JPH10145982A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a charger for charging an electronic apparatus quickly and conveniently up to such extent as the apparatus can be operated for a while. SOLUTION: When the secondary battery 158 for a portable telephone held in a holder is charged through a constant current charging circuit 153, terminal voltage V of the secondary battery 158 and variation thereof with time dV/dt are measured, respectively, by a voltmeter 154 and a differentiation circuit 155. The terminal voltage is then compared with the charging voltage V0 of the secondary battery 158 and the variation of terminal voltage with time dV/dt is compared with a threshold TH through a comparator 157. Based on these comparison results, a control section 151 controls to stop charging operation of the constant current charging circuit 153.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging apparatus, and more particularly, to a charging power for a portable telephone used for quick charging of a portable telephone, for example, installed in a station, a department store, an accommodation facility or the like. The present invention relates to a charging device incorporated in a vending machine or the like.

[0002]

2. Description of the Related Art At present, various portable electronic devices (for example, portable telephones, electronic organizers, notebook personal computers, etc.) have become widespread. There are various types of secondary batteries included in such devices, and the most commonly used ones are nickel-cadmium (NiCd) batteries and nickel-metal hydride (Ni
-MH) batteries and lithium ion (Li-ION) batteries.

[0003] Such secondary batteries have different charging characteristics according to their types, and therefore, a dedicated charging device is prepared for each secondary battery.

[0004] For example, in a NiCd (NiCd) battery or a nickel hydride (Ni-MH) battery, when the battery is 100% charged or overcharged, the temperature of the battery rapidly rises or the terminal voltage of the battery rapidly changes. Therefore, the charging device is required to incorporate a charge control circuit that fully considers such charging characteristics.

In a lithium ion (Li-ION) battery, charge control is usually performed by a constant current / constant voltage system. Therefore, when a terminal voltage reaches a charge voltage, control for switching from constant current charge to constant voltage charge is performed. Is required. Therefore,
There is a need for a charger that is designed to minimize the detection error of the charging voltage. Further, there is a need for a technology for accurately detecting a 100% state of charge in order to prevent ignition or smoking due to overcharging.

As described above, the charging device for the secondary battery is 100
On the premise of% charging, various charging controls have been proposed to prevent accidents due to overcharging.

[0007]

However, from the standpoint of a user of a portable electronic device, when the secondary battery of the device runs out and needs to be charged, the secondary battery is not necessarily charged 100%. I am not requesting. For example,
When the secondary battery of the mobile phone runs out and the device becomes unusable and needs to be charged while going out, and when it is necessary to make an emergency call, the phone holder can use it for 5 minutes or 10 minutes. If the phone works, it can often meet the needs at that time.

Considering such a case, if 100
Even if% charging cannot be achieved, a device that can easily and rapidly charge the electronic device for a certain period of time to such an extent that the electronic device can be operated is desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional example, and has as its object to provide a charging device which can easily and rapidly charge an electronic device for a certain period of time to the extent that it can operate. Aim.

[0010]

Means for Solving the Problems To achieve the above object, a charging device of the present invention has the following configuration.

That is, holding means for holding an electrical connection with an electrode of a secondary battery, first measuring means for measuring a terminal voltage of the secondary battery, and second measuring means for measuring a time change of the terminal voltage. Means, charging means for rapidly charging the secondary battery, first comparing means for comparing a terminal voltage measured by the first measuring means with a predetermined charging voltage for the secondary battery, and the second measuring means Second comparing means for comparing a time change of the terminal voltage measured by the means with a predetermined threshold value,
Charge control means for controlling the charging operation by the charging means to stop before the secondary battery is fully charged according to the comparison result obtained by the first and second comparison means. It has a charging device. With the above configuration, the present invention measures the terminal voltage of the secondary battery and the time change of the terminal voltage when charging the secondary battery held by the holding unit by the charging unit, and compares the measured terminal voltage with the secondary voltage. The battery is compared with a predetermined charging voltage, and the time change of the measurement terminal voltage is compared with a predetermined threshold. According to the comparison result, the charging operation by the charging means is performed so that the secondary battery is fully charged. Control to stop before.

According to still another aspect of the present invention, holding means for holding an electrical connection with an electrode of a secondary battery, measuring means for measuring a terminal voltage of the secondary battery, and quick charging of the secondary battery. A charging device is provided, comprising: charging means; and charging control means for controlling the charging operation by the charging means to stop before the terminal voltage measured by the measuring means reaches a maximum charging voltage. With the configuration described above, the present invention measures the terminal voltage of the secondary battery when charging the secondary battery held by the holding unit by the charging unit, and charges the battery before the measured terminal voltage reaches the maximum charging voltage. The charging operation by the means is controlled to be stopped. At this time, the charge control means determines that the charge capacity of the secondary battery is about 60 to 9 of its full charge.
It is preferable to control the charging operation to stop at 0%.

Here, a constant current charging circuit for charging with a constant current is used for the charging means, a voltmeter is used for measuring the terminal voltage of the secondary battery, and a differentiating circuit is used for measuring the time change of the terminal voltage. The device can be configured as follows.

Further, a configuration may be employed in which a register for setting a predetermined threshold is provided.

[0015] Further, it is possible to control the charging operation to be stopped when the measuring terminal voltage exceeds a predetermined charging voltage, and it is preferable to use a small value close to "0" as the threshold value.

The secondary batteries include NiCd batteries and Ni batteries.
-MH batteries, Li-ION batteries, etc.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an external perspective view of a charging power vending machine for a portable telephone according to a typical embodiment of the present invention. In this figure, a casing 1 of this charging power vending machine has a box shape, and is self-supporting with four legs 2 provided at the bottom. In the front part of the casing 1, a plurality of charging blocks 3, five in the upper stage and five in the lower stage in this embodiment, a total of ten charging blocks 3, are installed. A coin slot 4 and a coin return lever 5 are provided at a lower right portion of the lower charging block 3, and a coin return port 6 is provided at a lower portion. Note that a bill insertion slot may be provided so that bills can be used.

Each of the charging blocks 3 can be charged by mounting a telephone set of a plurality of types of portable telephones on the market that are compatible with the charging form. On the front surface of the door 7 of the charging block 3, a nameplate 8 indicating the name of a compatible model that can be charged in the block 3 is attached.

The nameplate 8 displays the names of compatible models that can be charged in the block 3. As a result, the device user can find a charge block that can be charged in the model of the telephone being carried by the user.

Further, as shown in FIG. 1, an operation panel 9 is provided on the right side of the door 7 of each charging block 3. The operation panel 9 has a charging block selection switch 10 from above. Door open / close key 11, four charging times (for example, 5
, 10 minutes, 15 minutes, and 30 minutes) are provided. Above the door 7, a charging indicator lamp 14 is provided to indicate whether the charging operation is in the standby state, the charging state, or the charging completion state.

The door 7 is opened and closed with the left edge of the charging block 3 as a fulcrum. When the door 7 is opened, a telephone storage room 16 is provided inside. The key 11 locks and unlocks the door 7 that opens and closes the telephone storage room 16. A charging holder (not shown), which is a telephone mounting holder for mounting a telephone to be charged, is provided at the bottom of the storage room 16. The mobile phone mounted on the charging holder is configured such that two charging terminals provided on the bottom of the telephone can come into contact with electrodes of the holder.

The door opening / closing key 11 and the key 13 provided at the center of the side edge of the door 7 constitute a lock mechanism for locking the door 7.

FIG. 2 is a block diagram showing the configuration of a charging power vending machine (hereinafter referred to as an apparatus) for a portable telephone.

As shown in FIG. 2, this device comprises:
.., 1000 corresponding to each of the 10 charging blocks, a power supply unit 60 for supplying power to the main unit and the charging unit,
And a CPU bus 70 for electrically connecting the main unit and the charging unit to each other.

Therefore, the main unit and the charging unit operate in a master-slave relationship. Also,
The charging unit has two modes, a standby mode and an active mode. Normally, the charging unit is in a standby mode. In the standby mode, power is supplied to only some components, thereby reducing the power consumption of the entire device. Then, only when the charging operation is required, the instruction from the main unit 50
Switch to active mode.

The charging units 100, 200,..., 10
No. 00 basically has a common configuration except that the shape, electrode position, charging voltage, etc. of the holder for attaching the mobile phone are different.

The main unit 50 controls the entire apparatus and performs control related to money transfer management.
A PU 51, a ROM 52 for storing various control programs executed by the CPU 51, a RAM 53 used as a work area for the control programs executed by the CPU 51, a coin receiving unit 54 for temporarily holding coins inserted from the coin slot 4, Coin stocker 54 for stocking input coins
a, a coin discriminator 55 for discriminating the inserted coin, and a change stocker 56 for stocking change coins.

If the coin temporarily stored in the coin receiving unit 54 is determined to be a counterfeit coin or a coin that cannot be accepted (for example, a 1-yen coin, a 5-yen coin, a foreign coin, etc.), When the return lever 5 is turned, the coin is returned to the coin return slot 6. If a change is required by the change calculation described later, the change is discharged to the coin return slot 6.

FIG. 3 is a block diagram showing the configuration of the charging unit 100.

The charging unit 100 executes a charging operation in response to a command from the CPU 51 of the main unit 50 via the CPU bus 70.

As shown in FIG. 3, the charging unit 100
Is a CPU 110 that controls the operation of the entire unit,
ROM 115 for storing various control programs executed by CPU 110, RAM 120 used as a work area for control programs executed by CPU 110, timer (TIMER) 130 for setting charging time, CPU 1
An interface (I / F) 140 for connecting the peripheral device 10 to the following peripheral devices, a quick charger 150 for charging a secondary battery of a mobile phone, a holder 160 for mounting a mobile phone, and a selection instruction from a charging block selection switch 10 are provided. A unit switch (SW) 170 to be transmitted to the CPU 110 via the interface (I / F) 140 and a locking or unlocking operation by the door opening / closing key 11 are sensed, and the sensing result is signaled as a signal via the interface (I / F) 140. CPU 11
0 to the key sensor 180 and the charging time selected and instructed by the selection button 12 to the interface (I / F) 1
Selection switch 19 to be transmitted to CPU 110 via 40
0 and a charge indicator lamp 14 for indicating the state of charge.

The charging indicator lamp 14 has a green LED 14G for lighting green and a yellow LED 1 for lighting yellow.
4Y, equipped with a red LED 14R for lighting red,
The lighting color changes according to the transition of the charging operation.

The (+) electrode 161 which contacts the electrode of the secondary battery of the mobile phone and the (-) electrode 1
62 are provided.

The secondary batteries actually mounted on the mobile phone include, for example, NiCd (NiCd) batteries and Ni-MH.
(Nickel-metal hydride) batteries and Li-ION (lithium ion) batteries.
There are various voltages such as V, 6V, 7.2V. Also, the electrode position of each battery varies according to its type and according to the manufacturer supplying the telephone. Further, the secondary battery is in the form of a battery pack of 3.6 V by connecting, for example, a NiCd (NiCd) battery having a nominal voltage of 1.2 V or a Ni-MH (Ni-MH) battery in three cells in series. It may be attached to a mobile phone. Such a battery pack is provided with a protection circuit, and the discharge voltage is 3.6 V, but the charge voltage is set to be considerably high (for example, 5.5 V) in some cases.

For these reasons, the electrode position and electrode shape of the holder 160, the charging voltage and the charging current of the quick charger 150, and the like are based on the specifications of a secondary battery or a battery pack mounted on a specific mobile phone. Although different for each charging unit so as to conform, the other configurations are common as described above, including the circuit configuration and charging method of the quick charger 150.

FIG. 4 is a block diagram showing a detailed configuration of the quick charger 150. The quick charger 150 can perform charging control according to a constant current method.

As shown in FIG. 4, the quick charger 150
Control unit 151 for controlling charging operation, control unit 151 and CP
An interface (I / F) 152 for inputting and outputting a control signal exchanged with the U110, a constant current charging circuit 153 for charging the secondary battery with a constant current, and measuring a terminal voltage (V) of the secondary battery to be charged. A voltmeter 154, a differentiation circuit (DIFF) 155 for calculating a time change (dV / dt) of the terminal voltage,
A register (REG) 156 for setting a threshold value (TH) used for comparison with the time change of the terminal voltage, and a comparator (CO) for comparing the time change (dV / dt) of the terminal voltage with the threshold value (TH)
MP) 157.

In FIG. 4, reference numeral 158 denotes charging 2
The next battery, CMD is a charge start command signal from CPU 110, TMR is a timer signal from CPU 110, STR is a charge start notification signal to CPU 110, and CMP is CPU 1
10 is a charge completion signal.

The comparator (COMP) 157 calculates dV / dt = T
When H, the value of the comparison result signal (RST) is output as “1”. When dV / dt> TH, the comparison result signal (RST) is output.
Is output as "0". If the value of the timer signal (TMR) is "1", it indicates that the charging time selected by the selection button 12 is ongoing, while if "0", it indicates that the charging time has expired. .

Next, the operation of the apparatus having the above configuration will be described with reference to the charging characteristics of the secondary battery shown in FIGS. 5 to 6 and the flowchart shown in FIG.

First, the charging characteristics of various secondary batteries will be examined.

FIG. 5 is a table showing charging characteristics of alkaline secondary batteries such as a Ni-Cd battery and a Ni-MH battery disclosed in Japanese Patent Application Laid-Open No. 7-313229 having a nominal voltage of 1.2 V (FIG. 5). (A)) and a charging characteristic curve (FIG. 5 (b)).

According to this figure, in the region where the charged amount is close to 0%, the battery voltage (terminal voltage) sharply rises from the cut-off voltage as the charging time elapses, and the charged amount increases with that. The rise of the battery voltage becomes gentle, and the battery voltage of the battery hardly changes with time when the charged amount is around 60%. When the charge amount further increases, the battery voltage increases. When the charge amount exceeds 100%, the battery voltage tends to saturate at a certain value or slightly decrease. The time required for 60% charging is estimated to be about 35 minutes.

FIG. 6 shows that charging control was performed on a Li-ION battery having a nominal voltage of 3.6 V disclosed in Nikkei Electronics November 20, 1995, page 108 using a constant current and constant voltage method. FIG. 9 is a diagram showing charging characteristics in the case.

According to this figure, in the region where the charged amount is close to 0%, the battery voltage (terminal voltage) sharply rises from the final voltage (2.5 to 3.2 V) as the charging time elapses, and at the same time, the charging is started. Although the amount increases, the battery voltage gradually rises gradually, and the timing of switching the charging method from constant current charging to constant voltage charging, that is, the terminal voltage of the battery becomes the charging voltage (4.1 to 4.2 V) It can be seen that the charging capacity has reached about 60% in the state where the voltage change has become small after reaching. The time required for 60% charging is estimated to be about 36 minutes.

From the above examination, whether the Ni-Cd battery, the Ni-MH battery, or the Li-ION battery is intended to achieve approximately 60% charging, the terminal voltage of the battery at the time of charging is determined by the following equation. The time change of the terminal voltage is monitored, and it can be understood that the control should be performed so that the charging is stopped when the voltage value becomes the charging voltage or when the time change becomes small.

In addition, as long as it is intended to achieve about 60% charging, it is not necessary to perform a precise control for preventing this by taking into account the state of ignition or smoking due to heat generation of the secondary battery due to overcharging. Therefore, the configuration of the charging circuit can be simplified.

The quick charger 15 using the above concept
The charge control operation of 0 will be described with reference to the flowchart shown in FIG. Here, it is assumed that the secondary battery is correctly attached to holder 160, and the electrodes of the secondary battery of the mobile phone and the electrodes 161 and 162 of holder 160 are in correct contact. The following control is intended for a battery in which the battery indicator of the mobile phone indicates that the battery has run out and the voltage of the secondary battery has dropped to the cutoff voltage.

First, the control unit 151 controls the interface (I
/ F) 152, in a step S400, the CPU 1
In step S405, the CPU 110 receives a timer signal (TMR) in which the value is set to "1" from the CPU 110.

Next, in step S410, the holder 16
The terminal voltage (V) of the secondary battery attached to the secondary battery 0 is measured as an initial value.
EG) 156 is set to a threshold value (TH). This value is a very small value close to “0”, and a ROM (not shown) of the control unit 151 is determined in advance in consideration of the type of the secondary battery that can be handled by the quick charger 150 and its charging characteristics. Is stored in The ROM also stores the charging voltage (V0) of the secondary battery. Further, step S4
At 20, the control unit 151 issues a charge start signal (STR) to the CPU 110. Note that the CPU 110 receives this signal and turns on the yellow LED 14Y of the charging display lamp 14 indicating that charging is in progress.

Now, the process proceeds to step S425.
The control unit 151 issues an instruction to the constant current charging circuit 153 to start charging the secondary battery with a constant current. Next, in step S430, it is checked whether or not a timer signal (TMR) whose value is set to “0” has been received from CPU 110 (time-out notification). Here, the timer signal (T
If (MR) is received, the process proceeds to step S455 to stop the charging operation. If the signal is not received, the process proceeds to step S435.

In step S435, the terminal voltage (V) of the secondary battery is measured by the voltmeter 154.
At 40, the measured value is the charge voltage (V
Check if it exceeds 0). Here, if V> V0, the process proceeds to step S455 to stop the charging operation. However, if V ≦ V0, the process proceeds to step S445. Then, in step S445, a differentiating circuit (DIF
F) Measure the terminal voltage change over time (dV / dt) at 155,
Further, in step S450, the comparator (COMP) 15
7, the time change (dV / dt) and the register (RE
G) Compare with the threshold (TH) set in 156.

Here, if dV / dt> TH, it is determined that the terminal voltage is still rising and the charging capacity has not reached about 60%, and the process returns to step S425 to perform constant current charging. To continue. On the other hand, dV / dt ≦ T
If it is H, it is determined that there is almost no change in the terminal voltage and the charging capacity has also reached about 60%, and the process proceeds to step S45.
Proceeding to 5, the charging operation by the constant current charging circuit 153 is stopped.

Finally, in step S460, a charging completion signal (CMP) is transmitted to CPU 110, and the charging operation ends. On the other hand, upon receiving this signal, the CPU 110 turns on the green LED 14G indicating that charging is completed.

It should be noted that the completion of charging referred to here means a normal one.
It shows a state of about 60% charge, not a state of 00% charge.

Further, such a device is installed and used in a public place, for example, a station yard, an underground mall, a hotel, a shopping center and the like.

Therefore, according to the above embodiment, the terminal voltage (V) of the secondary battery being charged and its time change (dV / dt) are monitored, and these values are compared with a predetermined value.
The charging operation can be stopped when the charging capacity is about 60% charged. Also, 100% of the secondary batteries are charged
If the battery is such that the terminal voltage has dropped to the cutoff voltage due to discharge, the control unit 15
The charging energy is estimated from the terminal voltage (V) of the secondary battery being charged in 1 and its time change (dV / dt), the charging current of the constant current charging circuit and the charging time, and the charging of the secondary battery being charged is performed. The charging operation may be stopped when the capacity reaches about 60% of the capacity. Further, as described above, the holder 160
The electrode position and shape of the battery, the charging voltage and charging current of the quick charger 150 conform to the standard of a secondary battery or a battery pack attached to a specific mobile phone. And the charging characteristics of the battery pack are determined in advance by experiments, the relationship between the charging voltage and the charging amount is empirically estimated, and in the actual charging operation, only the charging voltage is measured, and the charging voltage before the battery is fully charged That is, the charging operation may be stopped before the charging voltage reaches the maximum charging voltage. In this case, the charging voltage is about 6 times the maximum charging voltage.
It is desirable to stop the charging operation in the range of 0 to 90%.

Thus, the holder of the mobile phone can use the device installed in a public place in a short time even if the battery of the mobile phone carried by the user runs out, even if the battery is not 100% charged. Since a certain amount of power can be replenished, it is possible to cope with a case where a spare battery is not provided and the device needs to be used urgently.

By installing such a device in a large number of places, it is possible to provide a mobile phone user with further convenience.

In the quick charger as described above, the threshold (TH) for monitoring the change over time of the charging voltage (V0), the charging current, and the terminal voltage depends on the type of the secondary battery to be charged. Although it is necessary to set different values, there is an advantage that the basic circuit design can be shared even if the types of secondary batteries to be charged are different.

On the other hand, a charging power vending machine for a mobile phone is required to be compatible with as many types of mobile phones as possible (ie, various types of secondary batteries). The fact that the basic circuit design can be shared also contributes to a reduction in the manufacturing and development costs of a charging power vending machine for a mobile phone.

In the embodiment described above, the electronic device to be charged is a mobile phone, but the present invention is not limited to this. For example, the present invention can be applied to a portable electronic device using a secondary battery as a power source, such as an electronic organizer, a notebook computer, and a portable facsimile.

[0064]

As described above, according to the present invention, when charging the secondary battery held by the holding means by the charging means, the terminal voltage of the secondary battery and the time change of the terminal voltage are measured. The measurement terminal voltage is compared with a predetermined charging voltage of the secondary battery, the time change of the measurement terminal voltage is compared with a predetermined threshold, and the charging operation by the charging means is performed in accordance with the comparison result. Since the secondary battery is stopped before being fully charged, there is an effect that even if it is not possible to achieve 100% charging, the electronic device that operates on the secondary battery can be charged to an extent that it can operate for a certain period of time.

According to still another aspect of the present invention, when charging the secondary battery held by the holding means by the charging means, the terminal voltage of the secondary battery is measured, and the measured terminal voltage is measured before reaching the maximum charging voltage. In addition, since the charging operation by the charging means is controlled to be stopped, there is an effect that even if 100% charging cannot be achieved, the electronic device that operates on the secondary battery can be charged to an extent that it can operate for a certain period of time. Also, 1
Since the battery is not charged at 00%, for example,
There is an advantage that it is not necessary to consider heat generation and ignition of the secondary battery, and the circuit configuration can be simplified.

[0066]

[Brief description of the drawings]

FIG. 1 is an external perspective view of a charging power vending machine for a mobile phone, which is a typical embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a charging power vending machine for a mobile phone.

FIG. 3 is a block diagram showing a configuration of a charging unit 100.

FIG. 4 is a block diagram showing a configuration of a quick charger 150.

FIG. 5 is a diagram showing charging characteristics of a Ni—Cd battery or a Ni—MH battery.

FIG. 6 is a diagram showing charging characteristics of a Li-ION battery.

FIG. 7 is a flowchart illustrating a charging operation of quick charger 150 shown in FIG.

[Explanation of symbols]

 150 Quick charger 151 Control unit 152 Interface (I / F) 153 Constant current charging circuit 154 Voltmeter 155 Differentiating circuit (DIFF) 156 Register (REG) 157 Comparator (COMP) 158 Secondary battery 160 Holder 161, 162 electrode

Claims (13)

[Claims] 1. A holding unit that holds an electrical connection with an electrode of a secondary battery, a first measuring unit that measures a terminal voltage of the secondary battery, and a second measurement that measures a time change of the terminal voltage. Means, a charging means for rapidly charging the secondary battery, a terminal voltage measured by the first measuring means,
First comparing means for comparing a predetermined charging voltage to a secondary battery; second comparing means for comparing a time change of the terminal voltage measured by the second measuring means with a predetermined threshold value; A charging device, comprising: charging control means for controlling the charging operation by the charging means to stop before the secondary battery is fully charged, according to the comparison result obtained by the second comparing means. 2. The charging device according to claim 1, wherein said charging means has a constant current charging circuit for charging with a constant current. 3. The charging device according to claim 1, further comprising a register for setting the predetermined threshold. 4. The charging device according to claim 1, wherein the first measuring means includes a voltmeter, and the second measuring means includes a differentiating circuit. 5. The charging control means according to a comparison result by the first comparing means, controls to stop the charging operation when the measuring terminal voltage exceeds the predetermined charging voltage. The charging device according to claim 1, wherein 6. The second comparing means as the threshold value,
The charging device according to claim 1, wherein a small value close to "0" is used. 7. The secondary battery includes a NiCd battery, a NiCd battery,
The charging device according to claim 1, wherein the charging device includes a MH battery and a Li-ION battery. 8. The charging apparatus according to claim 1, wherein the charging control means controls the charging operation to stop when the charging capacity of the secondary battery is about 60% of the full charge. . 9. A holding unit for holding an electrical connection with an electrode of a secondary battery, a measuring unit for measuring a terminal voltage of the secondary battery, a charging unit for rapidly charging the secondary battery, and the measurement A charging control means for controlling the charging operation by the charging means to stop before the terminal voltage measured by the means reaches the maximum charging voltage. 10. The charging apparatus according to claim 9, wherein said charging means has a constant current charging circuit for charging with a constant current. 11. The charging device according to claim 9, wherein said measuring means includes a voltmeter. 12. The charging method according to claim 9, wherein the charging control means controls the charging operation to be stopped within a range of about 60 to 90% of a maximum charging voltage of the secondary battery. apparatus. 13. The secondary battery includes a NiCd battery, an N
The charging device according to claim 9, comprising an i-MH battery and a Li-ION battery.