JPH08140276A - I/o terminal structure of secondary battery pack, and i/o terminal structure of its charger - Google Patents

Abstract

PURPOSE: To provide a terminal contact structure of a battery pack which prevents the failure by short circuit of a charge terminal exposed to outside and can be refreshed with a secondary battery. CONSTITUTION: In the i/o terminal circuit structure of a chargeable secondary battery pack, a terminal +Vcc exclusively used for charge, a power voltage supply terminal +V, which supplies portable electronic device with power voltage, and a terminal exclusively used for discharge connected to the refresh circuit for recovery of memory effect of the secondary pack are installed each independently. Out of the above-mentioned three kinds of terminals, at least the terminal exclusively used for discharge is arranged in the position where it is not exposed to outside in a state that the secondary pack is installed in a portable electronic device, and a reverse blocking diode CD for is connected in forward direction between the terminal exclusively used for charge and the secondary battery cell within the secondary battery pack.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input / output terminal circuit structure of a secondary battery pack used in portable electronic equipment such as a mobile phone and a portable radio.

[0002]

2. Description of the Related Art Nickel cadmium (NiCd) is used as a power source for operating a mobile phone, a portable radio device, or the like.
Secondary batteries such as batteries, nickel-hydrogen (Ni-MH) batteries, and lithium-ion (Li-ion) batteries are often used. This is because it has a great advantage when compared with a secondary battery such as a lead-sealed battery in terms of battery capacity, weight, discharge current capacity, ease of charging circuit and the like. In this case, these secondary batteries are often used separately as mold packs, but this is convenient and easy to use because you can prepare multiple spare batteries and replace only the battery pack appropriately. This is because ease is required.

When the secondary battery pack as described above is charged, it is charged using a dedicated charger according to the specifications and characteristics of the type of battery, voltage, discharge capacity, etc. There are two types of charging, one is to charge the battery while it is still attached to the portable wireless device, and the other is to charge the spare battery pack. The charger is equipped with multiple charging slots so that either of them can be used. In many cases. In order to satisfy these functional specifications, it is necessary to consider the signal interface contact (input / output circuit contact) on the battery pack side separately for the charger side and the side of the mobile phone, portable wireless device, etc. The contact of must be provided at a position exposed to the outside when the main body is attached so that charging can be performed in the same manner when the battery pack alone or when the main body is attached. Further, since it is necessary to supply power and signals to the main body, the contact on the main body side needs to be provided on a surface that is in close contact with the main body when the main body is attached, that is, at a position that is not exposed to the outside during attachment.

Next, a brief description will be given of functions and characteristics in the case of charging and discharging by combining a secondary battery and a charger.
When the secondary battery is a nickel-cadmium battery or a nickel-hydrogen battery, when the battery that is not completely discharged to near the discharge end voltage is charged by the charger, the apparent discharge capacity decreases as the number of repetitions increases. An accident
This causes a substantial decrease in battery life. This decrease in discharge capacity is a chemical phenomenon caused by inactivation of the active material of the electrode, and is generally known as a memory effect. In order to reduce this memory effect, it is necessary to repeat charging and discharging at a specified capacity all the time.Therefore, a circuit called a refresh circuit for discharging a battery pack that is not completely discharged is built in the charger. Many. In this method, generally, a mere resistor is used to discharge to the discharge end voltage of the battery, and a switch for starting discharge may be provided in some cases. Normally, this refresh circuit works only for the spare battery pack,
It does not apply to the battery pack attached to the main body. The reason is that the battery pack attached to the main body may use the main body device even during charging, and if the discharge is just completed at this time, the main body cannot be used, which is inconvenient. .

FIG. 3 is a circuit explanatory view showing one configuration of an input / output terminal circuit structure of a conventional secondary battery pack. Each of the terminals shown on the left side of FIG. 3 is a contact for connecting to the charger, and each of the terminals on the right side is a contact for connecting to a mobile phone, a portable wireless device, or the like. In order to simplify the description, a mobile phone will be described as an example of a device (or application) to be attached when the type of the secondary battery pack is a three-element nickel metal hydride battery. Of course, other types of batteries may be used, and it is needless to say that the present invention can be applied to other devices and applications.

In FIG. 3, first, when charging the battery pack, each terminal on the left side of the battery pack 1 is connected to a corresponding terminal of a charger (not shown). Then, when the charger is operated, the charging voltage is applied from the charger between + Vcc and the E terminal, and charging is performed by the constant current method or the like. When the detector in the charger detects that the battery voltage has reached the specified value in this state, it is determined that charging has ended, and the charging operation is stopped. That is, the battery pack 1
Charging is completed. Next, when the battery pack 1 is attached to and used in the mobile phone, the terminals on the right side of the battery pack 1 are connected to the corresponding terminals of the mobile phone (not shown).
Then, the DC power supply voltage of the battery pack 1 is supplied to the mobile phone body from the + Vcc terminal on the right side, and the mobile phone is ready to be driven. As shown in FIG. 3, inside the battery pack 1, the above-mentioned left and right + Vcc terminals are directly connected, and this line is connected to the positive electrode of the internal secondary battery constituent element, that is, the secondary battery (single cell) BAT. Being connected, these terminals are commonly used for both charging and power supply. In addition, E is a ground terminal (negative potential).

Although not directly related to the operation of the embodiment of the present invention described later, other signal contacts provided in the battery pack 1 of FIG. 3 and internal components of the battery pack will be described. First, the TH terminal on the charger side is the output terminal of the thermistor RT arranged between the E (ground) terminal, that is, the ground terminal, and by applying the constant voltage supplied from the charger side, It is used to accurately measure the internal temperature of the pack 1. The operation of this part will be briefly described with reference to FIG. As shown in FIG. 4, a stabilized constant voltage power supply V is provided inside the charger.
And a precision resistor R, which are connected in series and are connected to the TH terminal. When the battery pack 1 is connected to the charger, the thermistor RT is further connected in series from the TH terminal to form a circuit closed loop via the E (ground) terminal. Thermistor RT
Is a temperature sensing element whose resistance changes with temperature,
For example, it is an element that has a first-order inversely proportional characteristic with respect to a change in temperature and whose resistance value decreases as the temperature rises. At this time, if the value of the thermistor RT at a certain temperature Ttemp is RTtemp, the voltage VR generated across the fixed resistor R inside the charger is VR = {V / (R + RTtem
p)} × R, which takes a unique value depending on the temperature. The internal temperature of the battery pack 1 can be measured from this voltage value.

T shown in FIG. 3 is a thermostat, which is a temperature sensing element that opens the circuit when the temperature exceeds a predetermined temperature and closes the circuit again when the temperature drops. Further, the PTC is an element called a poly switch, which is a kind of current breaker element that opens a circuit when a current of a predetermined current value or more flows and closes the circuit again when the current becomes a predetermined current value or less. These RT, T, and PTC elements operate when the battery pack 1 becomes abnormally hot or when an excessive current of a specified value or more flows, and are mounted to ensure the safety of the battery pack 1. It is what BA
T is a single cell of a nickel-hydrogen battery, and in the example of FIG. 3, three secondary batteries BAT are connected in series, so that the battery pack 1 having a nominal voltage of 3.6 V is configured.

Further, a terminal DC provided on both the charger side and the mobile phone side and directly connected internally has a terminal having an accessory function for detecting whether or not the main body of the mobile phone is installed in the charger. Is. The function of this terminal will be briefly described with reference to the overall connection conceptual diagram of FIG. (A) First, when the mobile phone body 2 to which the battery pack 1 is attached is placed on the charger 3, the charging terminal contacts of the charger 3 are connected to the input terminal contacts of the battery pack 1, Charging is done. And DC + 5V in the charger 3
The signal is applied to the base terminal of the transistor in the mobile phone body 2 through the two resistors (4.7 kΩ, 10 kΩ). At this time, the base potential becomes approximately +5 V, and this transistor is turned on. Since the transistor is in the ON state, the charger detection terminal 4 of the telephone control LSI becomes almost 0 V, and it is determined to be logic L, and the telephone is recognized as being placed in the charger 3. (B) Next, when the mobile phone body 2 is taken up from the charger 3 in order to make or receive a call from the telephone (that is, to use the telephone), the base terminal of the transistor and the charger 3
Since the DC (direct current) + 5V signal therein is cut off, the base potential becomes almost 0V and the transistor is turned off. At this time, the charger detection terminal 4 of the telephone control LSI
Is applied to + 3V through a pull-up resistor of 50 kΩ, is determined to be logic H, and the mobile phone body 2 is recognized as being taken up by the charger 3. (C) Since the telephone control LSI constantly monitors the above two recognition states, if the state changes from (a) to (b), the call start button of the telephone is not operated. Can be automatically put in a call. (D) When the state changed from (b) to (a) by the operation opposite to the above (c), that is, when the mobile phone body 2 is placed on the charger 3, press the call end button on the phone. It is possible to end the call without operating. As described above in (a) to (d), the battery pack 1
The functions of the telephone can be significantly expanded by effectively using the two DC terminals that are directly connected to each other.

[0010]

In the conventional input / output terminal circuit structure of the secondary battery pack as described above, the charging terminal + Vcc from the charger and the power supply terminal + Vcc to the telephone side are provided.
, And one of the + Vcc terminals is located on the part exposed to the outside when the battery pack is attached to the mobile phone body so that charging can be performed with the battery pack attached to the mobile phone body. It is essential to do this.
Since this + Vcc terminal is also used as an output terminal to the refresh circuit for recovering the memory effect, the secondary battery (nickel hydrogen battery cell) BA in the battery pack is used.
It is necessary to directly connect with T.

If the conventional battery pack is used in consideration of the above-mentioned preconditions, if the + Vcc terminal and the E terminal on the outside of the mobile phone are accidentally short-circuited by some method. If it happens, there is a risk that an excessive current will flow through the battery, leading to a serious accident such as heat generation, smoke emission, or ignition. Therefore, focusing on measures against such a short circuit, as shown in another conventional example of FIG. 6, a diode CD for preventing backflow is inserted between the + Vcc terminal on the charger side and the secondary battery BAT. In the unlikely event of a short circuit, we have devised measures to prevent excessive current from flowing.
1a is a battery pack having a diode CD inside. However, in that case, there is a problem that a refresh circuit for restoring the memory effect cannot be applied.

[0012]

The input / output terminal circuit structure of a secondary battery pack according to the present invention is removably mounted in a portable electronic device and can be charged in a mounted state or a separated state in the portable electronic device. In a secondary battery pack input / output terminal circuit structure, a dedicated charging terminal, a power supply voltage supply terminal for supplying a power supply voltage to a portable electronic device, and a refresh circuit for recovering the memory effect of the secondary battery pack are connected. The discharge-dedicated terminals are installed independently of each other, and at least the discharge-dedicated terminals among the above-mentioned three types of terminals are arranged at positions not exposed to the outside when the secondary battery pack is mounted on the portable electronic device. The diode for preventing backflow is connected in the forward direction between the terminal dedicated to charging and the secondary battery cell in the secondary battery pack. in this case,
Instead of separately installing the power supply voltage supply terminal and the discharge-dedicated terminal, the discharge-dedicated terminal and the power-supply voltage supply terminal may be commonly used.

The input / output terminal structure of the charger according to the present invention is adapted to be connected to the refresh circuit in the charger when the above-mentioned two types of secondary battery packs are individually charged. It is a thing.

[0014]

In the present invention, the diode is inserted and connected in the forward direction between the charging side terminal of the secondary battery pack and the secondary battery cell in the battery pack, and at the same time, the memory effect of the battery pack is restored. The discharge terminal connected to the refresh circuit is placed in a location that is not exposed to the outside when the battery pack is attached to the portable electronic device, and power is supplied from the secondary battery pack to supply power to the portable electronic device itself. The terminal circuit structure in which the terminals are arranged independently of each other prevents a large current from flowing even if the terminals exposed to the outside of the battery pack, for example, the charging terminal and the ground terminal are short-circuited. Further, the terminal circuit structure described above provides an input / output terminal circuit structure of a secondary battery pack that enables charging while the battery pack is mounted in a portable electronic device and refresh operation of the battery pack alone.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic block diagram showing an embodiment of an input / output terminal circuit structure of a secondary battery pack according to the present invention. In FIG. 1, 11, + V and + V1
Since the other part codes other than the above are the same as the part codes shown in the conventional example of FIG. In the description of the embodiments of the present invention, the type of the battery pack is limited to a nickel hydrogen battery (3 elements, 3.6 V), and the application of the battery pack is limited to a mobile phone. In this case, it goes without saying that the present invention can be applied to other types of battery packs and other uses.

Referring to FIG. 1, first, a case is shown in which the battery pack 11 in which the secondary battery BAT disposed inside is in a state close to that of the battery charging is attached to the body of the mobile phone and the phone is in use. explain. The power supply voltage is supplied from the battery pack 11 to the mobile phone main body through the main phone power supply output terminal + V. In addition, in the present embodiment, in addition to the telephone body power source output terminal + V, another discharge-dedicated terminal + V1 is attached to the mobile telephone body side from the line of the telephone body power source output terminal + V. At this time, even if the charge input terminal + Vcc is erroneously short-circuited, the diode CD inside the battery pack 11 prevents the excessive current from flowing to the outside. Also, the discharge-dedicated terminal + V1 connected to the refresh circuit for restoring the memory effect is not exposed to the outside when the battery pack 11 is attached to the mobile phone body, as described later. , There is no accidental short circuit.

Next, when the battery pack 11 is in a discharged state due to, for example, long-term use and is charged by using the charger 3, etc., the battery pack 11 is constructed through the diode CD by the forward current from the charging input terminal + Vcc. Do 3
The secondary batteries BAT are charged. This is the same whether the battery pack 11 is attached to the mobile phone body 2 or when the battery pack 11 alone is charged.

Further, the operation of the case where a refreshing circuit is applied to recover a single battery pack which has a memory effect and deteriorates in characteristics will be described. As described above, the discharge-dedicated terminal + V1 for discharging the internal secondary battery BAT in the refresh circuit is installed in a place not exposed to the outside when the battery pack 11 is attached to the mobile phone body 2. There is. As described above, it is inconvenient to use the telephone to discharge the battery pack 11 attached to the mobile phone main body 2 as described above. Therefore, the refresh discharge circuit is applied to the secondary battery pack. Limited to a single unit. In the charging slot of the charger 3 for charging a single secondary battery pack,
A receiving-side terminal (not shown) into which the discharge-dedicated terminal + V1 is fitted is arranged and is connected to a refresh discharge circuit (see reference numeral 13 in FIG. 2 described later).

Now, a description will be given of a case where a deteriorated battery pack 11 requiring a refresh operation is inserted into a single battery pack charging slot (not shown) for discharging. Normally, the charge input terminal + Vcc connected to the charge circuit in the charger 3 is disconnected from the charge circuit by operating the refresh start trigger button, and conversely the discharge-dedicated terminal + V1 and the refresh discharge circuit 13 are connected. Then, the discharging operation of the battery pack 11 is started. When the battery pack 11 is discharged and reaches a specified discharge end voltage, a battery voltage detection element (not shown) inside the charger 3 detects this discharge end voltage and disconnects the refresh discharge circuit 13 from the battery pack 11. The discharge is stopped, the charging circuit and the battery pack 11 are connected again, and the battery pack 11 is charged up to a predetermined voltage. The nickel-hydrogen secondary battery B deteriorated by the memory effect due to this charging.
The AT is refreshed and restored to its original performance as a secondary battery before deterioration. The functions of other constituent elements and terminals inside the battery pack, which are not mentioned in the description of the above-mentioned embodiments, are the same as those described in detail in the section of the description of the prior art. The description is omitted.

FIG. 2 is a circuit diagram of a schematic block diagram showing another embodiment of the present invention. In FIG. 1, the partial symbols other than 12 and 13 are the same as the partial symbols shown in the embodiment of FIG. 1, and therefore their explanations are omitted. The embodiment of FIG. 2 is different from the embodiment of FIG. 1 in that it is used only for discharge as shown in FIG. 1 as a connection terminal to the refresh discharge circuit 13 for recovering the performance deterioration of the battery pack 12 due to the memory effect. The terminal + V1 is not provided, and the terminal + V for supplying the power supply voltage to the main body of the mobile phone is also used as the discharge terminal. That is, when the battery pack 12 is inserted into the spare battery pack charging slot of the charger 3, the terminal + V for supplying the power supply voltage to the mobile phone body 2 side is just used as the discharge terminal for recovering the memory effect of the charger 2. Each terminal is formed and arranged so as to be fitted. Therefore, when the battery pack 12 is detached from the mobile phone main body 2 and taken out as a single battery pack 12, the power supply voltage supply terminal + V can be inserted into the charger 3, so that the refreshment is performed via the power supply voltage supply terminal + V. It is adapted to be connected to the discharge circuit 13. Since the charging / discharging and other operations of this embodiment are the same as the operations of the embodiment of FIG. 1, description thereof will be omitted.

As shown in the above embodiments, a charging contact and a discharging contact are separately provided as contacts of the input / output terminal circuit structure of a secondary battery pack used for a mobile phone, and The reverse current prevention diode is connected in series inside the secondary battery pack, and the discharge contacts are not exposed to the outside when the secondary battery pack is attached to the mobile phone. It has become possible to prevent serious accidents such as heat generation, smoke emission, or ignition caused by accidentally short-circuiting the discharge terminal during use. In addition, a refresh circuit for recovering the memory effect can be applied on top of it, as in the conventional secondary battery pack.

[0022]

As described above in detail, according to the present invention, the charging contact is used as the contact of the input / output terminal circuit structure of the secondary battery pack used in various portable electronic devices such as mobile phones and portable radios. And a discharge contact are provided separately, and a backflow prevention diode is connected in series inside the secondary battery pack as seen from the charging contact.The above discharge contact attaches the secondary battery pack to a portable electronic device. In this case, since the structure is not exposed to the outside, it is possible to prevent a serious accident such as heat generation, smoke generation or ignition caused by accidentally short-circuiting the discharge terminal while using a portable electronic device. Was obtained. Further, similarly to the conventional secondary battery pack, the effect that a refresh circuit for recovering the memory effect can be applied can be obtained.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram of a schematic block diagram showing another embodiment of the present invention.

FIG. 3 is a circuit explanatory diagram showing a configuration of an input / output terminal circuit structure of a conventional secondary battery pack.

FIG. 4 is an explanatory diagram of an operation of detecting temperature in a conventional battery pack.

FIG. 5 is a circuit explanatory diagram showing an overall connection concept of an input / output terminal circuit structure of a conventional secondary battery pack.

FIG. 6 is an explanatory view showing another conventional example of the input / output terminal circuit structure of the battery pack with the backflow prevention function.

[Explanation of symbols]

 1, 1a ,. 11, 12 Battery pack 2 Mobile phone body 3 Charger 4 Phone control LSI charger detection terminal 13 Refresh discharge circuit + Vcc charge input terminal E Ground terminal DC charger connection detection terminal TH Battery pack temperature detection terminal + V Phone body power supply output Terminal + V1 Discharge terminal BAT Secondary battery RT Thermistor CD diode T Thermostat PTC Poly switch

Claims (4)

[Claims] 1. A portable electronic device detachably mounted,
In the input / output terminal circuit structure of a secondary battery pack that can be charged in the portable electronic device in a mounted state or a separated state, a dedicated charging terminal, a power supply voltage supply terminal for supplying a power supply voltage to the portable electronic device, and A discharge-dedicated terminal connected to a refresh circuit for recovering the memory effect of the secondary battery pack is independently installed, and at least the discharge-dedicated terminal among the three types of terminals is the secondary battery. When the pack is attached to the portable electronic device, the pack is arranged at a position not exposed to the outside, and a diode for preventing backflow is provided between the charging-only terminal and the secondary battery cell in the secondary battery pack. An input / output terminal circuit structure of a secondary battery pack, which is connected in a forward direction. 2. The input / output terminal of the secondary battery pack according to claim 1, wherein the power supply voltage supply terminal and the discharge-dedicated terminal are common and the discharge-dedicated terminal is also used as the power-supply voltage supply terminal. Circuit structure. 3. The input / output terminal structure of a charger, wherein the discharge-dedicated terminal is connected to a refresh circuit in the charger when the secondary battery pack is charged as a single unit. 4. The input / output terminal structure of a charger, wherein the discharge-dedicated terminal is connected to a refresh circuit in the charger when the secondary battery pack is charged as a single unit.