JP2003017139A - Cell residual capacity measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly calculate cell residual capacity regardless of a state of cell usage and circumferential environment. SOLUTION: A detecting device 2 detects the value of current flowing through a lithium ion cell 31 housed in a cell pack 3 and the temperature (circumferential condition) by a current sensor 32 and a temperature sensor 33, and transmits the obtained information to an arithmetic unit 1. A temperature/non-chargeable electrical quantity memory table 4 records a temporarily non-chargeable electrical quantity in relation with temperature. A temperature/current/non- dischargeable electrical quantity memory table 5 records a temporarily non- dischargeable electrical quantity in relation with temperature and current. A self discharging electrical quantity memory table 6 records a self discharging electrical quantity of the cell. A timer 7 measures the charging time or the discharging time of the cell. A residual capacity memory 8 records the residual capacity up to now. The arithmetic unit calculates the residual capacity of the lithium ion cell 31 at present using above devices (hard wares) and the information related to the circumferential environment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery fuel gauging device, and more particularly, to a battery residual amount measuring device connected to or left connected to an external load or a charging device, or a condition left unused without being used. The present invention relates to a battery remaining amount measuring device for accurately measuring the amount of electricity (remaining amount) stored in a lithium-ion battery in an environment where it is exposed to electricity.

[0002]

2. Description of the Related Art Conventionally, the current amount of electricity (remaining amount) stored in a lithium-ion battery is accurately measured under the condition that it is connected to an external load or a charging device or is left unused and unused. A battery remaining amount measuring device is used as a measuring device for measurement.

FIG. 17 shows a conventional battery remaining amount measuring device 1
It is a block diagram showing an example of composition. In the conventional battery remaining amount measuring device shown in FIG. 17, a lithium ion battery 931 is a secondary battery to be charged.
1 is a current sensor 93 for detecting a charging / discharging current flowing through the lithium-ion battery 931 in the battery pack 93.
2. It is housed together with a temperature sensor 933 that detects the temperature of the battery. The detection signals from the current sensor 932 and the temperature sensor 933 are taken into the arithmetic unit 91 by the detection unit 92, the arithmetic unit 911 in the arithmetic unit 91 is activated, and the amount of electricity stored in the lithium ion battery 931 (remaining amount). 912) is calculated, and the result is output to the electric quantity display unit 99 which is an external device.

At the time of discharge, the remaining charge 912 is divided by the detected discharge current or a predetermined current value to obtain the remaining discharge time 913 (dischargeable time), and the remaining discharge time 913 is calculated by an external device. Output to a certain time display unit 910, and at the time of charging, the remaining charge time (chargeable time) is obtained by dividing the amount of electricity obtained by subtracting the remaining amount 912 from the full charge amount by the detected charging current or a predetermined current value. And the remaining charge time is displayed on the time display unit 91 which is an external device.
It outputs to 0. As the above-mentioned predetermined current value, an average current within a predetermined time, a planned current value to be passed from now on, or the like is used.

The operation algorithm 911 differs between charging and discharging (that is, when current is flowing) and non-charging and discharging (that is, when no current is flowing). During charging and discharging, the remaining amount memory 98 is used. The remaining amount is obtained by adding the charge electricity amount and subtracting the discharge electricity amount to the previous remaining amount recorded in, and the current remaining amount is obtained by subtracting the self-discharge amount from the previous remaining amount during non-charging / discharging. Find the amount. The amount of charging electricity is the charging current detected by the current sensor 932 and the timer 9
7 is obtained by multiplying the product of the time measured in 7 (that is, the quantity of electricity charged for a predetermined time) by the charging efficiency, and the quantity of electricity discharged is the discharge current detected by the current sensor 932 and the timer 9
It is obtained by dividing the product with the time measured in 7 (that is, the discharge electricity amount for a predetermined time) by the discharge efficiency.

Here, the above-mentioned charging efficiency is the ratio of the amount of electricity actually stored to the amount of charge (that is, the amount of charge that can be charged), and this value changes depending on temperature, current and remaining amount. . FIG. 18 is a graph showing an example of the relationship between temperature and charging efficiency in a conventional battery remaining amount measuring device.

It can be seen from the graph shown in FIG. 18 that the charging efficiency decreases as the temperature decreases. Further, the above-mentioned discharge efficiency is a ratio indicating the ratio of the total discharge charge amount of a predetermined current at a predetermined temperature to the total discharge charge amount of 0.2 C (A) at room temperature (20 ° C.), and changes depending on the temperature and the current. To do. FIG. 19 is a graph showing an example of the relationship between the discharge efficiency and the temperature in the conventional battery remaining amount measuring device.

From the graph shown in FIG. 19, the temperature is low,
It can be seen that the efficiency decreases as the current increases. For example,
When the charge electricity amount obtained by integrating the current detected at the charge efficiency of 0.9 is 1000C, the recognized actual charge electricity amount is 900C (1000C x 0.
9), and when the discharge electricity quantity obtained by integrating the current detected at the discharge efficiency of 0.9 is 1000 C, the actual discharge electricity quantity recognized is 1111 C (10
00C / 0.9).

The remaining amount of the lithium ion battery decreases even when the battery is left unused. This is a phenomenon called self-discharge, and its magnitude depends on the remaining amount, temperature, and standing period. FIG. 20 shows a period in which a battery is left in a fully charged state in a conventional battery remaining amount measuring device,
It is a graph which shows an example of the relationship between temperature and a remaining rate.

When the ratio of the remaining amount to the amount of electricity (full charge amount) in the fully charged state of the battery is the remaining amount ratio, the relationship between the temperature, and the remaining amount ratio of the battery left in the fully charged state. Is as shown in FIG. That is, the self-discharge amount is
It can be seen that the higher the temperature is, the larger the temperature is, and the more the temperature is increased. The values of the charging efficiency, the discharging efficiency, and the self-discharging amount are stored in the charging efficiency memory table 94, the discharging efficiency memory table 95, and the self-discharging amount memory table 9, respectively.
6 is stored, and values corresponding to various conditions detected at the time of calculation are selected and used.

[0011]

By the way, the conventional fuel gauging device is based on the idea that the charging / discharging efficiency changes depending on the temperature and the current. However, as a result of the experiment, when the conditions (temperature, current, etc.) change during charging / discharging, the charging / discharging efficiency does not change, but there is a quantity of electricity that cannot be charged / discharged under each charging / discharging condition. It turns out that the idea that the quantity changes is more appropriate.

FIG. 21 is a graph showing an example of the result of continuous charging under two kinds of charging conditions (temperature) in the conventional battery remaining amount measuring apparatus. After a full discharge,
Until fully charged at the specified temperature (charging current is 0.05C
Constant voltage constant current charging (up to (A)) (charging of preceding charge) and further charging at room temperature until fully charged again (graph of additional charging), but complete charging at a predetermined temperature Even after the battery is charged, the amount of electricity is charged to some extent by bringing the temperature to room temperature, and the total amount of electricity may be equal to the amount of electricity when continuously charged at room temperature from the completely discharged state to the fully charged state. I understand.

From this fact, when the charging condition changes,
It can be seen that the charging efficiency (the amount of electricity charged) is constant, and a portion of the amount of electricity cannot be charged temporarily. In other words, when the remaining amount is measured by the conventional way of thinking, assuming that the temperature becomes room temperature after charging at 0 ° C, for example, 0 ° C
Since the amount of electricity to be stored is estimated to be small, the remaining amount at room temperature becomes smaller than the actual remaining amount.

FIG. 22 is a graph showing an example of the results of continuous discharge under two types of discharge conditions (temperature and current) in the conventional battery remaining amount measuring apparatus. FIG. 23 is another graph showing an example of the result of continuous discharging under two kinds of discharging conditions (temperature and current) in the conventional battery remaining amount measuring apparatus. After full charge, constant current discharge was performed until the battery was completely discharged at a predetermined temperature (until the battery voltage reached 2.5V) (graph of preceding discharge), and further discharged at room temperature until it was completely discharged again (additional discharge). However, even after the complete discharge under the predetermined conditions,
(° C), a certain amount of electricity is further discharged, and the total amount of electricity changes from the fully charged state to the completely discharged state at room temperature (20
It can be seen that it is equal to the amount of electricity when continuously discharged at (° C).

Therefore, even if the discharge conditions change,
It can be seen that the discharge efficiency (discharged electricity amount) is constant, and a part of the electricity amount cannot be discharged temporarily. That is, when the fuel amount is measured by the conventional way of thinking, for example, 0 ° C
Assuming that the temperature reaches room temperature after the discharge of
Since the amount of electricity to be discharged is largely estimated at ° C, there arises a problem that the remaining amount at room temperature becomes smaller than the actual remaining amount.

In addition, while the remaining amount is calculated in consideration of the self-discharge amount during non-discharge, the self-discharge amount is indirectly obtained from a plurality of detected states (remaining amount, temperature, standing period). There is also a problem in that the accuracy deteriorates, and when the non-charged / discharged state is repeated, the residual amount recognized internally due to the accumulation of errors greatly differs from the actual residual amount. Further, it is generally known that the battery deteriorates due to repeated charging and discharging of electricity and its capacity decreases, but in the conventional device, there is a method of accurately recognizing the degree of deterioration and obtaining the remaining amount. There was no

Another problem is power consumption. An analog logic circuit, a CPU, or the like is often used for the detection device 92 of the fuel gauging device and the arithmetic device 91, and a lithium-ion battery 93 is used as an operating power source thereof.
1 is used. Originally, the lithium-ion battery 931 is a power source for operating an external load, and it is necessary to suppress the discharge of the other amount of electricity as much as possible, but the self-discharge amount of the battery is a size that cannot be ignored, and the conventional residual amount measurement Since the device constantly (periodically) measures the self-discharge amount during non-charging / discharging, the circuit or the CPU always operates and consumes electric power regardless of charging / discharging / non-charging.

The present invention has been made in view of the problems in the conventional charging device as described above, and a battery capable of accurately obtaining the remaining amount of the battery regardless of the usage state of the battery and the surrounding environment. It is an object of the present invention to provide a remaining amount measuring device.

[0019]

In order to solve the above problems, the present invention solves the above problems by detecting a current flowing through a lithium ion battery, a temperature sensor detecting the temperature of the lithium ion battery, and a sensor signal. A detection device,
An arithmetic unit that calculates the remaining amount of the lithium-ion battery (hereinafter sometimes simply referred to as "remaining amount", and this remaining amount may mean remaining time) based on the captured sensor signal, and a time A memory table (temperature / non-charged amount memory table) that records the relationship between the timer that measures the temperature and the amount of electricity (non-charged amount) that is considered to be temporarily unchargeable at a predetermined temperature, or a function that indicates the relation An algorithm that realizes a function (hereinafter, the memory table, the function, and the algorithm are collectively referred to as a relational description unit), and the amount of electricity that cannot be temporarily discharged at a temperature and a current and a predetermined temperature and a predetermined current (non-discharge amount) A means for describing the relationship between the detected current and the time measured by the timer is used to determine the charge / discharge electricity quantity within a predetermined time, and the remaining amount before and after the predetermined time that has been recorded is adjusted. The remaining amount after a lapse of a predetermined time is obtained by performing the above, and when the current is flowing in the charging direction, the non-charge amount at the predetermined temperature is obtained from the measured temperature by the relation describing means regarding the temperature / non-charge amount, The amount of chargeable electricity at the specified temperature is obtained by subtracting the amount of non-charge and the remaining amount from the amount of electricity in the fully charged state (full charge amount) of the set lithium-ion battery. Alternatively, the remaining charge time is obtained by dividing by the predetermined current value, and if the current is flowing in the discharge direction, the measured temperature and current are used to determine the temperature / current / non-discharge amount by the prescribed temperature / current The amount of dischargeable electricity at a predetermined temperature and a predetermined current is obtained by subtracting the amount of non-discharge from the remaining amount, and the amount of dischargeable electricity is detected discharge current or a predetermined amount. It has a configuration which is divided by the current value obtaining discharge remaining time.

With this configuration, when the charge / discharge current is flowing through the lithium ion battery, the remaining amount of the battery is independent of the charge / discharge conditions (temperature, remaining amount, current, etc.),
It can be obtained by integrating a pure amount of electricity based on the current detected by the current sensor. That is, when charging,
The chargeable amount of electricity (chargeable amount of electricity) can be obtained under the condition (temperature) at that time. Further, at the time of discharging, the amount of electricity that can be discharged (the amount of electricity that can be discharged) can be obtained under the conditions (temperature and current) at that time.

Further, a voltage sensor for detecting the voltage of the lithium-ion battery, a battery voltage (open voltage) in a state where no current flows in the lithium-ion battery (zero current state), and an amount of electricity stored in the lithium-ion battery ( When the current zero time reaches a predetermined time by measuring the current zero time (current zero time) by starting the timer measurement when the current zero state is detected The battery voltage (open circuit voltage) in the zero current state is measured at (open circuit voltage measurement time), and the remaining capacity is calculated from the measured open circuit voltage by means of the description means for the open circuit voltage / remaining capacity. A stable battery voltage is detected, and the remaining amount with respect to the full charge amount of the battery can be accurately obtained.

Furthermore, a relation describing means relating to the ratio of the open circuit voltage and the amount of electricity stored in the lithium ion battery (remaining rate) is provided, and the relationship between the open circuit voltage and the remaining rate from the measured open circuit voltage in the zero current state. By obtaining the remaining amount rate by the description means and obtaining the remaining amount by multiplying it by the full charge amount, a stable battery voltage at no load is detected,
It is possible to obtain an accurate remaining amount and a remaining amount ratio of the battery, which takes into consideration the influence of a current other than the normal current (eg, self-discharge current) and deterioration.

Further, when the remaining voltage ratio obtained by the open circuit voltage and the relationship description means relating to the open circuit voltage / remaining battery ratio is smaller than the stored predetermined remaining battery ratio, the remaining battery ratio and the remaining battery are updated. (For example, open circuit voltage
When the remaining rate obtained by matching with the remaining rate memory table is 50 to 80%, the remaining rate and the remaining rate are updated), so that the influence of the measurement error of the open circuit voltage is avoided. be able to.

Further, a relation describing means regarding the temperature and the open circuit voltage correction amount is provided, and when the current is zero, the relation describing means regarding the temperature / open circuit voltage correction amount obtains the open circuit voltage correction amount from the measured temperature and measures it. The open circuit voltage is corrected by the calculated open circuit voltage correction amount, the remaining battery rate is calculated from the corrected open circuit voltage by the description means for the open circuit voltage / remaining battery ratio, and the remaining battery capacity is calculated by multiplying it by the full charge amount. Therefore, even if the stable open-circuit voltage under no load fluctuates slightly depending on the temperature, it is possible to eliminate the influence by correcting the temperature.

Further, a cycle counter for counting the number of charge / discharge cycles of the lithium ion battery is provided so that the measurement time of the open circuit voltage can be extended according to the count number of the cycle counter. In addition to this configuration, it is also possible to realize a configuration in which the full charge amount is replaced with a stored predetermined remaining amount value when the measured open circuit voltage is equal to or higher than a predetermined value.

Further, when the battery voltage is equal to or higher than the predetermined value and the current value is equal to or lower than the predetermined value during charging, the full charge amount can be replaced with the stored predetermined remaining amount value. , When the fully charged state of the battery is detected,
For example, the full charge amount of the battery can be updated to a value when it changes due to the influence of deterioration or the like. In addition, an open circuit voltage sensor for detecting a battery voltage (open circuit voltage immediately before operation) just before the current starts to flow is provided, and all detection devices and arithmetic units when the current detection circuit included in the detection device detects a non-current zero state. When the current zero time reaches the open-circuit voltage measurement time, the operation of the detection device and arithmetic unit other than the current detection circuit and the open-circuit voltage detection circuit is interrupted, and the current detection circuit does not When the zero state is detected and the operation of the device is restarted, the open circuit voltage immediately before the operation is measured, the remaining charge rate is calculated from the measured open circuit voltage by means of the relational description means regarding the open circuit voltage / remaining charge rate, and it is multiplied by the full charge amount. Since the configuration is such that the remaining amount is obtained by stopping the operation of the arithmetic unit of the battery remaining amount measuring device in the zero current state, the power consumption in the zero current state can be eliminated. Moreover, even if the operation of the arithmetic unit is stopped in the zero current state, the open circuit voltage can be measured in the non-current zero state.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram showing the overall configuration of a battery fuel gauge according to a first embodiment of the present invention.

The battery remaining amount measuring apparatus according to the present embodiment is an arithmetic unit 1 for calculating the remaining amount of the lithium ion battery 31 under the current ambient conditions of the lithium ion battery 31.
Correspondence between the detection device 2 that detects the current ambient conditions of the lithium-ion battery 31 and captures it in the arithmetic unit, the battery pack 3 that stores the lithium-ion battery 31, and the temperature of the amount of electricity that cannot be temporarily charged. The temperature to record depending on the relationship
The non-charging amount memory table 4, the temperature / current / non-discharging amount memory table 5 that records the amount of electricity that cannot be temporarily discharged according to the correspondence relationship between the temperature and the current, and the self that records the self-discharging amount of the lithium ion battery 31. A discharge amount memory table 6, a timer 7 for measuring the charging time or discharging time of the lithium ion battery 31, and a remaining amount memory 8 for recording the remaining amount of the lithium ion battery 31 (electrical amount, here, electric charge amount). It has an electric quantity display unit 9 and a time display unit 10.

The battery pack 3 includes a lithium-ion battery 31 whose remaining amount is to be measured and a lithium-ion battery 3
1. A current sensor 32 that detects the value of the discharge current from 1 or the charging current to the lithium-ion battery 31, and a temperature sensor that detects the ambient temperature of the lithium-ion battery 31 (hereinafter, also simply referred to as “temperature”). Including 33. The electricity quantity display unit 9 and the time display unit 10 may be external devices.

The operation of the battery remaining amount measuring apparatus according to this embodiment will be described below with reference to FIG. Battery pack 1
The value of the charging / discharging current of the lithium ion battery 31 detected by the current sensor 32 included in 04 and the ambient temperature of the lithium ion battery 31 detected by the temperature sensor 33 are taken into the arithmetic unit 1 by the detection device 2.

In the arithmetic unit 1, the internal arithmetic algorithm 11 is activated to calculate the amount of electricity stored in the lithium ion battery 31. The processing method in the calculation algorithm 11 differs between charging and discharging (when current is flowing) and non-charging and discharging (when no current is flowing). It is the same. At the time of charging / discharging, the current (current) remaining amount is obtained by adding the charged electricity amount and subtracting the discharged electricity amount to the previous remaining amount recorded in the remaining amount memory 8. Here, the charge electricity amount is a product of the charge current detected by the current sensor 32 and the time measured by the timer 7 (that is, the charge electricity amount within a predetermined charge time),
The amount of discharged electricity is the product of the discharge current detected by the current sensor 102 and the time measured by the timer 107 (that is, the amount of discharged electricity within a predetermined discharging time).

When the lithium ion battery 31 is charged, the lithium ion battery 3 detected by the temperature sensor 33 is used.
By comparing the ambient temperature of No. 1 with the temperature / non-charge amount memory table 4, the non-charge amount under the current charging condition (ambient temperature) is obtained, and the non-charge amount and the remaining amount are set from the preset full charge amount. The current charging condition (ambient temperature and remaining amount) by subtracting
Calculate the chargeable amount in.

Further, at the time of discharging the lithium ion battery 31, by comparing the ambient temperature and the current of the lithium ion battery 31 detected by the temperature sensor 33 with the temperature / current / non-discharge amount memory table 5, the current discharge is performed. Calculate the non-discharge amount under the conditions (ambient temperature and current value) and subtract the non-discharge amount from the remaining amount to calculate the dischargeable amount 12 under the current discharge conditions (ambient temperature, current and remaining amount) To do.

Here, the temperature / non-charge amount memory table 4
21 is used for the data of FIG. 21, and the data of the temperature / current / non-discharge amount memory table 5 is added to the data of the above-mentioned graphs of FIGS. The amount of discharge electricity in the case of discharge is used. If the temperature is higher than room temperature (20 ° C), the charge amount will be equal to or higher than that at room temperature (20 ° C) in both charging and discharging. The value obtained by subtracting the charge amount in the case of) is defined as the non-charged amount / non-discharged amount, and this value is shown as a negative value for convenience. It is possible that the standard of the amount of electricity is not normal temperature (20 ° C.) but high temperature (for example, 60 ° C.), and the non-charged amount / non-discharged amount in this case are all indicated by positive values.

Various times (remaining charge time, remaining discharge time 13 etc.) are obtained by dividing the calculated various electric quantities (chargeable quantity, dischargeable quantity 12 etc.) by the detected discharge current or a predetermined current value. The various electric quantities are displayed on the electric quantity display unit 9 and various times are displayed on the time display unit 10. Here, as the predetermined current value, an average current within a predetermined time, a planned current value which is about to flow, or the like can be used.

According to the present embodiment, when the ambient temperature of the lithium ion battery 31 changes, the problem that the remaining amount does not match the actual remaining amount can be solved. (Second Embodiment) FIG. 2 is a block diagram showing the overall configuration of a battery remaining amount measuring apparatus according to a second embodiment of the present invention.

Compared with the configuration of the battery fuel gauge according to the first embodiment of the present invention, the configuration of the battery fuel gauge according to the second embodiment of the present invention has a self-discharge amount. The memory table 6 is eliminated and an open circuit voltage / remaining amount memory table 26 is added. The content structure of the battery pack 23 is different from that of the battery pack 3. In the battery pack 23,
A voltage sensor 34 is added to the contents of the battery pack 3.

Further, the calculation algorithm 21 is the same as the calculation algorithm 1 shown in FIG. 1 in terms of the processing method during charging / discharging, but there is a difference in the processing method during non-charging / discharging. The voltage during charging / discharging is the direction of current (charge or discharge).
The voltage during non-charging / discharging (when the current is zero) is saturated (stable) with the passage of time, although it varies depending on the magnitude.

FIG. 3 is a graph showing the change over time in the voltage at room temperature (20 ° C.) immediately after the zero current state. From the rough shown in FIG. 3, it can be seen that the voltage saturates completely under one hour, although the voltage saturation time slightly differs depending on the direction and magnitude of the current.

FIG. 4 is a graph showing the relationship between the saturation voltage (open circuit voltage) and the remaining amount. It can be seen from the graph shown in FIG. 4 that the amount of change in the open circuit voltage with respect to the remaining amount is relatively large and has a fixed relationship, so that the remaining amount can be obtained from the open circuit voltage. From the above, in the present embodiment, the remaining amount is obtained by the following method during non-charging / discharging.

First, when the current sensor 102 detects a state where the current is zero (current zero state), the timer 7 starts measuring the time, and the time of the current zero state (current zero time)
To measure. Then, the voltage at the time when the current zero time reaches 1 hour (open circuit voltage measurement time) is taken as the open circuit voltage, and this is detected by the voltage sensor 34. Then, the measured open circuit voltage is collated with the data of the open circuit voltage / remaining amount memory table 26 to obtain the remaining amount of the lithium ion battery 31. Here, the measurement time of the open circuit voltage is a waiting time until the voltage is saturated, and is not necessarily limited to one hour. It should be noted that, in the present embodiment, as compared with the conventional indirect measuring method of the self-discharge amount, it is extremely close to the method of directly measuring the remaining amount of the lithium ion battery 31, and thus the remaining amount of the lithium ion battery 31 is determined by the self-discharge amount. Can be taken into account to make an accurate measurement.

(Third Embodiment) FIG. 5 is a block diagram showing the overall structure of a battery fuel gauge according to a third embodiment of the present invention. The configuration of the battery fuel gauge according to the third embodiment of the present invention is higher than that of the battery fuel gauge according to the second embodiment of the present invention shown in FIG.・ The remaining memory table 26 is gone,
An open circuit voltage / remaining rate memory table 27 is added. Further, the arithmetic algorithm 31 is the same as the arithmetic algorithm 21 shown in FIG. 2 in the processing method at the time of charging / discharging, but there is a slight difference in the processing method at the time of non-charging / discharging.

The above-mentioned graph of FIG. 4 shows the initial characteristics of the open-circuit voltage and the remaining amount of the lithium-ion battery 31,
The relationship between the open-circuit voltage and the remaining amount of the lithium-ion battery 31 changes slightly by repeating charging and discharging. FIG. 6 is a graph showing initial (charge / discharge cycle 0 Cycle) characteristics and deterioration (charge / discharge cycle 300 Cycle) characteristics of the open circuit voltage and the remaining amount.

As for the deterioration characteristic, the maximum charged electricity amount (full charge amount) is smaller than the initial characteristic, and the change amount of the open circuit voltage with respect to the remaining amount is slightly larger. FIG. 7 is a graph showing the initial (charge / discharge cycle 0 Cycle) characteristic and the deterioration (charge / discharge cycle 300 Cycle) characteristic of the open circuit voltage and the remaining rate.
In the graph shown in FIG. 7, the horizontal axis (remaining amount) of the graph shown in FIG. 6 is changed to the remaining amount ratio (ratio of the remaining amount to the full charge amount). It can be seen that the deterioration characteristics are almost the same. That is, considering the long-term use of the battery, it can be said that it is advantageous in terms of accuracy to calculate the remaining amount by using the relationship between the open circuit voltage and the remaining amount ratio.

From the above, in the present embodiment, the remaining amount is obtained by the following method during non-charging / discharging. First, when the zero current state is detected, the voltage (open circuit voltage) is measured after the open circuit voltage measuring time (for example, 1 hour) has elapsed. Next, the remaining voltage ratio is obtained by collating the measured open circuit voltage with the data in the open circuit voltage / remaining battery ratio memory table 27. Further, the remaining amount is obtained by multiplying the remaining amount ratio by a preset amount of electricity (full charged amount) of the lithium ion battery in the fully charged state.

In the present embodiment, since it is not affected by the deterioration due to the charge / discharge cycle of the lithium ion battery, it is possible to accurately measure the remaining amount for a long period of time. (Fourth Embodiment) FIG. 8 is a block diagram showing the overall configuration of a battery remaining amount measuring apparatus according to a fourth embodiment of the present invention.

The configuration of the battery remaining amount measuring apparatus according to the fourth embodiment of the present invention is the same as the configuration of the battery remaining amount measuring apparatus according to the second embodiment of the present invention shown in FIG. An open circuit voltage correction amount memory table 41 is added. Further, the calculation algorithm 41 is the same as the calculation algorithm 31 shown in FIG. 5 in the processing method at the time of charging / discharging, but there is a slight difference in the processing method at the time of non-charging / discharging.

Looking at the characteristics shown in the graph of FIG. 7 in detail, when the remaining amount ratio is 80% or more, the voltage of the deterioration characteristic is slightly lower than the initial characteristic, and the remaining amount ratio is 50% or less. In the case, on the contrary, the voltage of the deterioration characteristic is slightly higher.
Further, when the remaining amount ratio is low, the characteristic difference between charging and discharging is also large. Based on the above characteristics, the remaining amount ratio is 50-80.
By using only the characteristics of%, it is possible to measure the remaining amount with higher accuracy.

FIG. 9 is a graph showing the relationship between the open circuit voltage and the remaining amount ratio when the temperature is changed. FIG. 10 is another graph showing the relationship between the open circuit voltage and the remaining rate when the temperature is changed. From the graph shown in FIG. 9, it can be seen that the range of medium-low residual ratio (70% or less)
In, it can be seen that the characteristics of the open-circuit voltage and the remaining rate greatly change. That is, if the relationship between the open circuit voltage and the remaining amount ratio is corrected according to the detected temperature, more accurate remaining amount measurement can be performed.

From the above, in the present embodiment, the remaining amount is obtained by the following method during non-charging / discharging. Figure 5 above
In the third embodiment of the present invention shown in Fig. 3, the measured open circuit voltage is collated with the open circuit voltage / remaining capacity ratio memory table 27 to directly obtain the remaining capacity, but in the present embodiment, it is measured first. The open circuit voltage correction amount is obtained by comparing the temperature with the temperature / open circuit voltage correction amount memory table 41, and the open circuit voltage considering the temperature is obtained by adding / subtracting this open circuit voltage correction amount to the measured open circuit voltage. The remaining amount is obtained by collating the temperature-corrected open circuit voltage with the open circuit voltage / remaining rate ratio memory table 27.

As another method of the same idea, using the temperature / open voltage / remaining rate memory table showing the relationship between the temperature, the open circuit voltage and the remaining rate, the remaining temperature is directly calculated from the measured temperature and open circuit voltage. A method of obtaining the rate is also possible. By using such a method, it becomes possible to measure the remaining amount without being affected by the temperature of the lithium ion battery 31. However, looking at the characteristics shown in the graph of FIG. 9 in detail, when the temperature is low, the characteristics at the time of charging change greatly, whereas the characteristics at the time of discharging are almost the same as at room temperature, and conversely When the value is high, the characteristics during discharge change greatly, while the characteristics during charge are almost the same as at room temperature (see FIG. 10). In other words, at temperatures other than room temperature, grasp the current direction (charging / discharging) before the zero current state and prepare an open-circuit voltage / remaining amount memory table according to the current direction, or depending on the current direction. It is necessary to prepare a temperature / open voltage correction amount memory table.

(Fifth Embodiment) FIG. 11 is a block diagram showing the overall structure of a battery fuel gauge according to a fifth embodiment of the present invention. The configuration of the battery remaining amount measuring apparatus according to the fifth embodiment of the present invention is the same as the configuration of the battery remaining amount measuring apparatus according to the third embodiment of the present invention shown in FIG. The memory 52 is added. Also,
The calculation algorithm 51 is the same as the calculation algorithm 31 shown in FIG. 5 in terms of the processing method during charging / discharging, but there are some differences in the processing method during non-charging / discharging.

FIG. 12 is a graph showing an example of the correspondence between the two for obtaining the remaining amount rate from the open circuit voltage. Figure 11
The open circuit voltage / remaining rate memory table 27 of
It is a numerical expression of the relationship between the open circuit voltage and the remaining charge ratio obtained from the remaining charge ratio characteristic. For example, the combination of the open circuit voltage and the remaining charge ratio shown in this table can be considered. Open circuit voltage
When tabular data is used for the remaining amount ratio memory table 27, if the detected open circuit voltage is 4.0 V, the remaining amount ratio is 85%. However, if the measured value of the open circuit voltage, which should be 4.0V, is 4.1V due to the effects of noise and measurement error, the residual rate is erroneously 95%.
Will be recognized. However, since the process of obtaining the remaining amount rate from the open-circuit voltage is performed during non-charging / discharging, it also has the meaning of correcting the remaining amount reduction due to self-discharge, deterioration, etc. In consideration of the above, the remaining amount obtained from the open circuit voltage may be smaller than the already recognized remaining amount but does not increase. Therefore, the remaining rate cannot increase, and if such a remaining rate is indicated, it is possible that the open circuit voltage value contains an error, and it is better not to update the remaining rate. desirable.

From the above idea, in the present embodiment, unlike the battery remaining amount measuring device of the third embodiment of the present invention shown in FIG. 5 described above, the remaining amount obtained during non-charging / discharging is determined. If the rate is less than the predetermined stored remaining rate (for example,
Only in the case of 50% to 80%), the remaining amount rate and the remaining amount are updated. FIG. 13 shows a charge / discharge cycle of 300
It is a graph which shows the time change of the open circuit voltage after repeating Cycle.

The above-mentioned FIG. 3 shows the initial (charge / discharge cycle 0Cy
Cle characteristic, the voltage is completely stable (saturated) one hour after the current stops flowing in this initial characteristic, while the charge / discharge cycle is 300C.
After repeating the cycle, it can be seen that the voltage is not saturated in 1 hour and is saturated in about 3 hours. That is, the voltage saturation time increases as the number of charge / discharge cycles increases, and this is considered to be due to deterioration of the battery due to charge / discharge.

The open circuit voltage measurement time, which is the waiting time until the open circuit voltage is measured, may be extended from the beginning (for example, 5 hours) in anticipation of deterioration due to this charge / discharge cycle. Although the process of obtaining the quantity rate is intended to be performed as many times as possible in order to make various kinds of corrections (deterioration correction, accumulated error, etc.), the longer the open-circuit voltage measurement time, the smaller the number of corrections (long time). Therefore, the method of extending the open circuit voltage measurement time according to the number of charge / discharge cycles is desirable.

Although the battery depends on the device used, the battery is often charged up to full charge or discharged up to full discharge, and the depth of charge / discharge varies. Therefore, it is difficult to define or count the charge / discharge cycle, but there is an idea that the charge / discharge cycle = 1 when the discharge charge is integrated and the total charge becomes equal to the full charge charge, for example. In the above embodiment, the open circuit voltage measurement time is made variable by the number of charge / discharge cycles measured by the method based on such an idea.

The battery remaining amount measuring apparatus according to the third embodiment of the present invention shown in FIG. 5 described above performs various calculations using the preset full charge amount (chargeable amount = full charge amount−non-charge). Amount-
The remaining amount and the remaining amount = full charge amount × remaining amount ratio) are performed, but when the lithium-ion battery 31 deteriorates due to the charge / discharge cycle, the amount of electricity that can be charged (full charge amount) decreases. There is an error in the remaining amount (remaining amount = full charge amount × remaining amount ratio). Therefore, even when the lithium ion battery 31 deteriorates due to the charge / discharge cycle, the residual rate obtained from the open circuit voltage indicates the residual rate with respect to the full charge amount of the lithium ion battery 31 at that time. You can learn the full charge.

From the above, in the present embodiment, the remaining amount is obtained by the following method during non-charging / discharging. That is, at the time of non-discharge, as in the battery remaining amount measuring apparatus according to the third embodiment of the present invention shown in FIG. 5, the measured open circuit voltage is collated with the open circuit voltage / remaining rate memory table, and the remaining amount is calculated. The rate is calculated, but in the next calculation of the remaining amount, the full charge amount recorded in the full charge amount memory 52 is used instead of the preset full charge amount.

At this time, in the initial state, the full charge amount recorded in the full charge memory 52 is set to a value according to the capacity specification of the battery, but charging / discharging is repeated several times and no charging / discharging occurs. When the open circuit voltage becomes equal to or higher than a preset voltage (full charge voltage, eg 4.1V), it is determined that the battery is in a fully charged state, and the remaining amount at that time is transferred to the full charge memory 52. Update the full charge.

(Sixth Embodiment) FIG. 14 is a block diagram showing the overall structure of a battery fuel gauge according to a sixth embodiment of the present invention. The configuration of the battery fuel gauge according to the sixth embodiment of the present invention is exactly the same as the configuration of the battery fuel gauge according to the fifth embodiment of the invention shown in FIG. However, there are some differences in the processing method of the arithmetic algorithm 61. In the battery remaining amount measuring apparatus according to the fifth embodiment of the present invention shown in FIG. 11 described above, the full charge amount is updated when the full charge state is detected during non-discharge, whereas in the present embodiment Then, when charging, the battery voltage is a preset voltage (full charge voltage, for example 4.15V)
When the charging current becomes equal to or more than the preset current (full charging current, for example, 0.05 C (A)) or less,
It is determined that the battery is in a fully charged state, and the remaining amount at this time is transferred to the fully charged memory 52 to update the fully charged amount.

Note that this embodiment is combined with the method of the battery remaining amount measuring apparatus according to the fifth embodiment of the present invention shown in FIG. 11 described above, so that charging and non-charging can be performed. It is also possible to perform the full charge amount update process on both. (Seventh Embodiment) FIG. 15 is a block diagram showing the overall configuration of a battery remaining amount measuring apparatus according to a seventh embodiment of the present invention.

The configuration of the battery remaining amount measuring apparatus according to the seventh embodiment of the present invention is the same as the configuration of the battery remaining amount measuring apparatus according to the third embodiment of the present invention shown in FIG. Compared to,
The battery pack 23 is changed to the battery pack 53, and the detection device 2 is changed to the detection device 72. An open voltage sensor 35 that detects the battery voltage in the zero current state in the non-current zero state is added to the battery pack 53. An open circuit voltage detection circuit 721 that receives an output from the open circuit voltage sensor 35 is added to the configuration 72. The calculation algorithm 71
In addition, a device operation stop process at the time of non-charging and discharging and a remaining amount updating algorithm at the time of restarting the device operation are added.

In the battery remaining amount measuring apparatus according to the third embodiment of the present invention shown in FIG. 5, the open circuit voltage is measured when the zero current state during non-charging / discharging reaches the open circuit voltage measuring time. Although the remaining amount rate and the remaining amount are updated, in the present embodiment, processing for further stopping the operation of a predetermined circuit and a predetermined device is performed. Here, the above-mentioned predetermined circuit and predetermined device for stopping the operation are the voltage detection circuit 7 of the detection device 72.
23, the temperature detection circuit 724, and the calculation algorithm 71.
It is the arithmetic unit 1 which is executing.

When the operation of the above-mentioned device is stopped, the open circuit voltage detection circuit 721 and the current detection circuit 72 of the detection device 72 are detected.
Although only 2 is operating, the current detection circuit 7
22 has a function of restarting the operation of the above-mentioned device when detecting a charge / discharge current when the device is stopped, and after the restart, all the above-mentioned devices start to operate again, and the arithmetic unit 1 When the operation of the apparatus is restarted, the open circuit voltage sensor 35 of the battery pack 53 detects the open circuit voltage of the battery immediately before the operation, and the open circuit voltage is collated with the data of the open circuit voltage / remaining rate memory table 27 to determine the remaining rate. Ask.

Further, the remaining amount is obtained by multiplying the remaining amount ratio by a preset amount of electricity (full charged amount) of the lithium ion battery 31 in the fully charged state. By adopting such a method, it becomes possible to stop the device that consumes a large amount of power during non-charging and discharging, and it is possible to suppress the amount of power consumption. FIG. 16 is a circuit diagram showing one configuration example of the open circuit voltage sensor 35 and the open circuit voltage detection circuit 721.

In general, the positive electrode side of the battery E is a charge / discharge FET (Tr1, Tr2) for controlling charge / discharge of the battery E.
Via the + terminal Tm1 of the battery pack,
The pole side is connected to GND via the current detection resistor R. To this standard circuit, a circuit is added from the + pole side of the battery E to a voltage holding amplifier AMP3 via a voltage holding switch SW (analog switch or the like) which is a normally closed type and can be opened and closed by an external signal. When the voltage holding switch SW is closed, the voltage output from the voltage holding amplifier AMP3 indicates the current voltage of the battery E.
Since the voltage holding capacitor C is connected to the input terminal of the voltage holding amplifier AMP3, when the voltage holding switch SW is opened, it holds the voltage immediately before the switch is opened. Here, if the voltage holding switch SW can be opened at the same time when the current flows in the battery E, the voltage of the battery in the current zero state is the voltage holding amplifier A.
It is obtained from the voltage output Eout of MP3.

The trigger signal for opening the voltage holding switch SW is a signal obtained by amplifying the voltage drop across the current detection resistor R by the switch control amplifier AMP2, or the voltage of the charging / discharging FET (Tr1, Tr2) as the switch control amplifier. A signal amplified by AMP1 or the like can be used. When the open circuit voltage sensor 35 and the open circuit voltage detection circuit 721 shown in FIG. 15 have the circuit configuration shown in FIG. 16, the output voltage output Eout is normally (that is, when the voltage holding switch SW is not operated) at present. Since it indicates the battery voltage of, the voltage sensor 34 and the voltage detection circuit 723 can also serve as both.

Further, although an example of using the memory table is shown in each embodiment, it is a well-known means to replace the memory table with a function, and the present invention also realizes the function of the memory table or realizes the function. It may be replaced with an algorithm. For example, FIG. 24 is a plot of the experimental values and the approximate curve (second-order polynomial) of the relationship between the open-circuit voltage and the residual rate, which is shown in FIG. 24 instead of the memory table regarding the relationship between the open-circuit voltage and the residual rate. A function (second-order polynomial) may be applied. Note that FIG.
4 has two data, charging and discharging, the charging data is the voltage when the battery voltage becomes almost constant after the battery is charged for a certain period of time after the battery is charged from the state where the remaining amount is zero to the predetermined remaining rate. It shows the relationship of the quantity ratio. The discharge data indicates the relationship between the voltage and the predetermined remaining amount rate when the battery voltage is discharged from the fully charged state to the predetermined remaining rate and then left for a certain period of time and the battery voltage becomes substantially constant.

[0070]

As described above, according to the present invention, the accurate remaining amount (remaining time) can be displayed even when the ambient temperature of the battery changes during charging. Further, the accurate remaining amount (remaining time) can be displayed even when the ambient temperature of the battery or the current changes during discharging.

Furthermore, even if the battery is left unused for a long period of time and the remaining amount decreases due to self-discharge,
The accurate remaining amount (remaining time) including self-discharge can be displayed. Further, even when the battery is used for a long period of time and the capacity decreases due to deterioration due to charge / discharge cycles, it is possible to display an accurate remaining amount (remaining time) including the decrease in capacity due to deterioration.

Furthermore, when the battery is left unused for a long period of time, the power consumption of the internal image path is extremely small, and the battery capacity is scarcely reduced, so that the amount of electricity can be efficiently supplied to the load. Can be supplied. In addition, since the remaining amount (remaining time) is highly accurate and the actual usage time of this device matches the usage time displayed on this device, the user should trust the displayed usage time. This makes it possible to use the device with peace of mind.

Furthermore, since the remaining amount (remaining time) is highly accurate and the time that the device can actually be used and the usage time displayed on the device match, the amount of electricity stored in the battery is calculated. Since it can be used up to the end effectively, it is possible to supply a sufficient amount of electricity to the load for a long time. In addition, the remaining battery power becomes zero even though the remaining usage time displayed on the device remains, and the system goes down while the user is using the device. It is possible to eliminate the trouble of being wasted.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a battery fuel gauging device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an entire configuration of a battery fuel gauge according to a second embodiment of the present invention.

FIG. 3 is a graph showing a temporal change in voltage at room temperature (20 ° C.) immediately after a state of zero current.

FIG. 4 is a graph showing the relationship between the saturation voltage (open circuit voltage) and the remaining amount.

FIG. 5 is a block diagram showing an overall configuration of a battery fuel gauge according to a third embodiment of the present invention.

FIG. 6 is an open circuit voltage and an initial amount of remaining charge (charge / discharge cycle 0 Cy).
characteristics and deterioration (charge / discharge cycle 300 Cycle)
e) A graph showing characteristics.

FIG. 7 shows the initial values of the open circuit voltage and the remaining rate (charge / discharge cycle 0
Cycle characteristics and deterioration (charge / discharge cycle 300 Cy)
is a graph showing cle characteristics.

FIG. 8 is a block diagram showing an overall configuration of a battery fuel gauging device according to a fourth embodiment of the present invention.

FIG. 9 is a graph showing the relationship between the open circuit voltage and the remaining amount rate when the temperature is changed.

FIG. 10 is another graph showing the relationship between the open circuit voltage and the remaining rate when the temperature is changed.

FIG. 11 is a block diagram showing an overall configuration of a battery residual quantity measuring device according to a fifth embodiment of the present invention.

FIG. 12 is a graph showing an example of a correspondence relationship between the two for obtaining the remaining rate from the open circuit voltage.

FIG. 13 is a graph showing a change with time of an open circuit voltage after repeating a charge / discharge cycle of 300 cycles.

FIG. 14 is a block diagram showing an overall configuration of a battery fuel gauging device according to a sixth embodiment of the present invention.

FIG. 15 is a block diagram showing an overall configuration of a battery fuel gauge according to a seventh embodiment of the present invention.

FIG. 16 is an open circuit voltage sensor 35 and an open circuit voltage detection circuit 72.
FIG. 3 is a circuit diagram showing a configuration example of 1.

FIG. 17 is a block diagram showing one configuration example of a conventional battery remaining amount measuring device.

FIG. 18 is a graph showing an example of a relationship between temperature and charging efficiency in a conventional battery remaining amount measuring device.

FIG. 19 is a graph showing an example of a relationship between discharge efficiency and temperature in a conventional battery remaining amount measuring device.

FIG. 20 is a graph showing an example of a relationship between a battery leaving period in a fully charged state, a temperature, and a remaining amount ratio in a conventional battery remaining amount measuring device.

FIG. 21 is a graph showing an example of a result when charging is continuously performed under two kinds of charging conditions (temperature) in the conventional battery remaining amount measuring device.

FIG. 22 is a graph showing an example of the results of continuous discharging under two types of discharging conditions (temperature and current) in the conventional battery remaining amount measuring device.

FIG. 23 is another graph showing an example of the result of continuous discharging under two kinds of discharging conditions (temperature and current) in the conventional battery remaining amount measuring apparatus.

FIG. 24 is a graph showing an example of an experimental value relating to the relationship between the open circuit voltage and the residual rate and its approximate curve.

[Explanation of symbols]

1 arithmetic unit 2 detector 3 battery pack 4 Temperature / non-charge amount memory table 5 Temperature / current / non-discharge amount memory table 6 Self-discharge amount memory table 7 timer 8 remaining memory 9 Electricity display 10 hours display 11 Calculation algorithm 12 Dischargeable amount 13 Remaining discharge time (= dischargeable amount ÷ current) 31 Lithium-ion battery 32 current sensor 33 Temperature sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G016 CA00 CB12 CB21 CB31 CC01                       CC03 CC04 CC05 CC06 CC07                       CC10 CC12 CC13 CC21 CC23                       CC27 CC28 CD06 CD10 CE00                       CF06                 5G003 BA01 CA04 CA14 EA05 GC05                 5H030 AA03 AA04 AS06 FF22 FF41                       FF42

Claims (12)

[Claims] 1. A battery remaining amount measuring device for measuring a dischargeable electricity amount and a dischargeable time of the battery as a battery remaining amount, which is executed when a current flowing through the battery is in a charging direction. As means to be determined, means for obtaining the non-charged amount of the battery by collating the ambient temperature of the battery with a graph showing a predetermined correspondence relationship between the temperature and the non-charged amount, and from a preset full charge amount of the battery A means for obtaining the chargeable electricity amount of the battery by subtracting the non-charged amount and the remaining amount; and a means for dividing the chargeable electricity amount by dividing the chargeable electricity amount by a charging current flowing through the battery or a predetermined current value. A means for obtaining a chargeable time is provided, and as means to be executed when the current flowing through the battery is in the discharging direction, the ambient temperature of the battery and the current value of the current flowing through the battery are set as a temperature and an electric current. Means for determining the non-discharge amount of the battery by collating with a graph showing a predetermined correspondence relationship between the non-discharge amount and the discharge amount of the battery by subtracting the non-discharge amount from the current remaining amount of the battery. A battery provided with means for obtaining a possible electricity quantity and means for obtaining a remaining discharge time of the battery by dividing the dischargeable electricity quantity by a discharge current flowing through the battery or a predetermined current value. Fuel gauge. 2. A current sensor for detecting a current flowing through a lithium ion battery, a temperature sensor for detecting a temperature of the lithium ion battery, a detection device for capturing a sensor signal, and a remaining lithium ion battery based on the captured sensor signal. An arithmetic unit for calculating the amount, a timer for measuring the charging time or the discharging time of the battery, and a temperature recording the relationship between the temperature and the amount of electricity considered temporarily unchargeable at a predetermined temperature.
A non-charge amount relation describing means and a temperature / current / non-discharge amount relation describing means for recording the relation between the temperature and the current and the quantity of electricity considered to be temporarily unable to discharge at a predetermined temperature / predetermined current are provided. The battery residual quantity measuring device according to claim 1, which is characterized in that. 3. When the current detected by the detection device is flowing in the charging direction, the non-charged amount of the lithium ion battery is obtained from the temperature detected by the detection device by the temperature / non-charged amount relation describing means, And the charge current or a predetermined current detected by the detection device is obtained by subtracting the non-charged amount and the remaining amount from the preset full-charged amount of the lithium-ion battery, and the chargeable amount of electricity of the lithium-ion battery. Obtain the chargeable time of the lithium-ion battery by dividing the chargeable amount of electricity by a value, if the current detected by the detection device is flowing in the discharge direction, the temperature detected by the detection device and From the current value, the non-discharge amount of the lithium ion battery is obtained by the temperature / current / non-discharge amount relation describing means, and the current remaining amount of the lithium ion battery Seeking dischargeable electricity quantity of the lithium-ion battery by subtracting et the non-discharge amount,
The remaining amount of the battery according to claim 2, wherein the dischargeable time of the lithium ion battery is obtained by dividing the dischargeable electricity amount by a discharge current detected by the detection device or a predetermined current value. Measuring device. 4. A voltage sensor for detecting the voltage of the lithium-ion battery is provided, and a battery voltage in a current zero state in which no current flows in the lithium-ion battery and an amount of electricity stored in the lithium-ion battery are provided. An open circuit voltage / remaining amount relationship describing means for recording the relationship is provided, and when the current zero state is detected, the timer measures the time during which the current zero state continues, and when the time reaches a predetermined time, 4. The battery voltage in the zero current state is measured, and the remaining amount of the lithium ion battery is obtained from the measured battery voltage by the open voltage / remaining amount relation describing means. Battery residual quantity measuring device. 5. A detection device is provided with an open circuit voltage / remaining rate ratio description means for recording the relationship between the open circuit voltage and the remaining rate of the lithium ion battery, and in a zero current state in which no current flows through the lithium ion battery. The open-circuit voltage / remaining-amount ratio relationship description means determines the remaining-amount ratio of the lithium-ion battery from the open-circuit voltage measured by Claim 2 or claim 3 for determining the remaining battery level
The battery remaining amount measuring device described. 6. The lithium ion before the measurement when the residual rate of the lithium ion battery obtained by the open voltage / remaining rate relation describing means from the open circuit voltage measured by a detection device is 50 to 80%. The battery remaining amount measuring device according to claim 5, wherein the battery remaining amount ratio and the remaining amount are updated with the remaining amount ratio and the remaining amount after the measurement. 7. The lithium-ion battery, which is provided with a temperature / open-circuit voltage correction amount relationship description means for recording the relationship between the ambient temperature of the lithium-ion battery and the open-circuit voltage correction amount, and is measured by a detection device in the zero current state. From the ambient temperature of, the open circuit voltage correction amount at the ambient temperature of the lithium ion battery is obtained by the temperature / open circuit voltage correction amount relationship description means, and the open circuit voltage measured by the detection device is corrected by the open circuit voltage correction amount, From the corrected open-circuit voltage, the open-circuit voltage / remaining-amount ratio relation describing means obtains the remaining-amount ratio of the lithium-ion battery, and multiplies it by the full charge amount to obtain the remaining amount of the lithium-ion battery. The battery remaining amount measuring device according to claim 5. 8. When the remaining rate of the lithium ion battery obtained by the open circuit voltage / remaining rate ratio describing means from the open circuit voltage measured by a detection device is smaller than a predetermined remaining rate, before measurement. 6. The battery remaining amount measuring device according to claim 5, wherein the remaining amount ratio and the remaining amount of the lithium ion battery are updated with the remaining amount ratio and the remaining amount after the measurement. 9. The battery according to claim 5, further comprising a cycle counter for counting the number of charge / discharge cycles of the lithium-ion battery, and extending the open circuit voltage measurement time according to the number of counts of the cycle counter. Quantity measuring device. 10. The battery remaining amount measuring device according to claim 5, wherein the full charge amount is replaced with a predetermined remaining amount value when the open circuit voltage measured by the detection device is equal to or higher than a predetermined value. . 11. The full charge amount is replaced with a predetermined remaining amount value when the battery voltage of the lithium ion battery is equal to or higher than a predetermined value and the current value is equal to or lower than a predetermined value during charging. Item 5. A battery remaining amount measuring device according to item 5. 12. A detection device comprising an open-circuit voltage sensor for detecting an open-circuit voltage immediately before an operation just before a current starts to flow in a lithium ion battery, and the detection device and the current detection circuit included in the detection device detect a non-current zero state. While restarting the operation of the arithmetic unit, when the current zero time reaches the open-circuit voltage measurement time, the operation of the circuits other than the current detection circuit and the open-circuit voltage detection circuit included in the detection device is interrupted, and the current When the detection circuit detects a non-current zero state and restarts the operation of the detection device and the arithmetic device, the open circuit voltage immediately before the operation is measured, and the open circuit voltage / remaining rate relationship description is based on the measured open circuit voltage. 6. The residual amount of the lithium ion battery is obtained by means, and the residual amount of the lithium ion battery is obtained by multiplying it by the full charge amount.
The battery remaining amount measuring device described.