JPH0837734A - Charging system - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a charging system capable of maximally effectively using a charged secondary battery and extending the life of the battery. [Constitution] When the cordless telephone 1 is set in the charger 2 after ending a call or the like, the battery voltage detecting unit 21 on the charger 2 side
The voltage value of the secondary battery 106 of the cordless telephone 1 detected in 9 is compared with the set reference voltage value (3.35V) stored in the RAM 215 in advance, and the voltage of the secondary battery 106 at this time is set to the set reference voltage value ( If the voltage is higher than 3.35V, charging of the secondary battery 106 is prohibited, and the reason why this charging is not performed is displayed on the display unit 209 of the charger 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery.

[0002]

2. Description of the Related Art Recently, as a cordless terminal, a cordless telephone capable of calling a caller from outside to talk is often used. Such a cordless telephone has a practical use of PHP (personal handy phone). Therefore, it is expected that it will become more popular in the future.

By the way, in such a cordless telephone, a battery is used for its power source. As such a battery, a secondary battery that is small and lightweight, has a relatively large capacity, and can be charged any number of times. Is often used.

However, it is known that such a secondary battery has a so-called memory effect, and a charging method in consideration of this memory effect was necessary. here,
The memory effect means that when the secondary battery is charged, if charging is repeated with the battery capacity remaining, it will gradually increase to 10%.
It is a phenomenon that 0% cannot be charged. For example, due to the characteristics of the secondary battery, if the battery is repeatedly used after being used for a while, the habit of not reaching 100% is added.
As a result, the usable time of the battery becomes shorter.

Therefore, conventionally, refresh charging has been used as a measure for removing such a memory effect. This refresh charging is for promoting the recovery of the battery performance by completely charging the remaining battery capacity once and then charging it again.

[0006]

However, even with such refresh charging, discharging / charging is repeated, so that if the refresh charging is performed more than necessary, the life of the battery itself may be shortened.

In particular, when the cordless telephone is used at home or the like, it is often set in the charger when the call is finished. Therefore, the battery is always charged and the charged battery is maximized. I could not use it up,
There has been a problem that the above-mentioned memory effect becomes prominent and the battery life is unnecessarily shortened.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a charging system in which the battery can be used up to the maximum extent and the life of the battery can be extended.

[0009]

According to the present invention, in a charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, a first setting is made in advance. Setting means for setting a reference voltage value and a second set reference voltage value, battery voltage detecting means for detecting the voltage of the secondary battery, and voltage value of the secondary battery detected by the battery voltage detecting means. And comparing means for comparing the first set reference voltage value and the second set reference voltage value set in the setting means, and starting charging of the secondary battery based on the comparison result of the comparing means. And a control means for controlling the stop.

In the present invention, the charging system is
Further, the display means is provided, and the information based on the comparison result is displayed on the display means. Also,
The present invention is a charging system having a cordless terminal that uses a secondary battery and a charger that charges the secondary battery of the cordless terminal, wherein the charger has a first set reference voltage value and a second preset reference voltage value. Setting means for setting a set reference voltage value, battery voltage detecting means for detecting the voltage of the secondary battery, voltage value of the secondary battery detected by the battery voltage detecting means and the setting means Comparing means for comparing the first set reference voltage value and the second set reference voltage value, and control means for controlling start / stop of charging of the secondary battery based on a comparison result of the comparing means. It is composed by.

Further, the present invention is a charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein the cordless terminal has a battery capacity of the secondary battery. And a battery capacity calculation means for calculating a battery capacity calculation means, wherein the charger is configured to set a first setting reference battery capacity value and a second setting reference battery capacity value in advance; Comparing the battery capacity value with the first setting reference battery capacity value and the second setting reference battery capacity value set in the setting means, and the secondary means based on the comparison result of the comparing means. And a control means for controlling the start / stop of charging of the battery.

Further, according to the present invention, the charger is further provided with a display means, and is configured to display information based on the comparison result on the display means. Further, the present invention is a charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein the cordless terminal has a first set reference voltage value and a first set reference voltage value in advance. Setting means for setting the set reference voltage value of 2, the battery voltage detecting means for detecting the voltage of the secondary battery, the voltage value of the secondary battery detected by the battery voltage detecting means and the setting means. Comparison means for comparing the set first set reference voltage value and the set second set reference voltage value, and control for controlling start / stop of charging of the secondary battery based on the comparison result of the comparing means. And means.

Further, according to the present invention, the cordless terminal is further provided with a display means, and is configured to display information based on the comparison result on the display means. Further, in the present invention, the control means starts charging when the comparison means detects that the voltage value of the secondary battery is lower than the first set reference voltage value, and the voltage of the secondary battery is reduced. The charging is stopped when the comparison unit detects that the value is higher than the second set reference voltage value.

In the present invention, the control means starts charging when the comparison means detects that the battery capacity value calculated by the battery capacity calculation means is lower than the first set reference battery capacity. However, when the comparison unit detects that the battery capacity value calculated by the battery capacity calculation unit is higher than the second set reference battery capacity, charging is stopped.

Further, in the present invention, the first set reference voltage value is a voltage value at the time of full charge, and the second set reference voltage value is a voltage of the secondary battery lower than the voltage value. In this case, the voltage value is set so that the memory effect does not occur even if charging is started.

In the present invention, the first set reference voltage value is a battery capacity value at the time of full charge, and the second set reference voltage value is a battery capacity of the secondary battery from the battery capacity value. When the capacity value is small, the battery capacity value is configured so that the memory effect does not occur even if charging is started.

[0017]

As a result, according to the present invention, the cordless terminal using the secondary battery can be connected to the charger for charging the secondary battery. The voltage of the secondary battery is compared with the second set reference voltage value set in the setting means in advance, and if the voltage of the secondary battery is higher than the set reference voltage value, the secondary battery is charged from the comparison result. Since the information based on the comparison result is displayed on the display means of the charger, it is possible to prevent the continuous charging state when the cordless terminal and the charger are connected, and the secondary battery The memory effect can be prevented, and the adverse effect on the battery life due to the memory effect can be eliminated.

Further, according to the present invention, a charger for charging the secondary battery can be connected to the cordless terminal using the secondary battery, and the secondary battery is calculated by the battery capacity calculating means on the cordless terminal side. Calculate the battery capacity, and on the charger side,
The battery capacity data calculated by the battery capacity calculation means of the cordless terminal is taken in, and the taken-in data is compared with the second set reference battery capacity data set in the setting means in advance, and based on the comparison result, Since the charging of the secondary battery is prohibited and the information based on the comparison result is displayed on the display means of the charger, it is possible to prevent the cordless terminal from being constantly charged when the charger is connected, The memory effect of the secondary battery can be prevented, and the adverse effect on the battery life due to the memory effect can be eliminated.

Further, according to the present invention, the charger for charging the secondary battery can be connected to the cordless terminal using the secondary battery, which is detected by the battery voltage detecting means on the cordless terminal side. The voltage of the secondary battery and the second set reference voltage value set in the setting means are compared, and from the comparison result, for example, when the voltage of the secondary battery is higher than the set reference voltage value, the secondary battery is charged. In addition to blocking, the information based on this comparison result is displayed on the display means of the cordless terminal.
When the cordless terminal and the charger are connected, it is possible to prevent the battery from being constantly charged, prevent the memory effect of the secondary battery, and eliminate the adverse effect of the memory effect on the battery life.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a cordless telephone and a charger to which the present invention is applied. In the figure, reference numeral 1 denotes a cordless telephone, which can be set in a charger 2 and is connected to a charging circuit (not shown) of the charger 2 in this set state.

Here, as shown in FIG. 2, the cordless telephone 1 includes a dial input key, a key input section 102 having keys for setting various function modes, an LCD for displaying various messages, etc. on the surface of the telephone body 101. The display unit 103, the transmitter 104, and the receiver 105 are included.

As shown in FIG. 3, the charger 2 also has a telephone holding portion 202 for setting the cordless telephone 1 in an upright state (see FIG. 1) on the charger main body 201. This telephone holding portion 202 Contacts 2031 and 203 for electrically connecting the cordless telephone 1 to a charging circuit (not shown)
2, 2033 are arranged. In addition, the charger body 201
On the front of the, a refresh key 204 for instructing a refresh operation, a charge key 205 for instructing charging, an LED 206 for displaying charging, and an LED 20 for displaying discharging.
7. Display unit 20 such as LCD for displaying various messages
Have nine. In addition, 210 is a power cord for connecting to a commercial power source.

FIG. 4 shows a circuit configuration of such a cordless telephone 1 and a charger 2. In this case, the cordless telephone 1 is provided with a secondary battery 106 as a power source for the telephone body 101. The positive terminal of the secondary battery 106 is connected to the contact 109 and the diode 11
0 through one end of the telephone body 101, the negative terminal is connected to the contact 108, and the telephone body 1
01 is connected to the other end. Further, one end of the telephone body 101 is connected to the contact 107 via the diode 111.

On the other hand, the charger 2 is configured such that a DC power source section 211 is connected to the power cord 210 to generate a predetermined DC power source output from a commercial power source. Then, the contacts 2031 and 2032 described above are connected to the output terminal of the DC power supply unit 211.
And the control circuit 212 and the attachment / detachment detector 21.
3 are connected.

In addition to the refresh key 204, the charge key 205, and the display unit 209 described above, the control circuit 212 includes an R
The OM 214 and the RAM 215 are connected to each other, and the contact 2033 described above is connected to the ROM in advance by key input from the refresh key 204 or the charge key 205.
A predetermined operation according to the control program stored in 214 is executed.

In the attachment / detachment detecting section 213, the cordless telephone 1 is set in the charger 2 as shown in FIG. 1, and the above-mentioned contacts 2031, 2032, 2033 are connected to the contacts 107, 108, 109 on the cordless telephone 1 side. The control circuit 2 detects the output of this connection state.
I am trying to give it to 12.

The RAM 215 stores various message information and voltage values. Here,
In addition to the reason display information and various status display information corresponding to the voltage value of the secondary battery 106 of the cordless telephone 1 when the attachment / detachment detection unit 213 detects the set state of the cordless telephone 1, a set reference voltage value ( For example, 3.35V) and the full charge voltage value (4.3V) are stored.

A switching element 216 is connected between the contacts 2031 and 2033 to connect the contacts 2033 and 2033.
Between 032, the switching element 217 and the resistor 218.
And a battery voltage detection unit 219.
Are connected.

The switching element 216 is used for the secondary battery 10
6 is charged, the switching element 217 is turned on by an instruction from the control circuit 212, and
At the time of discharging, the ON operation is performed according to an instruction from the control circuit 212. The battery voltage detection unit 219 detects the voltage value of the secondary battery 106 of the cordless telephone 1 at this time when the connection state with the cordless telephone 1 is detected by the attachment / detachment detection unit 213. The result is given to the control circuit 212.

Here, a set reference voltage may be set in the battery voltage detection unit 219 and the result of comparison between the set reference voltage value and the detected voltage value may be output to the control circuit 212.

Next, the operation of the embodiment configured as described above will be described with reference to the flow chart shown in FIG. Now, in step 501, as shown in FIG.
Is set in the charger 2 and the contacts 107, 108, 109 of the cordless telephone 1 are connected to the contacts 2031, 2032, 2033 of the charger 2 as shown in FIG. It is detected by the attachment / detachment detection unit 213.

Then, in step 502, the control circuit 21
In accordance with an instruction from 2, the battery voltage detection unit 219 detects the voltage value of the battery 106 of the cordless telephone 1, and gives this detection output to the control circuit 212.

In the control circuit 212, the voltage value of the battery 106 detected by the battery voltage detector 219 in step 503 and the set reference voltage value (3.35 stored in the RAM 215 in advance).
V).

Here, the voltage value of the secondary battery 106 detected by the battery voltage detector 219 is the set reference voltage value (3.35).
V), the control circuit 212 in step 504.
Then, the switching element 216 is turned on and the DC output from the DC power supply unit 211 is supplied to the battery 106 via the switching element 216 to start charging and display the status. In this case, from the RAM 215,
For example, the status display information of "currently charging" as shown in FIG. 6A is read and displayed on the display unit 209 of the charger 2 and the LED 206 for displaying charging is turned on.

In this case, while the secondary battery 106 is being charged, the voltage value of the secondary battery 106 detected by the battery voltage detector 219 and the full charge voltage value (4.3 V) stored in the RAM 215.
Is constantly compared and monitored.

After that, when the voltage value of the battery 106 detected by the battery voltage detection unit 219 reaches the full charge voltage value (4.3 V) stored in the RAM 215, the switching element 216 is turned off in step 505 to charge the battery. At the same time, the status display of the display unit 209 and the lighting of the LED 206 are turned off, and the process ends.

On the other hand, when it is determined in step 503 that the voltage value of the secondary battery 106 detected by the battery voltage detection unit 219 is higher than the set reference voltage value (3.35 V), the process proceeds to step 506 and the reason is displayed. To do. In this case, as a reason display indicating that charging is not performed without starting the charging of the secondary battery 106, for example, a reason corresponding to the value of the detected voltage as shown in FIG. 6B is selected for charging. Display unit 209 of container 2
To be displayed.

At this time, the reason display is whether the detachment of the cordless telephone 1 from the charger 2 is detected by the attachment / detachment detector 213, or the refresh key 204 and the charge key 2 are used.
Display continues until 05 is operated.

In the first embodiment, the reason display according to the detected voltage of the secondary battery 106 is performed only when the voltage of the secondary battery 106 is equal to or higher than the set reference voltage value (3.35V). However, when the cordless telephone 1 is set in the charger 2, the battery capacity (communication time) is calculated based on the voltage value detected by the battery voltage detection unit 219 and displayed in% (time display), or in FIG. It is also possible to display on the display unit 209 of the charger 2 as shown in (b) or (c).

Next, when refresh charging the secondary battery 106, the refresh key 204 of the charger 2 is operated. In this case, by operating the refresh key 204, the switching element 217 is turned on by the control circuit 212, and the secondary battery 106 is discharged via the switching element 217 and the resistor 218. At this time, as shown in FIG. 7, the secondary battery 106 is discharged until the voltage becomes equal to or lower than a predetermined voltage (3.35 V) at which the memory effect is not generated, and after reaching this state, the control circuit 212 turns off the switching element 217. Switching element 216
Is turned on to supply the DC output from the DC power supply unit 211 to the secondary battery 106 via the switching element 216 to start charging. In this case, for example, the state display information of “refresh charging” as shown in FIG. 6D is read from the RAM 215, and the display unit 2 of the charger 2 is read.
09 will be displayed.

When the secondary battery 106 is charged, the charging key 205 of the charger 2 is operated. In this case, by operating the charging key 205, the switching element 216 is turned on by the control circuit 212, and the DC power supply unit 2
The DC output from the battery 11 is supplied to the secondary battery 106 via the switching element 216 to start charging.

Therefore, according to such a first embodiment,
When the cordless telephone 1 is set in the charger 2 after ending a call or the like, the voltage value of the secondary battery 106 of the cordless telephone 1 detected by the battery voltage detection unit 219 on the charger 2 side and the setting reference stored in the RAM 215 in advance. Voltage value (3.35
V), and if the voltage of the secondary battery 106 at this time is higher than the set reference voltage value (3.35 V), the secondary battery 10
Since the charging of No. 6 is blocked and the reason why the charging is not performed is displayed on the display unit 209 of the charger 2, when the cordless telephone is set on the charging stand at the end of the call as in the conventional case, it is always Compared with charging, it is possible to prevent the memory effect of the secondary battery 106 and eliminate the adverse effect on the battery life due to the memory effect.
This allows the battery to be used up to maximum efficiency.
Moreover, since an appropriate reason is displayed according to the state of the secondary battery 106, the user can safely set the cordless telephone 1 in the charger 2 in any state, and the user can perform the next operation as a next operation. Operations such as refresh charging and quick charging can be arbitrarily selected. (Second Embodiment) In the first embodiment, all the means relating to the present invention are provided on the charger 2 side, but some circuits may be provided on the cordless telephone 1 side. In other words, normally, the cordless telephone 1 needs to display the battery capacity or the callable time, so it is natural to detect the battery voltage on the cordless telephone 1 side.

Therefore, in the second embodiment, the following is done. FIG. 8 shows the circuit configuration of the second embodiment, and the same parts as those in FIG. 4 are designated by the same reference numerals. In this case, the resistor 112 is connected in series with the secondary battery 106 of the cordless telephone 1.
Is connected, the voltage of the resistor 112 is detected by the voltage detection unit 113, the detection output of the voltage detection unit 112 is converted into digital data by the AD converter 114, and this digital data is given to the calculation unit 115, and this calculation is performed. The calculation result of the unit 115 is given to the telephone body 101.

In this case, the calculation unit 115 calculates the current value from the digital data and obtains the current consumption amount from this.
Then, the battery capacity corresponding to the current consumption is displayed on the display unit 103 of the cordless telephone 1 (for example,% display).
Here, when the attachment / detachment detection unit 213 of the charger 2 detects the connection state of the cordless telephone 1 and the charger 2, the control circuit 22
No. 0 is adapted to fetch the battery capacity data from the telephone body 117 via the contact 116 on the cordless telephone 1 side and the contact 2034 on the charger 2 side.

On the side of the charger 2, the acquired battery capacity data is compared with the set reference battery capacity value and the fully charged battery capacity value stored in the RAM 215, and the same processing as in the first embodiment is performed.

Even if the cordless telephone 1 is provided with not only the voltage detecting section but also the attachment / detachment detecting section so as to detect the connection state to the charger 2 in the cordless telephone 1, the battery voltage value The battery capacity data or the like may be output to the control circuit 220 of the charger 2.

Therefore, according to such a second embodiment,
In addition to the effects of the first embodiment, on the cordless telephone 1 side,
The voltage detector 113 detects the voltage of the resistor 112, and the calculator 115 calculates the battery capacity according to the amount of current consumption of the resistor 112 based on the detected output, and displays it so that the user can talk while checking the battery capacity. In addition, the battery capacity data is taken in by the control circuit 220 when the attachment / detachment detection unit 213 detects the connection state between the cordless terminal and the charger on the charger 2 side. It is not necessary to detect the battery voltage on the charger 2 side every time the battery is set on the charger 2. (Third Embodiment) In the second embodiment, some circuits of the means relating to the present invention are provided on the cordless telephone side, but all circuits may be provided on the cordless telephone 1 side. That is, in FIG. 4, only the power cord 210 and the DC power supply unit 211 are provided on the charger 2 side, and the other components are all provided on the cordless telephone 1 side.

FIG. 9 shows the circuit configuration of the third embodiment, and the same parts as those in FIG. 4 are designated by the same reference numerals. here,
Refresh key 2 provided on the charger 2 side of FIG.
05, ROM214, RAM215, the display part 209, and the control part 212 are provided in the telephone main body 118.

In this way, when the attachment / detachment detecting section 213 recognizes the connection state of the cordless telephone 1 to the charger 2, the telephone sets the voltage value data of the secondary battery 106 detected by the battery voltage detecting section 219 at this time. The control circuit of the main body 118 fetches the battery capacity corresponding to this level and the available call time indicating how much more call can be made from this voltage level, and displays it on the display unit 103 of the cordless telephone 1.

Here, the voltage value data of the secondary battery 106 detected by the battery voltage detection unit 219 is constantly supplied to the telephone main body 11
The control circuit in 8 may be loaded to display the battery capacity and talk time.

In addition, the voltage of the secondary battery 106 detected by the battery voltage detector 219 and the RAM in the telephone body 118 are stored in advance.
When the voltage value of the secondary battery 106 is higher than the set reference voltage value, this is indicated without charging the secondary battery 106. As a reason display, “not charging” or the like is displayed on the display unit 103 of the cordless telephone 1.

On the other hand, when the voltage of the secondary battery 106 is lower than the set reference voltage value, "insufficient battery" or the like is displayed on the display unit 1 of the cordless telephone 1 as a reason indication of the insufficient battery.
03 is displayed and an alarm sound (battery shortage warning sound) is sounded. Then, the switching element 216 is turned on by the control circuit in the telephone body 118, and the DC output from the DC power supply unit 211 is supplied to the secondary battery 106 via the switching element 216 to start charging. At this time, the fact that charging has started (for example, as shown in FIG.
(A)) is displayed on the display unit 103 of the cordless telephone 1.

Therefore, according to the third embodiment as well, when the cordless telephone is set in the charger at the end of the call, it is possible to prevent the constant charging, so that the memory effect of the secondary battery 106 is prevented. It is possible to eliminate the adverse effect on the battery life due to the memory effect,
This allows the battery to be used up to maximum efficiency. Moreover, since the appropriate reason display and notification are made according to the state of the secondary battery 106, the user can set the cordless telephone 1 in the charger 2 in any state without worry, and the user can An operation such as refresh charging or quick charging can be arbitrarily selected.

The present invention is not limited to the above-described embodiments, but can be modified and implemented as appropriate without departing from the scope of the invention. For example, the means according to the present invention may be distributed in any way between the charger side and the cordless telephone side, and the point is that the present invention can be implemented. In the above-described embodiments, the cordless telephone is described, but it may be a mobile telephone, a pager, an electric razor, etc. In short, the cordless terminal using the secondary battery can be applied to other electronic devices. Further, in the above embodiment, the battery voltage is detected and compared with the set reference voltage value only when the connection state is detected.However, regardless of the connection state, the battery voltage is always compared and monitored. It is possible to deal with and implement spontaneous discharge.

[0055]

As described above, according to the present invention, from the result of comparison between the voltage of the secondary battery detected by the battery voltage detecting means and the preset reference voltage value set in the preset means,
For example, if the voltage of the secondary battery is higher than the set reference voltage value, the charging of the secondary battery is prohibited, and the information based on the comparison result is displayed on the display means of the charger so that the cordless terminal and the charging It is possible to prevent the battery from being constantly charged when it is connected, prevent the memory effect of the secondary battery, and eliminate the adverse effect on the battery life due to the memory effect. be able to. Moreover, because the appropriate reason is displayed according to the state of the secondary battery, the user can set the cordless terminal on the charging stand with peace of mind in any state, and the user can perform refresh charging or Operations such as quick charging can be arbitrarily selected.

Further, according to the present invention, the capacity of the secondary battery is calculated by the battery capacity calculating means on the cordless terminal side,
On the other hand, when the connection state between the cordless terminal and the charger is detected on the charger side, the calculated battery capacity data described above is fetched, and the fetched data is compared with the set reference battery capacity data set in the setting means in advance. The charging of the secondary battery is prohibited based on the comparison result, and the information based on the comparison result is displayed on the display means of the charger, so that the cordless terminal and the charger are connected. It is possible to prevent the battery from being constantly charged, to prevent the memory effect of the secondary battery, and to eliminate the adverse effect on the battery life due to the memory effect, whereby the battery can be used up to the maximum extent. Moreover, because the appropriate reason is displayed according to the state of the secondary battery, the user can set the cordless terminal on the charging stand with peace of mind in any state, and the user can perform refresh charging or Operations such as quick charging can be arbitrarily selected.

Further, according to the present invention, for example, the voltage of the secondary battery is determined based on the comparison result of the voltage of the secondary battery detected by the battery voltage detecting means and the set reference voltage value set in the setting means in advance. If the voltage is higher than the voltage value, charging of the secondary battery is blocked, and information based on this comparison result is displayed on the display means of the cordless terminal. In that case, it is possible to prevent the battery from being constantly charged, to prevent the memory effect of the secondary battery, and to eliminate the adverse effect on the battery life due to the memory effect, whereby the battery can be used up to the maximum extent.

[Brief description of drawings]

FIG. 1 is an external view showing a cordless telephone and a charger used in a first embodiment of the present invention.

FIG. 2 is an external view showing a cordless telephone used in the first embodiment.

FIG. 3 is an external view showing a charger used in the first embodiment.

FIG. 4 is a diagram showing a circuit configuration of a cordless telephone and a charger used in the first embodiment.

FIG. 5 is a flowchart for explaining the operation of the first embodiment.

FIG. 6 is a diagram showing a display example on the display unit of the first embodiment.

FIG. 7 is a diagram for explaining the memory effect of the battery used in the first embodiment.

FIG. 8 is a diagram showing a circuit configuration of a second embodiment of the present invention.

FIG. 9 is a diagram showing a circuit configuration of a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cordless telephone, 101 ... Telephone main body, 102 ... Key input part, 103 ... Display part, 104 ... Transmitting part, 105 ... Ear receiving part, 106 ... Secondary battery, 107, 108, 109 ... Contact point, 110, 111 ... Diode, 112 ... Resistance, 113 ... Voltage detection section, 114 ... AD converter, 115 ... Calculation section, 116 ... Contact, 117 ... Telephone basic body, 118 ... Telephone basic body, 2 ... Charger, 201 ... Charger main body, Reference numeral 202 ... Telephone holding unit, 2031, 2032, 2033, 2034 ... Contact point, 204 ... Refresh key, 205 ... Charging key, 206, 207 ... LED, 209 ... Display unit, 210 ... Power cord, 211 ... DC power supply unit, 212 ... Control circuit, 213 ... Attachment / detachment detection section, 214 ... ROM, 215 ... RAM, 216, 217 ... Switching element, 218 ... Anti, 219 ... Battery voltage detection unit, 220 ... Control circuit.

Claims (11)

[Claims] 1. A charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein a first set reference voltage value and a second set reference voltage are provided in advance. Setting means for setting a value, a battery voltage detecting means for detecting the voltage of the secondary battery, a voltage value of the secondary battery detected by the battery voltage detecting means, and a setting for the setting means. The comparison means for comparing the first set reference voltage value and the second set reference voltage value, and the control means for controlling the start / stop of charging the secondary battery based on the comparison result of the comparison means. Charging system characterized by 2. The charging system according to claim 1, wherein the charging system further includes a display unit, and the information based on the comparison result is displayed on the display unit. 3. A charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein the charger has a first preset reference voltage value and a second preset reference voltage value. Setting reference voltage value of the setting means, a battery voltage detection means for detecting the voltage of the secondary battery, the voltage value of the secondary battery detected by the battery voltage detection means and the setting means Comparing means for comparing the first set reference voltage value and the second set reference voltage value, and control means for controlling start / stop of charging of the secondary battery based on a comparison result of the comparing means. A charging system comprising: 4. A charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein the cordless terminal is a battery for calculating a battery capacity of the secondary battery. And a battery capacity value calculated by the battery capacity calculation means, wherein the charger has a capacity calculation means, and the charger has a setting means for setting a first set reference battery capacity value and a second set reference battery capacity value in advance; And comparing means for comparing the first set reference battery capacity value and the second set reference battery capacity value set in the setting means, and charging start of the secondary battery based on the comparison result of the comparing means. A charging system comprising: a control unit that controls stop. 5. The charging system according to claim 3, wherein the charger is further provided with a display unit, and information based on the comparison result is displayed on the display unit. 6. A charging system having a cordless terminal using a secondary battery and a charger for charging the secondary battery of the cordless terminal, wherein the cordless terminal has a first set reference voltage value and a second preset reference voltage value. Setting reference voltage value of the setting means, a battery voltage detection means for detecting the voltage of the secondary battery, the voltage value of the secondary battery detected by the battery voltage detection means and the setting means Comparing means for comparing the first set reference voltage value and the second set reference voltage value, and control means for controlling start / stop of charging of the secondary battery based on a comparison result of the comparing means. A charging system comprising: 7. The charging system according to claim 6, wherein the cordless terminal further includes a display unit, and information based on the comparison result is displayed on the display unit. 8. The control unit starts charging when the comparison unit detects that the voltage value of the secondary battery is lower than the first set reference voltage value, and the voltage value of the secondary battery is set. 7. The charging system according to claim 1, 3 or 6, wherein charging is stopped when it is detected by the comparison means that is higher than the second set reference voltage value. 9. The control means starts charging when the comparing means detects that the battery capacity value calculated by the battery capacity calculating means is lower than the first set reference battery capacity, and The charging system according to claim 4, wherein charging is stopped when the comparison unit detects that the battery capacity value calculated by the capacity calculation unit is higher than the second set reference battery capacity. 10. The first set reference voltage value is a voltage value at full charge, and the second set reference voltage value is charged when the voltage of the secondary battery is lower than the voltage value. 7. The charging system according to claim 1, 3 or 6, wherein the voltage value is such that a memory effect does not occur even when the charging system is started. 11. The first set reference voltage value is a battery capacity value at the time of full charge, and the second set reference voltage value is
The charging system according to claim 4, wherein when the battery capacity value of the secondary battery is smaller than the battery capacity value, the battery capacity value does not cause a memory effect even if charging is started.