JPH0775260A - Charging of built-in storage battery - Google Patents

Abstract

PURPOSE:To prevent memory effect of a storage battery and make operation of a device possible even during the charging time of the battery by perfectly using a built-in storage battery up to the discharged voltage and starting the charging after the perfect discharging. CONSTITUTION:When contact at the mechanical boundaries t1, t2 between a charger 100 and an apparatus 200 is detected by a detector 23 of a charger 100 in the apparatus 200 comprising a storage battery 20, a voltage detector 21 stops (Sw-2) the transmission of alarm generated voltage drop of the storage battery 20 is detected. An output voltage of the storage battery 20 is used up to the perfect discharge voltage as the lower limit which may be used for operation of each circuit of the apparatus 200 through a DC/DC converter 22 and the charging is started after the storage battery 20 is discharged perfectly up to the discharge voltage. Thereby, the memory effect of the storage battery 20 can be prevented and the apparatus 200 can also be operated even during the charging time of the battery 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging system for a storage battery built in a device. Along with the personalization and portability of devices, the number of devices with built-in storage batteries is increasing. In such a device, it is desired that the built-in storage battery be charged so that the operation of the device is not hindered and the life of the storage battery after charging is not shortened.

[0002]

2. Description of the Related Art Conventionally, when a storage battery in the middle of discharging that has not been discharged to the so-called cutoff voltage of the complete discharge voltage of the storage battery is charged, it is automatically discharged to the cutoff voltage and then automatically started to be charged. As a result, it is well known that the so-called memory effect in which the life of the storage battery after charging is shorter than the expected life is suppressed, that is, the usable battery capacity after charging is prevented from decreasing. Further, the storage battery causes a rapid decrease in its remaining capacity when the battery voltage decreases to its full discharge voltage V ₀ , as in the example of the discharge characteristics of the storage battery in FIG. In other words, the voltage V ₁ slightly lower than the constant output voltage before the complete discharge voltage V ₀ in consideration of the damage of device data)
Then, a low battery voltage alarm was issued, and even though the storage battery still had a remaining amount, the connection with the device was disconnected and the use of the device was stopped.

[0003]

This conventional method of charging a storage battery is such that the complete discharge voltage of the storage battery is reached during the discharge period of the storage battery.
The constant output voltage before V ₀ begins to decrease and the voltage V ₁ is slightly decreased, and the battery is recharged. At that time, the device generated an alarm of battery voltage drop and disconnected the connection between the charger and the storage battery, which caused a problem that the device could not be used. Also, if charging is started before this storage battery is not completely discharged, the device can be used immediately, but as mentioned above, due to the memory effect, the life of the storage battery after charging is shortened. The problem arises. It is an object of the present invention to use a device even when it is recharged when the storage battery is discharged to some extent, and to prevent the memory effect that shortens the life of the storage battery after charging from being built into the device. It is to realize the charging method of the storage battery.

[0004]

In order to achieve this object, the basic structure of the present invention is that a device having a built-in storage battery generally boosts the output voltage of the battery to the operating voltage of the device.
Since it has a DC / DC converter, the device will operate without problems even if the battery discharges and the output voltage drops to a certain extent, and the output voltage of the storage battery (20) is A constant current source (10) for charging and the storage battery (20) are detected by detecting a lower limit complete discharge voltage (V ₀ ) of the storage battery capable of operating each circuit of the device through a DC / DC converter (22) for stepping up. ) Off connection with
Charger with voltage detection / control unit (11) that turns on (SW 1)
(100) and a charger presence / absence detector (23) for detecting mechanical contact at a boundary (t _1, t ₂ ) between the charger (100) and the storage battery
A device (200) incorporating the storage battery with a voltage detector (21) that detects a constant discharge voltage (V ₁ ) higher than the complete discharge voltage (V ₀ ) of the output voltage of (20) and generates an alarm. In the device (200), the presence / absence of the charger detector (23)
00) and the mechanical boundary (t _1, t ₂ ) between the device (200) are detected, the voltage detector (21) causes the storage battery (2
Stops the alarm generated when the voltage drop of (0) is detected.
(SW-2), the output voltage of the storage battery (20), through the DC / DC converter (32), to the lower limit complete discharge voltage (V ₀ ) of each circuit of the device (200) operable The storage battery (20) is used and configured to start charging after discharging the storage battery (20) to its complete discharge voltage (V ₀ ).

[0005]

When the operation of the present invention is sequentially followed by the configuration of FIG. 1, conventionally, (a) the storage battery 20 built in the device 200 is discharged and the remaining capacity becomes a constant discharge voltage V ₁ higher than the complete discharge voltage V _0. When the voltage detector 21 detects that the voltage has dropped, an alarm is generated and the device 200 cannot be used. In the present invention, (b) charger
Mechanical boundary between 100 and device 200 containing storage battery 20 t _1,
When the contact of t ₂ is detected by the presence / absence detector 23 of the charger in the device 200, the battery voltage generated by the voltage detector 21 is detected by the detection signal of the presence / absence detector 23 of the charger. The output of the low alarm is stopped when the switch SW-2 is turned off. Therefore, the device 200 can be used. At this time, since the output voltage of the storage battery 20 has not reached the complete discharge voltage V ₀ , the charger 100 does not start charging by the constant current source 10.
(The switch SW-1 of the constant current source 10 controlled by the voltage detection / control unit 11 is not turned on.) Therefore, the device 200 can use the built-in storage battery 20 up to the complete discharge voltage V ₀ . (c) Storage battery 2
When the output voltage of ₀ reaches the full discharge voltage V ₀ , charger 100
Starts charging by the constant current source 10. (Switch SW-1 of constant current source 10 is turned on.) (D) After charging is completed, stop charging. In this way, by using the storage battery 20 up to its full discharge voltage V ₀ , the memory effect of the storage battery 20 can be prevented, and since the alarm transmission is stopped while the charger is connected, The device 200 can be used.

[0006]

FIG. 2 is an explanatory diagram of a charging system for a storage battery built in a device according to a first embodiment of the present invention. As means for mechanically contacting the device 200 and the charger 100, FIG. ),
The presence or absence of the charger 100 is determined by providing a mechanical switch that is turned on when the plug P of the charger 100 is inserted into the receptacle R on the device 200 side. In addition, as shown in Fig.
200, the detection electrodes p _11, p ₁₂ of the charger 100 and the charging electrode p
_21, two sets of electrodes of the p ₂₂ provided, when the charger 100 is in contact with the device 200, by employing a structure in its charger detection electrode p _11, p ₁₂ are short-circuited, whether the battery charger 100 To determine.
3 is a circuit configuration diagram of the second embodiment of the present invention, FIG. 4 is a flowchart of the operation of the second embodiment, (a) the flowchart shows the operation of the charger 100, and (b) the flowchart. The operation of the device 200 is shown. In the second embodiment, the presence / absence of the charger 100 is determined by changing the load on the device 200 side (switching SW 3 from the storage battery 20 side to the resistance R side for a short time and immediately returning to the storage battery 10 side). To do. Charger
On the 100 side, a constant voltage source 10 ₁ and a constant current source 10 ₂ are prepared. First, referring to the flowchart in FIG. 4 (a), switch SW 1 and SW 2 are both turned off to start the operation. To do. SW 3 of the device 200 is on the storage battery 20 side. Then, by the voltage detection controller 11 in the charger 100, the voltage at the charging terminals t _{1 and} t ₂ at the mechanical boundary between the device 200 and the charger 100 is equal to or less than the complete discharge voltage V ₀ (YES). Whether or not (NO), then complete discharge voltage V
_{If it is 0} or less (YES), it is detected whether it is 0v (YES) or not (NO). Then, if it is 0v (YES), SW 3 is a resistor R
Since it is falling to the side, the switch SW 1 is turned on, and the voltage is supplied to _the device 200 via SW 3 by the constant voltage source 10 _{1 .}
Continues for the time indicated by timer # 1. And not 0v (N
O) If, because the storage battery is a less full discharge voltage V _0, when it becomes the start to a constant voltage charging of the battery 20 by turning on the switch SW 2 by the constant current source 10 _2, and charging end. Next equipment
For the operation on the 200 side, refer to the flowchart in (b) of FIG.
W3 is passed from the storage battery 20 side to the resistance R side, and after a certain time by the built-in timer # 2 of the charger presence / absence detector 23, the voltage detector 21
Detects whether the voltage at the charging terminals t _{1 and} t ₂ at the mechanical boundary between the device 200 and the charger 100 is 0v. If it is 0v, it is judged that there is no adapter (charger), and the alarm output switch (SW-4) generated by the voltage detector 21 is turned on.
Set to N. Further, if not non 0 v, because it is supplied with a voltage from the constant voltage source 10 _1, the adapter determines that (charger) There, the switch of the alarm output of the voltage detector 21 (SW-4)
Is turned off, and after a certain period of time by timer # 3, SW3 is returned to the storage battery 20 side. Furthermore, considering that the charger 100 is connected during the operation of the device 200, the above operation is repeated at the cycle of the timer # 4. At this time, the time relation of each timer is (timer # 2) <
(Timer # 1) <(Timer # 2 + Timer # 3) <(Timer # 4). In this way, the charger 100 is a device 200 with a built-in storage battery.
The battery 20 is used up to its full discharge voltage V ₀ . This prevents the so-called memory effect in which the battery capacity decreases after the storage battery 20 is charged, and the alarm output of the device 200 is stopped by SW-4 OFF during the charging period. 200 can be used.

[0007]

As described above, according to the present invention, since the storage battery built in the equipment is used up to its full discharge voltage and the charging is started after the complete discharge, the memory effect of the storage battery is prevented and the battery is The effect that the device can be operated even during the charging period of is obtained.

[Brief description of drawings]

FIG. 1 is a principle diagram showing a basic configuration of a charging system for a storage battery with a built-in device according to the present invention.

FIG. 2 is an explanatory diagram of a charging system for a storage battery with a built-in device according to the first embodiment of the present invention.

FIG. 3 is a circuit configuration diagram of a charging system for a storage battery with a built-in device according to a second embodiment of the present invention.

FIG. 4 is a flowchart of the operations of the charger and the device according to the second embodiment of the present invention.

FIG. 5 is a diagram showing an example of discharge characteristics of a storage battery.

[Explanation of symbols]

10 is a constant current source, 11 is a voltage detector / controller, 100 is a charger,
20 is a storage battery, 21 is a voltage detector, 22 is a DC / DC converter,
23 is a charger presence / absence detector, and 200 is a device with a built-in storage battery.

Claims (1)

[Claims] 1. A charging method for a storage battery built in a device, the storage battery being capable of operating each circuit of the device through a DC / DC converter (22) for boosting an output voltage of the storage battery (20). The lower limit of full discharge voltage (V ₀ ) is detected and the constant current source (1
(0) and the storage battery (20) is turned off (SW 1) is turned on the charger (100) having a voltage detection and control unit (11), the charger (10
0), the presence / absence of a charger (23) that detects mechanical contact at the boundary (t _1, t ₂ ) and the complete discharge voltage (V ₀ ) of the output voltage of the storage battery (20). Is a device (200) with a built-in storage battery having a voltage detector (21) that detects a high constant discharge voltage (V ₁ ) and generates an alarm, and a detector for the presence / absence of a charger in the device (200) When the contact of the mechanical boundary (t _1, t ₂ ) between the charger (100) and the device (200) is detected by (23),
The voltage detector (21) detects the voltage drop of the storage battery (20) and stops the alarm generation (SW-2), and the storage battery (20)
Output voltage of the device through the DC / DC converter (32)
(200) is used up to the lower limit of full discharge voltage (V ₀ ) of each circuit operable, and the storage battery (20) is discharged to the full discharge voltage (V ₀ ) and then charging is started. Storage system built-in battery charging method