JP2007205883A - Secondary battery capacity estimation device, program, and secondary battery capacity estimation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery capacity estimation device, a program, and a secondary battery capacity estimation method capable of estimating easily the battery capacity of the secondary battery. <P>SOLUTION: This secondary battery capacity estimation device 10a for estimating the battery capacity of the secondary battery 30 has a battery voltage measuring part 11 for measuring a terminal voltage of the secondary battery 30 in a constant-current charging mode when the secondary battery 30 is charged by a constant-current constant-voltage charging method, and an operation part 16 for estimating the battery capacity of the secondary battery 30 based on the terminal voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a secondary battery capacity estimation device, a program, and a secondary battery capacity estimation method, and in particular, when a secondary battery is charged using a constant current constant voltage charging method, the battery capacity of the secondary battery is estimated. The present invention relates to a secondary battery capacity estimation device, a program, and a secondary battery capacity estimation method.

  Lithium ion secondary batteries are high energy density batteries, and contribute to the downsizing of equipment as a main power source for personal computers and mobile phones. In recent years, attention has been paid to such a feature of high energy density, and a battery having a unit cell capacity of about 100 Ah, which is assumed to be applied to a backup power source for automobiles and stationary use, has been manufactured.

  In such various applications, lithium ion secondary batteries are used, and in any application, an important point is to grasp the battery capacity of the lithium ion secondary batteries. This is because when the battery is the main power source of the device, the battery capacity directly affects the service provision time. This situation is the same for a battery for stationary use. In particular, with stationary batteries, there are many facilities that require reliability, such as a communication power supply system, and it is important to know the battery capacity of a lithium ion secondary battery.

Conventionally, grasping the battery capacities of various batteries has been often performed by measuring the internal resistance of those batteries. However, the measurement of the internal resistance of the battery requires the battery maintainer to connect a measuring instrument to the terminal of the target battery, and the battery capacity cannot be measured automatically.
For this reason, a method for estimating the battery capacity of a battery that is focused on the charge characteristics after the battery is discharged is also known (Patent Document 1).

  This Patent Document 1 pays attention to voltage aging characteristics during charging and discharging from cycle test data of a lithium ion secondary battery, and during charging, 4.0 (V) to 4.15 (V). The rate of change in time for the voltage to rise is obtained, and the relationship between this ratio and capacity is obtained. On the other hand, during discharge, the time during which the voltage decreases from 3.75 (V) to 3.6 (V) is used as an index for estimating the capacity, and the relationship between the rate of change of this time and the capacity is clarified. . However, the technique of Patent Document 1 estimates the deterioration state of the positive electrode and the negative electrode, and cannot estimate the battery capacity of the battery.

Further, a method described in Patent Document 2 is known as a method for estimating the capacity of a lithium ion secondary battery. In Patent Document 2, a lithium-ion secondary battery is charged by a constant current constant voltage charging method, and the charging current after reaching the constant voltage charging mode is a value that is 1/2 of the current value in the initial constant current charging mode. The time to decrease to a maximum is calculated, and the relationship between this time and battery capacity is clarified.
JP 2003-308885 A Japanese Patent No. 3370047

  However, in the method described in Patent Document 2, it is necessary to perform processing such as monitoring of the charging mode, time measurement, and current measurement in order to estimate the capacity of the battery, and the capacity of the battery is easily estimated. However, there was a problem that the practicality was low.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a secondary battery capacity estimation device, a program, and a secondary battery capacity estimation method that can easily estimate the battery capacity of a secondary battery. It is to provide.

  The present invention has been made to solve the above problems, and the invention according to claim 1 is a secondary battery capacity estimation device for estimating a battery capacity of a secondary battery, wherein the secondary battery is defined. Battery voltage measuring means for measuring a terminal voltage of the secondary battery in a constant current charging mode when charging by a current constant voltage charging method, and a battery capacity for estimating a battery capacity of the secondary battery based on the terminal voltage A secondary battery capacity estimation device comprising an estimation means.

  The invention according to claim 2 is a battery voltage for measuring a secondary battery and a terminal voltage of the secondary battery in a constant current charge mode when the secondary battery is charged by a constant current constant voltage charging method. A secondary battery capacity estimation apparatus comprising: a measurement unit; and a battery capacity estimation unit that estimates a battery capacity of the secondary battery based on the terminal voltage.

  The invention according to claim 3 further includes battery data storage means for preliminarily storing battery capacity estimation data in which a relationship between the terminal voltage and the battery capacity of the secondary battery is recorded, and the battery capacity estimation means. The battery capacity of the secondary battery is estimated by reading out the battery capacity of the secondary battery corresponding to the terminal voltage measured by the battery voltage measuring means from the battery capacity estimation data. The secondary battery capacity estimation apparatus according to 1 or 2.

  The invention according to claim 4 further includes a determination unit that determines that the secondary battery has deteriorated when a terminal voltage measured by the battery voltage measurement unit is greater than a predetermined voltage. The secondary battery capacity estimation apparatus according to any one of claims 1 to 3, wherein the secondary battery capacity estimation apparatus is characterized by the following.

  The invention according to claim 5 further comprises alarm issuing means for issuing an alarm when the battery capacity estimated by the battery capacity estimating means is below a predetermined capacity. The secondary battery capacity estimation apparatus according to any one of the preceding sections.

  According to a sixth aspect of the present invention, there is provided a battery voltage measuring means for measuring a terminal voltage of the secondary battery in a constant current charging mode when the computer is charged by a constant current constant voltage charging method. A program for causing a battery capacity estimation unit to estimate a battery capacity of the secondary battery based on the terminal voltage.

  The invention according to claim 7 is a battery voltage measurement process for measuring a terminal voltage of the secondary battery in a constant current charging mode when the secondary battery is charged by a constant current constant voltage charging method, and the terminal And a battery capacity estimation process for estimating a battery capacity of the secondary battery based on a voltage.

In the present invention, when the secondary battery is charged by the constant current constant voltage charging method, the terminal voltage of the secondary battery in the constant current charging mode is measured by battery voltage measuring means, and the secondary battery is based on the terminal voltage. The battery capacity was estimated by battery capacity estimation means.
As a result, the secondary battery capacity can be estimated simply by measuring the terminal voltage of the secondary battery in the constant current charging mode when performing the constant current constant voltage charging method. Can be easily performed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 1st Embodiment of this invention is demonstrated.
FIG. 1 is a block diagram illustrating an example of a configuration of a secondary battery capacity estimation system using the secondary battery capacity estimation apparatus according to the first embodiment of the present invention. The secondary battery capacity estimation system includes a secondary battery capacity estimation device 10a, a secondary battery 30, and a charger 40.
The charger 40 is used when charging the secondary battery 30. In the present embodiment, the charger 40 charges the secondary battery 30 by a constant current constant voltage charging method.

FIG. 2 is a diagram for explaining the constant current constant voltage charging method according to the present embodiment. In FIG. 2, the horizontal axis represents the charging time (h). The scale on the left side of the vertical axis indicates the terminal voltage (V) of the secondary battery 30, and the scale on the right side of the vertical axis indicates the charging current (CA). Note that CA in the current display indicates a current value obtained by setting the nominal capacity of the secondary battery to C (Ah) and multiplying this by a certain coefficient.
In the constant current constant voltage charging method, first, the secondary battery 30 is charged by supplying a constant current (0.2 (CA) in FIG. 2) from the charger 40 to the secondary battery 30. The mode in which the charger 40 charges the secondary battery 30 with a constant current is referred to as a constant current charging mode, and the time during which the constant current charging mode continues is referred to as a constant current duration (5 (h) in FIG. 2). In this constant current charging mode, the terminal voltage of the secondary battery 30 gradually increases toward a predetermined voltage (4.1 (V) in FIG. 2) (curve g01).

  When the charging of the secondary battery 30 proceeds in the constant current charging mode and the terminal voltage of the secondary battery 30 reaches the set voltage (4.1 (V) in FIG. 2), the output of the charger 40 thereafter. The secondary battery 30 is charged while maintaining the voltage at a constant voltage (4.1 (V) in FIG. 2). A mode in which the charger 40 charges the secondary battery 30 with a constant voltage is referred to as a constant voltage charging mode. In this constant voltage charging mode, the charging current flowing through the secondary battery 30 gradually decreases from the constant current (0.2 (CA) in FIG. 2) toward 0 (CA) (curve g02).

FIG. 3 is a diagram showing charging characteristics when the initial charging current in the constant current charging mode of FIG. 2 is changed. In FIG. 3, the horizontal axis represents the charging time (h). The scale on the left side of the vertical axis indicates the terminal voltage (V) of the secondary battery 30, and the scale on the right side of the vertical axis indicates the charging current (CA). The curves g08 and g05 in FIG. 3 correspond to the curves g01 and g02 in FIG. 2, respectively.
A curve g03 to a curve g05 indicate current values of current flowing through the secondary battery 30 when the secondary battery 30 is charged by the constant current constant voltage charging method. Curves g06 to g08 indicate the terminal voltages of the secondary battery 30 when the secondary battery 30 is charged by the constant current constant voltage charging method.

  Curves g03 and g06 show the charging characteristics when the initial charging current in the constant current charging mode is 1 (CA), and the duration of the constant current charging mode is t01. Curves g04 and g07 show the charging characteristics when the charging current in the constant current charging mode is 0.5 (CA), and the duration of the constant current charging mode is t02. Curves g05 and g08 show the charging characteristics when the charging current in the constant current charging mode is 0.2 (CA), and the duration of the constant current charging mode is t03. Thus, when the charging current in the constant current charging mode is increased, the duration of the constant current charging mode is shortened (t01 <t02 <t03). Therefore, when the initial charging current changes, the terminal voltage is measured within the duration of the constant current charging mode corresponding to the charging current. In FIG. 3, the terminal voltage of the secondary battery 30 in the constant voltage charging mode is 4.1 (V), and the terminal voltage of the secondary battery 30 in the constant current charging mode is the terminal voltage 4.1 (V ), The constant current constant voltage charging method is switched from the constant current charging mode to the constant voltage charging mode.

  Returning to FIG. 1, the secondary battery 30 is a battery that can be repeatedly charged and discharged, for example, a lithium ion secondary battery or a lead storage battery. Here, the case where the secondary battery 30 is a lithium ion secondary battery will be described. The secondary battery 30 has a battery capacity such as a discharge characteristic or a charge characteristic that changes depending on the number of times of charging / discharging or the passage of time.

FIG. 4 is a graph showing an example of the discharge characteristics of the secondary battery 30 whose capacity has been reduced to various values, and shows the relationship between the discharge time and the terminal voltage when discharged at a constant current. In FIG. 4, the horizontal axis represents the discharge time (h) of the secondary battery 30, the vertical axis represents the terminal voltage (V) during discharge of the secondary battery 30, and the discharge characteristics of the curves g1 to g4 are 2 This corresponds to the capacity of the secondary battery 30.
In FIG. 4, curves g1 to g4 indicate discharge characteristics when the battery capacity of the secondary battery 30 is 60 (%), 70 (%), 80 (%), and 100 (%), respectively. . Here, when the battery capacity is 100 (%), it means that the secondary battery 30 is new.
As can be seen from FIG. 4, the capacity of the secondary battery 30 is 100 (%) (curve g4), 80 (%) (curve g3), 70 (%) (curve g2), 60 (%) (curve g1). As the battery deteriorates, the discharge time of the secondary battery 30 is shortened to about 10 hours, about 8 hours, about 7 hours, and about 6 hours.

FIG. 5 is a graph showing an example of characteristics when the secondary batteries 30 having various capacities are charged by the constant current constant voltage method. In FIG. 5, the horizontal axis indicates the charging time (h) of the secondary battery 30. The scale on the left side of the vertical axis indicates the terminal voltage (V) of the secondary battery 30, and the scale on the right side of the vertical axis indicates the charging current (CA) of the secondary battery 30.
Curves g11 and g21 in FIG. 5 indicate that the secondary battery 30 having the discharge characteristics with a battery capacity of 60 (%) (curve g1 in FIG. 4) is completely discharged, and then determined under predetermined charging conditions. The charging characteristics when the secondary battery 30 is charged by the current constant voltage charging method are shown. Further, the curves g21 and g22, the curves g31 and g32, the curves g41 and g42 in FIG. 5 have a battery capacity of 70% (curve g2 in FIG. 4) and 80% (curve g3 in FIG. 4). , 100 (%) (curve g4 in FIG. 4), each of the secondary batteries 30 is completely discharged, and then the secondary batteries are subjected to a constant current and constant voltage method under a predetermined charging condition. The charging characteristic when charging 30 is shown. Here, in any case of the secondary battery 30 having a battery capacity of 60 (%), 70 (%), 80 (%), or 100 (%), the charging initial current Ia, the charging setting are set as predetermined charging conditions. The voltage is Va (= 4.1 (V)).

Curves g11, g21, g31, and g41 show the relationship between the charging time (h) and the charging current (A) when the secondary battery 30 is charged by the constant current constant voltage charging method. Curves g12, g22, g32, and g42 show the relationship between the charging time (h) and the terminal voltage (V) when the secondary battery 30 is charged by the constant current constant voltage charging method.
As can be seen from the curves g11, g21, g31, and g41 in FIG. 5, the battery capacity of the secondary battery 30 deteriorates to 100 (%), 80 (%), 70 (%), and 60 (%). Accordingly, the terminal voltages V (100), V (80), V (70), and V (60) of the secondary battery 30 at a predetermined time tb within the duration of the constant current charging mode that is the constant current charging mode are large. It will become. V (100) indicates a terminal voltage when the battery capacity is 100%.

Returning to FIG. 1, the secondary battery capacity estimation device 10 a includes a battery voltage measurement unit 11, a charging current measurement unit 12, a time measurement unit 13, a battery data / measurement condition input unit 14, a battery data storage unit 15, and a calculation unit 16 (battery (Capacity estimation unit, determination unit), power supply unit 17, display unit 18, alarm issuing / transmitting unit 19 (alarm issuing unit), and external connection interface unit 20.
The battery voltage measurement unit 11 measures the terminal voltage of the secondary battery 30 and outputs the measured voltage value to the calculation unit 16. The charging current measurement unit 12 measures the current flowing through the secondary battery 30 and outputs the measured current value to the calculation unit 16. The timekeeping unit 13 outputs time information such as the current time to the calculation unit 16.

The battery data / measurement condition input unit 14 includes an input device such as a keyboard. The battery data / measurement condition input unit 14 receives secondary battery data (manufacturer, manufacturing year, manufacturing lot, etc.) for the secondary battery 30 based on the operation of the administrator of the secondary battery capacity estimation system according to the present embodiment. In addition, secondary battery capacity estimation data and the like are acquired and output to the battery data storage unit 15.
The battery data storage unit 15 stores secondary battery data and secondary battery capacity estimation data output from the battery data / measurement condition input unit 14. The secondary battery capacity estimation data is, for example, a secondary battery capacity estimation table as shown in FIG. 6 below.

FIG. 6 is a diagram illustrating an example of a secondary battery capacity estimation table recorded in the battery data storage unit 15 according to the present embodiment. In FIG. 6, the horizontal axis indicates the terminal voltage (V), and the vertical axis indicates the battery capacity (%) of the secondary battery 30. Curves g7 to g10 use a lithium ion secondary battery with a rated capacity of 40 (Ah) as the secondary battery 30 and reduce the capacity of the battery through a high-temperature accelerated deterioration test. The relationship between the capacity and the terminal voltage obtained by performing the constant current constant voltage charging method) is shown. The characteristics are shown when the charging current in the constant current charging mode is 0.2 (CA) and the terminal voltage in the constant voltage charging mode is 4.1 (V). The secondary battery capacity estimation table may be created using conditions other than these as the type of secondary battery, the charging current in the constant current charging mode, and the terminal voltage in the constant voltage charging mode.
A curve g7 is data in which the relationship between the terminal voltage and the battery capacity when the time from the start of charging of the secondary battery 30 in the constant current charging mode is 30 minutes is recorded. Curves g8 to g10 show the relationship between the terminal voltage and the battery capacity when the time after starting charging the secondary battery 30 in the constant current charging mode is 60 minutes, 90 minutes, and 120 minutes, respectively. Recorded data. Here, the relationship between the terminal voltage and the battery capacity at 30 minutes, 60 minutes, 90 minutes, and 120 minutes after the start of charging of the secondary battery 30 in the constant current charging mode is shown. Although the estimation table is recorded, the relationship between the terminal voltage and the battery capacity at other times may be recorded as the secondary battery capacity estimation table.
As shown in FIG. 6, when the battery capacity of the secondary battery 30 decreases, the terminal voltage increases. The secondary battery capacity estimation data such as the secondary battery capacity estimation table (FIG. 6) is obtained by the administrator of the secondary battery capacity estimation system according to the present embodiment and the like in the constant current charging mode of the secondary battery 30 and the battery capacity. It is acquired by examining the relationship with.

Returning to FIG. 1, the calculation unit 16 acquires the value of the terminal voltage of the secondary battery 30 measured by the battery voltage measurement unit 11. Moreover, the calculating part 16 acquires the time when the current output from the charging current measuring part 12 becomes a constant current and the current time from the time measuring part 13, so that the secondary battery 30 of the constant current charging mode is obtained. The time from when charging is started is calculated. Then, the calculation unit 16 stores the battery capacity of the secondary battery 30 based on the terminal voltage of the secondary battery 30 and the time since the charging of the secondary battery 30 is started in the constant current charging mode. Read from the secondary battery capacity estimation data recorded in the unit 15.
The power source unit 17 receives power from an AC power source 21 such as a commercial power source, and drives each unit of the secondary battery capacity estimation device 10a by supplying power to the arithmetic unit 16 of the secondary battery capacity estimation device 10a. Let The display unit 18 includes a display device such as an LCD (Liquid Crystal Display). The display unit 18 displays data such as the battery capacity of the secondary battery 30 obtained by the calculation unit 16 on the screen.

The alarm issuing / transmitting unit 19 issues an alarm by sounding an alarm or the like when the battery capacity of the secondary battery 30 obtained by the calculation unit 16 is lower than a predetermined capacity stored in advance in the battery data storage unit 15. Issue. In addition, the alarm issuing / transmitting unit 19 transmits an e-mail to the administrator of the secondary battery capacity estimation system according to the present embodiment via the external connection interface unit 20 via a network such as the Internet. Then, it is notified that the battery capacity of the secondary battery 30 is lower than a predetermined capacity (for example, 30 (%)).
The external connection interface unit 20 performs data communication with an external device by connecting the secondary battery capacity estimation device 10a to a network such as a LAN (Local Area Network).

  FIG. 7 is a flowchart showing an example of processing of the secondary battery capacity estimation system according to the present embodiment. As a premise for estimating the battery capacity of the secondary battery 30, the battery data / measurement condition input unit 14 includes storage battery data input from the battery data / measurement condition input unit 14 (manufacturer, year of manufacture, lot, etc. of the secondary battery 30). ) Or secondary battery capacity estimation data (see FIG. 6) is acquired (step S06) and recorded in the battery data storage unit 15.

  When estimating the battery capacity of the secondary battery 30, it is first determined whether or not the secondary battery 30 is in a fully discharged state (step S01). If the secondary battery 30 is not in a fully discharged state, “No” is determined in step S01, the secondary battery 30 is discharged until it is in a fully discharged state (step SS02), and the process proceeds to step S03. On the other hand, if the secondary battery 30 is in a fully discharged state, “Yes” is determined in step S01, and the process proceeds to step S03.

Then, the secondary battery 30 is charged by the charger 40 using the constant current constant voltage charging method (step S03). In addition, the calculation unit 16 calculates the time from the start of charging the secondary battery 30 in the constant current charging mode based on the time output from the time measuring unit 13. And the calculating part 16 measures the terminal voltage of the secondary battery 30 in constant current charge mode (step S04).
The calculation unit 16 is created based on the terminal voltage of the secondary battery 30 measured in step S04, the time after starting the charging of the secondary battery 30 in the constant current charging mode, and the capacity of the secondary battery. Then, the battery capacity of the secondary battery 30 is read from the secondary battery capacity estimation data recorded in the battery data storage unit 15 (step S05).

  And the calculating part 16 determines whether the battery capacity of the secondary battery 30 calculated | required by step S05 is more than predetermined capacity (for example, 30 (%)) (step S07). The predetermined capacity data is input from the battery data / measurement condition input unit 14 together with the secondary battery data and the secondary battery capacity estimation data in the process of step S06, for example.

  If the battery capacity obtained in step S05 is not greater than or equal to the predetermined capacity, it is determined as “No” in step S07, and an alarm is issued (step S08). That is, a warning message such as “the battery capacity of the secondary battery has become smaller than the predetermined capacity” is displayed on the display unit 18, or from the alarm issuing / transmitting unit 19 through the external connection interface unit 20. A warning mail is transmitted to the administrator of the secondary battery capacity estimation system according to the present embodiment. Thereafter, the battery capacity of the secondary battery 30 is displayed on the display unit 18.

On the other hand, when the battery capacity calculated | required by step S05 is more than predetermined capacity, it determines with "Yes" by step S07, and the display part 18 displays the battery capacity of the secondary battery 30 (step S09).
And the calculating part 16 determines whether the charge of the secondary battery 30 by the constant current constant voltage charging method was completed (step S10). This determination is performed based on whether or not the current value output from the charging current measuring unit 12 is equal to or less than a predetermined threshold (for example, the measured value is 0).
If the charging of the secondary battery 30 is not completed, “No” is determined in step S10, and the charging of the secondary battery 30 by the constant current constant voltage charging method is continued (step S11). And it progresses to step S10 again.

On the other hand, when the charging of the secondary battery 30 is completed, “Yes” is determined in Step S10, and the processing according to the flowchart of FIG.
Note that the arithmetic unit 16 determines that the secondary battery 30 has deteriorated when the terminal voltage of the secondary battery 30 measured in step S05 described above is greater than a predetermined voltage, and displays it on the display unit 18. You may make it do. The data for the predetermined time is input from the battery data / measurement condition input unit 14 together with the secondary battery data and the secondary battery capacity estimation data in the process of step S06, for example.

Next, the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 2nd Embodiment of this invention is demonstrated.
FIG. 8 is a block diagram illustrating an example of a configuration of a secondary battery capacity estimation system using the secondary battery capacity estimation apparatus according to the second embodiment of the present invention. The secondary battery capacity estimation device 10b according to the present embodiment is different from the secondary battery capacity estimation device 10a (FIG. 1) according to the first embodiment in that the secondary battery 30 is incorporated. Since the configuration of the secondary battery capacity estimation device 10b is the same as the configuration of the secondary battery capacity estimation device 10a (FIG. 1), the same reference numerals are given and description thereof is omitted.
Moreover, since the process of the secondary battery capacity estimation apparatus 10b by this embodiment is the same as the process of the flowchart shown in FIG. 7, the description is abbreviate | omitted.

Next, the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 3rd Embodiment of this invention is demonstrated.
FIG. 9 is a block diagram illustrating an example of a configuration of a secondary battery capacity estimation system by the secondary battery capacity estimation apparatus according to the third embodiment of the present invention. This secondary battery capacity estimation system includes a secondary battery capacity estimation device 10 c and a charger 40. In addition, in this embodiment, about the part which takes the structure similar to 1st Embodiment (FIG. 1), the same code | symbol is attached | subjected and the description is abbreviate | omitted.
The secondary battery capacity estimation device 10c includes a battery voltage measurement unit 11, a battery data storage unit 15, a calculation unit 16, an alarm issue / transmission unit 19, an external connection interface unit 20, and a secondary battery 30. The battery voltage measurement unit 11, the battery data storage unit 15, the calculation unit 16, the alarm issue / transmission unit 19, and the external connection interface unit 20 are arranged on the substrate 51 and supply power from the secondary battery 30 or an external power source. To drive.
In the first embodiment, the battery data storage unit 15 stores various data (such as the secondary battery capacity estimation table of FIG. 6) regarding the secondary battery 30 input from the battery data / measurement condition input unit 14. However, in the present embodiment, the battery data storage unit 15 stores various data regarding the secondary battery 30 in advance.
The processing of the secondary battery capacity estimation device 10c according to the present embodiment is the same as the processing of the flowchart shown in FIG.

In the secondary battery capacity estimation system according to the first to third embodiments of the present invention described above, when charging the secondary battery 30 by the constant current constant voltage charging method, the terminal voltage of the secondary battery 30 and the constant current The battery capacity of the secondary battery 30 is obtained from the secondary battery capacity estimation data recorded in the battery data storage unit 15 based on the time from the start of charging the secondary battery 30 in the charging mode. . Accordingly, it is not necessary for a human to calculate the battery capacity by measuring the terminal voltage of the battery, so that the battery capacity of the secondary battery 30 can be easily obtained.
Even in the assembled battery in which the secondary battery 30 is combined, it is possible to perform capacity estimation / determination determination of an arbitrary cell only by measuring the charging characteristics of each cell in the assembled battery at the time of charging.

  In the embodiment described above, the battery voltage measurement unit 11, the charging current measurement unit 12, the time measurement unit 13, the battery data / measurement condition input unit 14, the battery data storage unit 15, the calculation unit 16, and FIGS. The function of the power supply unit 17, the display unit 18, the alarm issue / transmission unit 19, the external connection interface unit 20, or a program for realizing a part of this function is recorded on a computer-readable recording medium. The secondary battery capacity estimation apparatus may be controlled by causing the computer system to read and execute the recorded program. The “computer system” here includes an OS and hardware such as peripheral devices.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

It is a block diagram which shows an example of a structure of the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 1st Embodiment of this invention. It is a figure for demonstrating the constant current constant voltage charging method by this embodiment. It is a figure which shows the charge characteristic at the time of changing the initial stage charge current in the constant current charge mode of FIG. It is a graph which shows an example of the discharge characteristic of the secondary battery 30 in which the capacity | capacitance fell to various values. It is a graph which shows an example of the characteristic at the time of charging the secondary battery 30 of various capacity | capacitance with a constant current constant voltage method. It is a figure which shows an example of the secondary battery capacity estimation table recorded on the battery data storage part 15 by this embodiment. It is a flowchart which shows an example of a process of the secondary battery capacity estimation system by this embodiment. It is a block diagram which shows an example of a structure of the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 2nd Embodiment of this invention. It is a block diagram which shows an example of a structure of the secondary battery capacity estimation system by the secondary battery capacity estimation apparatus of the 3rd Embodiment of this invention.

Explanation of symbols

10a to 10c ... secondary battery capacity estimation device, 11 ... battery voltage measurement unit, 12 ... charging current measurement unit, 13 ... timing unit, 14 ... battery data / measurement condition input unit, DESCRIPTION OF SYMBOLS 15 ... Battery data storage part, 16 ... Operation part, 17 ... Power supply part, 18 ... Display part, 19 ... Alarm issuing / transmission part, 20 ... External connection interface part, 30 ... Secondary battery, 40 ... Charger, 50 ... Substrate

Claims (7)

A secondary battery capacity estimation device for estimating the battery capacity of a secondary battery,
Battery voltage measuring means for measuring a terminal voltage of the secondary battery in a constant current charging mode when charging the secondary battery by a constant current constant voltage charging method;
Battery capacity estimating means for estimating the battery capacity of the secondary battery based on the terminal voltage;
A secondary battery capacity estimation device comprising: A secondary battery,
Battery voltage measuring means for measuring a terminal voltage of the secondary battery in a constant current charging mode when charging the secondary battery by a constant current constant voltage charging method;
Battery capacity estimating means for estimating the battery capacity of the secondary battery based on the terminal voltage;
A secondary battery capacity estimation device comprising: Battery data storage means for storing in advance battery capacity estimation data in which the relationship between the terminal voltage and the battery capacity of the secondary battery is recorded;
The battery capacity estimating means estimates the battery capacity of the secondary battery by reading out the battery capacity of the secondary battery corresponding to the terminal voltage measured by the battery voltage measuring means from the battery capacity estimation data. The secondary battery capacity estimation apparatus according to claim 1 or 2, characterized in that   4. The apparatus according to claim 1, further comprising a determination unit that determines that the secondary battery has deteriorated when a terminal voltage measured by the battery voltage measurement unit exceeds a predetermined voltage. The secondary battery capacity estimation device according to any one of the items.   The secondary according to any one of claims 1 to 4, further comprising alarm issuing means for issuing an alarm when the battery capacity estimated by the battery capacity estimating means is below a predetermined capacity. Battery capacity estimation device. Computer
Battery voltage measuring means for measuring the terminal voltage of the secondary battery in the constant current charging mode when charging the secondary battery by a constant current constant voltage charging method;
Battery capacity estimating means for estimating the battery capacity of the secondary battery based on the terminal voltage;
Program to function as. A battery voltage measurement process for measuring the terminal voltage of the secondary battery in the constant current charging mode when charging the secondary battery by a constant current constant voltage charging method;
A battery capacity estimation process for estimating a battery capacity of the secondary battery based on the terminal voltage;
A secondary battery capacity estimation method comprising:

Images