JP2001160421A - Measuring method of degradation rate in cellular phone cell pack and cellular phone cell pack measurement equipment using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure degradation state of a cellular phone cell pack when used for different kind of a cellular phone and having a different charging voltage, and to measure a continuous call time of the cell pack when connected to a cellular phone. SOLUTION: A database in which a relation between the drop rate of a stable voltage and the degradation rate for each of a plurality of cellular phone is recorded is prepared, and a measurement of the drop rate of a stable voltage for each cellular phone cell pack to be measured when connecting it with load (2) is carried out, and a search for the data of each measured cellular phone cell pack in the database (7) is carried out to compute the degradation rate of the measured cellular phone cell pack, and by these procedures a degradation state and a continuous telephone call time capability of a cell pack when equipping in a cellular phone can be measured and displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the measurement of the state of deterioration of battery packs of portable telephones having different models and charged voltages, and the measurement of continuous talk time when the portable telephone is attached to a portable telephone.

[0002]

2. Description of the Related Art Conventionally, the deterioration state of a mobile phone battery pack is measured by measuring the internal impedance of the battery and calculating the deterioration rate, or by discharging the battery pack to a usable voltage value after charging it to a full charge. Since the calculation is based on the time required, the accuracy is lacking, and there is a disadvantage that the measurement is performed for a long time.

[0003]

Accordingly, there has been an increasing demand for a device for measuring the state of deterioration of a portable telephone battery pack having a different model and voltage and a continuous talk time accurately and in a short time, and it has been invented to meet the demand. Was.

[0004]

In order to solve the above-mentioned problems, the present measuring apparatus discharges a cell phone to be measured from a point of time without fully charging the cell phone battery under test, and discharges the battery pack in a short time to achieve a stable voltage drop. The deterioration rate is obtained and the deterioration rate is measured. From the deterioration rate, the state of deterioration of the battery pack of the cell phone to be measured and the continuous talk time when the cell phone is mounted on the cell phone and used is measured.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the relationship between the stable voltage drop rate and the deterioration rate with respect to the voltage of each model of a mobile phone battery pack is recorded and stored in advance, and the mobile phone battery pack to be measured is discharged at a constant current. Then, the deterioration rate is measured by comparing with the stable voltage drop rate obtained by the above method, and from the deterioration rate, the deterioration state of the battery pack of the cell phone to be measured and the continuous talk time when the cell phone is mounted on the cell phone and used is measured. .

Most mobile phone battery packs are lithium ion batteries, and their discharge characteristics are the discharge characteristics (11), (12), and (13) of the mobile phone battery pack shown in FIG. The discharge characteristics of the mobile phone battery pack are as follows: the discharge characteristic (11) of the cell phone battery pack having a deterioration rate of 0%; It is divided into the discharge characteristics (13) of the telephone battery pack.

The usable energy stored when a battery having a discharge characteristic of 0% deterioration is charged to full charge is the voltage axis, the discharge characteristic of a mobile phone battery pack with 0% deterioration (11), and the lower limit of use. The area is surrounded by the voltage value (17). In the case of a battery having a discharge characteristic (12) of a mobile phone battery pack having a deterioration rate of A percent, the usable energy stored when the battery is fully charged is represented by a voltage axis,
The area is defined by the discharge characteristic (12) of the mobile phone battery pack and the lower limit operating voltage value (17). The area has a relationship of 100 to 100-A.

The method for determining the relationship between the stable voltage drop rate and the deterioration rate will be described with reference to the drawings. In FIG. 2, when the mobile phone battery pack having the deterioration rate of 0% is fully charged and discharged, the mobile phone having the deterioration rate of 0% is obtained. The discharge characteristic (11) of the telephone battery pack is obtained, but this discharge characteristic is in a sharp voltage drop state from the start of discharge to a stable voltage drop rate start time (16), and then in a stable voltage drop state. Over time, the voltage drops again.

The stable voltage drop state is from the start time of the stable voltage drop rate (16) to the time when the minimum voltage value of the stable voltage drop rate (15) is reached. The stable voltage drop rate is a gradient of the discharge characteristics (11), (12), and (13) of the mobile phone battery pack in a stable voltage drop state.

[0010] The discharge characteristics of a non-degraded cell phone battery pack similar to a new one, that is, the discharge characteristic (11) of a cell phone battery pack having a deterioration rate of 0%, deteriorates after repeated charging and discharging several times, and the deterioration rate A Percent of the cell phone battery pack discharge characteristics (12). Further, after repeated charge / discharge several times, the discharge characteristic (13) of the battery pack of the mobile phone with the deterioration rate of B percent is reached. The stable voltage drop rate tends to increase as the battery deteriorates.

When a battery with a deterioration rate of A percent is fully charged, the energy is 100-A / 100 as compared with a fully charged mobile phone battery pack with a deterioration rate of 0 percent. Specifically, a mobile phone battery pack having a deterioration rate of 30% can store only 70% of energy compared to a new one.

[0012] A fully-charged mobile phone battery pack that has not been deteriorated is fully charged and discharged at a constant current until the lower limit operating voltage value (17) is reached, the available energy is calculated, and the voltage drop rate for each voltage is calculated. Measure and record as data for a mobile phone battery pack with 0% degradation. The battery is fully charged again and discharged at a constant current until the lower limit operating voltage value (17) is reached, the usable energy is calculated, the voltage drop rate for each voltage is measured, and the deterioration rate (100-100 (usable energy / The usable energy of the battery having the deterioration rate of 0% is recorded as data of the battery of the percentage). Similarly, until the deterioration rate reaches 50%, the relationship between the stable voltage drop rate and the deterioration rate for each voltage with respect to the battery model is recorded and stored as battery characteristic data.

In FIG. 2, the discharge characteristic of the mobile phone battery pack having the deterioration rate of A percent is (12), and the mobile phone battery pack of the same model as this mobile phone battery pack having the deterioration rate of A percent is the measured mobile phone battery pack. Assuming that the battery pack of the telephone has been charged to the charging voltage value (18), the discharge characteristic (20) of the battery pack of the mobile phone under test shows a stable voltage after several minutes from the discharge start time (19) of the battery pack of the mobile phone under test. The state is lowered and overlaps with the discharge characteristic (12) of the mobile phone battery pack having the deterioration rate of A percent.

The cell pack under test is discharged at a constant current to obtain a stable voltage drop rate after the battery pack enters a stable voltage drop state, and the stable voltage drop rate for the same type of voltage as the cell pack under test is obtained. The relationship between the voltage value and the stable voltage drop rate is searched for the relation between the voltage value and the stable voltage drop rate, and the deterioration rate is measured.

If the voltage value of the battery pack of the portable telephone under test is lower than the lowest voltage value (15) of the stable voltage drop rate shown in FIG. 2, the discharge characteristics will be in a sharp voltage drop state. In this case, since the relationship between the voltage drop rate and the deterioration degree is applied to the consistency even in the same model battery, the deterioration rate is measured by comparing the data of the relation between the internal impedance and the deterioration degree. In this case, the accuracy is slightly lacking.

Although the internal impedance increases as the deterioration proceeds, the measurement method is as follows. Assuming that the charging voltage is V0 and the voltage value when a constant current flows for several seconds is V1,
The formula for calculating the internal impedance is (V0-V1) / constant current value.

Since the discharge characteristics depend on the battery temperature, a more accurate measurement of the deterioration rate can be obtained by making the database a relationship between the stable voltage drop rate and the deterioration rate with respect to the model, voltage and battery temperature.

The measured deterioration rate indicates how long the battery pack of the cell phone under test can be used in the future and its life is about to expire.

The energy currently accumulated is calculated from the measured deterioration rate and the voltage, and the continuous talk time when the cell phone to be measured is directly attached to the cell phone is calculated and displayed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIG. 1. A database (7) shows the relation between the stable voltage drop rate, the deterioration rate and the deterioration rate, and the relation between the internal impedance and the deterioration rate with respect to the voltage value of the cell phone battery pack. Keep a record.

The mobile phone battery pack (1) to be measured is connected to a constant current load (2). When the mobile phone battery pack (1) to be measured is connected to a mobile phone, the battery pack is discharged by a constant current flowing during a call. A few minutes after the start of the discharge, a stable voltage drop occurs. At this time, the voltage of the battery pack of the cell phone to be measured is digitally converted by the A / D converter (3).
The data is serial-converted by the microcomputer (4), the serial data is sent to the personal computer (6) through the RS232C interface (5), and the voltage at this time is stored as V1 in the personal computer (6).

The mobile phone battery pack (1) to be measured continues to discharge at a constant current, and after a few minutes, sends the voltage of the mobile phone battery pack (1) to the personal computer (6) as data.
It is stored as the voltage V2 by the personal computer (6).

In the personal computer (6), the stable voltage drop rate R is obtained at (V1-V2) / hour. The database (7) is searched from a voltage close to the voltage V2 of the same type of the mobile phone battery pack to be measured, and based on the relationship between the stable voltage drop rate close to the obtained stable voltage drop rate R and the deterioration rate, the measured mobile phone battery pack is obtained. The degradation rate of the is measured.

Based on the measured deterioration rate of the battery pack of the mobile phone to be measured, whether the battery pack for the mobile phone to be measured is still usable enough, is it better to replace it, is it about to be broken, or is it out of order? Is displayed on the screen and printed.

The available energy is calculated from the measured deterioration rate and voltage value of the cell phone battery pack (1), and the continuous talk time when the cell phone battery pack (1) is attached to the cell phone. Is calculated by the personal computer (6), displayed on a screen, and printed.

[0026]

The present invention is embodied in the form described above and has the following effects.

Since the stable voltage drop rate is measured and the deterioration rate is measured several minutes after the start of discharging the battery pack of the mobile phone under test, the measurement can be performed in a short time.

When the battery pack of the cell phone to be measured is measured, since the energy used is small, it can be mounted on the cell phone immediately after the measurement and used.

[Brief description of the drawings]

FIG. 1 is a block diagram of a mobile phone battery pack measuring device.

FIG. 2 is a discharge characteristic graph of a mobile phone battery pack.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mobile phone battery pack to be measured 2 Constant current load 3 A / D converter 4 Microcomputer 5 RS232C interface 6 Personal computer 7 Database 11 Discharge characteristics of mobile phone battery pack with 0% deterioration rate 12 Discharge characteristics of mobile phone battery pack with 0% deterioration rate Discharge Characteristics 13 Discharge Characteristics of Cell Phone Battery Pack with Deterioration Rate B Percent 14 Full Charge Voltage Value 15 Stable Voltage Drop Rate Minimum Voltage Value 16 Stable Voltage Drop Rate Start Time 17 Lower Limit Operating Voltage Value 18 Charge Voltage of Cell Phone Battery Pack Under Test Value 19 Discharge start time of mobile phone battery pack under test 20 Discharge characteristics of mobile phone battery pack under test

Claims (2)

[Claims] 1. The relationship between the stable voltage drop rate and the deterioration rate with respect to the voltage is recorded and stored for each type of battery pack based on the constant current discharge characteristics of the mobile phone battery pack. A measuring method for measuring a deterioration rate of a battery pack of a mobile phone under test by collating with a stable voltage drop rate obtained by discharging. 2. A cell phone battery pack measuring apparatus using the measuring method according to claim 1, for measuring the deterioration state of the cell phone battery pack and the continuous talk time when the cell phone battery pack is attached to the cell phone.