JP2003068368A - Nickel-metal hydride battery capacity estimation method - Google Patents

Abstract

(57) [Problem] To provide a method for accurately estimating the capacity of a nickel-metal hydride battery in a short time after measuring the correlation between the capacity and the change in internal resistance without measuring the actual capacity. To provide. A between the battery from discharging starting time T1 until the discharge end time T2, when obtained by constant current discharge, the difference [Delta] V2-delta between the voltage V ₂ and the discharge end just before the voltage V ₃ of immediately after the start of discharge
V1 divided by the discharge current I1, the internal resistance change (ΔV
After determining the correlation between (2-ΔV1) / I1 and the capacity of the battery by actual measurement, the internal resistance change (ΔV2-ΔV1) / I1 of the test battery for which the capacity is to be estimated is calculated by discharging under the same conditions as above. And its internal resistance change (ΔV2-
A capacity estimation method for a nickel-metal hydride battery is characterized in that the capacity of the test battery is estimated based on the correlation using ΔV1) / I1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacity estimation method for a nickel hydrogen battery.

[0002]

2. Description of the Related Art A secondary battery deteriorates due to repeated charging and discharging and its capacity decreases. When the capacity drops below the standard value, the battery must be replaced. For example, a lead-acid battery for communication power backup has an initial capacity of 70
%, For nickel-cadmium batteries and nickel-hydrogen batteries, 60% of the initial capacity is a standard for replacement. If a battery whose capacity has dropped below the reference value is used as it is, an emergency backup power supply or the like may cause a problem related to human life in the worst case. Therefore, it is necessary to always know the capacity of the secondary battery used.

However, in order to accurately measure the capacity of the secondary battery, it usually takes a long time. For example, in a nickel-hydrogen battery, after discharging to 1.0 V / cell, it is charged at 0.1 CmA for 16 hours, and after 1 hour of rest, discharged at 0.2 CmA to 1.0 V / cell, and the discharge capacity at that time Is measured and used as the actual capacity. here,
CmA is a current value obtained by dividing the nominal capacity by 1 hour. Therefore, it takes about one day for measurement. Moreover, since the battery cannot be used for its original purpose during the capacity measurement, it is not preferable to measure the capacity too often.

In order to solve this problem, a method of estimating the capacity of the secondary battery in a shorter time has been devised. For example, in a lead storage battery, the capacity can be estimated from the measured value of the internal resistance by using a linear relationship that holds between the internal resistance and the capacity. However, in order to use this method, it is necessary to prepare a large number of batteries of the same type and different degrees of deterioration for each battery to be used, and to find the relationship between the internal resistance and the capacity. Also in the nickel-cadmium battery, there is known a method of estimating the capacity from the measured value of the internal resistance by using a relational expression that holds between the internal resistance and the capacity. In order to use this method, only the internal resistance and initial capacity of the undegraded battery are needed, and it is excellent in that it is not necessary to prepare a large number of degrading batteries and calculate the relational expression, but other than nickel-cadmium batteries. Cannot be applied to.

[0005]

It has been known that the internal resistance of the nickel-metal hydride battery to which the present invention is applied increases as the capacity decreases. However, the quantitative relationship that generally holds is not clear, and the only way to confirm the capacity is to actually discharge the battery and measure the capacity.

The problem to be solved by the present invention is to determine the capacity of a nickel-hydrogen battery in a short time after measuring the correlation between the capacity and the change in internal resistance, without measuring the actual capacity. It is to provide a way to estimate well.

[0007]

In order to solve the above-mentioned problems, the present invention provides a capacity estimation method for a nickel-hydrogen battery, which is used alone or by connecting a plurality thereof as described in claim 1. Then, only for the same type of nickel-hydrogen battery, the correlation between the battery capacity and the change in internal resistance value under discharge under the specified conditions was obtained by actual measurement, and then the test battery for capacity estimation was selected. A capacity estimation method for a nickel-hydrogen battery is configured by estimating the capacity of the test battery by the correlation using the change in internal resistance value obtained by discharging under the predetermined condition.

Further, according to the present invention, as described in claim 2, there is provided a method for estimating the capacity of a nickel-hydrogen battery, which is used alone or by connecting a plurality of batteries. After determining the correlation between the battery capacity and the change in internal resistance value during charging under predetermined conditions by actual measurement, the internal battery obtained by charging the test battery subject to capacity estimation under the predetermined conditions A capacity estimation method for a nickel-hydrogen battery is configured by estimating the capacity of the test battery based on the correlation using a change in resistance value.

Further, according to the present invention, as described in claim 3, there is provided a method for estimating the capacity of a nickel hydrogen battery, which is used alone or by connecting a plurality of batteries. The specific capacity obtained by dividing the capacity by the nominal capacity or the capacity of the undegraded battery and the standardized internal resistance value change obtained by dividing the change in internal resistance value under discharge under the specified conditions by the initial value of the electrolytic solution resistance. After determining the correlation between the actual measurement, using the standardized internal resistance change obtained by discharging the test battery to be subjected to capacity estimation under the predetermined conditions, the capacity of the test battery by the correlation A method for estimating the capacity of a nickel-hydrogen battery, which is characterized in that it is estimated.

Further, according to the present invention, as described in claim 4, there is provided a method for estimating the capacity of a nickel hydrogen battery, which is used alone or by connecting a plurality of batteries. The specific capacity obtained by dividing the capacity by the nominal capacity or the capacity of the undegraded battery and the standardized internal resistance value change obtained by dividing the change in internal resistance value during charging under predetermined conditions by the initial value of the electrolyte resistance. After determining the correlation between the actual measurement, using the standardized internal resistance change obtained by charging the test battery for capacity estimation under the predetermined conditions, the capacity of the test battery by the correlation A method for estimating the capacity of a nickel-hydrogen battery, which is characterized in that it is estimated.

Further, in the present invention, as described in claim 5, in the method for estimating the capacity of a nickel-hydrogen battery according to claim 1 or 3, the discharge under the predetermined condition is a constant discharge time. And a constant discharge current, the internal resistance value change is a value obtained by dividing the difference between the battery voltage immediately after the start of discharge and the battery voltage immediately before the end of discharge by the discharge current value. A characteristic estimation method for a nickel-hydrogen battery is constructed.

Further, in the present invention, as described in claim 6, in the capacity estimation method for the nickel-hydrogen battery according to claim 2 or 4, charging under the predetermined condition is performed at a constant charging time. And charging at a constant charging current, the internal resistance value change is a value obtained by dividing the difference between the battery voltage immediately before the end of charging and the battery voltage immediately after the start of charging by the charging current value. A characteristic estimation method for a nickel-hydrogen battery is constructed.

Further, in the present invention, as described in claim 7, in the capacity estimation method of the nickel hydrogen battery according to claim 5 or 6, the discharge time or the charge time is 100 milliseconds or more. A capacity estimation method for a nickel-hydrogen battery, which is characterized by being 10 seconds or less.

Further, according to the present invention, as described in claim 8, in the capacity estimation method for a nickel-hydrogen battery according to claim 5 or 6, the discharge current value or the charging current value is 0. A method for estimating the capacity of a nickel-hydrogen battery is characterized in that it is not less than a current value corresponding to a 5-hour rate and not more than a current value corresponding to a 2-hour rate.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION To outline the present invention, the present invention relates to a method for estimating the capacity of a nickel-hydrogen battery, for example, by discharging or charging the battery at a constant current for a short time, The capacity of the battery is estimated using the correlation established between the capacity and the change in internal resistance value during discharging or charging.

The present invention will be described below with reference to embodiments. In the following, the nickel-hydrogen battery is simply called a battery, and the battery voltage is simply called a voltage.

First, a battery that has deteriorated due to long-term use,
Alternatively, a battery of the same type that is deteriorated due to overcharge, charge / discharge at high temperature, numerous charge / discharge cycles, or the like is prepared. These batteries are discharged at a constant current for a short time (pulse discharge) or short-time charge (pulse charge), and the voltage changes immediately after the start of discharge and immediately before the end of discharge or immediately before the end of charge and immediately after the start of charge. Measure the voltage change of. Further, using the same type of non-deteriorated battery, the initial value of the electrolytic solution resistance is obtained from the voltage change and the current value immediately after the start of discharge.

FIG. 1 is a conceptual diagram showing the relationship between time and voltage in the case of constant current discharge, and FIG. 2 is a conceptual diagram showing the relationship between time and voltage in the case of constant current charging.

In the case of the constant current discharge shown in FIG. 1, when the discharge is started at the discharge start time T1, the voltage changes from the open circuit voltage V ₁ before the discharge to the voltage V ₂ immediately after the start of the discharge. Falls sharply. This sudden voltage change, that is,
The voltage change immediately after the start of discharge is represented by ΔV1. After that, until the discharge end time T2, the voltage gradually changes and reaches the voltage V ₃ immediately before the end of discharge. The voltage rises sharply immediately after the end of discharge, but does not immediately return to the voltage V ₁ before discharge. The reason for this is that the battery system consisting of the electrodes and the electrolytic solution is thermodynamically in a non-equilibrium state due to discharge,
It is that the state does not return to the equilibrium state immediately. However, since the battery system eventually reaches an equilibrium state and the voltage returns to the voltage V ₁ before discharge, the voltage change immediately after the end of discharge is defined as the difference between the voltage V ₁ and the voltage V _3, and this is represented by ΔV2.

In FIG. 1, the rapid voltage change ΔV1 immediately after the start of discharge is due to the voltage drop due to the resistance of the electrolytic solution. On the other hand, the gradual voltage change that occurs until the end of the subsequent discharge (as can be seen from the figure, this is ΔV2-Δ
(Equal to V1) is a voltage change mainly due to an electrode reaction. As can be seen from the figure, ΔV2-ΔV1 is obtained as the difference between the voltage V ₂ immediately after the start of discharge and the voltage V ₃ immediately before the end of discharge.

In the present invention, the voltage change ΔV2-ΔV1 mainly due to the electrode reaction and the internal resistance value change (ΔV2-ΔV) during discharge obtained by dividing the voltage change by the discharge current I1.
1) / I1 and the actual capacity are based on a new finding that an approximately linear relationship is established.

The correlation between the change in the internal resistance value and the actual capacity is also recognized in the charging process of the battery.

In the case of the constant current charging shown in FIG. 2, when the charging is started at the charging start time T3, the voltage changes from the open circuit voltage V ₄ before charging to the voltage V ₅ immediately after the charging is started. Rises sharply. This abrupt voltage change, that is, the voltage change immediately after the start of charging is represented by ΔV1. After that, until the charging end time T4, the voltage gradually changes and reaches the voltage V ₆ immediately before the end of charging. The voltage drops sharply immediately after the end of charging, but does not immediately return to the voltage V ₄ before charging. The reason for this is that the battery system consisting of the electrodes and the electrolyte is thermodynamically non-equilibrium due to charging,
It is that the state does not return to the equilibrium state immediately. However, eventually the battery system reaches an equilibrium state and the voltage returns to the voltage V ₄ before charging, so the voltage change immediately after the end of charging is defined as the difference between the voltage V ₆ and the voltage V _4, and this is represented by ΔV2.

In FIG. 2, the rapid voltage increase ΔV1 immediately after the start of charging is due to the voltage increase due to the electrolytic solution resistance. On the other hand, the gradual voltage change that occurs until the end of charging after that (this is ΔV2-
(Equal to ΔV1) is a voltage change mainly due to an electrode reaction. As can be seen from the figure, ΔV2-ΔV1 is obtained as the difference between the voltage V ₆ immediately before the end of charging and the voltage V ₅ immediately after the start of charging.

In the present invention, as in the case of the above discharge, the voltage change Δ mainly due to the electrode reaction in the case of this charge.
V2-ΔV1 and change in internal resistance value during charging obtained by dividing this voltage change by the charging current I1 (ΔV2-ΔV1)
/ I1 and the actual capacity approximately have a linear relationship,
It is also based on the new finding.

In the present invention, a plurality of batteries of the same type having different capacities are prepared, and the actual capacity of the battery and the change in internal resistance value during discharging or the change in internal resistance value during charging are measured using each battery. Then, based on the result, the correlation between the actual capacity and the change in internal resistance value during discharge,
Alternatively, after obtaining the correlation between the actual capacity and the change in the internal resistance value during charging, the capacity of the battery is estimated using the correlation. Specifically, a battery of the same type as the battery used when the above correlation was obtained was used as a test battery for capacity estimation, and the internal resistance value change during discharging or charging was determined as the above correlation. It is obtained by actual measurement under the same conditions as the case, and the capacity corresponding to the change in internal resistance obtained thereby is obtained by the above correlation, and the capacity is estimated to be the capacity of the test battery. In this way, after obtaining the above-mentioned correlation, the capacity of the battery can be accurately estimated in a short time by actually measuring the change in the internal resistance value.

The above correlation is specific to the target battery type of the same type, and was applied only to estimating the capacity of the same type battery, but this correlation is applied to the battery type. It can be converted into a general-purpose correlation.

That is, the actual capacity is divided by the nominal capacity or the capacity of the undegraded battery to convert it into a specific capacity, and the change in the internal resistance value is divided by the initial value of the electrolytic solution resistance, that is, the value in the undegraded battery to standardize the internal resistance. If the value changes, the correlation between the specific capacity and the change in the standardized internal resistance value is a correlation that does not depend on the capacity or size of the battery. Therefore,
Once this correlation is obtained, it is not necessary to prepare many deteriorated batteries of each type, but only the initial value of the electrolyte resistance value of each type of battery can be measured. The capacitance can be estimated with high accuracy within a short time by the above relational expression using the normalized internal resistance value change calculated from the result of one measurement. A specific example of this method will be described in the following examples.

It is appropriate that the charging / discharging time in constant current charging / discharging required for estimating the battery capacity is about 100 milliseconds to 10 seconds. Further, the charging / discharging current is suitably about 0.5 CmA to 2 CmA, but the current value used for measuring the initial value of the electrolytic solution resistance does not need to be the same value as other measurements, and a smaller current value can be used. It doesn't matter. Here, CmA is a current value obtained by dividing the nominal capacity by 1 hour, and a numerical value when the current is expressed with this as a unit (for example, 0.
5 and 2) are called time rates. The time resolution required to measure voltage changes is 1 to ensure the accuracy of capacity estimation.
It is less than a millisecond.

[0030]

EXAMPLES The present invention is described in detail below based on examples, but the present invention is not limited to these examples.

The initial capacity of a nickel hydrogen battery (hereinafter referred to as battery 1) having A size and a nominal capacity of 2500 mAh was measured and found to be 2560 mAh. Using this battery, after charging for 16 hours at a charging current of 250 mA and then discharging for 1 second at a discharging current of 2.5 A (1 CmA), the voltage change (corresponding to ΔV1 in FIG. 1) immediately after the start of discharge is ΔV0. , Its ΔV0 was 41 mV. Prepare 7 batteries of the same type as Battery 1, 250 at 45 ° C each
It was deteriorated by repeating charging for 72 hours at 500 mA and discharging at 500 ° C. at 25 ° C. and a final voltage of 1.0V. When the capacity dropped from 60% to 90% of the nominal value, the charging was stopped for 72 hours, and the current value was 2.5 A (1 CmA).
The change in the closed circuit voltage of the battery when pulse-discharged for 1 second was observed.

As a result, the correlation between the internal resistance value change (ΔV2-ΔV1) / I1 and the capacity in this pulse discharge can be obtained, and the capacity of a battery of the same type as the battery 1 is estimated by using the correlation. be able to. That is,
The internal resistance change (ΔV2−ΔV1) / I1 in the discharge of the test battery of the same type as the battery 1 which is the target of capacity estimation is
The internal resistance value change (ΔV2-Δ) obtained by actual measurement under the same conditions as the case of obtaining the above correlation is obtained.
The capacity corresponding to V1) / I1 is obtained by the above correlation (in this case, approximated by the linear relationship represented by the linear expression), and the capacity is estimated to be the capacity of the test battery. However, the capacity estimation method illustrated here is applied only to a battery of the same type as the battery used when obtaining the above correlation.

Next, the initial capacity of a nickel metal hydride battery (hereinafter referred to as battery 2) of D size having a nominal capacity of 7500 mAh was measured and found to be 7126 mAh. Using this battery, when the battery was charged at a charging current of 750 mA for 16 hours and then discharged at a discharging current of 7.5 A (1 CmA) for 1 second, the voltage change ΔV0 immediately after the start of discharging was 18 mV. Prepare 7 batteries of the same type as Battery 2, 75 at 45 ° C each
It was deteriorated by repeating charging at 0 mA for 72 hours and discharging at 400C at 25 ° C and a final voltage of 1.0V. When the capacity dropped from about 60% to 90% of the nominal value, the repeated charging for 72 hours was stopped, and the current value was 7.5 A (1 Cm
The change in the closed circuit voltage of the battery during pulse discharge for 1 second in A) was observed.

As a result, the correlation between the internal resistance value change (ΔV2-ΔV1) / I1 and the capacity in this pulse discharge can be obtained, and the capacity of a battery of the same type as the battery 2 is estimated by using the correlation. be able to. That is,
The internal resistance value change (ΔV2-ΔV1) / I1 in the charging of the test battery of the same type as the battery 2 which is the target of the capacity estimation,
The internal resistance value change (ΔV2-Δ) obtained by actual measurement under the same conditions as the case of obtaining the above correlation is obtained.
The capacity corresponding to V1) / I1 is obtained by the above correlation (in this case, approximated by the linear relationship represented by the linear expression), and the capacity is estimated to be the capacity of the test battery. As described above, after obtaining the above-mentioned correlation, the capacity of the battery can be accurately estimated in a short time by actually measuring the change in the internal resistance value. However, the capacity estimation method illustrated here is applied only to a battery of the same type as the battery used when obtaining the above correlation.

Next, the above correlations are converted to those applicable to any type of battery. First, the actual capacity of the battery is divided by the nominal capacity or the capacity of the non-deteriorated battery to convert it into the specific capacity. Next, the internal resistance value change (ΔV2-ΔV1) / I1 is divided by the initial value of the electrolytic solution resistance, that is, the value in the undeteriorated battery to convert it into a normalized internal resistance value change. When such conversion is performed, it is found that the specific capacity after conversion and the change in the standardized internal resistance value have a correlation independent of the battery type.

In FIG. 3, the voltage change ΔV1 immediately after the start of pulse discharge and the voltage change ΔV2 immediately after the end of discharge in the batteries 1 and 2 were measured, and the standardized internal resistance value change ((ΔV2- ΔV1) / I1) / (ΔV0 / I0) was calculated, and it was plotted on the horizontal axis, and the vertical axis was plotted by taking the specific capacity (the actual capacity divided by the nominal capacity or the undegraded battery capacity). The results are shown. Here, I0 is the current value when the undegraded voltage change ΔV0 is measured, and ΔV0
/ I0 is the initial value of electrolyte resistance (value for undeteriorated batteries)
be equivalent to. I1 is the current value when the voltage change ΔV2-ΔV1 of the deteriorated battery is measured. Since I0 and I1 are the same in FIG. 3, the normalized internal resistance value change, that is, ((ΔV2-ΔV1 V1) / I1) / (ΔV0 / I0)
Is represented by (ΔV2-ΔV1) / ΔV0 which is equal to that. As already described with reference to FIG. 1, the voltage change ΔV2-ΔV1 is obtained as the difference between the voltage V ₂ immediately after the start of discharge and the voltage V ₃ immediately before the end of discharge.

Although the battery 1 and the battery 2 have different sizes and nominal capacities, it is clear from FIG. 3 that the normalized internal resistance value change (ΔV2-ΔV1) / ΔV0 (horizontal axis in the figure). )
And the specific capacity (vertical axis in the figure) are approximated by the same linear relationship represented by a linear relational expression. That is, in this case, the relational expression between the specific capacity of the battery and the change in the normalized internal resistance value is a linear expression, and moreover, the battery 1 (indicated by a white circle in the figure) and the battery 2 (indicated by a black square in the figure). Applicable to both). The regression rate when battery 1 and battery 2 were approximated by the same straight line was 0.962.

Next, after using a battery of the same type as the already deteriorated battery 1 at 25 ° C. and 200 mA for 16 hours,
Discharge pulse width is 10 milliseconds, 100 milliseconds, 1 second, 2
Second, 5 seconds, and 10 seconds were changed, and the regression rate of the linear relationship that holds between the standardized internal resistance value change (ΔV2-ΔV1) / ΔV0 and the specific capacity at that time was calculated. 0.929, 0.957, 0.983, in order from millisecond
It became 0.987, 0.984, and 0.988. Therefore, it is sufficient if the discharge pulse width is 100 milliseconds or more and 10 seconds or less, and the accuracy cannot be improved even if the discharge time is extended for 10 seconds or more. That is, it is appropriate that the discharge time is 100 milliseconds or more and 10 seconds or less.

Next, using a battery of the same type as the already deteriorated battery 1, the pulse width was fixed at 1 second, and the discharge current or charging current value was 200 mA, 400 mA, 1.0 A,
Normalized internal resistance value change (△ V2- △ V
1) / ΔV0 and the specific capacity, the regression rate of the linear relationship established was found.
04, 0.935, 0.967, 0.983, and from charging 200 mA, 0.911, 0.933,
The values were 0.964 and 0.979, and the accuracy was higher when the current value was larger, and the accuracy was higher when discharging at the same current value. In this case, the charge / discharge current values of 1.0 A and 2.0 A are 0.4 CmA and 0.8 C, respectively.
It corresponds to mA. Even in this current range, the accuracy is slightly improved as the current value increases, but the current value is 0.5 CmA or more and 2.0 CmA or less due to the reason that the current value that the measuring device can output is limited. Is appropriate.

Next, using a battery of the same type as the already deteriorated battery 1, the discharge pulse width is 1 second and the discharge current is 2.
5A, the voltage change immediately after the start of discharge was measured while changing the time resolution. Measured time resolution is 1 microsecond, 1
It was 0 microseconds, 100 microseconds, 1 millisecond, and 10 milliseconds. Normalized internal resistance value change at this time (ΔV2-
When the regression rate of the linear relationship that holds between ΔV1) / ΔV0 and the specific capacity is obtained, 0.983, 0.983, 0.981, 0.978, in order from the time resolution of 1 microsecond,
It was 0.951. Therefore, it is understood that the time resolution of 1 millisecond or less is necessary to estimate the battery capacity with sufficient accuracy.

The correlation shown in FIG. 3 is used as a method for estimating the specific capacity and capacity of a battery of any type using the correlation between the change in standardized internal resistance value and the specific capacity shown in FIG. The case will be described below as an example.

A test battery of any type, which is the target of capacity estimation, is discharged under the same conditions as when obtaining the correlation shown in FIG. 3, and the normalized internal resistance value at that discharge is determined from the voltage change at that time. Calculate the change. For this calculation, the initial value of the electrolyte resistance of a battery of the same type as the test battery (value in the undeteriorated battery) is required, but if that value has already been calculated, use that value, and if not calculated. Obtained by actual measurement. The specific capacity corresponding to the change in the standardized internal resistance value calculated in this way is obtained by the correlation shown in FIG.
It is estimated that the specific capacity is the specific capacity of the test battery. The specific capacity thus estimated is multiplied by the nominal capacity of a battery of the same type as the test battery or the capacity of the undegraded battery to obtain the estimated capacity of the test battery. In this way, after obtaining the above-mentioned correlation, the specific capacity and the capacity of a battery of any type can be accurately estimated in a short time by obtaining the above-mentioned normalized internal resistance value change by actual measurement. it can.

In the above description, the value in constant current discharge or constant current charge is used as the internal resistance value change in discharge or charge, but in addition to this, for example,
Internal resistance change when the battery is discharged through the resistor for a certain period, or series resistance (safety resistance) for a certain period
The same effect can be obtained by using the internal resistance value change when the battery is charged by a constant voltage power supply.

As described above, according to the deterioration determination method of the present invention, the capacity of the nickel-hydrogen battery is not measured by discharging after the correlation between the capacity and the change in the internal resistance is obtained. Moreover, it has become possible to accurately estimate in a short time.

[0045]

By carrying out the present invention, the capacity of a nickel-hydrogen battery is accurately estimated in a short time after measuring the correlation between the capacity and the change in internal resistance, without measuring the actual capacity. Can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between battery voltage and time when a nickel-hydrogen battery is subjected to constant current pulse discharge.

FIG. 2 is a diagram showing a relationship between battery voltage and time when a nickel-hydrogen battery is subjected to constant current pulse charging.

FIG. 3 is a diagram showing a correlation between a specific capacity of a nickel hydrogen battery and a change in a standardized internal resistance value.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayasu Arakawa             2-3-1, Otemachi, Chiyoda-ku, Tokyo             Inside Telegraph and Telephone Corporation F term (reference) 2G016 CA00 CB06 CB12 CB23 CB33                       CC01 CC04 CC09 CC23                 5G003 EA05 EA09                 5H028 BB00 EE01 EE05                 5H030 AA00 AS03 FF41 FF42 FF43                       FF44

Claims (8)

[Claims] 1. A method for estimating the capacity of a nickel-hydrogen battery, which is used alone or by connecting a plurality of batteries, wherein only the nickel-hydrogen battery of the same type is targeted, and the capacity of the battery and the internal resistance in discharging under a predetermined condition. After determining the correlation with the value change by actual measurement, using the internal resistance value change obtained by discharging the test battery to be capacity estimation target under the predetermined conditions, the correlation of the test battery A method for estimating the capacity of a nickel metal hydride battery, which comprises estimating the capacity. 2. A method for estimating the capacity of a nickel-hydrogen battery, which is used alone or by connecting a plurality of batteries, wherein only the nickel-hydrogen battery of the same type is targeted, and the capacity of the battery and the internal resistance during charging under a predetermined condition. After determining the correlation with the value change by actual measurement, using the internal resistance value change obtained by charging the test battery that is the target of capacity estimation under the predetermined conditions, the correlation of the test battery of the A method for estimating the capacity of a nickel metal hydride battery, which comprises estimating the capacity. 3. A method for estimating the capacity of a nickel-hydrogen battery, which is used alone or by connecting a plurality of batteries, wherein only the nickel-hydrogen battery is targeted, and the capacity of the battery is divided by the nominal capacity or the capacity of the undeteriorated battery. After obtaining the correlation between the specific capacity obtained and the normalized internal resistance value change obtained by dividing the internal resistance value change during discharge under a predetermined condition by the initial value of the electrolytic solution resistance by actual measurement, A capacity estimation method for a nickel-hydrogen battery, characterized in that the capacity of the test battery is estimated by the correlation using the standardized internal resistance value change obtained by discharging the target test battery under the predetermined condition. . 4. A method for estimating the capacity of a nickel-hydrogen battery, which is used alone or by connecting a plurality of batteries, wherein only the nickel-hydrogen battery is targeted, and the capacity of the battery is divided by the nominal capacity or the capacity of the undeteriorated battery. After obtaining the correlation between the specific capacity obtained and the standardized internal resistance change obtained by dividing the internal resistance change during charging under predetermined conditions by the initial value of the electrolytic solution resistance by actual measurement, Using the change in the standardized internal resistance value obtained by charging the target test battery under the predetermined condition, the capacity of the test battery is estimated by the correlation, and the capacity of the nickel hydrogen battery is estimated. . 5. The method for estimating the capacity of a nickel-hydrogen battery according to claim 1 or 3, wherein the discharge under the predetermined condition is a discharge with a constant discharge time and a constant discharge current, and the internal resistance is The capacity estimation method for a nickel-hydrogen battery, wherein the change in value is a value obtained by dividing the difference between the battery voltage immediately after the start of discharge and the battery voltage immediately before the end of discharge by the discharge current value. 6. The method for estimating the capacity of a nickel-hydrogen battery according to claim 2 or 4, wherein the charging under the predetermined condition is a charging with a constant charging time and a constant charging current, and the internal resistance is The method of estimating the capacity of a nickel-hydrogen battery, wherein the value change is a value obtained by dividing a difference between a battery voltage immediately before charging completion and a battery voltage immediately after charging start by the charging current value. 7. The method for estimating the capacity of a nickel-hydrogen battery according to claim 5 or 6, wherein the discharging time or the charging time is 100 milliseconds or more and 10 seconds or less. Capacity estimation method. 8. The method for estimating the capacity of a nickel-hydrogen battery according to claim 5 or 6, wherein the discharge current value or the charging current value is equal to or more than a current value corresponding to a 0.5 hour rate and is a 2-hour rate. A method for estimating the capacity of a nickel-hydrogen battery, which is equal to or less than a corresponding current value.