JPH0937484A - Method for detecting life of battery, and detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the life even in backup period by detecting the voltage of a battery, using a main power source at the time of turning the power on, and estimating the lifetime, and comparing the lifetime with the passage of time measured during backup period. SOLUTION: During the ON time of the main power of electronic equipment, the detection voltage of a battery 1 is digitalized by an A/D converter 2, and is taken into a microcomputer 3, and the comparison between the detected voltage value and the reference value (life voltage) is performed. Based on this comparison result, the lifetime is estimated. And, when the main power of the electronic equipment is cut off and the backup begins, a timer 4 begins to count clock signals CLK. If the set time of the timer 4 is over during the backup period, this detects that the battery has come to the end of its life, and informs the user of abnormality to attract attention.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery life detecting method and apparatus for detecting and outputting the life of a battery used for backup of a main power source of electronic equipment or the like, particularly during a backup period.

[0002]

2. Description of the Related Art Conventionally, the life of a battery has been detected by detecting the battery voltage at the time when the main power is turned on or at a certain time while the main power is turned on, and detecting the life when the detected value is below a certain voltage. However, it cannot detect the voltage level drop during the backup period. Therefore,
There is also a method in which the life counter is subtracted according to the time even during the backup period to predict the dead time of the battery (JP-A-60-51422). This conventional example is shown in FIG.
This will be specifically described with reference to FIG. In the figure, when the voltage level of the power supply 31 to the load 33 decreases, the backup power supply 32 replaces and backs up the load 33, and at the same time, the power failure detection device 34 detects the voltage level decrease and starts the timer 35. . The timer 35 outputs a pulse signal at a constant interval defined by the size of the load 33 only during the period when the power supply is cut off, and inputs it to the life counter 36. The life counter 36 stores the life (count setting value) of the backup power supply immediately before the power supply is cut off, and during the backup period, the subtraction circuit 3 is output according to the output of the timer 35.
The count value is decremented by 7 and the fact that the battery life is approaching is successively displayed on the display 38.

[0003]

However, in the prior art as described above, since the load on the backup power supply is large even during the backup period, a large-capacity backup separate power supply and a power failure detection device in addition to the backup power supply. There was a problem of needing. Therefore, the present invention is
An object of the present invention is to detect when the battery has reached the end of its life with a simple electric circuit even when the main power supply is cut off, to notify it, and to provide reliable backup.

[0004]

In order to solve the above problems, the present invention detects the voltage of a battery when the main power source of an electronic device or the like is turned on, estimates the life time based on the detected voltage, and during the backup period. The battery life is detected from the comparison between the life time and the elapsed time measured during the backup period, and the detection output notifies the battery life. Further, means for detecting the voltage of the battery, operation control means for estimating the life time based on the detected voltage of the battery, the elapsed time is set and the elapsed time during the backup period is measured, and the set life time is set. It is characterized by comprising timer means for outputting when the time is measured. Further, during the backup period, the life time is set, the elapsed time during the backup period is measured, and a power source such as a capacitor for supplying electric power to timer means that outputs when the set life time is measured is provided. The notification means for blinking a display lamp or the like operated by the output of the timer means is provided.

Even during the backup period when the battery is low, the life can be detected and notified by simple electric circuit means, and reliable backup can be provided.

[0006]

When the main power supply of an electronic device or the like is turned on, the voltage of the battery is detected using the main power supply, the life time is estimated based on the detected voltage and the timer means is set, and the power supply such as the capacitor is supplied during the backup period. Is used to detect the battery life by comparing the life time with the elapsed time measured during the backup period.

[0007]

EXAMPLES Examples of the present invention will be described. FIG.
It is a block diagram which shows the structure of one Example of this invention. In the figure, 1 is a battery used for backup of a memory (not shown) which is an electronic device, and 2 is a battery 1
A / D converter connected to the
Convert. Reference numeral 3 is a microcomputer connected to the A / D converter 2, and 4 is a timer for counting the clock signal CLK. Reference numeral 5 denotes an auxiliary backup power source such as a capacitor for operating the timer 4 and a clock signal oscillator (not shown) during backup by the battery 1. The operation of the embodiment configured as described above will be described.

While the main power source of the electronic device (not shown) is turned on, the detected voltage of the battery 1 is digitized by the A / D converter 2 and taken into the microcomputer 3. In the microcomputer 3, the detected voltage value and the reference value (lifetime voltage)
Compare with. Further, based on the comparison result, the microcomputer 3 determines that the battery life is a life when the detected voltage is equal to or lower than the life voltage, and outputs the life voltage. If the voltage is very close to the life voltage, the life time is determined according to the voltage. Guess. Concerning the estimation, for example, the relationship between the battery voltage and the time at the load that is the backup target is as shown in FIG. 2. Therefore, if the predetermined voltage at the point B shown in FIG. The estimated life at the time when the voltage of is detected is time t _B −t _A. The microcomputer 3 presets this time in the timer 4.

The detection of the voltage of the battery, the estimation of the life time, and the setting of the timer only have to be performed when the main power of the electronic device is turned on or at a constant time during the main power is turned on. During this time, the auxiliary backup power supply 5 such as a capacitor is charged by the main power supply. The main power supply of the electronic device is cut off, backup of the main power supply by the battery 1 starts, and the timer 4 starts counting the clock signal CLK. The auxiliary backup power supply 5 activates the timer 4 and generates the clock signal CLK. There is no problem if the timer 4 does not exceed the set time during the backup period. However, when the timer 4 exceeds the set time during the backup period, the battery life is detected and output there. This output can activate a notification means such as a lamp display. Also, when the power is turned on next time, the timer is read, and when the time is over, the abnormality is notified during the backup period so that attention can be called.

When the time is over, it is possible to notify the user of the battery life by a blinking display of a red lamp or the like, and call the user's attention to ensure the backup.

[0011]

As described above, according to the present invention,
Even during the backup period when the battery is low, the battery life can be detected with a simple circuit and a warning can be displayed without detecting the battery voltage, so backup can be performed reliably.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between battery voltage and time under a certain load.

FIG. 3 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1 Battery 2 A / D Converter 3 Microcomputer 4 Timer 5 Auxiliary Backup Power Supply (Capacitor etc.)

Claims (4)

[Claims] 1. A battery life is detected by detecting a battery voltage when the main power is turned on, estimating a life time based on the detected voltage, and comparing the life time with an elapsed time measured during the backup period during the backup period. Is detected,
A method of detecting battery life, characterized by notifying by detection output. 2. A means for detecting a voltage of a battery, an arithmetic control means for estimating a life time based on the detected voltage of the battery, a life time is set, and an elapsed time during a backup period is measured and set. A battery life detecting device comprising: a timer unit that outputs the time when the life time is measured. 3. A power supply such as a capacitor for supplying electric power to a timer means for measuring the elapsed time during the backup period during which the life time is set during the backup period and measuring the set life time. The battery life detection device according to claim 2, wherein 4. The battery life detecting device according to claim 2, further comprising a notifying unit which operates by an output of the timer unit.