JPH08106926A - Battery pack, charging device, and portable electronic appliance - Google Patents

Abstract

PURPOSE: To provide a battery pack, a charging device, and a portable electronic appliance capable of charging in an optimum system according to kinds of batteries. CONSTITUTION: A controller 7 detects the potential difference V between the voltage of a battery detecting terminal 35b installed in a battery pack 31 and the voltage of a positive terminal 35a and discriminates the kind of a battery cell. When the potential difference is (0), the kind of the battery is a nickel hydrogen battery, and a constant current control signal S1 is sent to a charging device 11. When the constant current control signal S1 is supplied, the charging device 11 charges the battery cell through a constant current charging circuit 37. When the potential difference becomes VBAT≈V, the kind of the battery is a lithium battery, the constant current control signal S1 is supplied to the charging device 11, and the battery cell is charged through the constant current charging circuit 37. After that, when voltage between terminals of the battery pack 31 reached around 4.1V, a constant voltage control signal S2 is supplied to the charging device 11, the battery cell is charged through a constant voltage charging circuit 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack including a rechargeable secondary battery, a charging device for charging battery cells of the battery pack, and a portable electronic device including the battery pack and the charging device.

[0002]

2. Description of the Related Art Conventionally, mobile phones, PHSs (Persons)
al Handy Phone System) terminal, PDA (Personal Digi)
portable electronic devices such as tal Assistant) are equipped with batteries so that they can be used after being carried. As the battery, for example, a lithium (Li) battery as a secondary battery,
There are nickel hydrogen (NiMH) batteries, primary batteries, and the like. Lithium batteries, nickel-hydrogen batteries, and the like are often used because they have excellent discharge characteristics and can be recharged. If the primary battery is not in a situation to charge the secondary battery, for example,
Used for emergency. The rechargeable secondary battery is charged by a dedicated charging device according to the type of the battery. For example, in the case of a lithium battery, it is necessary to use a constant current constant voltage charging device, and in the case of a nickel hydrogen battery, it is necessary to use a constant current charging device.

[0003]

By the way, in the conventional battery pack, the type of the battery pack can be visually confirmed by displaying a label or the like, and in the conventional charging device, the charging usually corresponds to only a specific type of battery. Since the system was adopted, there were the following problems. (B) For example, if a lithium-ion battery is incorrectly charged with a nickel-hydrogen battery charger, the lithium battery will be overcharged. If different types of batteries are charged, the battery will be in a dangerous state. . (B) Therefore, there is a problem that a charging device that can be used must be prepared for each type of battery. (C) Further, for this purpose, it is necessary to check the type of the battery one by one and use a charging device suitable for the battery, which is troublesome.

Therefore, an object of the present invention is to provide a battery pack, a charging device and a portable electronic device which can automatically detect the type of a battery and can charge the battery in an optimum method.

[0005]

To achieve the above object, a battery pack according to the invention of claim 1 comprises a plurality of battery cells, an output terminal for outputting a combined output voltage of the plurality of battery cells, and a plurality of the plurality of battery cells. And a battery detection terminal indicating the type of the battery cell. In a preferred embodiment, the battery detection terminal is in a non-connection state or an intermediate cell of a plurality of battery cells or the output terminal according to the types of the plurality of battery cells as described in claim 2, for example. It may be connected to any of the positive electrode terminals.

Further, the battery detection terminal is in a non-connection state when the plurality of battery cells are nickel-metal hydride batteries, and when the plurality of battery cells are primary batteries, for example. May be connected to an intermediate cell of the plurality of battery cells, and may be connected to a positive electrode terminal of the output terminal when the plurality of battery cells are lithium batteries. The charging device according to the invention of claim 4 is a constant voltage charging means for generating a constant charging voltage, a constant current charging means for generating a constant charging current, and a plurality of battery cells forming a battery pack. And a charging control means for switching the constant voltage charging means and the constant current charging means to charge the plurality of battery cells according to the determination result of the battery determining means. It is characterized by

In a preferred embodiment, the battery discriminating means is in a non-connected state or an intermediate cell of the plurality of battery cells, according to the kind of the plurality of battery cells, as described in claim 5, for example. A battery detection terminal connected to one of the positive electrode terminals of the output terminals that output the combined output voltage of the plurality of battery cells, and the type of the plurality of battery cells is determined by the potential difference between the output terminal. Good.

The constant voltage charging means is turned on only when a constant voltage source for generating a constant voltage and a constant voltage control signal are supplied from the charging control means. And a first switch means for supplying the constant voltage generated by the constant voltage source to the output terminal as a charging voltage, and the constant current charging means includes a constant current source for generating a constant current. Second switch means that is turned on only when a constant current control signal is supplied from the charging control means and supplies the constant current generated by the constant current source to the output terminal as a charging current. It may be configured from.

The charging control means may charge the constant current charging means when the plurality of battery cells are nickel-hydrogen batteries, and the plurality of battery cells may be lithium batteries. In this case, the constant current charging means may charge the battery to a predetermined level, and then the constant voltage charging means may charge the battery. Further, the constant voltage charging means detects the voltage of the output terminal, for example, as described in claim 8, and when the voltage exceeds a predetermined value,
You may make it provide the overcharge prevention means which forcibly stops the charge by the said charge control means.

Further, as described in claim 9, for example, a constant voltage charging means for generating a constant charging voltage, a constant current charging means for generating a constant current charging current, a plurality of battery cells, and the plurality of battery cells. An output terminal that outputs a combined output voltage of the battery cells, and a battery detection terminal that indicates the types of the plurality of battery cells, a removable battery pack, the battery detection terminal, and a potential difference between the output terminals. Battery discrimination means for discriminating the types of the plurality of battery cells, and charging control for switching the constant voltage charging means and the constant current charging means in accordance with the discrimination result of the battery discrimination means to charge the plurality of battery cells. Means may be provided.

[0011]

According to the present invention, the type of a plurality of battery cells constituting a battery pack is discriminated by the battery discriminating means, and the plural battery cells are charged with a constant voltage charging means or a constant current according to the discrimination result of the battery discriminating means. Charge by means. Therefore, since the type of the battery cell is discriminated and the battery is charged according to the discrimination result, it is possible to automatically detect the type of the battery and charge the battery in an optimum method.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. A. Configuration of Example A-1. Configuration of PHS Terminal to which Charging Device is Applied FIG. 1 is a PHS to which a charging device according to an embodiment of the present invention is applied.
It is a block diagram which shows the structure of a terminal. In the figure, reference numeral 1 denotes a transmission / reception unit, which includes a frequency conversion unit including a reception unit and a transmission unit, and a modem including a reception unit and a transmission unit. The reception unit of the frequency conversion unit mixes the signal received by the antenna ANT, which is input via the antenna switch for distributing the transmission / reception, with the local oscillation signal of the predetermined frequency output from the PLL synthesizer. Frequency conversion is performed from the 9 GHz band to an IF (intermediate frequency) signal near the 1 MHz band. In addition, the transmission unit of the frequency conversion unit uses a π / 4 shift QP supplied from a modem described later.
By mixing the modulated wave of SK with a local oscillation signal of a predetermined frequency output from the PLL synthesizer, 1.9G
The frequency is converted into the Hz band, and the antenna ANT radiates through the antenna switch. Next, the reception unit of the above-mentioned modem demodulates the IF signal from the frequency conversion unit, separates it into IQ data into a data string, and sends it to the communication control unit 2.
Further, in the transmission section of the modem, IQ data is created from the data supplied from the communication control section 2, and the π / 4 shift QP is generated.
Modulates SK and sends it to the frequency converter of the transceiver 1.

Next, the communication control section 2 is composed of a transmission side and a reception side, and performs frame synchronization and slot data format processing. The receiving side extracts data for one slot from the received data supplied from the modem of the transceiver 1 at a predetermined timing, extracts a unique word (synchronization signal) from this data, and generates a frame synchronization signal. After descrambling the control data section and the audio data section, the control data is sent to the control section 7 and the audio data is sent to the audio processing section 3. Further, the transmitting side adds control data and the like to the audio data supplied from the audio processing unit 3, and also adds unique words and the like after adding scramble and the like,
Transmission data for one slot is created, inserted into a predetermined slot in the frame at a predetermined timing, and transmitted to the modem of the transmission / reception unit 1.

Next, the voice processing unit 3 described above is composed of a speech codec and a PCM codec. The speech codec performs compression / expansion processing of digital data, and is composed of a receiving side and a transmitting side. On the receiving side, the ADPCM audio signal (4 bits × 8 KHz = 32 K) supplied from the communication control unit 2
bps) is a PCM audio signal (8 bits × 8 KHz = 64)
It is decompressed by decoding into Kbps and output to the PSM codec. The transmitting side encodes the PCM audio signal supplied from the PCM codec into an ADPCM audio signal, compresses it, and sends it to the communication control unit 2.
The PCM codec described above performs analog / digital conversion processing, and the receiving side converts the PCM audio signal supplied from the speech codec into an analog audio signal by D / A conversion, and causes the speaker 4 to sound.
On the transmitting side, the analog audio signal input from the microphone 5 is
It is converted to a PCM signal by the / D conversion and sent to the speech codec.

Next, the key input section 6 comprises a numerical keypad for inputting the telephone number of the other party, a switch for on-hook / off-hook, a volume switch for changing the voice output, and the like. The states of these keys and switches are supplied to the control unit 7. Next, the control unit 7 controls the entire device according to a predetermined program. The ROM 8 stores programs executed by the control unit 7 and various parameters. Further, the RAM 9 is used as a working area in which data generated according to the control of the control unit 7 is stored. Next, the display unit 10 is composed of a liquid crystal display for displaying an operation mode, various data and the like, and an LED for indicating ON / OFF of a switch and the like. indicate.

Reference numeral 11 is a charging device, which generates a constant-current charging current from a DC voltage supplied from the outside to charge the battery of the power supply unit 12, and a DC voltage of the constant voltage. A constant voltage charging circuit that generates a charging current to charge the battery of the power supply unit 12 is provided. Charging device 11
Controls the operations of the constant current charging circuit and the constant voltage charging circuit according to the instruction of the control unit 7, and adopts an appropriate charging method according to the type of the battery mounted in the main body. The details of the constant current charging circuit and the constant voltage charging circuit will be described later. The power supply unit 12 has a battery pack and supplies power to each unit. In addition, a detection signal for detecting the type of battery pack is output to the control unit 7.

A-2. External Configuration of PHS Terminal Next, FIG. 2A is a front view showing the external configuration of the PHS terminal described above, and FIG. 2B is a side view of the PHS terminal.
In FIG. 2A, 19 is a liquid crystal display, which displays the operating state, telephone number, call duration, and the like. Then 20
Is a dial button for inputting a ten-key pad, characters, symbols and the like. Reference numeral 21 denotes a call button, and when the call button is pressed, it goes off hook. Reference numeral 22 denotes an off button, which is off-hook by pressing the call button and then on-hook by pressing the off button.
Reference numeral 23 is a transceiver / extension button, which is used when the PHS terminals directly talk with each other. Reference numeral 24 is a response / hold button. Reference numeral 25 denotes various function buttons for calling a telephone directory which is a database of telephone numbers registered in advance, redialing, registering / deleting abbreviated numbers, measuring call duration, and the like. Further, reference numeral 26 is a volume button used for pre-post search in the telephone directory and volume adjustment. Also,
In FIG. 2B, 30 is a power source of the PHS terminal,
And a slide switch for switching between a transceiver and a telephone. Reference numeral 31 is a battery container for accommodating the battery pack mounted in the PHS terminal. Further, in FIGS. 2A and 2B, 32
Is a plug provided at the bottom of the main body and is not shown in the figure.
The plug 33 of the C adapter is connected.

A-3. Configuration of Battery Pack Next, the above-mentioned battery pack 34 will be described. FIG.
3A is an external view showing the external configuration of the battery pack, FIGS. 3B to 3D are views showing the relationship between the battery and each terminal, and FIG. 3B is a nickel-hydrogen battery, FIG. 3 (c) is a primary battery and FIG. 3 (d) is a lithium battery. In FIG. 3A, the battery pack 34 is mounted on the back side of the main body of the PHS terminal, and contains either a nickel hydrogen battery, a primary battery, or a lithium battery. P
On the joint surface with the main body of the HS terminal, the (+) terminal 35 of the battery
a, a battery detection terminal 35b for detecting the battery type of the battery pack, a thermistor terminal 35c for outputting a signal corresponding to the temperature of the battery cell, and a (-) terminal 35d of the battery
Is provided. The circuit configuration of these terminals and the battery is
It depends on the type of battery.

In the case of a nickel hydrogen battery, FIG. 3 (b)
As shown in, the battery detection terminal 35b is in an electrically floating state. Further, in the case of a primary battery, as shown in FIG.
As shown in (c), the battery detection terminal 35b is connected to the (+) side of the intermediate cell that constitutes the battery, so that the intermediate potential of the battery is taken out. Further, in the case of a lithium battery, as shown in FIG.
5b is connected to the (+) terminal 35a of the battery. The battery detection terminal 35b described above, as shown in FIG.
It is connected to the above-mentioned control unit 7 via a resistor R whose one end is grounded. The control unit 7 detects the potential difference V between the voltage supplied through the resistor and the voltage of the (+) terminal 35a, and the battery pack attached to the main body is a nickel hydrogen battery or a primary battery. It is determined whether or not the battery is a lithium battery. That is, in the case of a nickel hydrogen battery, the potential difference V is "0" because the battery detection terminal 35b is electrically floating. On the other hand, in the case of a primary battery, 0 <V <VBAT, and in the case of a lithium battery, VBAT≈V.

A-4. Circuit Configuration of Charging Device Next, FIG. 4 is a circuit diagram showing the configuration of the above-described charging device. In the figure, 32a and 32b are the plugs 3 described above.
It is a terminal of No. 2, and the plug 33 of the AC adapter is fitted therein, and the DC voltage is supplied from the AC adapter. This DC voltage is supplied to the constant current charging circuit 37 via the diode D1.
And to the constant voltage charging circuit 40. Also, terminal 3
7a and 37b are output terminals of the charging device.
The (+) terminal 35 provided on the battery pack 34 described above.
It is adapted to be pressed against the a and (-) terminals 35d.

The constant current charging circuit 37 is for generating a constant current from the DC voltage supplied through the diode D1. The DC voltage is supplied to the collector of the transistor Tr1. The emitter of the transistor Tr1 is connected to the terminal 37a via the resistor RL and the diode D2 which are connected in series. The transistor Tr
The base current of 1 is controlled by the high precision shunt regulator 38. Further, the base of the transistor Tr1 is connected to the collector of the transistor Tr2 whose emitter is grounded via a resistor. The transistor T
The constant current control signal S1 from the controller 7 is supplied to the base of r2. The constant current control signal S1 is for operating the above-mentioned constant current charging circuit 37 and supplying a constant-current charging current to the battery pack 34. When the constant current control signal S1 is supplied, the transistors Tr2 and Tr1 are turned on, the base current of the transistor Tr1 is controlled by the high precision shunt regulator 38, and the direct current voltage from the AC adapter is charged by the constant current. The current I is supplied to the terminal 37a. The charging current I at this time becomes the charging current I = Vref / RL = 2.5 / RL (A) from the reference voltage Vref (= 2.5V) of the high precision shunt regulator 38 and the resistor RL.

Next, the constant voltage charging circuit 40 described above is provided in parallel with the constant current charging circuit 37 and generates a constant voltage from the DC voltage supplied through the diode D1. The transistors Tr3 and Tr4 form a Darlington-connected amplifier circuit. The constant voltage control signal S2 from the control unit 7 is supplied to the base of the transistor Tr3. The collector of the transistor Tr4 is connected to the cathode of the diode D1 while the emitter is connected to the above-mentioned terminal 37a via the diode D3. The diode D
Between the cathode of 1 and the cathode of the diode D3,
The regulator 41 and the FET 42 connected in series are connected. The regulator 41 generates a constant voltage from the DC voltage and outputs it. Further, the FET 42 is turned on when the constant voltage control signal S2 is supplied, and the constant voltage generated by the regulator 41 is applied to the terminal 37a.
To be supplied to Reference numeral 43 denotes an overvoltage detector, which detects a charging voltage so as not to cause overcharge when a lithium battery is charged with a constant voltage, and outputs an overcharge signal S3 to the control unit 7 when overcharge occurs. Supply.

As described above, in the charging device 11 described above,
The constant current charging circuit 37 operates when the constant current control signal S1 is supplied, and the constant voltage charging circuit 40 operates when the constant voltage control signal S2 is supplied.

B. Operation of Embodiment Next, the operation of the above-described embodiment will be described. When the charging voltage of the battery pack 34 becomes equal to or lower than a predetermined value, a display indicating that charging is required is displayed on the liquid crystal display 19, or an alarm sound is emitted. Therefore, as shown in FIG. 2A, the user fits the plug 33 of the AC adapter into the plug 32 provided on the PHS terminal. Plug 33 is plug 32
Then, the control unit 7 firstly detects the potential difference V between the voltage supplied via the resistor R and the voltage of the (+) terminal 35a.
Is detected to determine whether the battery pack attached to the main body is a nickel hydrogen battery, a primary battery, or a lithium battery. Hereinafter, the charging operation will be described for each type of battery of the battery pack 34.

(A) Nickel-hydrogen battery When the potential difference V is "0", the battery is a nickel-hydrogen battery. In this case, the control unit 7 controls the constant current control signal S1.
Is supplied to the charging device 11. In the charger 11, when the constant current control signal S1 is supplied, the transistor Tr
2. The transistor Tr1 is turned on, the base current of the transistor Tr1 is controlled by the high precision shunt regulator 38, and the DC voltage from the AC adapter is supplied to the terminal 37a as the constant charging current I. As a result, the battery of the battery pack 34 is charged with the charging current I. When the charging current I is small (0.2
(less than c), the timer detects the completion of charging, while when the charging current I is large (0.5c or more), the completion of charging is detected by the peak detection by digital data by the A / D converter or the temperature detection.

(B) Lithium Battery On the other hand, when the potential difference V is VBAT≈V, the battery is a lithium battery. In this case, the control unit 7
First, the constant current control signal S1 is supplied to the charging device 11. In the charging device 11, when the constant current control signal S1 is supplied, the transistors Tr2 and Tr1 are turned on, the high-precision shunt regulator 38 controls the base current of the transistor Tr1, and the DC voltage from the AC adapter is constant. The charging current I of the current is supplied to the terminal 37a. As a result, the battery of the battery pack 34 is charged with the charging current I. When the terminal voltage of the battery pack 34 reaches around 4.1V (4.2V according to the characteristics of the lithium battery), the control unit 7 supplies the constant voltage control signal S2 to the charging device 11. In the charging device 11, when the constant voltage control signal S2 is supplied, F
The ET 42 is turned on, and the constant voltage generated by the regulator 41 is supplied to the terminal 37a. As a result, the battery of the battery pack 34 is charged with the constant voltage. Charging is completed by a timer. Further, when the charging voltage becomes higher than the predetermined value and there is a danger of overcharging, the overvoltage signal S3 is supplied from the overvoltage detector 43 to the control unit 7. When the overcharge signal S3 is supplied, the control unit 7 stops the supply of the constant voltage control signal S2 and forcibly ends the charging. The type of the battery pack may be stored when the battery pack is replaced. In this case, the control unit 7 detects the voltage of the terminal 35a of the battery pack and if the battery is fully charged, the type of the battery pack is stored based on the voltage from the terminal 35b.

(C) Primary Battery If the potential difference V is 0 <V <VBAT, the battery is a primary battery. In this case, the charging device does not operate.

[0028]

According to the present invention, a battery detection terminal for determining the type of battery cell is provided, the type of battery cell is determined by the battery detection terminal, and the battery is charged according to the determination result. As a result, the following effects can be obtained. (1) Since the type of battery is automatically determined, it is not necessary to check the type of battery one by one, and charging can be performed with a charging method that matches the battery. (2) Also, since the charging method is automatically selected according to the type of battery, the battery is not in a dangerous state and can be charged under optimal conditions. (3) Therefore, it is not necessary to prepare a charging device for each type of battery, and the cost can be reduced. (4) Further, since the type of battery can be discriminated, detection data matching the type of battery being used can be used in life detection for voltage, and the accuracy of battery life display can be improved.

[Brief description of drawings]

FIG. 1 is a PH to which a charging device according to an embodiment of the present invention is applied.
It is a block diagram which shows the structure of an S terminal.

FIG. 2 is a schematic diagram showing an external configuration of a PHS terminal of this embodiment.

FIG. 3A is a schematic diagram showing the structure of a battery pack used in the PHS terminal of this embodiment, and FIGS. 3B to 3D show the circuit configuration of each battery type incorporated in the battery pack. It is a circuit diagram and (e) is a circuit diagram of an interface between a battery pack and the PHS terminal concerned.

FIG. 4 is a circuit diagram showing a configuration of a charging device according to the present embodiment.

[Explanation of symbols]

 1 Transmitter / Receiver 2 Communication Controller 3 Voice Processor 4 Speaker 5 Microphone 6 Key Input 7 Controller (Battery Discriminating Means, Charging Control Means) 8 ROM 9 RAM 10 Display 11 Charging Device 12 Power Supply 31 Battery Pack 35a (+ ) Terminal (output terminal, positive electrode terminal) 35b battery detection terminal 35c thermistor terminal 35c 35d (-) terminal (output terminal) 37 constant current charging circuit (constant current charging means) 38 high precision shunt regulator (constant current source) Tr1 transistor (transistor) Constant current source) Tr2 Transistor (second switch means) 40 Constant voltage charging circuit (constant voltage charging means) 41 Regulator (constant voltage source) 42 FET (first switch means) 43 Overvoltage detector (overcharge prevention means)

Claims (9)

[Claims] 1. A battery pack comprising: a plurality of battery cells, an output terminal that outputs a combined output voltage of the plurality of battery cells, and a battery detection terminal that indicates types of the plurality of battery cells. . 2. The battery detection terminal is connected to either a non-connected state, an intermediate cell of the plurality of battery cells, or a positive electrode terminal of the output terminal, depending on the types of the plurality of battery cells. The battery pack according to claim 1, wherein: 3. The battery detection terminal is in an unconnected state when the plurality of battery cells are nickel hydrogen batteries, and is an intermediate cell of the plurality of battery cells when the plurality of battery cells are primary batteries. The battery pack according to claim 1, wherein the battery pack is connected to a positive electrode terminal of the output terminal when the plurality of battery cells are lithium batteries. 4. A constant voltage charging means for generating a constant voltage charging voltage, a constant current charging means for generating a constant current charging current, and a battery discriminating means for discriminating the types of a plurality of battery cells constituting a battery pack. And a charging control unit for charging the plurality of battery cells by switching the constant voltage charging unit and the constant current charging unit in accordance with the determination result of the battery determining unit. 5. The output terminal for outputting the combined output voltage of the battery cells, which is in a non-connection state, an intermediate cell of the plurality of battery cells, or the plurality of battery cells, according to types of the plurality of battery cells. The battery charger according to claim 4, wherein the type of the plurality of battery cells is discriminated by a potential difference between a battery detection terminal connected to any one of the positive electrode terminals and the output terminal. 6. The constant voltage charging means is turned on only when a constant voltage source for generating a constant voltage and a constant voltage control signal is supplied from the charging control means, and is generated by the constant voltage source. A constant current source for generating a constant current; and a constant current control from the charge control means. And a second switch means that is turned on only when a signal is supplied and supplies the constant current generated by the constant current source as a charging current to the output terminal. The charging device according to claim 4. 7. The charging control means charges the constant current charging means when the plurality of battery cells are nickel hydrogen batteries, and the constant current charging means when the plurality of battery cells are lithium batteries. 5. The charging device according to item 4, wherein the battery is charged by the constant voltage charging means after being charged to a predetermined level by. 8. The constant voltage charging means comprises an overcharge preventing means for detecting the voltage of the output terminal and forcibly stopping the charging by the charging control means when the voltage exceeds a predetermined voltage. The charging device according to claim 4, wherein: 9. A constant voltage charging means for generating a constant charging voltage, a constant current charging means for generating a constant charging current, a plurality of battery cells, and a combined output voltage of the plurality of battery cells. Output terminal and a battery detection terminal indicating the type of the plurality of battery cells, the battery pack is removable, the type of the plurality of battery cells is determined by the potential difference between the battery detection terminal and the output terminal. And a charge control means for switching the constant voltage charging means and the constant current charging means to charge the plurality of battery cells according to the determination result of the battery determining means. Portable electronic device.