water are added. If infrared light in a short wavelength range is used, the absorption rate is small, and therefore, measurement with a longer optical path length becomes possible. Although the optical path length was set to 1 mm in the measurement of FIGS. 3 and 7, it is possible to measure up to an optical path length of about 300 mm, but if the optical output characteristics of the light source are good, an optical path length longer than that can be used. It becomes possible to measure. In addition, FIG. 8 is a diagram paired with FIG. 7, and shows measurement data of changes in specific gravity and transmittance of the electrolyte with the passage of discharge time at various wavelengths of infrared light (1450, 1600, 1650 nm) (optical path length 1 mm )
Is. As can be seen from these figures, wavelengths 1500 to
The transmittance at 1900 nm increases with discharge,
The transmittance at 300 to 1500 nm decreases with discharge. The amount of change is small, but the wavelength is 1000 to 13
Even at 00 nm, the transmittance decreased with discharge (Fig. 7).

FIG. 9 is measurement data showing fluctuations in the absorption spectrum before and after discharge in the case where the optical path length is 10 mm, including a shorter infrared wavelength range. Fig. 10 is a pair with Fig. 9 and shows various wavelengths of infrared light (980, 1170, 1200 nm).
2 is measurement data of changes in specific gravity and transmittance of the electrolyte solution with the lapse of discharge time.

Next, a description will be given of an apparatus configuration example to which the measuring method of Embodiments 1 and 2 (FIGS. 1 and 2) described above is applied. FIG. 11 shows the case of Example 1, in which sample 10 is an electrolyte solution of a storage battery to be measured, and red light emitted from a light source 11 (LED, coherent light source such as semiconductor laser diode or fiber laser, halogen lamp and filter, etc.). The sample 10 is irradiated with external light, the transmitted light is received by the light receiving element (photoelectric conversion element) 12, and the emitted light measuring instrument 13 measures the light intensity. Part of the infrared light emitted from the light source 11 is branched by the half mirror 14 and is received by the power monitor light receiving element 15.
The light is received by and is measured by the incident light measuring device 16. Sample 10 is calculated from the ratio of the measured values of emitted light and incident light.
Can be calculated. FIG. 12 is an example in which the configuration of FIG. 11 is simplified. It is composed of a light source 11 and a light receiving element 12. The sample 10 is put in the optical path in the procedure 1, and the sample 10 is removed from the optical path in the procedure 2. The transmittance can be calculated from the ratio of the light intensity measured values in each of these procedures. FIG. 13 shows a configuration example for calculating the conversion formula in the first embodiment, in which the electrolytic solution 18 of the storage battery 17 is taken out as the sample 10 by the pump 19 and the specific gravity of the electrolytic solution is measured by the hydrometer 20. The light intensity measurement and the specific gravity measurement are continuously performed while discharging from the charged state of the storage battery. Once the conversion formula is calculated, thereafter, specific gravity measurement is not necessary unless the specifications of the storage battery are changed.

FIG. 14 shows the case of the second embodiment, in which the light source 11
Switching the light from the standard sample 22 by the mirror 21
And the sample to be measured 10 are switched to allow light to pass therethrough for measurement. FIG. 15 is an example in which the configuration of FIG. 14 is simplified.
The sample 10 is put into the optical path by and the standard sample 22 is replaced in step 2. The difference from the initial value can be obtained from the difference between the two measured values.

Next, the structure of the measuring instrument according to this embodiment will be described. FIG. 16 shows the appearance of the measuring instrument 30, and the measuring instrument 30 is provided with a sensor 32 inserted into the electrolytic solution via a cord 31. 17 and 18 show the detailed configuration of the sensor 32, respectively. The sensor 32 has the same configuration as that of FIG. 11 described above, and the light source 11 and the light receiving element 1 are provided inside the case 33.
2, the half mirror 14, the monitor light receiving element 15, the light guiding element 34 (optical fiber) or the prism 36 for the optical path is arranged, and the electrolyte is filled in the outside of the case 33 between the optical windows 35 provided opposite to the case 33. The light transmitted through the electrolytic solution is measured. FIG. 19 shows a storage battery 17
The state where the sensor 32 is exposed to the electrolytic solution 18 and the measurement is performed is shown.

20 to 23 show the case 3 of the storage battery 17.
7 itself is provided with an optical window 38 for measuring transmitted light, and
A configuration example in which a measurement light source 11 and a light receiving element 12 are arranged in the periphery thereof is shown. FIG. 20 shows that the light is transmitted through the storage battery electrolyte in the lateral direction, and FIG. 21 is that the light is transmitted through the electrolyte in the depth direction, respectively, and FIG.
1 and the light receiving element 12 are arranged, and scattered light or reflected light in the electrolytic solution is measured. FIG. 23 shows an example in which transmitted light is reciprocated in the depth direction of the electrolytic solution (or in the horizontal direction) by using a prism or a reflecting mirror 39.

Next, a specific circuit configuration example of the above-described first and second embodiments will be described. FIG. 24 shows a circuit in the case of the first embodiment, in which infrared light from the light source (LED) 11 passes through the beam splitter, passes through the sample 10 (cell), and receives the light receiving element (P
D) The light is received at 12, and the received light signal is given to the division circuit 41 through the preamplifier. Further, part of the light for power monitoring is received by the monitor light receiving element (monitor PD) 15, and is given to the division circuit 41 via the monitor amplifier. Output Vo of division circuit 41 (= -Vx · Vy / Vz)
Is given to the voltmeter V. This voltmeter V displays a scale (corresponding to FIG. 4 and FIG. 5) according to the conversion formula obtained in advance by the above-mentioned flow chart procedure so that the pointer of the voltmeter can be read to charge the storage battery. Completion and electric capacity are known. Changes in the storage battery can be handled by changing the voltmeter, adjusting the zero point, and adjusting the amplifier amplification.

FIG. 25 shows a concrete circuit configuration example of the second embodiment. In this circuit, the received light signal signals V1 and V2 of the transmitted light by the sample 10 and the standard sample 22 are given to the subtraction circuit 42, and this subtraction circuit 42 is provided. 42 output Vo (= V2-V
1) is given to the voltmeter V. The voltage V1 corresponds to the electric capacity of the storage battery, and the charging is completed when the output voltage Vo becomes zero during charging. FIG. 26 shows an example of a circuit configuration in the case where the standard sample is replaced with an electric signal for measurement in the above circuit, and in this circuit, the electrolytic solution first becomes the standard value in the sample 10 (the storage battery electrolytic solution before use may be used). To adjust the V2 value, that is, the amplification degree of the amplifier (AMP2) to make the output voltage Vo zero. Next, the standard electrolytic solution is discharged from the sample 10, the electrolytic solution of the storage battery to be measured is put into the sample 10, and the measurement is started. Note that in FIG. 26, the voltage V2 is obtained by using a light receiving element or an amplifier in order to replace the standard sample with an electric signal, but instead of this, a predetermined DC voltage source may be used.

FIGS. 27 (a) and 27 (b) are configuration examples in the case where the circuit of FIG. 24 is digitized, and FIGS. 28 (a) and 28 (b).
25A and 25B are configuration examples when the circuit of FIG. 25 is digitized. FIG. 25A shows a case of analog-digital (A / D) conversion, and FIG. 25B shows a case of voltage-frequency (V / f) conversion. . 29 (a) and 29 (b) are examples of analog and digital configurations when a lock-in amplifier is used in the specific circuit of the first embodiment. In the case of analog, the lock-in amplifier has the functions of an active filter and an amplifier, and its output is given to the arithmetic circuit (addition / subtraction or multiplication / division) 43.

The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, by providing the configuration for power monitor in the above, the measurement accuracy can be improved. If strict accuracy is not required, the configuration can be omitted. When used as a measuring instrument for a storage battery installed in an electric vehicle, the manufacturer determines the correlation (corresponding to a conversion formula) between the specific gravity or electric capacity of the storage battery and the light transmittance in advance, and the battery based on that is obtained. By creating a meter, it is possible to know the remaining capacity, the required charging time, and the completion of charging at the time of charging only by measuring transmitted light in normal use.

[0031]

EFFECT OF THE INVENTION According to the storage battery electric capacity measuring method and device according to the present invention, since the fluctuation of the infrared absorption spectrum due to charging and discharging of the storage battery electrolyte is utilized, the conventional refractive index and Unlike optical measurement methods that use floats, infrared light transmission intensity of storage battery electrolyte is not affected by changes in the external environment, such as disturbance of the electrolyte surface, and does not require a complicated configuration. By measuring, the specific gravity of the storage battery electrolyte or the electric capacity of the storage battery can be accurately and continuously known.

Further, it is possible to detect the life judgment of the storage battery, the necessity of replenishing water, etc. early and surely before the electric characteristics of the storage battery largely change, which are difficult with the conventional method of measuring the storage battery terminal voltage. it can. Furthermore, if a region with a long wavelength of infrared light (wavelength longer than 1450 nm) is selected, since the absorption rate in the storage battery electrolyte is large, it is possible to perform sufficient measurement even if the optical path length is short, and a measuring instrument ( The size of the sensor can be reduced. In addition, if the wavelength of infrared light is selected to a region having a high transmittance of the electrolytic solution (wavelength shorter than 1450 nm), that is, a region having a low absorptance (for example, around 1170 nm), infrared light can be transmitted with a long optical path length. Therefore, it is possible to accurately measure the specific gravity of the electrolytic solution in a storage battery having a deep electrolytic cell, which has been impossible in the prior art.

[Brief description of drawings]

FIG. 1 is a flowchart showing a processing procedure of a measuring method according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a measuring method according to a second embodiment of the present invention.

FIG. 3 is a wavelength characteristic diagram of infrared light transmittance of a storage battery electrolyte before and after charging.

[Fig. 4] Infrared light transmission intensity of the storage battery electrolyte (wavelength: 165
(0 nm) and specific gravity.

FIG. 5: Infrared light transmission intensity of the storage battery electrolyte (wavelength: 165
It is a correlation diagram of 0 nm) and electric capacity.

FIG. 6 is a diagram showing a reaction in charging / discharging a storage battery.

FIG. 7 is a wavelength characteristic diagram of infrared light transmittance.

FIG. 8 is a measurement diagram of change in transmittance with respect to discharge time.

FIG. 9 is a wavelength characteristic diagram of infrared light transmittance.

FIG. 10 is a measurement diagram showing changes in transmittance with respect to discharge time.

FIG. 11 is a diagram showing a configuration example of an apparatus to which the measuring method of Example 1 is applied.

FIG. 12 is a diagram showing a modification of FIG. 11.

FIG. 13 is a diagram showing a configuration example of an apparatus to which the measuring method of Example 1 is applied.

FIG. 14 is a diagram showing a configuration example of an apparatus to which the measuring method of Example 2 is applied.

FIG. 15 is a diagram showing a modified example of FIG.

FIG. 16 is an external view of a measuring instrument according to an embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a configuration of a sensor portion of the measuring instrument.

FIG. 18 is a cross-sectional view showing a modified configuration of a sensor portion.

FIG. 19 is a cross-sectional view showing a configuration example in which a sensor is arranged in a storage battery.

FIG. 20 is a cross-sectional view showing a configuration example in which a sensor is arranged in a storage battery.

FIG. 21 is a cross-sectional view showing a configuration example in which a sensor is arranged in a storage battery.

FIG. 22 is a cross-sectional view showing a configuration example in which a sensor is arranged in a storage battery.

FIG. 23 is a cross-sectional view showing a configuration example in which a sensor is arranged in a storage battery.

FIG. 24 is a diagram showing a circuit configuration example to which the measurement method of the first embodiment is applied.

FIG. 25 is a diagram showing an example of a circuit configuration to which the measurement method of Example 2 is applied.

FIG. 26 is a diagram showing a modification of FIG. 25.

FIG. 27 is a block diagram showing a case where the circuit of FIG. 24 is digitized.

FIG. 28 is a block diagram showing a case where the circuit of FIG. 25 is digitized.

FIG. 29 is a block diagram showing another example of the circuit to which the first embodiment is applied.

[Explanation of sign]

 10 sample 11 light source 12 light receiving element 17 storage battery 18 electrolyte solution 22 standard sample 41 division circuit 42 subtraction circuit

Claims (4)

[Claims] 1. A storage battery electricity characterized by irradiating a storage battery electrolyte with light to cause the storage battery electrolyte to absorb light in an infrared region, measuring the intensity of light transmitted through the storage battery electrolyte, and converting the measured value into the storage battery capacity. Capacity measurement method. 2. The storage battery electric capacity measuring method according to claim 1, wherein the storage battery capacity is converted from the measured value by using a correlation between the light intensity and the specific gravity or the capacity obtained in advance. 3. The storage battery capacity is converted by comparing the light intensity transmitted through a standard sample having optical characteristics corresponding to the initial value of the storage battery electrolyte or the electric signal value corresponding thereto with the measured value. The storage battery electric capacity measuring method according to claim 1, which is characterized in that. 4. A light irradiating means for irradiating the storage battery electrolyte with light containing a wavelength component in the infrared region, a light receiving means for receiving light transmitted through the storage battery electrolyte, and a light intensity corresponding to the light intensity received by the light receiving means. A storage battery electric capacity measuring device, comprising: a signal processing means for processing the converted electric signal to output a signal converted into the storage battery capacity.