JPH08308118A - Battery charger - Google Patents

Abstract

PURPOSE: To provide a battery charger which can indicate the charging capacity and required charging time with high accuracy and the charging operation of which can be controlled without shortening the cycle life of a secondary battery. CONSTITUTION: At the time of charging a battery 19 to be charged, a voltage detecting circuit 14 and current detecting circuit 13 respectively detect the charging voltage and charging current at the charging starting time and during the charging operation and a microcomputer 16 calculates the charging capacity and required charging time based on the charging capacity from the initial charging voltage and current at the charging starting time and charging voltage and current during the charging operation. A displaying means displays the calculated charging capacity and charging time. The microcomputer 16 also automatically controls the charging operation during the calculated charging time. Therefore, the secondary battery 19 can be charged accurately and efficiently without shortening the cycle life of the battery 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a secondary battery.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a configuration of a conventional charging device. A charging device 11 is provided with a power supply terminal t3 and a charging terminal t1, and a power supply 20 is connected to the power supply terminal t3. A secondary battery 19 to be charged is connected between the charging terminal t1 and the ground terminal t2. In the charging device 11,
A microcomputer 16 for controlling the entire operation is provided, and the microcomputer 16 has a timer 1 for setting a time during a charging operation.
7 and display device 1 displaying various data during charging operation
And 8 are connected.

Similarly, the microcomputer 16 turns on the charging operation.
The charging operation ON-OFF circuit 15 that performs -OFF control and the voltage detection circuit 14 that detects the charging voltage are connected, and the power supply 20 is supplied to the charging operation ON-OFF circuit 15 via the power supply terminal t3. The charging operation ON-OFF circuit 15 is connected to a constant voltage / constant current circuit 12 that performs control such that the charging voltage and the charging current are constant, and the output terminal of the constant voltage / constant current circuit 12 has a voltage The detection circuit 14 and the secondary battery 19 are connected via the charging terminal t1.

The operation of the conventional charging device having such a configuration will be described. When the secondary battery 19 to be charged is connected between the charging terminal t1 and the ground terminal t2 and charging is started, the charging operation ON-OFF circuit 15 is turned ON by the command of the microcomputer 16, and the power from the power source 20 is supplied. , Is supplied to the secondary battery 19 via the constant voltage / constant current circuit 12 that operates according to a command from the microcomputer 16.

In this case, generally, the charging current of the secondary battery 19 rises to a constant current value immediately after the start of charging, but when the charging current reaches the constant current value, the constant voltage / constant current circuit 1
2, the charging current is set to a constant current value so as not to increase any more, and the charging current is kept at the constant current value until the charging capacity of the secondary battery 19 reaches 80%. This charging current gradually decreases and approaches 0 when the charging capacity of the secondary battery 19 reaches 80%.

On the other hand, the charging voltage is equal to that of the secondary battery 19
Gradually increases until the charging capacity of the battery reaches 80%, and thereafter, the charging capacity becomes 8 by the constant voltage / current circuit 12.
Control is performed so that a constant voltage value when 0% is reached is held.

Charge voltage information from the voltage detection circuit 14 and charge time information from the timer 17 are input to the microcomputer 16, and the microcomputer 16 calculates the charge capacity of the secondary battery 19 based on the information. The required charging time is calculated, and the display device 18 displays the charging capacity of the secondary battery 19 and the required charging time.

The charge capacity of the secondary battery 19 is 80%.
When the charging current value has decreased to a predetermined value after a predetermined time after the voltage detection value of the voltage detection circuit 14 becomes constant, the remaining remaining time is set in the timer 17, and the timer 17 is set to end. When the remaining time is counted, the charging operation ON-OFF circuit 15 is turned off by the command of the microcomputer 16, and the charging operation ends.

[0009]

In the above-mentioned conventional charging device, the microcomputer 16 determines the charging capacity of the secondary battery 19 and the required charging time based on the charging voltage of the secondary battery 19 and the time from the start of charging. Since the rechargeable battery 19 is charged up to about 80% of the charge capacity and the charge voltage becomes a constant value, the calculation of the charge capacity and the required charging time is stored in the microcomputer 16. The charging operation is performed with reference to the general charging characteristic data of the secondary battery 19 that is being charged, and sufficient calculation accuracy may not always be obtained for the secondary battery 19 that is currently being charged.

Also, the secondary battery 1 in a state of being almost fully charged
Even when the battery 9 is charged, the remaining remaining time is set in the timer 17 as if the charging current value has decreased to a predetermined value after a predetermined time after the voltage detection value of the voltage detection circuit 14 becomes constant. Since the charging is completed after the charging is performed for a certain time, there is a problem that the cycle life of the secondary battery 19 is shortened.

The present invention has been made in view of the current state of the charging device as described above, and an object thereof is to constantly display the charging capacity and the required charging time with high accuracy and to control the charging of the secondary battery. It is an object of the present invention to provide a charging device that can be operated without shortening the cycle life.

[0012]

In order to achieve the above object, the invention according to claim 1 is a charging device for charging a battery to be charged, and a charging state detecting means for detecting a charging voltage and a charging current, Calculation means for calculating the charging capacity of the battery to be charged by the initial charging voltage and initial charging current at the start of charging and the charging voltage and charging current during the charging process, and a display for displaying the charging capacity calculated by the calculating means And means.

Similarly, in order to achieve the above object, in the invention according to claim 2, in the invention according to claim 1, the calculating means further calculates a charging time required for charging based on the charging capacity. The display means also displays the charging time.

Similarly, to achieve the above object, the invention according to claim 3 is different from the invention according to claim 2 in that the charging is automatically performed over the charging time. It is a feature.

[0015]

According to the first aspect of the present invention, when the battery to be charged is charged, the charging state detecting means detects the charging voltage and the charging current, and the charging state detecting means detects the charging initial voltage and the charging at the start of charging. By the initial current and the charging voltage and the charging current in the charging process, by the calculating means,
The charge capacity of the battery to be charged is calculated, and the display means
The calculated charge capacity is displayed.

According to the invention of claim 2, in addition to the operation of the invention of claim 1, the calculating means further calculates the charging time required for charging based on the charging capacity, and the displaying means The calculated charging time is displayed.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, the charging operation is automatically performed during the charging time calculated by the calculating means.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the charging characteristics of this embodiment. The same parts as those of FIG. 3 already described are assigned the same reference numerals. ing.

In the present embodiment, as shown in FIG. 1, a current detection circuit 13 for detecting a charging current is connected to a microcomputer 16 in addition to the conventional charging device already described with reference to FIG. The detection circuit 13 is connected to the output terminal of the constant voltage / constant current circuit 12.

The configuration of the other parts of this embodiment is the same as that of the conventional charging device already described with reference to FIG.
No duplicate explanation will be given.

The operation of this embodiment having such a configuration will be described. When the secondary battery 19 to be charged is connected between the charging terminal t1 and the ground terminal t2 and charging is started, the charging operation ON-OFF circuit 15 is turned ON by the command of the microcomputer 16, and the power from the power source 20 is supplied. , The secondary battery 19 through the constant voltage / constant current circuit 12 that operates according to the command from the microcomputer 16.
Is supplied to.

As shown by the dotted line in FIG. 2, when the charging current rises to a constant current value immediately after the start of charging, the constant voltage / constant current circuit 12 operates and the charging current is the charging capacity of the secondary battery 19. The constant current value is maintained in the area A until reaching 80%. When this charging current is continuously supplied to the secondary battery 19, the charging voltage gradually increases as shown in the area A of FIG. The charging current information from the current detection circuit 13, the charging voltage information from the voltage detection circuit 14, and the time information from the start of charging from the timer 17 are input to the microcomputer 16, and in the area A, the microcomputer 16 determines the voltage. Based on the charging voltage information from the detection circuit 14, the secondary battery 19
The charging capacity of the battery and the required charging time are calculated, and the display device 18
The charging capacity of the secondary battery 19 calculated in step 1 and the required charging time are displayed.

When the secondary battery 19 is continuously charged, the charging voltage reaches a constant voltage value, the constant voltage / constant current circuit 12 is activated, and the charging voltage is changed as shown in the region B of FIG. It is maintained at a constant voltage value. On the other hand, the charging current gradually decreases so as to approach the current value 0. In the area B, the microcomputer 16 calculates the charging capacity of the secondary battery 19 and the required charging time based on the charging current information from the current detection circuit 13, and the secondary battery 19 calculated by the display device 18 is calculated. The charging capacity of and the required charging time are displayed in real time.

In this way, in this embodiment, for example, when the microcomputer 16 has a constant voltage value for the charging voltage and a constant current value for the charging current, the charging capacity of the secondary battery 19 is 80% and the required charging time is The display of 1 hour is displayed on the display device 18.

Then, in the present embodiment, after a lapse of a certain time after entering the area B, the microcomputer 16 determines the required charging time based on the charging voltage information from the voltage detecting circuit 14 and the current information from the current detecting circuit 13. Is calculated, the calculated required charging time is set in the timer 17, and when the timer 17 counts the required charging time,
The charging operation ON-OFF circuit 15 is controlled to be OFF, and the charging operation is properly ended without deteriorating the cycle life of the secondary battery 19.

As described above, according to the present embodiment, the microcomputer 16 uses the charging voltage information from the voltage detection circuit 14 and the charging current information from the current detection circuit 13 in the secondary charging process in each charging process. The charging capacity and the required charging time of the battery 19 are displayed on the display device 18 in real time, the charging operation 0N-0FF circuit 15 is turned off after the required charging time, and the cycle life of the secondary battery 19 is not shortened.
It becomes possible to automatically and properly terminate the charging of the secondary battery 19.

[0028]

According to the first aspect of the present invention, when charging the battery to be charged, the charging state detecting means detects the charging voltage and the charging current, and the charging state detecting means detects the charging voltage at the beginning of charging. Voltage and initial charging current,
The charge capacity and the charge current in the charging process are used to calculate the charge capacity of the battery to be charged by the calculation means, and the calculated charge capacity is displayed on the display means. It becomes possible to grasp accurately in real time.

According to the invention described in claim 2, in addition to the effect obtained in the invention described in claim 1,
The charging time required for charging is further calculated based on the charging capacity, and the charging time calculated by the display means is displayed. Therefore, the necessary charging time can be grasped to prevent unnecessary charging and prevent the battery to be charged. It is possible to suppress the reduction of cycle life.

According to the invention of claim 3, in addition to the effect obtained by the invention of claim 2, since the charging operation is performed during the charging time calculated by the calculating means, the charging time required automatically is obtained. It becomes possible to charge the battery during the period.

[Brief description of drawings]

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

FIG. 2 is a characteristic diagram showing charging characteristics of the same embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional charging device.

[Explanation of symbols]

 11 Charging Device 12 Constant Voltage / Constant Current Circuit 13 Current Detection Circuit 14 Voltage Detection Circuit 15 Charging Operation ON-OFF Circuit 16 Microcomputer 17 Timer 18 Display Device 19 Secondary Battery 20 Power Source

Claims (3)

[Claims] 1. A charging device for charging a battery to be charged,
A charging state detecting means for detecting a charging voltage and a charging current,
Calculation means for calculating the charging capacity of the battery to be charged by the initial charging voltage and initial charging current at the start of charging and the charging voltage and charging current during the charging process, and a display for displaying the charging capacity calculated by the calculating means And a charging device. 2. The calculation means, based on the charge capacity,
The charging device according to claim 1, further comprising calculating a charging time required for charging, and the display means also displaying the charging time. 3. The charging device according to claim 2, wherein the charging device is configured to automatically perform charging for the charging time.