JPH0992340A - Charging method of battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a full charge in constant current and voltage charging method by judging the charge end in a terminal current after unconditionally performing a constant voltage charge only for a prescribed time in the transfer to the constant voltage charge. SOLUTION: In charging of a battery, a current is supplied to the battery when the charging is started, and whether the terminal current becomes a prescribed value or not is judged to continue the charging. When the terminal voltage becomes a prescribed value, the count-out of a timer is performed to switch to constant voltage charge, and whether the timer of a prescribed time passed or not is judged. When the timer time passed or a prescribed time passed from the transfer to constant voltage charge after constant current charge is ended, the terminal current is detected while continuing the constant voltage charge, and whether the terminal current becomes substantially zero or not is judged. When the substantially zero terminal current is judged, the charging is ended. Even when a phenomenon of temporarily carrying no terminal current is present, such a state that the charging is ended thereby, resulting in an insufficient charging is never caused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for charging a battery, and enables charging without excess or deficiency.

[0002]

2. Description of the Related Art As a battery charging method, there is a constant current constant voltage charging method in which a constant current and a constant voltage are charged with a strong current until a constant voltage is reached, and then supplementary charging is performed with a constant voltage until no current flows from a battery terminal.

[0003]

In the above constant current / constant voltage charging method, when the terminal voltage of the battery reaches a predetermined voltage due to charging with the constant current, a weak current flowing between the terminals of the battery by applying the constant voltage. Then, the charging is continued until this current becomes almost zero.However, if the battery is not discharged so much, the current flowing between the terminals becomes almost zero even if a voltage is applied when switching to constant voltage charging, and charging is continued. Although it ends, there are times when it is not actually fully charged. The present invention, without being confused by such apparent charge termination state,
The challenge is to ensure that the battery can be fully charged.

[0004]

Means for Solving the Problems Terminal voltage V of battery B
A constant strong current until a predetermined voltage H is reached, and then a constant voltage is applied to continue charging until the terminal current I of the battery B becomes substantially zero. At this time, control is performed such that the constant voltage charging is performed unconditionally for a predetermined time A and then the end of charging at the terminal current I is determined.

[0005]

When the charging is started, initially, a strong current is supplied to the terminals of the battery B to perform charging in a short time, and when the terminal voltage V reaches the predetermined voltage H, a predetermined voltage is applied between the terminals of the battery B. Switch to apply the voltage. Then
This switching causes a weak current I to the terminal of the battery B.
Will flow and will continue charging. Even when the terminal current I does not flow immediately after switching at the time of switching from the constant current charging to the constant voltage charging and gradually starts to flow with the passage of time, constant voltage charging is performed unconditionally for a predetermined time A from the switching. Therefore, the charging does not end and the charging does not become insufficient due to the phenomenon that the apparent charging current becomes zero.

[0006]

Next, embodiments of the present invention will be described. In the charging device of the present invention, as shown in FIG. 2, the central processing unit 1 and the battery B are connected by the charging circuit 4, and the current flowing between the terminals of the battery B is detected by the current detecting circuit 5 to be connected to the central processing unit 1. The voltage between the terminals of the battery B is detected by the voltage detection circuit 6 and input to the central processing unit 1. Further, the charging time is measured by the timer 3 and read by the central processing unit 1, and the display 2 displays the charging / discharging state of the battery.

Next, a specific example of charge control is rated at 30V and 35V.
A case of charging the AH battery will be described with reference to FIG. When charging is started in step S1, a current of 4.5 A is supplied to the battery B in step S2, and step S3
Then, it is determined whether the terminal voltage has reached 28.8 V and charging is continued. In step S3, the terminal voltage V is 2
If the voltage reaches 8.8 volts, the timer is counted up in step S4, and the charging voltage is set to 30 in step S5.
Switching to constant voltage charging with a volt, it is determined in step S5 whether the timer time T has passed a predetermined time A, for example, 5 minutes.

When 5 minutes have passed since the timer time T, that is, the constant current charging is completed and the constant voltage charging is started, the terminal current I is detected in step S8 while continuing the constant voltage charging in step S7, and step S9. In step S10, it is determined whether the terminal current I has become substantially zero. If it is determined that the terminal current I has become substantially zero, the charging is completed in step S10. As described above, in this charging method, the unconditional charging is performed for 5 minutes when the constant current charging is switched to the constant voltage charging.
Even if there is a phenomenon that the terminal current does not flow temporarily, charging will not end and there will be insufficient charging,

[Brief description of drawings]

FIG. 1 is a flowchart of charge control.

FIG. 2 is a block diagram of charge control.

[Explanation of symbols]

 B Battery V Terminal voltage H Specified voltage I Terminal current A Specified time

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[Procedure amendment]

[Submission date] October 5, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

Next, a concrete example of charge control will be given with a rated voltage of 24 V and 35 V.
A case of charging the AH battery will be described with reference to FIG. When charging is started in step S1, a current of 4.5 A is supplied to the battery B in step S2, and step S3
Then, it is determined whether the terminal voltage has reached 28.8 V and charging is continued. In step S3, the terminal voltage V is 2
If the voltage reaches 8.8 volts, the timer is counted up in step S4, and the charging voltage is set to 30 in step S5.
Switching to constant voltage charging with a volt, it is determined in step S5 whether the timer time T has passed a predetermined time A, for example, 5 minutes.

Claims (1)

[Claims] 1. A constant strong current flows until the terminal voltage (V) of the battery (B) reaches a predetermined voltage (H), and then a constant voltage is applied so that the terminal current (I) of the battery (B) is substantially zero. In the constant-current constant-voltage charging method in which the charging is continued until, the constant-voltage charging is performed unconditionally for a predetermined time (A) when shifting to constant-voltage charging, and then the end of charging at the terminal current (I) is determined. A method for controlling the charging of a battery, which is controlled to