JP2000060015A - Charge control equipment and method, charge control system and providing medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and surely enable charging of a secondary battery despite irregularities of a protective voltage and a charging voltage. SOLUTION: When the terminal voltage of a secondary battery 3 is higher than a reference voltage VL, a voltage detection circuit 21 outputs a detection signal to a constant voltage control signal generation circuit 22, which generates a constant voltage control signal. When the input voltage (charging voltage) of a charging circuit 1 is higher than a reference voltage VH, a voltage detecting circuit 23 outputs a detection signal to a switch off signal generating circuit 24, which generates a switch off signal. When an input voltage is lower than the reference voltage VL, a control circuit 25 supplies a charging current outputted from a charging circuit 1 as it is, to the secondary battery 3. When the input voltage is higher than the reference voltage VL, the control circuit 25 charges the secondary battery 3 by a constant voltage mode through a built-in constant voltage circuit. When the input voltage becomes higher than the reference voltage VH, charging operation is stopped. When a charging current is cut off, the charging circuit 1 decreases the charging voltage to be outputted slightly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging control device and method, a charging control system, and a providing medium, and more particularly, to charging a secondary battery in three states so that the secondary battery can be reliably charged. The present invention relates to a charging control device and method, a charging control system, and a providing medium.

[0002]

2. Description of the Related Art The present applicant has proposed, for example, Japanese Patent Application Laid-Open No. Hei 7-274404 as a charging device for charging a secondary battery. In this proposal, when the terminal voltage of the secondary battery reaches the protection voltage before full charge, the charge voltage is periodically changed so that even if the protection voltage and the charge voltage vary, it is ensured. To be able to charge.

[0003]

However, the above-mentioned conventional charging device has a problem that the control is complicated because the charging voltage is controlled so as to periodically change.

The present invention has been made in view of such a situation. By charging a secondary battery in three states, the secondary battery can be charged regardless of variations in protection voltage and charging voltage.
It is intended to allow the secondary battery to be charged easily and reliably.

[0005]

According to a first aspect of the present invention, there is provided a charge control device for detecting a voltage of a secondary battery and supplying the charge control device when the voltage of the secondary battery is lower than a first reference voltage. A first charging unit that charges the secondary battery based on the electric power, and a second charging unit that charges the secondary battery with a voltage higher than the first reference voltage and
And a stopping means for stopping the charging when the voltage of the secondary battery is higher than the second reference voltage.

According to a second aspect of the present invention, there is provided a charging control method, comprising: a detecting step of detecting a voltage of a secondary battery; and, when the voltage of the secondary battery is lower than a first reference voltage, based on supplied power. A first charging step of charging the secondary battery; a second charging step of charging at a constant voltage when the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage; Stopping the charging when the voltage of the battery is higher than the second reference voltage.

According to a third aspect of the present invention, there is provided a charge control device for controlling charging of a secondary battery, comprising: a detecting step of detecting a voltage of the secondary battery; and a step of detecting a voltage of the secondary battery from a first reference voltage. When the voltage is small, a first charging step of charging the secondary battery based on the supplied electric power, and when the voltage of the secondary battery is larger than the first reference voltage and smaller than the second reference voltage, the voltage is changed to a constant voltage. A program for executing a process including a second charging step of performing charging and a stopping step of stopping charging when the voltage of the secondary battery is higher than the second reference voltage is provided.

According to a fourth aspect of the present invention, there is provided a charging control device for supplying power for charging a secondary battery, detecting means for detecting a charging current for the secondary battery, and detecting a charging current for the secondary battery. A voltage control unit that changes the voltage for charging the secondary battery output from the supply unit to a smaller value when the voltage becomes lower than the reference value.

According to a fifth aspect of the present invention, there is provided a charging control method for supplying a power for charging a secondary battery, a detecting step for detecting a charging current to the secondary battery, and a charging current to the secondary battery. And a voltage control step of changing the voltage for charging the secondary battery, which is output in the supply step, to a smaller value when the voltage becomes smaller than the reference value.

According to a sixth aspect of the present invention, there is provided a supply medium for supplying a power for charging a secondary battery to a charging control device for controlling charging of the secondary battery, and detecting a charging current to the secondary battery. A detecting step, and a step of outputting in a supplying step when a charging current to the secondary battery becomes smaller than a reference value.
A computer-readable program for executing a process including a voltage control step of changing a voltage for charging a secondary battery to a smaller value is provided.

According to a seventh aspect of the present invention, in the charging control system, the first device includes a voltage detecting means for detecting a voltage of the secondary battery, and when the voltage of the secondary battery is lower than the first reference voltage.
A first charging unit for charging the secondary battery based on the power supplied from the first device, and a constant value when the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage. A second charging unit configured to perform charging with a voltage; and a stopping unit configured to stop charging when a voltage of the secondary battery is higher than a second reference voltage. And a current detecting means for detecting a charging current to the secondary battery, and charging the secondary battery output from the supplying means when the charging current to the secondary battery becomes smaller than a reference value. Voltage control means for changing the voltage to a smaller value.

According to another aspect of the present invention, there is provided a charge control method for the first device, wherein a voltage detection step for detecting a voltage of the secondary battery and a voltage of the secondary battery is smaller than the first reference voltage. A first charging step of charging the secondary battery based on the power supplied from the first device; and a case where the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage. A second charging step of charging at a constant voltage, and a stopping step of stopping charging when the voltage of the secondary battery is higher than a second reference voltage. A supplying step for supplying power for charging the secondary battery, a current detecting step for detecting a charging current to the secondary battery, and a supplying step when the charging current to the secondary battery becomes smaller than a reference value. More voltage to charge the rechargeable battery Characterized in that it comprises a voltage control step of changing the old value.

According to a ninth aspect of the present invention, there is provided a charge control system for charging a secondary battery of a first device from a second device, wherein the first device has a voltage for detecting a voltage of the secondary battery. Detecting, when the voltage of the secondary battery is lower than the first reference voltage, based on the power supplied from the first device,
A first charging step of charging the secondary battery; a second charging step of charging at a constant voltage when the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage; When the voltage of the secondary battery is higher than the second reference voltage,
Performing a process including a stopping step of stopping charging,
A step of supplying power to charge the secondary battery to the second device, a current detecting step of detecting a charging current to the secondary battery, and when the charging current to the secondary battery becomes smaller than a reference value. And a computer-readable program for executing a process including a voltage control step of changing a voltage for charging the secondary battery output in the supply step to a smaller value.

[0014] The charging control device according to claim 1 and claim 2.
In the charge control method described in the above, and the providing medium described in the claim 3, when the voltage of the secondary battery is lower than the first reference voltage, the secondary battery is charged based on the supplied power, and When the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage, charging is performed at a constant voltage,
When the voltage of the secondary battery is higher than the second reference voltage, charging is stopped.

[0015] A charge control device according to claim 4, and claim 5
In the charging control method described in the above, and the providing medium described in the claim 6, when the charging current to the secondary battery becomes smaller than the reference value, the voltage supplied to the secondary battery is controlled to be small. You.

In the charge control system according to claim 7, the charge control method according to claim 8, and the providing medium according to claim 9, in the first device, the voltage of the secondary battery is equal to the first voltage. When the voltage is lower than the reference voltage, the secondary battery is charged based on the power supplied from the second device. When the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage, the voltage is constant. When the voltage of the secondary battery is higher than the second reference voltage, the charging is stopped. Second
In the device described above, when the charging current to the secondary battery becomes smaller than the reference value, the voltage supplied to the secondary battery is controlled to be small.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

According to the first aspect of the present invention, there is provided a charge control device for detecting a voltage of the secondary battery (for example, the voltage detection circuits 21 and 23 in FIG. 1) and a first reference voltage. When it is smaller, the first charging means (for example, the switch 4 in FIG. 2) for charging the secondary battery based on the supplied power.
1) and the voltage of the secondary battery is higher than the first reference voltage,
When the voltage is lower than the second reference voltage, a second charging unit (for example, the constant voltage circuit 43 in FIG. 2) that performs charging at a constant voltage;
Stop means for stopping charging when the voltage of the next battery is higher than the second reference voltage (for example, the switch 42-1 of FIG.
42-2).

According to a fourth aspect of the present invention, there is provided a charging control device for supplying power for charging a secondary battery (for example, a constant current circuit 67 and a constant voltage circuit 68 in FIG. 3), and charging the secondary battery. The detecting means (for example, the current detecting circuit 65 in FIG. 3) for detecting the current, and the voltage for charging the secondary battery output from the supplying means when the charging current to the secondary battery becomes smaller than the reference value, And a voltage control means (for example, the voltage control circuit 70 in FIG. 3) for changing the value to a smaller value.

According to a seventh aspect of the present invention, in the charging control system, the first device includes a voltage detecting means (for example, the voltage detecting circuit 21 and the voltage detecting circuit 2 shown in FIG. 1) for detecting the voltage of the secondary battery.
3) and first charging means (for example, the switch shown in FIG. 2) for charging the secondary battery based on the power supplied from the first device when the voltage of the secondary battery is lower than the first reference voltage. 41) and second charging means for charging at a constant voltage when the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage (for example, the constant voltage circuit 43 in FIG. 2).
And when the voltage of the secondary battery is higher than the second reference voltage,
Stop means for stopping charging (for example, switch 42 in FIG. 2)
-1, 42-2), and the second device includes a supply unit (for example, a constant current circuit 67 and a constant voltage circuit 68 in FIG. 3) for supplying power for charging the secondary battery, and a secondary battery. Current detecting means (for example, the current detecting circuit 65 in FIG. 3) for detecting the charging current to the secondary battery, and charging the secondary battery output from the supplying means when the charging current to the secondary battery becomes smaller than the reference value. Voltage control means (for example, the voltage control circuit 70 in FIG. 3) for changing the voltage to be applied to a smaller value.

One embodiment of the charging control device of the present invention is as follows.
This will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of the charge control device of the present invention. Terminals 11 'and 12' of charging circuit 1 built in a predetermined AC adapter
Are terminals 11 and 12 of a charge control circuit 2 built in an electronic device such as a portable personal computer.
Are connected via the cords 4-1 and 4-2, respectively. The charging current from the charging circuit 1 flows through the path of the terminal 11 ′, the code 4-1, the terminal 11, the control circuit 25, the secondary battery 3, the terminal 12, and the terminal 12 ′. The voltage detection circuit 21 of the charge control circuit 2 detects the terminal voltage of the secondary battery 3, and the voltage detection circuit 23 detects the terminal voltage of the secondary battery 3 via the control circuit 25 (terminals 11 and 12). To detect the charging voltage). In response to these detection results,
The constant voltage control signal generation circuit 22 or the switch OFF signal generation circuit 24 generates a corresponding control signal and supplies it to the control circuit 25.

The control circuit 25 responds to a control signal from the constant voltage control signal generation circuit 22 or the switch OFF signal generation circuit 24 to charge the secondary battery of the charging current supplied from the charging circuit 1 via the terminal 11. 3 is controlled.

FIG. 2 is a block diagram showing a configuration of the control circuit 25 of FIG. The switch 41 performs an ON or OFF operation in response to a control signal from the constant voltage control signal generation circuit 22 or the switch OFF signal generation circuit 24. The switches 42-1 and 42-2 perform an ON or OFF operation in response to a control signal from the constant voltage control signal generation circuit 22. The constant voltage circuit 43 includes a constant voltage control signal generation circuit 22.
The constant voltage control process is executed in response to the control signal from.

FIG. 3 is a block diagram showing a configuration of the charging circuit 1 of FIG. In the power supply circuit 61, an AC voltage supplied via a household power line (not shown) or the like is converted into a DC voltage and output from a terminal 62. The power output from the terminal 62 is further divided into a resistor 64, a PNP transistor 6
6, via the constant current circuit 67 and the constant voltage circuit 68,
The signal is supplied to the charge control circuit 2 from the terminal 11 '. Terminal 1
2 'is connected to the terminal 63 of the power supply circuit 61. The current detection circuit 65 detects a current flowing through the resistor 64 and supplies a detection result to the control circuit 71. Voltage detection circuit 69
Detects the charging voltage output to the charging control circuit 2,
The detection result is supplied to the control circuit 71.

The PNP transistor 66 turns on when a low level signal is input to the base of the PNP transistor 66 from the control circuit 71.
The charging current is output via the constant current circuit 67 and the constant voltage circuit 68. The voltage control circuit 70 is controlled by the control circuit 71 and controls the magnitude of the output voltage (charging voltage) output from the terminals 11 'and 12'.

For example, a code 4 having a length of 1 m to 2 m
1,4-2 has an impedance of 1Ω to 2Ω. Accordingly, the output voltage from the charging circuit 1 drops by that amount until the output voltage reaches the charging control circuit 2, so that the control circuit 71 controls the charging control circuit 2 by this voltage drop.
Output voltage to be set higher in advance.

In addition, the control circuit 71 controls the overall operation of the charging circuit 1 and executes various processes according to a predetermined computer program stored therein.

FIG. 4 is a flowchart illustrating the charging process of the charging control circuit 2. First, in step S1, the control circuit 25 sets the switch OFF signal generation circuit 24
And the input charging voltage between the terminals 11 and 12 (the terminal voltage of the secondary battery 3 via the control circuit 25) is higher than the reference voltage V _H (for example, 4.5 V) (input voltage> V _H ). If the input voltage is not higher than the reference voltage V _H (input voltage ≦ V _H ), the process proceeds to step S2, where the control circuit 25 monitors the output of the constant voltage control signal generation circuit 22 and checks the terminal of the secondary battery 3 The voltage is larger than the reference voltage V _L (for example, 4.2 V) (input voltage>
_VL ). When the terminal voltage of the secondary battery 3 is not higher than the reference voltage _VL (input voltage ≦ _VL ),
Proceeding to step S3, the control circuit 25 turns on the switch 41, turns off the switches 42-1 and 42-2, and
The secondary battery 3 is charged through.

That is, at this time, the charging current output from the charging circuit 1 is supplied to the terminal 11 ', the code 4-1 and the terminal 1
1, switch 41, secondary battery 3, terminal 12, code 4-
2. Flow through the path of the terminal 12 ', and the secondary battery 3 is charged. At this time, of the constant current circuit 67 and the constant voltage circuit 68 of the charging circuit 1, the constant current circuit 67 mainly functions. Such charging is performed in the period T ₁ of the FIG.

As the charging of the secondary battery 3 progresses,
When the terminal voltage of the secondary battery 3 increases and its value becomes higher than the reference voltage _VL , this is detected by the voltage detection circuit 21. At this time, the constant voltage control signal generation circuit 22 outputs a control signal. At this time, from step S2 to step S
Proceeding to 5, the control circuit 25 turns off the switch 41,
The switches 42-1 and 42-2 are turned on, and the constant voltage circuit 4
3 is set to the operating state. As a result, the charging current input from the terminal 11 flows through the path of the switch 42-1, the constant voltage circuit 43, the switch 42-2, the secondary battery 3, and the terminal 12,
The secondary battery 3 is charged by the constant voltage circuit 43 in the constant voltage mode. Such charging is performed in the period T ₂ of the FIG.

Next, in step S6, the control circuit 2
5 monitors the output of the voltage detection circuit 21 and
It is determined whether or not is fully charged. Since the terminal voltage of the secondary battery 3 slightly decreases (decreases by ΔV) in the full charge state, whether or not the battery is fully charged can be detected by detecting this ΔV. If the battery is not fully charged, the process returns to step S1, and the subsequent processes are repeatedly executed.

When the charging of the secondary battery 3 proceeds further,
Of the constant current circuit 67 and the constant voltage circuit 68 of the charging circuit 1,
Instead of the constant current circuit 67, which mainly functioned until then,
The constant voltage circuit 68 mainly functions. When the constant voltage circuit 68 starts functioning, the value of the charging current output from the terminal 11 'gradually decreases as shown in FIG.
However, now, the constant voltage circuit 68 and the constant voltage circuit 43
Therefore, when the charging current is reduced in this state, the value of the voltage drop caused by the impedance components of the codes 4-1 and 4-2 becomes smaller, and the input of the terminal 11 is correspondingly reduced. voltage rises to a value higher than the reference voltage V _H. At this time, the voltage detection circuit 23 outputs a detection signal, and the switch OFF signal generation circuit 24 outputs a switch OFF signal to the control circuit 25 in response to the detection signal. S
In 4, the control circuit 25 controls the switches 42-1, 42
-2 is turned off. If the switch 41 is not turned off, the switch 41 is also turned off at this time. That is, thereby, the charging operation is temporarily stopped, and the charging current is cut off. This operation is performed in the period T ₃ in FIG.

As will be described later, when the charging current is interrupted (when the charging current becomes smaller than a predetermined reference value), the control circuit 71 of the charging circuit 1 controls the voltage control circuit 70 to reduce the output voltage to the previous output voltage. The value is changed to a slightly smaller value (step S28 in FIG. 7 described later). As a result, the terminal 11 ′,
Therefore, drops the input voltage of the terminal 11, at step S1, the input voltage, the determination of the reference voltage V _H is smaller than performed. Since the input voltage is not reduced to a value lower than the reference voltage _VL , in step S2, it is determined that the terminal voltage is higher than the reference voltage _VL ,
Proceeding to step S5, the control circuit 25 switches the switch 4 again.
2-1 and 42-2 are turned on, and the constant voltage circuit 43
In the constant voltage mode, charging of the secondary battery 3 is restarted.

The charging current flowing when charging is resumed is
Because it is still smaller, due to the impedance of the code 4-1 and 4-2, the input voltage rises again terminal 11, it becomes greater than the reference voltage V _H. As a result, the switches 42-1 and 42-2 are turned off again. Therefore, the control circuit 71 of the charging circuit 1 controls the voltage control circuit 70 again to change the output voltage to a slightly smaller value again.

As a result of repeating the above operations, 2
The secondary battery 3 is charged in the switching operation mode in which the charging state and the charging stop state are repeated. As a result, the reference voltage V _H (protection voltage) detected by the voltage detection circuit 23 varies, or the charging circuit 1
There is variation in the rated voltage output from 1 'and 12'
Even when the rated voltage is higher than the protection voltage, the secondary battery 3
Can be reliably protected from overvoltage, and charging can be reliably performed.

If it is determined in step S6 that the battery is fully charged, the control circuit 25 proceeds to step S7,
The switches 42-1 and 42-2 are turned off, and if the switch 41 is still on, this is also turned off and the charging operation is terminated.

That is, in this embodiment, as shown in FIG. 6, the input voltage (terminal voltage) is changed to the reference voltage V _L.
If lower, the electric power supplied from the charging circuit 1 is performed through charging fed directly to the secondary battery 3, when a voltage between the reference voltage V _L and the reference voltage V _H is a constant voltage charging is performed, when greater than the reference voltage V _H is the charging operation is stopped. Thereby, the secondary battery 3 can be protected from a normal abnormal overvoltage. Further, by providing the constant voltage circuit 43 and performing the constant voltage operation in a state where the charging current is small, the charging voltage is increased by using the impedance of the cords 4-1 and 4-2, and the charging is stopped. Then, by repeating the operation of slightly lowering the charging voltage, the secondary battery 3 can be charged by the switching operation naturally (without generating a special waveform for switching charging).

FIG. 7 is a flowchart illustrating the charging process of the charging circuit 1. First, in step S21, the control circuit 71 of the charging circuit 1
6 is turned on, and the charging operation is executed by the constant current circuit 67 and the constant current circuit 68. As described above, when the terminal voltage of the secondary battery 3 is low, the constant current circuit 67 of the constant current circuit 67 and the constant voltage circuit 68 mainly functions to perform charging in the constant current mode. As the terminal voltage of the secondary battery 3 increases as the process proceeds, the constant voltage circuit 68 mainly functions instead of the constant current circuit 67, and charging is performed in the constant voltage mode.

In step S22, the control circuit 71 monitors the output of the current detection circuit 65 and
Output current (charging current) flowing between the emitter and collector
Is larger than the allowable maximum value I _MAX (output current> I _MAX ), that is, whether or not an overcurrent occurs. If it is determined that the output current is an overcurrent, the process proceeds to step S23, where the control circuit 71
6 is turned off to stop charging. Step S
At 24, the control circuit 71 waits until a certain time has elapsed, and after the certain time has elapsed, returns to step S21 and repeats the subsequent processing.

If it is determined in step S22 that the output current is not larger than the allowable maximum value _IMAX (output current ≦ _IMAX ), that is, it is determined that the current is not an overcurrent, the process proceeds to step S25 and the control circuit 71 Is a voltage detection circuit 6
9 is monitored, and it is determined whether the output voltage is larger than the allowable maximum value V _MAX (output voltage> V _MAX ), that is, whether the output voltage is overvoltage. If it is determined that the output voltage is an overvoltage, the process returns to step S23, and the control circuit 71 repeats the subsequent processing. Step S2
In 5, the output voltage is not greater than the allowable maximum value V _MAX (output a voltage ≦ V _{M AX),} i.e., if it is determined not to be over-voltage, the process proceeds to step S26, the control circuit 71, for example, From the output of the voltage detection circuit 69,
It is determined whether the secondary battery 3 has reached a full charge.

If it is determined in step S26 that the battery has not yet reached full charge, the process proceeds to step S27.
The control circuit 71 determines in step S4 in FIG.
By turning off 1, 42-1, 42-2 (by the switching operation), as shown in FIG.
It is determined whether or not the output current has stopped flowing (the output current has become smaller than the reference value). If it is determined that the output current to the secondary battery 3 has stopped flowing, step S2
Proceeding to 8, the control circuit 71 controls the voltage control circuit 70 to lower the output voltage. After the process of step S28 is completed, or when it is determined in step S27 that the output current to the secondary battery 3 is flowing (output current is not 0), the process returns to step S22, and the control circuit 71 returns to step S22. The subsequent processing is repeated.

If it is determined in step S26 that the secondary battery 3 has reached full charge, the control circuit 71 ends the charging process.

The embodiment of FIG. 1 can be modified as shown in FIG. In FIG. 8, the voltage detection circuit 2 of FIG.
Instead of 3, a voltage detection circuit 91 is provided. The voltage detection circuit 91 detects a voltage between both ends of the control circuit 25 and outputs a detection result to the switch OFF signal generation circuit 24. The other configuration is the same as that in FIG. 1 and the description thereof is omitted.

FIG. 9 shows the configuration of the charge control circuit 2 when a lithium ion battery requiring more accurate voltage control is used as the secondary battery 3. In the charging control circuit 2 of FIG. 9, an FET 122 having a parasitic diode 122A is used as the switch 41 of the control circuit 25 of FIG. The FET 122 is connected to the constant voltage circuit 43 or the switch O
Based on the output of the FF signal generation circuit 24, the driving circuit 121
Is driven. Further, in this configuration example, when the overdischarge detection circuit 111 detects the overdischarge voltage (for example, 2.5 V) from the terminal voltage at both ends of the lithium ion battery 101, the detection signal is output to the drive circuit 112. FE having a parasitic diode 113A
T113 is turned off. Other configurations are the same as those in FIG.

In this specification, provided media for providing a user with a computer program for executing the above processing include a recording medium such as a magnetic disk and a CD-ROM,
Transmission media via networks such as the Internet and satellites are also included.

In this specification, the system is
It is assumed that the device as a whole is constituted by a plurality of devices.

[0047]

As described above, according to the charge control device according to the first aspect, the charge control method according to the second aspect, and the providing medium according to the third aspect, the voltage of the secondary battery is reduced to the second level. When less than the reference voltage of 1, based on the supplied power,
When the secondary battery is charged and the voltage of the secondary battery is higher than the first reference voltage and lower than the second reference voltage, charging is performed at a constant voltage, and the voltage of the secondary battery is higher than the second reference voltage. At this time, since the charging is stopped, the secondary battery can be easily and reliably charged regardless of the variation in the protection voltage and the charging voltage.

The charge control device according to claim 4, and claim 5
According to the charging control method described in the above, and the providing medium according to the claim 6, when the charging current is smaller than the reference value,
Since the voltage supplied to the secondary battery was reduced,
The secondary battery can be easily and reliably charged regardless of the variation in the protection voltage and the charging voltage.

According to the charging control system of the seventh aspect, the charging control method of the eighth aspect, and the providing medium of the ninth aspect, in the first device, the voltage of the secondary battery is the second voltage. When the charging current is smaller than the reference value in the second device, the voltage supplied to the secondary battery is reduced when the charging current is smaller than the reference value. The stop state can be automatically repeated, and the secondary battery can be charged simply and reliably regardless of the variation in the protection voltage and the charging voltage.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a charge control device of the present invention.

FIG. 2 is a block diagram showing a configuration of a control circuit 25 of FIG.

FIG. 3 is a block diagram showing a configuration of a charging circuit 1 of FIG.

FIG. 4 is a flowchart illustrating a charging process of a charging control circuit 2 of FIG. 1;

FIG. 5 is a diagram showing a switching operation of a control circuit 25 of FIG. 2;

FIG. 6 is a diagram illustrating three modes of the control circuit 25.

FIG. 7 is a flowchart illustrating a charging process of the charging circuit 1 of FIG. 3;

FIG. 8 is a block diagram showing a configuration of another embodiment of the charge control device of the present invention.

FIG. 9 is a block diagram showing a configuration of still another embodiment of the charge control device of the present invention.

[Explanation of symbols]

1 charging circuit, 2 charging control circuit, 3 secondary battery,
11, 11 ', 12, 12' terminals, 21, 23
Voltage detection circuit, 22 constant voltage control signal generation circuit, 2
4 switch OFF signal generation circuit, 25 control circuit,
41, 42-1, 42-2 switches, 43 constant voltage circuit, 61 power supply circuit, 62, 63 terminals, 64
Resistance, 65 current detection circuit, 66 PNP transistor, 67 constant current circuit, 68 constant voltage circuit, 69
Voltage detection circuit, 70 voltage control circuit, 71 control circuit, 91 voltage detection circuit, 101 lithium ion battery, 111 overdischarge detection circuit, 112, 121
Drive circuit, 113, 122 FET, 113-A, 1
22-A Parasitic diode

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2G016 CA00 CB12 CB31 CC01 CC04 CC23 CC27 CD04 CD06 CD09 2G035 AB02 AB03 AC01 AC18 AD02 AD03 AD04 AD23 AD28 AD47 AD49 5G003 AA01 BA01 CA04 CA14 CC07 GA01 GC05 5H030 AA03 AS18 BB04 FF42 FF42 FF04 FF

Claims (9)

[Claims] 1. A charging control device for controlling charging of a secondary battery, comprising: detecting means for detecting a voltage of the secondary battery; and when the voltage of the secondary battery is lower than a first reference voltage,
A first charging unit that charges the secondary battery based on the supplied power, a voltage of the secondary battery being higher than the first reference voltage,
A second charging unit that performs charging at a constant voltage when the voltage is lower than the second reference voltage; and a stopping unit that stops charging when the voltage of the secondary battery is higher than the second reference voltage. Characteristic charge control device. 2. A charging control method for controlling charging of a secondary battery, comprising: a detecting step of detecting a voltage of the secondary battery; and when the voltage of the secondary battery is lower than a first reference voltage,
A first charging step of charging the secondary battery based on the supplied power, wherein the voltage of the secondary battery is higher than the first reference voltage;
A second charging step of performing charging at a constant voltage when the voltage is lower than the second reference voltage; and a stopping step of stopping charging when the voltage of the secondary battery is higher than the second reference voltage. Characteristic charge control method. 3. A charging control device for controlling charging of a secondary battery, comprising: a detecting step of detecting a voltage of the secondary battery; and when the voltage of the secondary battery is smaller than a first reference voltage,
A first charging step of charging the secondary battery based on the supplied power, wherein the voltage of the secondary battery is higher than the first reference voltage;
A second charging step of performing charging at a constant voltage when the voltage is lower than the second reference voltage; and a stopping step of stopping charging when the voltage of the secondary battery is higher than the second reference voltage. A providing medium for providing a program to be executed. 4. A charging control device for controlling charging of a secondary battery, a supply unit for supplying power for charging the secondary battery, a detecting unit for detecting a charging current to the secondary battery, When the charging current to the secondary battery becomes smaller than a reference value, voltage control means for changing the voltage for charging the secondary battery output from the supply means to a smaller value. Control device. 5. A charging control method for controlling charging of a secondary battery, comprising: a supplying step of supplying electric power for charging the secondary battery; a detecting step of detecting a charging current to the secondary battery; When the charging current to the secondary battery becomes smaller than a reference value, a voltage control step of changing the voltage for charging the secondary battery output in the supplying step to a smaller value. Control method. 6. A charging control device for controlling charging of the secondary battery, a supplying step of supplying power for charging the secondary battery, a detecting step of detecting a charging current to the secondary battery, When the charging current to the secondary battery becomes smaller than a reference value, a computer that executes a process including a voltage control step of changing the voltage for charging the secondary battery output in the supplying step to a smaller value is executed. A providing medium for providing a readable program. 7. A charging control system for charging a secondary battery of a first device from a second device, wherein the first device comprises: voltage detecting means for detecting a voltage of the secondary battery; When the voltage of the secondary battery is lower than the first reference voltage,
On the basis of the power supplied from the first device,
First charging means for charging a secondary battery, wherein the voltage of the secondary battery is higher than the first reference voltage,
A second charging unit that performs charging at a constant voltage when the voltage is lower than a second reference voltage; and a stopping unit that stops charging when the voltage of the secondary battery is higher than the second reference voltage; A second device, a supply unit that supplies power for charging the secondary battery, a current detection unit that detects a charging current for the secondary battery, and a charging current for the secondary battery that is smaller than a reference value. And a voltage control means for changing a voltage for charging the secondary battery, which is output from the supply means, to a smaller value. 8. A charge control method of a charge control system for charging a secondary battery of a first device from a second device, wherein the charge control method of the first device detects a voltage of the secondary battery. A voltage detecting step of: when the voltage of the secondary battery is lower than a first reference voltage,
On the basis of the power supplied from the first device,
A first charging step of charging a secondary battery, wherein the voltage of the secondary battery is higher than the first reference voltage,
A second charging step of performing charging at a constant voltage when the voltage is lower than a second reference voltage; and a stopping step of stopping charging when the voltage of the secondary battery is higher than the second reference voltage; A charging control method of the second device, a supply step of supplying power for charging the secondary battery, a current detecting step of detecting a charging current to the secondary battery, and a charging current to the secondary battery. A voltage control step of changing a voltage for charging the secondary battery, which is output in the supply step, to a smaller value when the voltage becomes lower than a reference value. 9. A charging control system for charging a secondary battery of a first device from a second device, a voltage detecting step of detecting a voltage of the secondary battery in the first device; When the voltage of the secondary battery is lower than the first reference voltage,
On the basis of the power supplied from the first device,
A first charging step of charging a secondary battery, wherein the voltage of the secondary battery is higher than the first reference voltage,
A second charging step of performing charging at a constant voltage when the voltage is lower than the second reference voltage; and a stopping step of stopping charging when the voltage of the secondary battery is higher than the second reference voltage. A power supply step of supplying power to charge the secondary battery to the second device; a current detection step of detecting a charging current to the secondary battery; and a charging current to the secondary battery. A computer-readable program for executing a process including a voltage control step of changing the voltage for charging the secondary battery output in the supply step to a smaller value when the voltage becomes lower than a reference value. A providing medium characterized by the above-mentioned.