JP2001235525A - Characteristic evaluation method of lead storage battery and characteristic evaluation device of lead storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for evaluating a lead storage battery simply and accurately. SOLUTION: Concerning this evaluation device 10 of the lead storage battery, in a measuring device 12, internal impedances of the lead storage battery are measured on plural frequencies of three or more points for prescribing a circle on two-dimensional coordinates prescribed by plotting the real part of the internal impedance selected in the frequency range of 1-100 Hz on the X-axis and a value obtained by multiplying the imaginary part by -1 on the Y-axis. In a calculation means 14, RΩ, Rct and Cd are obtained by referring values of plural internal impedances measured on the plural frequencies relative to a relation between RΩ, Rct and Cd derived from an equivalent circuit composed of a series circuit between a parallel circuit between a charge-transfer resistance value (Rct) and an electric double layer capacity value (Cd), and an electrolyte solution resistance value (RΩ), and the plural internal impedances of the lead storage battery measured on the plural frequencies. In a determination means 16, the remaining capacity and/or the deteriorated state of a test lead storage battery are determined from the calculation means 14 and the calculated RΩ, Rct and Cd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating the characteristics of a lead storage battery, and more particularly to a practical and effective evaluation of the remaining capacity and deterioration of a lead storage battery mounted on a vehicle such as an automobile. The present invention relates to a method (inspection method) and its device.

[0002]

2. Description of the Related Art A lead-acid battery is mounted on a vehicle such as an automobile as a secondary battery, and is used as a power source for starting an engine, automobile equipment, and the like. In such a case, it is particularly necessary to accurately evaluate the remaining capacity and the state of deterioration of the lead storage battery. For example, when an automobile is stopped, the engine cannot be started after the stop unless the lead storage battery has sufficient remaining capacity to start the engine next time. Of course, in other cases, it is desired to accurately evaluate the remaining capacity and the state of deterioration of a secondary storage battery such as a lead storage battery.

Various methods have been proposed for testing the state of charge and the state of deterioration of such lead storage batteries. For example, a method has been proposed in which a lead storage battery is completely discharged, its capacitance is measured, and a deterioration state is determined from the measured capacitance. However, this method
Since it is necessary to completely discharge the lead storage battery, there is a problem that the inspection method cannot be applied to the lead storage battery in use, in addition to waste of power due to the discharge. In addition, this test method takes time to discharge completely,
After all, the measurement time was long, so it was not a practical method. Therefore, various methods have been developed that can inspect a lead storage battery in a short time while preventing waste of power consumption.

Japanese Patent Application Laid-Open No. Hei 4-95788 (Patent No. 25)
No. 36257) describes the measurement results of the internal impedance of a lead-acid battery by calculating the inductance component (L), the electrolyte resistance (Rs), the charge transfer resistance (θ), the electric double layer capacitance (Cd), and the work of the lead-acid battery. Burg impedance (W),
The optimum solution is obtained by applying the equivalent circuit represented by the following equation (1-1) consisting of the Workburg coefficient (σ), and the inductance component (L), the electrolyte resistance value (Rs), and the charge transfer resistance value (θ) are obtained. , An electric double layer capacity value (Cd), a workburg impedance (W), and a workburg coefficient (σ) are compared with an initial value to determine a life of the lead storage battery. .

[0005]

(Equation 1)

Japanese Patent Application Laid-Open No. 4-141966 (Patent No. 2)
No. 546050) describes the measurement of the internal impedance of a lead-acid battery as the impedance of the frequency at which the phase becomes 0 and the change of the imaginary part of the impedance with respect to the frequency between 0.1 and 10 Hz. Discloses a method for determining the deterioration state of a lead storage battery from the impedance at a frequency at which a value obtained by dividing by a change amount with respect to the frequency approaches −1.

Japanese Patent Application Laid-Open No. 5-135806 (Patent No. 2)
No. 792784) (a) measures the internal impedance of a lead-acid battery at a frequency of two to three points between 0.001 and 1 Hz, and determines the imaginary part of the impedance to be −0.
^Plotted against the fifth power (f ^-1/2 ), the remaining capacity of the lead storage battery is determined from the value of the Y intercept, and (a)
A method is disclosed in which the internal impedance is measured at a frequency of 01 to 0.05 Hz, the real part is plotted against the imaginary part, and the remaining capacity of the lead storage battery is determined from the value of the gradient.

[0008]

The above-mentioned methods have the following problems, respectively, and are practically and effectively used for evaluating the characteristics of lead-acid batteries, particularly lead-acid batteries mounted on vehicles such as automobiles. Could not. It is described in detail below.

The method described in Japanese Patent Application Laid-Open No. 4-95788 discloses an inductance component (L) and an electrolyte resistance (Rs) shown in equation (1-1) based on the measurement results of the internal impedance of a lead storage battery. , Charge transfer resistance (θ), electric double layer capacitance (Cd), Workburg impedance (W), and Workburg coefficient (σ). For this reason, it is necessary to measure the internal impedance at least at six frequencies, and there has been a problem that the calculation for obtaining the optimum solution of the six parameters becomes very complicated. That is, the measurement at a number of frequencies and the complicated calculation described in JP-A-4-95788 not only increase the measurement time but also increase the price of the measurement device,
There is a problem that it is not practical to evaluate a lead storage battery mounted on a vehicle.

In the method described in Japanese Patent Application Laid-Open No. 4-141966, it is necessary to search for a frequency at which the phase of the internal impedance becomes zero and perform measurement. It is necessary to find and measure a frequency at which the value obtained by dividing the change in the imaginary part with respect to the frequency by the change in the impedance with respect to the real part is about -1. That is, Japanese Unexamined Patent Publication No.
In the method of 1966, it is necessary to find a frequency at which the value of the internal impedance satisfies a specific condition.
Therefore, a device that enables measurement by changing the frequency is required, and a device that determines whether the above-described specific condition is satisfied is also required. Such a process requires a complicated measuring device, which increases the price of the device, and is particularly impractical for evaluating the characteristics of a lead storage battery mounted on a vehicle.

The method described in Japanese Patent Application Laid-Open No. 5-135806 uses the value of the internal impedance at 0.001 to 1 Hz as an index. However, such 1H
The measurement in the low-frequency region below z is more complicated than the measurement in the region above 1 Hz, which complicates the configuration of the measuring device, especially the frequency oscillating circuit, and increases the price of the device. There is a problem that becomes. Also, 0.00
Since the value of the internal impedance at 1 to 1 Hz tends to greatly change depending on the temperature, for example, when measuring a lead-acid battery installed in a place where the temperature greatly changes, such as a lead-acid battery mounted on a vehicle, However, there is a problem that correction becomes indispensable depending on the temperature.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention have made intensive studies and as a result, have come to invent a method for evaluating the characteristics of a lead storage battery of the present invention. The gist of the method for evaluating the characteristics of the lead storage battery of the present invention will be described below with reference to FIGS. In the present invention, the inspection of the residual capacity, the deterioration state, and the like of the lead storage battery are collectively referred to as the characteristic evaluation of the lead storage battery.

According to the lead storage battery characteristic evaluation method of the present invention, first, the equivalent circuit of the lead storage battery is simplified, and the equivalent circuit has at least a charge transfer resistance value (Rct) as illustrated in FIG. 1 or FIG. It is composed of a parallel circuit with the electric double layer capacitance value (Cd) and a series circuit with the electrolytic solution resistance value (RΩ), and the impedance is represented as an equivalent circuit defined by the following equation.
Details of the equivalent circuit will be described later.

[RΩ + (Rct / (1 + jωCd))] (A-1) where ω = 2πf

In the lead-acid battery evaluation characteristic method of the present invention, as shown in FIG. 3, (1) the value obtained by multiplying the imaginary part by -1 with the real part of the internal impedance of the lead-acid battery on the Y-axis The internal impedance of the lead-acid battery is measured for a plurality of frequencies at three or more points selected in the frequency range of 1 to 100 Hz, which define the impedance circle in the two-dimensional coordinates defined by plotting in FIG.

Further, in the method for evaluating the characteristics of a lead storage battery according to the present invention, as illustrated in FIG. 3, (2) a parallel circuit of a charge transfer resistance value (Rct) and an electric double layer capacitance value (Cd); Electrolyte resistance (RΩ), charge transfer resistance (Rct), electric double layer capacitance (Cd), and measured at multiple frequencies derived from an equivalent circuit composed of a series circuit with the liquid resistance (RΩ) The electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric resistance value are referred to the relational expression with the internal impedance of the plurality of lead storage batteries by referring to the plurality of internal impedance values measured at a plurality of frequencies. The double layer capacitance value (Cd) is determined.

Finally, in the method for evaluating the characteristics of a lead storage battery of the present invention, as shown in FIG. 3, (3) the calculated electrolyte resistance value (RΩ), charge transfer resistance value (Rct), electric double layer The remaining capacity and / or deterioration state of the tested lead storage battery is determined from all or at least one of the capacity values (Cd).

Further, an apparatus for evaluating a lead storage battery according to the present invention is an apparatus for implementing the above-described method for evaluating a lead storage battery, and includes a measuring unit, a calculating unit, and a determining unit. The measuring unit performs the above-described process (1), the calculating unit performs the above-described process (2), and the determining unit performs the above-described process (3).

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the lead storage battery characteristic evaluation method and lead storage battery characteristic evaluation device of the present invention will be described below with reference to the accompanying drawings.

[0020] shows a circuit example of an equivalent circuit using the present invention in an equivalent circuit diagram 1 and 2. FIG. 1 is a diagram showing a first equivalent circuit used in the present invention, the electrolyte resistance value (RΩ) and the charge transfer resistance value (Rc).
FIG. 3 is a configuration diagram of an equivalent circuit including an electric double layer capacitance value (Cd). The equivalent circuit of FIG. 1 has a charge transfer resistance value (Rc
t) and the electric double layer capacitance value (Cd) are connected in parallel,
An electrolyte resistance value (RΩ) is connected in series to this parallel circuit. Therefore, the impedance of the equivalent circuit is defined by the following equation.

[RΩ + (Rct / (1 + jωCd))] (A-2) where ω = 2πf

FIG. 2 shows a second equivalent circuit used in the present invention, which is a resistance value of an electrolyte (RΩ) and a resistance value of a charge transfer (Rc).
t ′ and Rct ″), the electric double layer capacitance value (Cd ′ and C
3 is a configuration diagram of an equivalent circuit composed of d ″). FIG. In the equivalent circuit of FIG. 2, the electric double layer capacitance value (Cd) of FIG. 1 is converted into the first electric double layer capacitance value (Cd ′) and the second electric double layer capacitance value (Cd).
d ''), and the charge transfer resistance value (Rct) of FIG.
Are replaced with a first charge transfer resistance value (Rct ′) and a second charge transfer resistance value (Rct ″). The impedance of the equivalent circuit of FIG. 2 is defined by the following equation.

[RΩ + (Rct ′ / (1 + jωCd ″)) + (Rct ″ / (1 + jωCd ″))) (B-1) where ω = 2πf

Japanese Patent Application Laid-Open No. 4-95788 discloses a formula 1
As shown in FIG. 1, an equivalent circuit including six parameters is shown. In order to accurately grasp the characteristics of the lead-acid battery, it is desirable to analyze the equivalent circuit disclosed in Japanese Patent Application Laid-Open No. 4-95788. However, for example, in the case of evaluation of a lead-acid battery mounted on a vehicle, the present invention is applied. The analysis using the equivalent circuit shown in FIG. 1 or 2 is sufficient. Rather, it is more practical to reduce the number of parameters obtained by applying the equivalent circuit shown in FIG. 1 or 2 of the present invention to reduce the measurement frequency and the time and cost involved in the calculation. high. In particular, when determining the remaining capacity of a lead storage battery mounted on an automobile, two significant figures are sufficient, and the method of the present invention is more practical than the method disclosed in JP-A-4-95788.

FIG. 8 illustrates the relationship between the measurement result at three points and the circle as an example in FIG. That is, two-dimensional coordinates defined by plotting a value obtained by multiplying the real part of the internal impedance of the lead-acid battery by the X-axis and the imaginary part by −1 on the Y-axis in correspondence with the impedance defined by the equation A or the equation B. The internal impedance of the lead-acid battery is measured at a plurality of frequencies at least at three or more points that define the impedance circle in the above.

Measurement Frequency In the present invention, measurement is performed at any three to five points (at most six points) selected in a frequency range of 1 to 100 Hz.

First, the reason why the frequency range of 1 to 100 Hz is selected will be described. The above frequency range is
Electrolyte resistance (RΩ), charge transfer resistance (R
ct), because the frequency range is particularly effective for obtaining the electric double layer capacitance value (Cd). That is, 1H
If it is not less than z, it can be easily implemented on the measurement and on the device, and it is within 100 Hz, which is about twice the commercial frequency, and it is not high frequency, so there is no problem on the measurement and the device configuration. .

In the method disclosed in Japanese Patent Application Laid-Open No. 5-135806, the remaining capacity of the lead-acid battery is determined from the internal impedance of the lead-acid battery at two or three frequencies between 0.001 and 1 Hz. However, according to the study by the inventors, as described above, rather than using the measurement data at 0.001 to 1 Hz, 1 to 1 according to the embodiment of the present invention is used.
The use of 100 Hz measurement data was more effective and easier in determining the residual capacitance of a lead storage battery.

Next, the reason why measurement is performed at three to five or six frequencies will be described. In determining the electrolyte resistance (RΩ), charge transfer resistance (Rct), and electric double layer capacitance (Cd), it is necessary to measure at least three frequencies to define the impedance circle (see FIG. 8). is there. The greater the number of measurements at different frequencies, the higher the accuracy of determining the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd). However, when the number of measurements increases, the measurement time increases, and the variable frequency oscillation circuit becomes complicated,
Calculation after measurement becomes longer. Therefore, in practice, 3
The measurement is performed at frequencies of up to 5 points, at most 6 points.

Next, the relationship between the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), the electric double layer capacity value (Cd), and the remaining capacity and / or deterioration state of the lead storage battery will be considered.

[0031] Remaining capacity and / or deterioration state of lead storage battery
First Embodiment FIG. 4 is a graph illustrating the relationship between the electric double layer capacity (Cd) and the remaining capacity of a lead storage battery. In the determination of the remaining capacity of the lead storage battery in the inspection method of the present invention, FIG.
As shown in FIG. 3, a relational expression between the electric double layer capacity value (Cd) and the remaining capacity of the lead storage battery is obtained in advance, and the electric double layer capacity value (C) obtained from a plurality of measurement results of the internal impedance is obtained.
By comparing d) with the above relational expression, the remaining capacity of the lead storage battery can be determined.

It was found that the residual capacity of the lead storage battery had a linear relationship with the electric double layer capacity (Cd) as described below.

Residual capacity (%) = α × Cd + β (C)

Note that α and β change depending on the temperature of the lead storage battery.

Remaining capacity and / or deterioration status of lead storage battery
Second Embodiment FIG. 5 is a graph illustrating the relationship between the charge transfer resistance (Rct) and the remaining capacity of a lead storage battery. In the determination of the remaining capacity of the lead storage battery in the inspection method of the present invention, FIG.
As shown in FIG. 2, a relational expression between the charge transfer resistance value (Rct) and the remaining capacity of the lead storage battery is obtained, and the charge transfer resistance value (Rc) obtained from a plurality of measurement results of the internal impedance is obtained.
The remaining capacity of the lead storage battery can be determined by comparing t) with the above relational expression.

It has been found that the residual capacity of the lead storage battery has a linear relationship with the charge transfer resistance (Rct) as described below.

Remaining capacity (%) = γ × Rct + δ (D)

Note that γ and δ change depending on the temperature of the lead storage battery.

Remaining capacity and / or deterioration status of lead storage battery
Third Embodiment Regarding the relationship with the state of the lead-acid battery In the evaluation method of the lead-acid battery according to the present invention, the determination of the deterioration state of the lead-acid battery is further performed in advance by determining the electrolyte resistance (R
Ω), the charge transfer resistance (Rct), the electric double layer capacitance (Cd), and the relationship between the deterioration state of the lead storage battery and the electrolyte resistance (RΩ) obtained from the measurement results of the internal impedance. By comparing the charge transfer resistance value (Rct) and the electric double layer capacitance value (Cd) with the above relational expression, it is possible to determine the deterioration state of the lead storage battery.

The remaining capacity of a lead-acid battery may be affected by the state of deterioration of the battery and the temperature. Therefore, it may be necessary to correct (interpolate) the value of the remaining capacity of the lead storage battery obtained as described above with the value of the battery deterioration state and the temperature. At this time, the remaining capacity of the lead storage battery determined from the electric double layer capacity value (Cd) is corrected based on the determination result of the battery deterioration state determined from the electrolyte resistance value (RΩ) and the charge transfer resistance value (Rct). be able to.

Effect of Temperature on Remaining Capacity The relationship between the temperature of the lead storage battery and the electrolyte resistance (RΩ) and charge transfer resistance (Rct) is determined in advance, and the electrolyte resistance (RΩ) and charge transfer resistance are determined. By comparing the measurement result of the value (Rct) with the relationship, the temperature of the lead-acid battery can be obtained. Therefore, the lead-acid battery of the lead-acid battery obtained from the electrolyte resistance value (RΩ) and the charge transfer resistance value (Rct) can be obtained. The influence of the temperature on the remaining capacity can be corrected by the temperature.

In determining the state of charge and deterioration of the lead storage battery, the temperature is measured separately from the method of the present invention, and the measured value is used to correct the influence of temperature on the state of charge and deterioration. Is also possible.

Electrolyte resistance (RΩ), charge transfer resistance
(Rct), Method of Calculating Electric Double Layer Capacitance (Cd) Electrolyte resistance (RΩ), charge transfer resistance (Rct), electric double layer capacitance (derived from the equivalent circuits of FIGS. 1 and 2) By referring to a plurality of values of the internal impedance actually measured at the above-mentioned plurality of frequencies in the relational expression between Cd) and the internal impedance of the lead storage battery, the electrolyte resistance value (R
Ω), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) are preferably a statistical method, for example, a method of obtaining an optimal solution by a least square method.

However, when evaluating the characteristics of a lead storage battery mounted on a vehicle, it is desirable to find the optimum solution more easily. As a simpler method than the least square method, the following method can be mentioned.

First Method M Among the above-mentioned 1 to 100 Hz, the first frequency (F) at any three to four points selected in the frequency range of 5 to 100 Hz.
a) and any one selected in the frequency range of 1 to 5 Hz.
At the second frequency (Fb) at the point, the internal impedance of the lead-acid battery is measured a plurality of times, and from the measured values, the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) ).

In the first method M, the first frequency (Fa)
About the internal impedance of 3-4 points measured by
As illustrated in FIG. 6, the real part of the internal impedance is plotted on the X-axis, and the value obtained by multiplying the value of the imaginary part of the internal impedance by −1 is plotted on the Y-axis (cole colle plot).
t) Obtain the trajectory of the circle passing through the three or four points and calculate the trajectory X
The shaft intercepts Xa and Xb (Xa <Xb) are obtained, Xa is defined as the electrolyte resistance value (RΩ), and Xb−Xa is defined as the charge transfer resistance value (R).
and ct), (a Xa + Xb) × 0.5 and X _m, further, the real part of the internal impedance in the Y-axis, the frequency X
The coordinates C _m which is the axis, plotted lowest frequency Fa 'and the measured value of the second frequency Fb of the first frequency Fa, a straight line of which connecting the two plotted points, the X _m described above the corresponding frequency is omega _m, the electric double layer capacitance Cd (R
ct × ω _m ) ⁻¹ .

Electrolyte resistance (RΩ) and charge transfer resistance (Rc) derived from the equivalent circuits shown in FIGS.
t), even when the number of parameters to be obtained is five or less, as in the relational expression between the electric double layer capacitance value (Cd) and the internal impedance, mathematically and strictly solving the parameters of the above relational expression requires an operation. Is complicated, the scale of the arithmetic unit is increased, and the price is increased. Therefore, the practical value of obtaining the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) by simple calculations as in the present invention is extremely high.

In the case where the above-mentioned simple first method M is performed, the frequency to be measured is set to the first frequency Fa at any three to four points selected in the frequency range of 5 to 10 Hz,
The second of any one point selected in the frequency range of 1 to 5 Hz
It is particularly preferable to set the frequency to Fb. The reason is,
This is because it is preferable to use a measured value in a frequency range of 5 to 100 Hz in obtaining the trajectory of the circle in the above-mentioned cole cole plot. Further, in order to obtain the locus of a circle, it is necessary that the number of measurement points is three or more. In obtaining the trajectory of the circle, more preferably, the first
One point of the measurement frequency Fa of 5 to 10 Hz,
1 point in 10-30 Hz, 1 point in 50-100 Hz
This is a point.

The present inventors, in the coordinates C _m, a linear relationship to the real part and the frequency of the internal impedance in the range of frequency obtained was found to be approximately in the range of 1 to 10 Hz. Therefore, the range of the first frequency Fb is preferably about 1 to 5 Hz, and the lowest frequency Fa ′ among the first frequencies Fa is selected from one point of 5 to 10 Hz. Is preferred.

In the method disclosed in Japanese Patent Application Laid-Open No. 4-141966, it is necessary to search for a frequency at which the value of the internal impedance satisfies a specific condition. Therefore, a device capable of performing measurement with changing the frequency is required. A device for determining whether a specific condition is satisfied is required. Therefore, there has been a problem that the measuring device is complicated and the price is high. On the other hand, in the method of the present invention, since the frequency to be measured can be determined in advance, the above-mentioned problem is not caused, and it is practically preferable.

In the method of the above-described embodiment of the present invention, the characteristic evaluation (inspection) of the lead storage battery according to the method of the embodiment of the present invention is performed at an appropriate time interval, and is obtained by the previous inspection. At least one of the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) is determined as the electrolyte resistance value (RΩ) obtained in the current inspection. , The charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) are compared with at least one of the values, and the comparison result is used to correct the determination of the remaining capacity and the deterioration state of the lead storage battery. Can be used together.

By using the above method together, it is possible to improve the accuracy of the determination of the state of charge and the state of deterioration of the lead storage battery and / or to simplify the calculation for the determination.

In determining the lead storage battery mounted on a vehicle such as an automobile, the influence of the surrounding environment such as temperature can be easily corrected by repeating the inspection at appropriate time intervals from several seconds to several tens of seconds. Especially effective.

When the method for evaluating a lead storage battery of the present invention is used for a lead storage battery mounted on a vehicle such as an automobile, the inspection method of the present invention is implemented immediately before the driver starts the engine, and the inspection is performed. It is more effective to use the result to correct the judgment in the tests after the test. The reason is that the environment before the driver starts the engine of the vehicle is because there are few devices and equipment of the running car,
This is because the environment of the inspection of the present invention is favorable without being affected by those.

When the method for evaluating a lead storage battery of the present invention is used for a lead storage battery mounted on a vehicle, it is effective to perform the method while the engine of the vehicle is stopped. The reason is that in a situation where the engine is stopped and the alternator is stopped, it is unlikely that large noise will occur in the frequency range that needs to be measured by the method of the present invention.

When the method for evaluating a lead storage battery according to the present invention is used for determining whether or not to stop idling when a vehicle stops, the inspection method of the present invention is implemented immediately after the engine stops for the above-described reason. Is preferred.

[0057]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example (experimental example) of an embodiment of the above-described method for evaluating a lead storage battery of the present invention will be described with reference to the accompanying drawings.

In the embodiment of the present invention, an equivalent circuit composed of the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) is shown in FIGS. Things.

FIG. 4 is a graph exemplifying a result obtained by adjusting the remaining capacity of the lead-acid battery of 75 Ah in advance and determining the relationship between the remaining capacity of the lead-acid battery and the electric double layer capacity value (Cd). The electric double layer capacity value (Cd) was calculated from a measurement result of the internal impedance of the lead storage battery by an arithmetic expression described later. Residual capacity and electric double layer capacity value (C
The relationship d) shows temperature dependence, but shows almost linearity (linearity). If the electric double layer capacity value (Cd) is known, the remaining capacity of the lead storage battery can be estimated. The remaining capacity of a normal lead storage battery without deterioration is defined by the following equation (1).

[0060]

## EQU2 ## Remaining capacity (%) = 0.181 × Cd + 0.064 (1)

Measurement Conditions and Results of Lead-Acid Batteries (1) A 100% -charged lead-acid battery was discharged for 1 hour at a current of 15A or (b) discharged for 10 minutes at a current of 30A. After that, the remaining capacity of the lead storage battery was determined. (2) The ambient temperature of the battery was set at 20 ° C. (3) As a result of obtaining and calculating the measured internal impedance, the electric double layer capacitance value (Cd) was 3.6 [F]. (4) As a result of determining the remaining capacity by equation (1), 72%
It became. Since the actual remaining capacity is 73%, it has been found that the remaining amount can be determined fairly accurately by the lead storage battery evaluation method of the present invention.

As described above, the relationship between the electric double layer capacity value (Cd) and the remaining capacity of the lead storage battery is determined in advance,
The remaining capacity of the lead storage battery can be determined by comparing the value of the electric double layer capacity value (Cd) obtained from the measurement result of the internal impedance with the above relationship.

In the equation (1), the ambient temperature is 20 ° C., but as shown in FIG. 3, the temperature of the lead storage battery is changed to 20 ° C., 40 ° C., and 60 ° C. In such a case, the characteristics tend to shift, and if the temperature of the lead storage battery is known, the remaining capacity can be calculated by interpolation.
Therefore, the characteristics are checked at a certain temperature, the temperature is detected by a temperature sensor or the like attached to the lead storage battery at an arbitrary temperature, and the characteristics (remaining capacity value) obtained in advance are shifted (interpolated) according to the temperature. , The characteristic (remaining capacity value) at that temperature can be calculated.

When the lead storage battery is deteriorated, although the remaining capacity is reduced with respect to the normal lead storage battery, its characteristics show linearity similarly to the normal lead storage battery. It is possible to correct the remaining capacity.

The correction based on the state of deterioration of the battery and the correction based on the temperature of the battery at the time of the determination can also be performed using the electrolyte resistance value (RΩ) obtained from the measurement result of the internal impedance.

FIG. 6 is a graph showing the relationship between the electrolyte resistance (RΩ) and the remaining capacity (SOC) of a normal lead storage battery and a deteriorated lead storage battery depending on the temperature. The electrolyte resistance value (RΩ) does not change depending on the remaining capacity (SOC), but changes depending on the temperature and the degree of deterioration. Therefore, the remaining capacity can be corrected using the electrolyte resistance value (RΩ) obtained from the measurement result of the internal impedance.

The charge transfer resistance (Rct) and the remaining amount of the lead-acid battery
The relationship between the charge transfer resistance (Rct) illustrated in FIG. 5 and the remaining capacity of the lead-acid battery also indicates the relationship between the electric double-layer capacity (Cd) and the remaining capacity of the lead-acid battery. Thus, the remaining capacity of the lead-acid battery could be determined in the same manner as the remaining capacity of the lead-acid battery was determined from the relationship.

Electrolyte resistance (RΩ), charge transfer resistance
(Rct), Calculation method of electric double layer capacity value (Cd) Next, electrolyte resistance value (RΩ), charge transfer resistance value (Rct), electric double layer capacity when measuring the remaining capacity of a lead storage battery for an automobile A specific example of a method for deriving the value (Cd) will be described. The measurement frequency of the internal impedance is 100 Hz,
The four points of 20 Hz, 6 Hz and 2 Hz were used. From the measurement results of the internal impedance at these four points, the electrolyte resistance (RΩ),
Charge transfer resistance (Rct), electric double layer capacitance (Cd)
Was calculated. The reasons for choosing these four frequencies are as follows.

As illustrated in FIG. 7, the internal impedance was measured while changing the frequency, and the real part of the internal impedance was plotted on the X-axis and the imaginary part was multiplied by −1 (cole colle plot). . As illustrated in FIG. 7, the characteristic can be represented by two parts, a part indicating a characteristic of an arc and a characteristic like a straight line. Here, since the characteristics of the arc can be represented by the equivalent circuit shown in FIG. 1, by grasping the trajectory of the arc, the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric It is possible to derive the multilayer capacitance value (Cd).

For example, since the trajectory of a circle passing through three points is uniquely determined, the equation of the circle can be obtained very easily. Therefore, three frequencies 100 Hz, 20 Hz,
The locus of the circle was grasped by 6 Hz. As shown in FIG.
The plot around Hz deviates from the locus of the circle, and the frequency to be measured must be 5 to 1 in order to obtain the equation of the circle with high accuracy.
The frequency is preferably in the range of 00 Hz.

As for the number of measurement frequencies, a minimum of three measurement points are required for obtaining the equation of the circle, and at the maximum, considering the decrease in practical value due to the increase in the number of measurement points, , 5-6 points, preferably 3-4 points or less. Further, since the accuracy is highest when the plots for obtaining the trajectory of the circle are equally spaced on the circumference, the frequency of the first measurement frequency Fa is one of 5 to 10 Hz, 10 to 3 Hz.
It is most desirable to use one point out of 0 Hz and one point out of 50-100 Hz.

FIG. 7 shows an arc (broken line) calculated from a circle formula obtained by a method described later. Assuming that the X-axis intercept of the circular orbit is Xa, Xb (Xa <Xb), Xa corresponds to the electrolyte resistance value (RΩ), and (Xb−Xa) corresponds to the charge transfer resistance value (Rct). In the equation of a circle passing through three points, Xa and Xb (Xa <
Xb) is determined, and Xa is the electrolyte resistance value (RΩ), (X
b−Xa) is calculated as the charge transfer resistance value (Rct).

[0073] Here, previously obtained the (Xa + Xb) × 0.5 as X _{m. Xm} is the real part of the impedance indicating the center coordinates of the circle. If the frequency indicating the top of the circle is f _max , the electric double layer capacitance value (Cd) is (Rct × 2π
× f _max ) ⁻¹ . However, since the measured frequency is not always the vertex on the circumference, the frequency indicating the vertex of the circle is obtained approximately from the following characteristics.

The internal impedance is measured by changing the frequency, the frequency is represented on the X axis, and the real part of the internal impedance is represented by Y.
FIG. 8 shows the plotted results as axes. It can be seen that the frequency range in which a direct relationship is obtained between the real part of the internal impedance and the frequency is in the range of about 1 to 10 Hz.
FIG. 8 also plots results obtained at two frequencies of 6 Hz and 2 Hz. By obtaining a formula of a straight line connecting two points, X _m is substituted into the formula of the straight line, and a frequency f _m approximately indicating a vertex of a circle is obtained. Electric double layer capacitance (Cd) is calculated by _{(Rct × 2π × f m)} -1.

[0075] frequency f _m is, in most cases 4~5Hz
Therefore, when the above method is performed, the frequency at any one point selected in the frequency range of 1 to 5 Hz and the frequency of 5 to 1
It is preferable to measure at a frequency selected from one point out of 0 Hz. In particular, it is more efficient to use the smallest frequency among three or four frequencies measured to grasp the locus of a circle.

An arithmetic expression for calculating the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) when measured at three frequencies will be described. When measured at four frequencies, the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) were determined at three points in any combination, and were determined for each combination. The average of the judgment results can be taken. Alternatively, the minimum value of the determination results obtained by combining each of them from the safety side of the measurement may be used. In any case, the same calculation is performed for the case where measurement is performed at four frequencies, as in the case where measurement is performed at three points. First, an equation of an arbitrary circle is calculated from the measurement results of the internal impedance measured at three frequencies.

FIG. 9 is a graph showing coordinates plotting internal impedances measured at three points of frequencies f ₁ , f ₂ and f ₃ . The following three equations are obtained, and there are three unknowns and three equations. Therefore, coefficients a, b, and r that determine the trajectory of the circle can be obtained.

[0078]

[Number 3] measured in _{f 1: (X 1 -a)} 2 + (Y 1 -b) 2 = measured by _{^{r 2 ... (2) f 2}} : (X 2 -a) 2 + (Y 2 -b) ² = measured by _{^{r 2 ... (3) f 3}} : (X 3 -a) 2 + (Y 3 -b) 2 = r 2 ... (4)

As a result of solving the above three equations (2) to (4), the coefficients a, b, and r are as follows.

[0080]

(Equation 4)

Here, the coefficients (factors) A to F are expressed as follows.

[0082]

A = X ₁ −X ₂ (8) B = X ₂ −X ₃ (9) C = Y ₁ −Y ₂ (10) D = Y ₂ −Y ₃ (11) E = ^{_{X 1 2 -X 2 2 + Y}} 1 2 -Y 2 2 ... (12) F = X 2 2 -X 3 2 + Y 2 2 -Y 3 2 ... (13)

In FIG. 9, since R _CT is the chord of a circle on the real axis, X at two points where Y = 0 is obtained from the equation of the circle.
_RCT is calculated from the distance between these two points.

[0084]

(X−a) ² = r ² (14) X = a ± r (15) R _CT = 2 · r (16) RΩ = ar (17)

FIG. 10 is a graph showing coordinates plotting the internal impedance measured at the fourth frequency.
The frequency f _m which indicate the vertices of the circle, the real and the relationship of the frequency of the internal impedance in the frequency range sandwiching the f _m, as shown in FIG. 8, for a range, since there is almost linearity, linear approximation Can be obtained by The real component measured at the first frequency f ₁ is X ₁ ,
Assuming that a real component measured at the fourth frequency f ₄ is X ₄ , f _m is represented by the following equation. Where f ₁ > f _m > f
₄

[0086]

(Equation 7)

Therefore, the electric double layer capacitance value (Cd) is expressed by the following equation.

[0088]

(Equation 8)

In the determination of a lead storage battery mounted on an automobile, the influence of the surrounding environment such as temperature can be easily corrected by repeating the inspection at appropriate intervals from several seconds to several tens of seconds. Is particularly effective.

Table 1 below shows an example in which the remaining capacity is measured every minute when idling is stopped, and a comparison is made between a case where the past judgment result is referred to and a case where the judgment is made independently.

[0091]

[Table 1] Table 1 Comparison of remaining capacity determination methods Remaining capacity determination: Single Remaining capacity determination: Refer to the past 95% 95% Immediately after 1 minute 93% 94% After 2 minutes 91% 93% 3 minutes After 92% 92.8% After 4 minutes 93% 92.8% After 5 minutes 94% 93%

As a method of referring to the past judgment results, an average value was used in the remaining capacity judgment during the same idle stop period by sequentially using the judgment results measured every minute. The remaining capacity in the case of the single case decreases until immediately after the lapse of 2 minutes from immediately after the idle stop, and the determination after the lapse of 3 minutes shows an increasing tendency. On the other hand, the remaining capacity of the past reference decreases until three minutes have elapsed, and has shown a substantially constant value thereafter.
During the idle stop period, although the discharge from the storage battery may be small, the storage battery is not charged. The cause of the increase in the remaining capacity is largely affected by the surrounding environment such as temperature. Therefore, the case where the determination is made with reference to the past determination result is more effective than the case where the capacity determination is performed alone because the influence of the surrounding environment such as the temperature can be easily corrected.

Apparatus for Evaluating Lead- Acid Batteries The apparatus for evaluating characteristics of lead-acid batteries according to the present invention is an apparatus for implementing the above-described method for evaluating a lead-acid battery. FIG. 11 illustrates a configuration of the lead storage battery evaluation device. Lead storage battery evaluation device 1
0 is the measuring means 12 for measuring the internal impedance of the lead-acid battery at a plurality of frequencies, and the electrolyte resistance value (R
Ω), charge transfer resistance value (Rct), and electric double layer capacitance value (Cd), and the calculated electrolyte resistance value (RΩ), charge transfer resistance value (Rct), electric double layer capacitance value (Cd) determining means 16 for determining the remaining capacity and / or deterioration state of the lead storage battery tested.

The measuring means 12 comprises, for example, a variable frequency oscillating circuit, an impedance measuring device, and a computer having a storage circuit. The variable frequency oscillating circuit and the impedance measuring circuit are connected to a lead-acid battery whose characteristics are to be evaluated. And connecting a computer device to the impedance measurement circuit. Variable frequency oscillation circuit is 1-100Hz
At least three points that define an impedance circle in two-dimensional coordinates defined by plotting a value obtained by multiplying the real part of the internal impedance by -1 and the imaginary part by −1 and plotting the result on the Y axis, selected in the frequency range of Are oscillated and applied to the lead storage battery, and the impedance measuring device measures the internal impedance of the lead storage battery at each frequency. The computer device inputs the specific value of the internal impedance measured by the impedance measuring device and stores it in the storage circuit.

The calculating means 14 is constituted by, for example, a computer device having the above-mentioned storage circuit, and the above-described formula (A-1) or (B-
At least the charge transfer resistance (Rc) defined in 1)
t), the resistance value of the electrolyte (RΩ), and the resistance value of the charge transfer (Rc) derived from an equivalent circuit composed of a series circuit of a parallel circuit of the electric double layer capacitance value (Cd) and the resistance value of the electrolyte (RΩ).
t), referring to the relational expression between the electric double layer capacity value (Cd) and the internal impedance of a plurality of lead-acid batteries measured at a plurality of frequencies, referring to the values of the plurality of internal impedances measured at a plurality of frequencies, the electrolyte resistance. The value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) are determined.

The judging means 16 is composed of, for example, the above-mentioned computer device and is provided from the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) calculated by the calculating means 14. The remaining capacity and / or deterioration state of the tested lead storage battery is determined. Such a determination is
For example, the relationship between the above-described electrolyte resistance value (RΩ), charge transfer resistance value (Rct), electric double layer capacitance value (Cd), and remaining capacity and / or deterioration state is displayed as a graph from a computer device to a display device. Thus, the determination may be made by a human eye or automatically by a determination process of a computer device.

[0097]

As described above, according to the present invention,
Arbitrary 3 ~ selected in the frequency range of 1 ~ 100Hz
By measuring the internal impedance at the five frequencies and substituting the measurement results into an arithmetic expression, the remaining capacity and the deterioration state of the lead storage battery can be determined, so that the measurement can be performed in a short time and easily. Further, since the measurement frequency is a fixed frequency of 3 to 5 points, the cost of the apparatus can be reduced.

According to the present invention, since the remaining capacity of the lead storage battery can be accurately determined, it is very effective to use it for determining whether or not to stop idling when the vehicle stops.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first equivalent circuit used in the present invention, which is an electrolyte resistance value (RΩ) and a charge transfer resistance value (Rc).
FIG. 3 is a configuration diagram of an equivalent circuit including an electric double layer capacitance value (Cd).

FIG. 2 is a diagram illustrating a second equivalent circuit used in the present invention, which includes an electrolyte resistance value (RΩ) and a charge transfer resistance value (Rct ′).
And Rct ″), and the electric double layer capacitance value (Cd ′ and Cd ′)
3 is a configuration diagram of an equivalent circuit composed of d ″). FIG.

FIG. 3 is a flowchart showing a process of a lead storage battery evaluation characteristic method of the present invention.

FIG. 4 is a graph illustrating a relationship between an electric double layer capacity value (Cd) and a remaining capacity of a lead storage battery.

FIG. 5 is a graph illustrating a relationship between a charge transfer resistance value (Rct) and a remaining capacity of a lead storage battery.

FIG. 6 is a graph showing a relationship between the electrolyte resistance (RΩ) and the remaining capacity (SOC) of the lead storage battery depending on the temperature of the normal lead storage battery and the deteriorated lead storage battery.

FIG. 7 is a graph illustrating a method of calculating an electrolyte resistance value (RΩ), a charge transfer resistance value (Rct), and an electric double layer capacitance value (Cd).

FIG. 8 is a graph illustrating the relationship between frequency and the real component of impedance.

FIG. 9 is a graph showing coordinates plotting internal impedance measured at three frequencies.

FIG. 10 is a graph showing coordinates plotting internal impedance measured at a fourth frequency.

FIG. 11 is a configuration diagram of a lead storage battery evaluation device of the present invention.

[Explanation of symbols]

 10. Lead storage battery evaluation device 12. Measurement means 14. Calculation means 16. Judgment means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Michihiro Shimada Inventor 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Yoshio Maruyama 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Tetsuya Kano 23-6 Tokiwashita Funamachi, Iwaki City, Fukushima Prefecture 23-6 Inside Furukawa Battery Co., Ltd. 23-23 F-term in Furukawa Battery Co., Ltd. (reference) 2G016 CA03 CB06 CB12 CC01 CC27 2G028 AA01 BE10 CG08 DH05 5H030 AA08 AS08 FF22 FF41 FF52

Claims (13)

[Claims] An impedance is defined by the following equation, comprising at least a parallel circuit of a charge transfer resistance value (Rct) and an electric double layer capacitance value (Cd) and a series circuit of an electrolyte resistance value (RΩ). It is a method of evaluating the lead storage battery of a lead storage battery expressed by an equivalent circuit, wherein [RΩ + (Rct / (1 + jωCd))] (A) where ω = 2πf The real part of the internal impedance of the lead storage battery is represented by X The value obtained by plotting the value obtained by multiplying the imaginary part by −1 on the axis on the Y axis defines the impedance circle in two-dimensional coordinates defined by 1 to 10.
The internal impedance of the lead-acid battery is measured for a plurality of frequencies at three or more points selected in the frequency range of 0 Hz, and the charge transfer resistance value (Rct) and the electric double layer capacitance value (C
d) Electrolyte resistance value (RΩ), charge transfer resistance value (Rct), electric double layer capacitance value derived from an equivalent circuit composed of a series circuit of the parallel circuit with d) and the electrolytic solution resistance value (RΩ) (Cd) and the relational expression between the internal impedances of the plurality of lead-acid batteries measured at the plurality of frequencies, the electrolyte resistance value (RΩ) by referring to the values of the plurality of internal impedances measured at the plurality of frequencies. , The charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd), and the calculated electrolyte resistance value (RΩ) and charge transfer resistance value (Rc
and t) determining a remaining capacity and / or a deterioration state of the tested lead storage battery from all or at least one of the electric double layer capacity values (Cd). 2. A relational expression between the electric double layer capacity value (Cd) and the remaining capacity of the lead storage battery is obtained in advance, and the electric double layer capacity value (Cd) obtained from a plurality of measurement results of the internal impedance is obtained. ) Is checked against the relational expression of the remaining capacity of the lead-acid battery to determine the remaining capacity of the lead-acid battery, and the correction based on the deterioration state of the lead-acid battery and the correction based on the temperature of the lead-acid battery at the time of this determination. The method for evaluating a lead storage battery according to claim 1, wherein: 3. The method according to claim 2, wherein the electric double layer capacity value (Cd) and the remaining capacity of the lead storage battery are defined as a straight line having a temperature-dependent gradient. 4. A plurality of relational expressions between the electric double layer capacity value (Cd) and the remaining capacity of the lead storage battery are prepared for a plurality of predetermined temperatures in advance, and the temperature of the lead storage battery is measured. 4. The lead storage battery evaluation characteristic method according to claim 3, wherein a characteristic of the lead storage battery according to the temperature of the lead storage battery is evaluated by interpolation using a relational expression of two approximate temperatures among the plurality of relational expressions. 5. 5. The method according to claim 1, wherein the correction based on the deterioration state of the lead-acid battery and the correction based on the temperature at the time of the determination are performed based on the electrolyte resistance value (RΩ) and the charge transfer resistance value (Rct) obtained from a plurality of measurement results of the internal impedance. 3. The method according to claim 2, wherein the evaluation is performed using the electric double layer capacitance value (Cd). 6. A charge transfer resistance value (Rc) of a lead storage battery in advance.
t) and the relational expression between the remaining capacity of the lead-acid battery and the charge transfer resistance value (Rct) obtained from the plurality of measurement results of the internal impedance are compared with the relational expression for the remaining capacity of the lead-acid battery. 2. The method according to claim 1, wherein the remaining capacity of the storage battery is determined, and a correction based on the deterioration state of the lead storage battery and a correction based on the temperature of the lead storage battery are performed.
The evaluation characteristic method of the lead storage battery described in the above. 7. A method according to claim 1, wherein the correction based on the deterioration state of the battery and the correction based on the temperature of the lead-acid battery are performed based on the electrolyte resistance value (RΩ) obtained from the plurality of measurement results of the internal impedance.
7. The method according to claim 6, wherein the evaluation is performed using the electric double layer capacity value (Cd). 8. The method according to claim 7, wherein the plurality of measurement frequencies are any three to four selected within a frequency range of 5 to 100 Hz.
A first frequency (Fa) of a point, and a second frequency of an arbitrary point selected in a frequency range of 1 to 5 Hz.
2. The method for evaluating characteristics of a lead-acid battery according to claim 1, wherein the frequency is Fb. 9. Derivation of the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd): (a) The real part of the measured internal impedance is set on the X axis,
A value obtained by multiplying the imaginary part by −1 is plotted on the Y axis. (B) Among them, 3 measured at the first frequency (Fa)
(C) X-axis intercepts Xa and Xb of the orbit (where Xa <X
b) is determined, and (d) the section Xa is defined as the electrolyte resistance value (RΩ).
b−Xa) as the charge transfer resistance value (Rct), and (Xa +
The xb) × 0.5 and X _m, and (e) the real part of the internal impedance to coordinate the frequency is X axis to the Y axis, the lowest frequency of the first frequency (Fa) (Fa ') the plotting the measured values in the second frequency (Fb), a straight line of which connecting the two plots, the frequency corresponding to X _m described above and omega _m and (f) the electric double layer capacitance (Cd) (Rct ×
and obtaining the omega _m) ^-1, evaluation properties method of the lead storage battery of claim 1, wherein. 10. The method according to claim 1, wherein the first measurement frequency (Fa) includes one of 5 to 10 Hz, one of 10 to 30 Hz, and one of 50 to 100 Hz. Item 7. The method for evaluating a lead storage battery according to Item 6. 11. The characteristic evaluation of the lead storage battery is performed at predetermined time intervals, and the electrolyte resistance value (R
Ω), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd), at least one of which is the electrolyte resistance value (RΩ), the charge transfer resistance value ( Rc
and t) comparing at least one of the electric double layer capacitance values (Cd) with each other, and using the comparison result to correct the remaining capacity of the lead storage battery and the deterioration state. The evaluation characteristic method of the lead storage battery described in the above. 12. A lead storage battery evaluation characteristic method according to claim 1, wherein said process is performed on a lead storage battery mounted on a vehicle during an engine stop period of the vehicle. . 13. An impedance constituted by a parallel circuit of at least a charge transfer resistance value (Rct) and an electric double layer capacitance value (Cd) and a series circuit of an electrolyte resistance value (RΩ). This is a lead storage battery evaluation characteristic device of a lead storage battery expressed by an equivalent circuit, [RΩ + (Rct / (1 + jωCd))] (B) where ω = 2πf 1 to 100 Hz is selected. At a plurality of frequencies of at least three points that define an impedance circle in two-dimensional coordinates defined by plotting a value obtained by multiplying the real part of the internal impedance on the X axis and the imaginary part by −1 on the Y axis. Measuring means for measuring the internal impedance of the charge transfer resistance (Rct) and the electric double layer capacitance (C
d) and an equivalent circuit resistance (RΩ) derived from an equivalent circuit composed of a series circuit of the electrolyte resistance (RΩ) and the parallel circuit.
Ω), the charge transfer resistance value (Rct), the electric double layer capacitance value (Cd), and the internal impedance of the plurality of lead-acid batteries measured at the plurality of frequencies. Calculating means for calculating the electrolyte resistance value (RΩ), the charge transfer resistance value (Rct), and the electric double layer capacitance value (Cd) with reference to the impedance value; Charge transfer resistance (Rc
t), a device for evaluating characteristics of a lead-acid battery, comprising: a judging means for judging a remaining capacity and / or a deterioration state of the tested lead-acid battery from the electric double layer capacity value (Cd).