JP2001035546A - Detection method for life duration of battery and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To notify a user that a battery needs to be replaced by detecting life duration of a secondary battery, using a relatively simple method. SOLUTION: A secondary battery 2 has characteristics, such as potential drop from a fully charged condition to a shutoff condition and a required time until the battery shutoff. The battery properties changes as the battery is being used, when the life duration is neared, even if the battery is fully charged it will get shutoff in a short period. When the secondary battery is used for electronic appliances, its performance is understood by using a personal computer for detecting the expiration of the duration life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting the life of a battery, and more particularly, to the life of a battery capable of detecting the life of the secondary battery as well as detecting the remaining amount of the battery. The present invention relates to a detection device.

[0002]

2. Description of the Related Art In recent years, with the development of electronic devices such as various information devices and communication devices, opportunities to use rechargeable batteries for various electronic devices have been increasing. In such a secondary battery, when the secondary battery runs out of battery, charging is performed, and power can be supplied again for driving the electronic device. For this purpose, the electronic device detects whether or not the secondary battery has run out of battery by means of a battery remaining amount measuring means, and notifies the user by issuing a warning when the battery runs out. There is something that is. Then, when a warning or display of battery exhaustion is issued, the user performs a charging operation on the secondary battery.

[0003]

However, in the above-described conventional battery remaining amount detecting device, it is not possible to measure whether or not the secondary battery is dead and to prompt the user to perform a charging operation. Even if it can be done, it cannot be determined whether or not the secondary battery has reached the end of its life. If the voltage falls below a certain battery voltage, the battery is almost exhausted and a warning is issued. Therefore, in the related art, when the user charges the secondary battery in response to the detection of the exhaustion of the battery by the battery remaining amount detecting device, the user does not notice that the secondary battery has reached the end of its life. Nevertheless, a situation in which the battery runs out again in a short time may occur, and there is a risk that the electronic device will not operate during operation or data will be destroyed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to detect the life of a secondary battery while detecting the end of charge of the secondary battery. An object of the present invention is to provide a device that can avoid troubles of various electronic devices due to battery life.

[0005]

According to the present invention, in order to achieve the above object, the present invention calculates a discharge characteristic of a secondary battery from a measured remaining amount of a battery while detecting battery exhaustion of the secondary battery. The gist is that the life of the battery is detected from the calculated discharge characteristics and the discharge characteristics in the initial state.

According to a first aspect of the present invention, as a method for detecting the life of a battery, the discharge characteristics of an initial state of a secondary battery are stored, and the discharge characteristics of the secondary battery after a predetermined time has elapsed. Is determined from the discharge characteristics of the secondary battery at the time of the initial state and the discharge characteristics of the secondary battery after the lapse of the predetermined time. Therefore, the electronic device using the secondary battery can be operated smoothly.

According to a second aspect of the present invention, as a method for detecting the life of a battery, in an initial state of a secondary battery, a time-dependent change in a battery voltage from a fully charged state to a dead battery is measured and stored. From this measured value, the discharge characteristics in the initial state of the secondary battery are obtained and stored, and after the secondary battery is charged, the time-dependent change in the battery voltage from the fully charged state to the battery exhaustion is measured and stored. The current discharge characteristics of the secondary battery are obtained from the values, and the discharge characteristics in the initial state of the secondary battery and the current discharge characteristics are compared to determine whether or not the secondary battery has reached the end of its life. Based on the discharge characteristics of the secondary battery at the initial stage, the battery life is determined more accurately by estimating the battery life based on the result of comparing the discharge characteristics of the secondary battery after a predetermined time has elapsed. It has the effect of being able to leave.

According to a third aspect of the present invention, as a battery life detecting device, a battery remaining amount detecting means for detecting a charged state of a secondary battery from a fully charged state to a dead battery is detected. First storage means for storing the remaining battery power;
Control means for measuring a change over time of the remaining battery value from the fully charged state detected by the remaining battery level detection means to when the battery runs out, and calculating a discharge characteristic of the secondary battery; Second storage means for storing discharge characteristic data;
A service life determining means for determining whether or not the service life of the secondary battery has been reached based on the current discharge characteristic data of the secondary battery calculated by the control means and the initial discharge property data of the secondary battery; By detecting the life of the battery, the operation of the electronic device using the secondary battery can be smoothly performed.

According to a fourth aspect of the present invention, in the battery life detecting apparatus according to the third aspect, the control means detects the voltage of the secondary battery in order to detect the remaining battery level. This has the effect that the life of the battery can be detected by a simple method of measuring the voltage of the battery.

According to a fifth aspect of the present invention, in the battery life detecting device according to the third or fourth aspect, the control means determines that the battery has run out based on the result of the remaining battery level detected by the remaining battery level detecting means. The battery life is detected as a part of the operation for detecting the dead battery, and has the effect that both the dead battery and the battery life can be detected without requiring an extra configuration. .

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a battery life detecting device for implementing the battery life detecting method of the present invention. The battery life detecting device includes a charging control unit 3 connected to the primary power supply 1 and charging the secondary battery 2, a battery remaining amount detecting unit 4 for detecting the remaining battery amount of the secondary battery 2, A timer 5 for determining the timing of the detection operation of the amount detection unit 4, a temperature sensor 6 for detecting the temperature of the secondary battery 2, a CPU 7 as a system control unit for controlling the entire operation of the life detecting device, and connection to the CPU 7. DRAM as storage means for storing the remaining battery value (measurement data) detected by the remaining battery detection unit 4
(Dynamic random access memory) 8, a flash memory 9 as storage means for storing initial discharge characteristic data of the secondary battery 2, and a program ROM 10 in which a program for determining the life of the secondary battery 2 is stored. ,
An input unit 11 such as a keyboard and a touch panel for inputting various initial data and commands to the CPU 7 is provided. As the storage means for storing the initial discharge characteristic data of the secondary battery 2, in addition to the flash memory 9, a peripheral storage device such as a hard disk or an optical disk may be used.

The charge control unit 3 also detects whether or not the secondary battery 2 is fully charged, and controls the timer 5 based on the detection result to control the charging time. The battery level detector 4 detects whether the secondary battery 2 is fully charged or has run out of battery by measuring the voltage of the secondary battery 2. The battery remaining amount detection unit 4 also detects the temperature of the secondary battery 2 at the time of voltage measurement based on a signal from the temperature sensor 6, and performs a correction corresponding to this temperature to make the secondary battery 2 fully charged. Or battery dead. DRA
M8 stores various measurement data necessary for obtaining the remaining battery value, such as the voltage value of the secondary battery 2, the temperature value measured by the temperature sensor 6, the operation time value of the timer 5 during the charging operation, and the like. You. Also, the flash memory 9
In addition to the discharge characteristics data in the initial state of the secondary battery, the full charge voltage value, reference data such as the battery exhaustion voltage value, and correction data for voltage detection, and even the current state of the secondary battery Battery level data (current data)
Are stored.

The operation of the battery life detecting device having such a configuration will be described below. FIG. 2 is a flowchart illustrating a charging operation of secondary battery 2 by the battery life detecting device according to the present embodiment. When the charging operation is started, a processing step (hereinafter simply referred to as a step) ST1 is performed.
In, the charging control unit 3 charges the secondary battery 2 under the control of the CPU 7. Then, the charging control unit 3 checks whether or not the secondary battery 2 is fully charged after a predetermined time has elapsed (step ST2). If the secondary battery 2 has not been fully charged, the charging operation of step ST1 is performed. When the secondary battery 2 reaches a full charge, the CPU 7
Is reset (step ST3), the battery remaining amount detection unit 4 starts the voltage monitoring operation of the secondary battery 2, and starts the timer 5 to start timer counting (step ST4).

Thus, the voltage from the fully charged state of the secondary battery 2 to the battery exhaustion is measured, and the charged state corresponding to the passage of time is detected. FIG. 3 is a discharge characteristic diagram showing an example of a voltage change with the lapse of time from the fully charged state of the secondary battery 2 to the exhaustion of the battery. As shown in this figure, in the initial state of the secondary battery 2, when the battery is fully charged, the voltage is charged until it reaches V1, and the secondary battery 2 exhibits a discharge characteristic as shown by a characteristic curve (1) with the passage of time. Voltage drops. This voltage is measured at predetermined time intervals by the remaining battery power detector 4, and the measured value is stored in the flash memory 9. Then, when the reduced voltage reaches Vb, it is determined that the battery has run out. The time from when the secondary battery 2 is fully charged to when it is determined that the battery is exhausted is also measured (according to the timer count in step ST4). In the initial state, the time is measured as t1. You. Then, after the use time of the secondary battery 2 elapses, for example, 4 years and 5 years, the voltage is charged until the voltage reaches V2 at the time of full charge, and the discharge as represented by the characteristic curve (2) with the elapse of time. The voltage decreases due to the characteristics. Then, when the reduced voltage reaches Vb, it is determined that the battery has run out. In the latter case, the secondary battery 2
The time from when the battery is fully charged until the battery is determined to be exhausted is measured as t2. The above is the operation of detecting the remaining battery charge by the battery life detecting device according to the present embodiment.

Next, the battery life detecting operation in the present embodiment will be described. FIG. 4 is a flowchart for explaining the battery life detecting operation. This battery life detection operation is executed as a timer interrupt operation for the battery remaining amount detection operation. When this battery life detection operation starts,
The time from the fully charged state of the secondary battery 2 to the battery exhaustion, current calculation during that time, and voltage detection are performed (step ST11). Based on the data obtained by these processes, the current discharge characteristics of the secondary battery 2 are calculated and compared with the discharge characteristics (reference) in the initial state stored in the flash memory 9 (step ST).
12). Then, the deterioration rate of the secondary battery 2 is calculated by activating the life detection program by the CPU 7 (step ST13). As a result of this calculation, the current battery discharge characteristics (discharge characteristics) of the secondary battery 2 reached 60% of the reference (since the battery life is generally defined when t2 becomes 60% of t1). It is checked whether or not the battery life has been reached (step ST14). If it has reached 60%, a warning is displayed indicating that the battery life has been reached (step ST15).
A series of battery life detection operations ends. On the other hand, step S
If the battery exhaustion characteristic does not reach 60% of the reference in the check processing of T14, the secondary battery 2
Since the battery life has not yet reached, the process is shifted to the initial flow (step ST16), and the battery life detecting operation is terminated.

Note that the discharge characteristics of the secondary battery 2 in the initial state may be stored in the flash memory 9 from the beginning, or in the initial stage of use of the secondary battery.
The battery voltage is measured and stored over time from the fully charged state to the battery exhaustion, and the discharge characteristics in the initial state of the secondary battery are obtained from the measured values to obtain the flash memory 9.
May be stored.

As described above, by storing various programs and data in the storage means, the CPU 7 as the system control unit performs the life detecting operation. In particular, the secondary battery 2 is often used for a personal computer or the like, and the CPU 7 and the memories 8, 9, and 10 are originally attached as electronic equipment. In many cases, the characteristics of the rechargeable battery can be grasped by utilizing the functions of the personal computer simply by installing a program corresponding to the purpose. Therefore, the life can be detected only by making simple and trivial improvements, and the effect is great.

[0018]

As described above, according to the present invention,
While detecting the battery exhaustion of the secondary battery, calculate the discharge characteristics of the secondary battery from the measured remaining battery level, and detect the battery life from the calculated discharge characteristics and the discharge characteristics in the initial state. Therefore, the battery life of the secondary battery can be detected by a simple method, and the operation of the electronic device using the secondary battery can be performed smoothly.

The battery life detecting device includes a battery remaining amount detecting means for detecting a charged state of the secondary battery from a fully charged state to a dead battery, and a first battery storing the detected battery remaining amount. A storage unit, a control unit that measures a change over time of a battery remaining amount value from a fully charged state to a battery exhaustion detected by the battery remaining amount detection unit, and calculates a discharge characteristic of the secondary battery; Second storage means for storing the initial discharge characteristic data of the secondary battery, and the life of the secondary battery based on the current discharge characteristic data of the secondary battery calculated by the control means and the initial discharge characteristic data of the secondary battery. And the life determining means for determining whether or not the battery life has been reached, the battery life can be detected with a relatively simple configuration, and the electronic device using the secondary battery can be operated without trouble. Various effects such as Obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a battery life detecting device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a charging operation for the secondary battery 2 by the battery life detecting device according to the embodiment.

FIG. 3 is a discharge characteristic diagram showing an example of a voltage change over time from a fully charged state of the secondary battery 2 to a battery exhaustion in the embodiment.

FIG. 4 is a flowchart for explaining a battery life detecting operation in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary power supply 2 Secondary battery 3 Charge control part 4 Battery remaining amount detection part 5 Timer 6 Temperature sensor 7 CPU (system control part) 8 DRAM 9 Flash memory 10 Program ROM 11 Input part

Claims (5)

[Claims] A discharge characteristic of the secondary battery in an initial state is stored, a discharge characteristic of the secondary battery after a predetermined time has elapsed is determined, and a discharge characteristic of the secondary battery in the initial state and the discharge characteristic of the secondary battery are determined. A method for detecting the life of a battery, comprising determining whether or not the life of the secondary battery has expired based on the discharge characteristics of the secondary battery after a lapse of time. 2. In the initial state of the secondary battery, a time-dependent change in the battery voltage from the fully charged state to the exhaustion of the battery is measured and stored, and the discharge characteristics in the initial state of the secondary battery are obtained from the measured values. After charging the secondary battery, further measure and store the time-dependent change of the battery voltage from the fully charged state to the battery exhaustion, and store the current discharge characteristic of the secondary battery from the measured value. A battery life detecting method for comparing the discharge characteristics in an initial state of the present invention with the current discharge characteristics to determine whether or not the life of the secondary battery has reached its end. 3. A battery remaining amount detecting means for detecting a charged state of the secondary battery from a fully charged state to a dead battery, a first storage means for storing the detected remaining battery amount, a battery remaining amount Control means for measuring a change over time of a remaining battery value from a fully charged state to a dead battery detected by a detection means, and calculating a discharge characteristic of the secondary battery; and initial discharge characteristic data of the secondary battery. And a second storage unit for storing the current discharge characteristic data of the secondary battery calculated by the control unit and the initial discharge characteristic data of the secondary battery to determine whether the secondary battery has reached the end of its life. A battery life detecting device comprising a life determining means for determining. 4. The control means detects the remaining battery power.
The battery life detecting device according to claim 3, wherein a voltage of the secondary battery is detected. 5. The battery life detecting device according to claim 3, wherein the control means determines that the battery has run out based on the result of detecting the remaining battery power by the remaining battery power detecting means.