JPH0638387A - Device for confirming service life of battery - Google Patents

Abstract

PURPOSE:To accurately confirm the remaining service life of a battery by providing a means which charges and discharges the battery, means which measures the time required to discharge the battery, and means which displays the measured results of the measuring means. CONSTITUTION:When a control circuit 1 repeats discharging and charging of a battery 7 a plurality of times, a charge circuit 2 starts the charging upon receiving a charge starting signal from the circuit 1 and, upon completing the charging signal to the circuit 3. A discharge circuit 3, on the other hand, starts the discharging upon receiving a discharge starting signal from the circuit 1 and, upon completing the discharging, outputs a discharge completing signal to the circuit 1. A discharging time measuring circuit 4 starts measurement upon receiving a measurement starting signal from the circuit 1 at the time of starting, for example, the third discharging operations, stops the measurement upon receiving a discharge completing signal from the circuit 3, and outputs the measured time, namely, the time required for discharging the battery 7 to a display circuit 5. The circuit 5 displays the measured results of the circuit 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for checking battery life, and more particularly to a device for checking battery life of a secondary battery having a cycle life such as Ni-Cd battery.

[0002]

2. Description of the Related Art Conventionally, for primary batteries such as manganese batteries and alkaline batteries, there is a life confirmation device that utilizes the characteristic that the discharge voltage decreases monotonously as the life approaches. There is no device that confirms the cycle life of a secondary battery such as. Therefore, it is estimated how many times the battery has been charged and discharged based on the date when it was used and the frequency of charging and discharging, and the life is judged, or the operating time (time until the battery runs out) of the device has started to be used. The life was judged based on the fact that it was much shorter than the time when it was sometimes used, and it was significantly lower than when it was first used.

[0003]

Since the above-mentioned conventional battery life confirmation apparatus for a secondary battery is under the control of a person,
There is a problem that the judgment of the life is ambiguous and that the battery must be properly managed to know the life.

Further, there is a problem that a temporarily inactive battery is mistaken for its life because it has been stored for a long period of time without being used.

An object of the present invention is to measure the discharge time at the N-th discharge while repeating discharge → charge a plurality of times so that it can be displayed as a number, and to perform discharge → charge a plurality of times before measurement. Accordingly, it is an object of the present invention to provide a battery life confirmation device that eliminates the above-mentioned drawbacks and correctly measures the cycle life of a secondary battery.

[0006]

The battery life confirmation apparatus of the present invention includes a charging means for charging a battery, a discharging means for discharging the battery, a means for measuring the time required for the discharging, and a display of the measurement result. And a control means for controlling charging and discharging.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram of a battery life confirmation apparatus according to an embodiment of the present invention.

In FIG. 1, the battery life confirmation apparatus of this embodiment comprises a control circuit 1, a charging circuit 2, a discharging circuit 3, a discharging time measuring circuit 4, a display device 5, and a changeover switch 6.
And a battery 7.

Here, the control circuit 1 controls the overall operation of the battery life confirmation apparatus of this embodiment. As the overall operation, when the operator connects the battery 7 and presses the start switch 8, The steps are: discharge → charge → discharge → charge → discharge and measurement → charge. The charging circuit 2 starts charging by the charging start signal from the control circuit 1. At this time, the changeover switch 6 is set so that the charging circuit 2 is connected to the battery 7 by the changeover signal from the control circuit 1. When the charging is completed, the charging circuit 2 outputs a charging completion signal to the control circuit 1. The discharge circuit 3 starts discharging in response to a discharge start signal from the control circuit 1. At this time, the changeover switch 6 is set so that the discharge circuit 3 is connected to the battery 7 by the changeover signal from the control circuit 1. When the discharging is completed, the discharging circuit 3 outputs a discharging completion signal to the control circuit 1. The discharge time measurement circuit 4 starts measurement by the measurement start signal from the control circuit 1 during the third discharge operation. The measurement is stopped by the discharge completion signal from the discharge circuit 3, and the measured time, that is, the time required for discharging is output to the display circuit 5. The display circuit 5 displays the measurement result from the discharge time measuring circuit 4.

Further, the details of each block will be described.

The charging circuit 2 may be a charging circuit of a commonly used charger, for example, a -ΔV charging circuit.

FIG. 2 is a detailed circuit diagram of the discharge circuit 3 of the battery life confirmation apparatus of this embodiment, and FIG. 3 is a detailed circuit diagram of the discharge time measurement circuit 4 of the battery life confirmation apparatus of this embodiment.

In FIG. 2, terminals B1 and B2 are in discharge.
The battery is connected to. The discharge start signal from the control circuit 1 resets the comparator 32, whereby the output of the comparator 32 changes from "L" to "H", and the changeover switch 31 is turned on.

When the changeover switch 31 is turned on, a current flows through the discharge resistor Rd, and the battery is discharged.
The comparator 32 compares the voltage across the discharge resistor Rd, that is, the battery voltage with the voltage of the reference voltage generator 33 set to the cutoff voltage, and when the battery voltage becomes the cutoff voltage, the output is changed from "H". Set to "L". Comparator 32
When the output of is changed from "H" to "L", the changeover switch 31
Turns off and the discharge stops. At the same time, the edge detection circuit 34 detects the falling edge of the comparator 32,
Output the discharge completion signal.

Here, as the discharge resistance, for example, 1c
A resistance value that causes discharge, that is, discharge for 60 minutes is selected.

In FIG. 3, when the measurement start signal is input, the counter 44 is reset, the flip-flop 41 is set, and the output thereof opens the AND gate 43. When the AND gate 43 is opened, the pulse from the transmission circuit 42 that outputs a pulse every minute is sent to the counter 4
It is input to 4 and is counted up. The flip-flop 41 is reset by the discharge completion signal, and at the same time, the AND gate 43 is closed and the count up of the counter 44 is stopped. At this time, the contents of the counter 44 are
It indicates the time (x minutes) from the start to the end of discharge.

The display circuit 5 is a commonly used 7-segment display device, and displays the contents of the counter 44 of the discharge time measuring circuit 4 by numbers. Although the control circuit 1 can be easily assembled by random logic, it may be software controlled by using a microprocessor.

In the above description, the case where discharge → charge is performed for 3 cycles has been described, but the number of times is not limited, and may be, for example, 2 cycles or 4 cycles. Further, the discharge has been described as 1c discharge for about 60 minutes, but the discharge is not limited to this and may be 2c or 3c.

[0020]

As described above, the battery life confirmation apparatus of the present invention measures the discharge time at the time of the third discharge while repeating discharge-> charge three times and displays it by a number. It is possible to know the current discharge time from the discharge time that was about 60 minutes with 1c discharge at the beginning of use,
There is an effect that the life of the battery can be easily determined.

Further, by performing discharge → charge twice before the measurement, there is an effect that the inactivity of the battery due to long-term storage or the like can be removed and the correct life can be judged.

That is, the discharge time is measured at the time of the N-th discharge while the discharge → charge is repeated a plurality of times so that it can be displayed as a numeral. There is an effect that the cycle life of the battery can be accurately measured.

[Brief description of drawings]

FIG. 1 is a block diagram of a battery life confirmation apparatus according to an embodiment of the present invention. In FIG. 1, the battery life confirmation apparatus of the present embodiment is

FIG. 2 is a detailed circuit diagram of a discharge circuit 3 of the battery life confirmation apparatus of this embodiment.

FIG. 3 is a detailed circuit diagram of a discharge time measuring circuit 3 of the battery life confirmation apparatus of this embodiment.

[Explanation of symbols]

 1 Control Circuit 2 Charging Circuit 3 Discharging Circuit 4 Discharge Time Measuring Circuit 5 Display Device 6 Changeover Switch 7 Battery 31 Changeover Switch 32 Comparator 33 Reference Voltage Generating Circuit 34 Edge Detection Circuit 41 F / F 42 Oscillation Circuit 43 AND 44 Counter

Claims (1)

[Claims] 1. A charging means for charging a battery, a discharging means for discharging the battery, a means for measuring a time required for the discharging, a means for displaying the measurement result, and a control for the charging and the discharging. A battery life confirmation device comprising: a control means for performing the operation.