JPH0878063A - Charge type secondary battery pack - Google Patents

Abstract

PURPOSE: To discharge a secondary battery forcibly without detaching a charge type secondary type pack from an electronic apparatus by combining the secondary battery, discharging terminals, charging terminals, a reverse current preventive means, and a switching means so as to conduct specified action. CONSTITUTION: When a charge type secondary battery pack 1 is connected to an electronic apparatus, a charging plus terminal 4, a charging minus terminal 5, and a discharge permission signal terminal 8 are inn an open state, so that the base and the emitter of a transistor 9 are at a same potential, and the transistor 9 is in a cutoff state. Even if the charging plus terminal 4 and the charging minus terminal 5 are short-circuited mutually, the discharge from the charging terminals of a secondary battery 2 is prevented. In order to make the discharge from the charging plus terminal 4 and the charging minus terminal 5 possible, the discharge permission signal terminal 8 is to be set to a low level, that is, to be grounded in a state that the charge type secondary battery pack 1 is connected to the electronic apparatus or in a state that the charge type secondary battery pack 1 is left alone. Then, the transistor 9 is set in an on state so that the discharge from the charging plus terminal 4 and the charging minus terminal 5 is made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rechargeable secondary battery pack used in electronic equipment such as portable radios.

[0002]

2. Description of the Related Art Regarding a conventional rechargeable secondary battery pack,
This will be described with reference to FIG. The rechargeable secondary battery pack 1 is
A rechargeable secondary battery 2, a discharge terminal comprising a discharge + terminal 6 and a discharge-terminal 7 for supplying power to an electronic device (for example, a portable wireless device) serving as a load of the secondary battery 2, The secondary battery 2 is composed of a charging positive terminal 4 for charging the secondary battery 2 and a charging negative terminal 5 and a backflow preventing diode 3 for preventing discharge from the charging terminal.

First, the discharge operation of this conventional rechargeable secondary battery pack will be described. Rechargeable secondary battery pack 1
Is mechanically fixed to an electronic device, and a discharge terminal including a discharge + terminal 6 and a discharge-terminal 7 is mechanically and electrically coupled to a power input terminal of the electronic device. Secondary battery 2
Supplies power from the discharge terminal to the electronic device via the power input terminal of the electronic device. At this time, the discharge + terminal 6 and the discharge − terminal 7 are structured so that they cannot be contacted from the outside, and the discharge + terminal 6 and the discharge − terminal 7 are short-circuited due to the carelessness of the operator. Are prevented.

Next, the charging operation of the rechargeable secondary battery pack when charging the secondary battery will be described. The rechargeable secondary battery pack 1 is charged separately from the discharge terminal so that the rechargeable secondary battery pack 1 can be charged both when it is fixed to the electronic device and when it is only the rechargeable secondary battery pack 1. And a charging terminal composed of the charging-terminal 5 is provided. By connecting the rechargeable secondary battery pack 1 to the charger, a charging current is supplied from the charging terminal to charge the secondary battery 2. The positive terminal 4 for charging and the negative terminal 5 for charging are exposed to the outside even when the rechargeable secondary battery pack 1 is fixed to the electronic device. A diode 3 for preventing backflow is inserted between the positive terminal 4 for charging and the secondary battery 2 because a short circuit may occur due to caution.

In the rechargeable secondary battery pack 1 configured as described above, when the secondary battery 2 is charged without using electronic equipment until the secondary battery 2 is completely discharged, that is, when shallow charging / discharging is recovered, the secondary battery 2 is charged. The battery capacity apparently decreases. Such a phenomenon is generally known as a memory effect of a secondary battery. In order to eliminate this memory effect, it is necessary to completely discharge the secondary battery 2 and then fully charge it. Figure 5
In order to completely discharge the conventional rechargeable secondary battery pack 1 shown in FIG. 1, use an electronic device until the secondary battery 2 is completely discharged, or from a charging terminal composed of a positive terminal 4 for charging and a negative terminal 5 for charging. Since it is impossible to discharge the rechargeable secondary battery pack 1, the rechargeable secondary battery pack 1 is once detached from the electronic device, and the charger is used to forcibly discharge it from the discharge terminal composed of the discharge + terminal 6 and the discharge − terminal 7. It was necessary to prepare a dedicated discharger different from the above.

[0006]

As described above, in the conventional rechargeable secondary battery pack, when the secondary battery is forcibly completely discharged in order to prevent and eliminate the memory effect of the secondary battery. , Had the following problems. Each time the battery needs to be discharged, the rechargeable secondary battery pack must be removed from the electronic device, which is inconvenient. Since it is necessary to prepare a dedicated discharger in addition to the charger, the manufacturer of the charger and the discharger has a restriction that the charger and the discharger cannot be integrated, and the user side costs Also, problems such as an increase in storage space occur.

In view of the above points, the present invention has been made to solve such a problem, and an object of the present invention is to discharge from a charging terminal without removing a rechargeable secondary battery pack from an electronic device. An object of the present invention is to provide a rechargeable secondary battery pack that is capable of housing a charger and a discharger in the same case.

[0008]

In order to achieve the above object, the present invention provides a secondary battery, a discharge terminal for supplying power from the secondary battery to an external load, and the secondary battery described above. In a rechargeable secondary battery pack having a charging terminal for charging a battery from an external charger, a backflow means for preventing backflow of charging current between the secondary battery and the charging terminal, and the backflow prevention means. And a switching unit arranged in parallel with the secondary battery for switching to a dischargeable state from the secondary battery via the charging terminal.

[0009]

Therefore, according to the present invention, the secondary battery of the rechargeable secondary battery pack can be discharged without being removed from the electronic device, and the memory effect can be easily eliminated. Further, since the charger and the discharger can be housed in the same case, it is possible to provide a convenient and inexpensive charger / discharger.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first rechargeable secondary battery pack according to the present invention.
It is a figure which shows the Example of. The discharging operation for supplying power to the electronic device of the rechargeable secondary battery pack and the charging operation for charging the secondary battery are the same as those in the conventional technique shown in FIG. In the rechargeable secondary battery pack 1 shown in FIG. 1, a switching transistor 9 is connected in parallel with a backflow preventing diode 3 inserted between a positive + terminal 4 for charging and a secondary battery 2, and its emitter is The secondary battery 2 is connected, and the collector is connected to the positive terminal 4 for charging. The transistor 9 is biased by the resistors 10 and 11, and the resistor 11 is connected to the discharge permission signal signal terminal 8. The operation of this embodiment will be described in detail below.

When the rechargeable secondary battery pack 1 is connected to an electronic device, the positive terminal 4 for charging, the negative terminal 5 for charging, and the discharge permission signal terminal 8 are open, so that the base and emitter of the transistor 9 are connected. Have the same potential, and the transistor 9 is cut off. That is, for charging + terminal 4
Even if the terminal 5 for charging is short-circuited, discharge from the charging terminal of the secondary battery 2 is prevented. To enable discharging from the positive terminal 4 for charging and the negative terminal 5 for charging, in a state where the rechargeable secondary battery pack 1 is connected to an electronic device or in a state where only the rechargeable secondary battery pack 1 is connected, Discharge enable signal terminal 8 is Lo
At the w level, that is, when grounded, the transistor 9 is turned on, and discharging from the charging + terminal 4 and the charging − terminal 5 becomes possible.

Therefore, like the example of the charger / discharger in which the charger and the discharger shown in FIG. 6 are housed in the same case, the charge + terminal 4, the charge-terminal 5, and the discharge permission signal terminal 8 are charged / discharged. 18 and the secondary battery 2 is connected to the discharger 21, the discharge permission signal terminal 8 is set to the low level, that is, grounded, and conversely, when the secondary battery 2 is connected to the charger 20, discharge is performed. By opening the permission signal terminal 8, it is possible to charge and discharge from the charging + terminal 4 and the charging − terminal 5, and it is also possible to prevent a short circuit of the charging terminal when the electronic device is actually used. Hereinafter, the charging / discharging operation will be described in detail. The secondary battery pack 1 is connected to the charger / discharger 18 in which the charger 20 and the discharger 21 are housed in the same case. When the secondary battery pack 1 is connected, the switch 22 controlled by the controller 19 connects the secondary battery 2 to the discharger 21, and the controller 19 sets the discharge permission signal terminal 8 to Low.
The level, that is, grounding, causes the secondary battery 2 to start discharging. The control unit 19 uses the voltage of the positive terminal 4 for charging,
That is, the voltage of the secondary battery 2 is monitored, and when the discharge end voltage is reached, the switch 22 is controlled to set the secondary battery 2 to the charger 20.
And the discharge permission signal terminal 8 is opened or set to the Hi level to start charging the secondary battery 2.

FIG. 2 shows a second embodiment of the present invention in which the switching transistor in the first embodiment shown in FIG.
The operation is the same as that of the first embodiment shown in FIG. 1 except that the operation is changed to.

FIG. 3 shows a third embodiment of the present invention in which the logic of the discharge permission signal terminal 8 in the first embodiment shown in FIG. 1 is inverted. In the third embodiment of the present invention, in order to invert the logic, a logic inversion transistor 13 is provided between the transistor 9 and the discharge permission signal terminal 8. That is, in the third embodiment, in order to enable discharging from the positive terminal 4 for charging and the negative terminal 5 for charging, the discharge permission signal terminal 8 is set to Hi level to turn on the transistors 13 and 9. Then, it is possible to discharge from the positive terminal 4 for charging and the negative terminal 5 for charging.

FIG. 4 shows a fourth embodiment of the present invention in which discharging can be performed from a charging terminal by a mechanical operation regardless of an electric signal. In the fourth embodiment of the present invention, a switch 16 is connected in parallel with the backflow prevention diode 3 and is normally open. The rechargeable secondary battery pack 1 is provided with a push button 17 for pressing the switch 16, and the control unit 1 in the charger / discharger 18 shown in FIG.
When the push button 17 is mechanically controlled by 9, when the secondary battery 2 is connected to the discharger 21 in the charger / discharger 18, the push button 17 is pushed to charge the + terminal 4 for charging and charge. -The discharge from the terminal 5 becomes possible.

[0016]

As described above, according to the present invention, the secondary battery can be forcibly discharged without removing the rechargeable secondary battery pack from the electronic device. Also,
Since it is possible to discharge from the charging terminal of the rechargeable secondary battery pack, it is possible to house the charger and the discharger for charging and discharging the rechargeable secondary battery pack in the same case, Since it is easy to use and a low-cost system can be constructed, it is effective for use in rechargeable secondary battery packs for all electronic devices.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a rechargeable secondary battery pack of the present invention.

FIG. 2 is a diagram showing a second embodiment of the rechargeable secondary battery pack of the present invention.

FIG. 3 is a diagram showing a third embodiment of the rechargeable secondary battery pack of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the rechargeable secondary battery pack of the present invention.

FIG. 5 is a diagram showing an example of a conventional rechargeable secondary battery pack.

FIG. 6 is a diagram showing an example of charge / discharge of the rechargeable secondary battery pack according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rechargeable secondary battery pack 2 Secondary battery 3 Reverse current prevention diode 4 Charging + terminal 5 Charging − terminal 6 Discharge + terminal 7 Discharging − terminal 8 Discharge permission signal input terminal 9, 13 Transistors 10-11, 14-15 Resistance 12 FET 16 Switch 17 Push Button 18 Charger / Discharger 19 Controller 20 Charger 21 Discharger 22 Switch

Claims (3)

[Claims] 1. A secondary battery, a discharging terminal for supplying power from the secondary battery to an external load, and a charging terminal for charging the secondary battery from an external charger. In a rechargeable secondary battery pack having a backflow prevention means for preventing a backflow of a charging current between the secondary battery and a charging terminal, and the secondary battery arranged in parallel with the backflow prevention means to the charging terminal. A rechargeable secondary battery pack, comprising: a switching unit for switching to a dischargeable state via a battery. 2. The rechargeable secondary battery pack according to claim 1, further comprising a discharge permission signal input terminal to which a discharge permission signal is externally provided, and switching the switching means according to the discharge permission signal. Rechargeable rechargeable battery pack. 3. The rechargeable secondary battery pack according to claim 1, wherein the switching unit is a mechanically switchable switching unit.