JP3138583B2 - Battery full charge detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a full charge detection control method for detecting full charge of a NiCd battery or the like.

[0002]

2. Description of the Related Art Conventionally, as one method of detecting the full charge of a NiCd battery, there is a -ΔV detection control method. At the end of charging, in which the NiCd battery is rapidly charged, the voltage reaches a peak and then drops (FIG. 7). The battery voltage drop (ΔV) at the end of charging is detected to control charging.

The operation of the conventional -ΔV detection control method will be described. FIG. 8 shows a flowchart of the processing. While the battery is charging,
The battery voltage V is detected at regular intervals. Therefore, the voltage V at the peak when the battery voltage is completely increased is stored as the _Vpeak value. After this, the battery voltage is continuously detected and the peak value V
_When the voltage drops by a certain value ΔV or more with respect to _peak (V
It is determined that charging has been completed at ( _peak− V ≧ ΔV), and control such as stopping charging is performed.

[0004]

Since the conventional -.DELTA.V detection control method uses the above-described operation, a high voltage or a low voltage due to an external influence is detected even at the initial stage of charging, and as a result, the voltage is erroneously detected. There were problems such as performing -ΔV detection control. When a high voltage is erroneously detected as shown in FIG. 9, if the next normal voltage value to be detected is ΔV or less,
It is determined by mistake that it is the end of charging. In addition, when a low voltage is erroneously detected as shown in FIG. 10, it is erroneously determined that the voltage has dropped by ΔV or more from the previously detected normal voltage value.

[0005] For this reason, even if charging is not completed due to one erroneous detection, it is possible to determine that the battery is full and stop charging, or depending on the value and timing of the erroneous detection, overcharging may be caused. There was sex.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a method for more accurately detecting the full charge of a battery.

[0007]

A battery full-charge detection method according to the present invention includes the following elements in a battery full-charge detection method for detecting full charge of a battery by utilizing a voltage drop characteristic during charging. It is characterized by having. (a) voltage detection means for detecting a battery voltage at regular intervals during charging; (b) peak value storage means for storing a peak value of the battery voltage detected by the voltage detection means; (c) the voltage detection Means during voltage drop
Voltage drop detecting means for determining that the battery voltage detected at regular time intervals becomes equal to or less than a predetermined value from the peak value stored in the peak value storing means for a predetermined plurality of times consecutively as full charge. .

[0008] The battery full-charge detection method according to the present invention comprises:
A battery full-charge detection method for detecting full charge of a battery by utilizing a voltage drop characteristic during charging includes the following elements. (a) voltage detection means for detecting a battery voltage at regular time intervals during charging; and (b) average value calculation means for computing an average value of a plurality of voltages continuously detected by the voltage detection means at regular time intervals. (C) peak value storage means for storing the peak value of the average value calculated by the average value calculation means; and (d) the peak value during the voltage drop by the average value calculation means.
Voltage drop detecting means for determining that the battery has been fully charged when a plurality of consecutive detections that the average value calculated every predetermined time becomes equal to or less than a predetermined value from the peak value stored in the peak value storing means are performed. .

[0009]

[0010]

According to the full charge detection system of the present invention, the voltage
The battery voltage detected at regular intervals during the fall
From the threshold value to a specified value or less continuously for a specified number of times.
If it is detected, it is determined that the battery is fully charged. Therefore,
The fixed time and the number of times above are appropriate for the type and capacity of the battery
Depending on battery type and capacity
Full charge detection according to the voltage drop characteristic can be realized. That
Therefore, even if the battery type and capacity are different,
Correspondingly, the full charge can be accurately determined.

In addition, during the voltage drop, detection is performed at regular intervals.
The average value of multiple output voltages is less than the specified value from the peak value
Is fully charged when it is continuously detected for several times
Is determined. Therefore, as in the above case,
Flexible handling of different types and capacities
Charge can be accurately determined. Moreover, the average value of multiple voltages
Since it is used, malfunction due to noise etc. can be prevented.
You. Therefore, the full charge can be determined more accurately.

[0012]

[0013]

【Example】

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described. FIG.
FIG. 2 is a diagram showing a configuration of the device of the present invention. In the figure, 1
Is a constant current power supply for charging the battery, and 2 is a control unit that performs all controls of the present invention. For example, A / D
A converter or the like is used. The control unit 2 includes an average value calculating means 6 for calculating an average value of a plurality of voltages, and a voltage drop detecting means 7 for determining full charge. Reference numeral 3 denotes an input terminal of the control unit, to which a battery voltage at regular intervals is input. Reference numeral 4 denotes a control unit output terminal. Reference numeral 5 denotes a switching circuit that controls charging by an output, 8 denotes a voltage detecting unit that detects a battery voltage during charging, and 9 denotes a peak value storing unit that stores a peak value of the average calculated by the average calculating unit 6.

Next, the operation will be described. FIG. 2 shows a flowchart of the first embodiment. During charging of the battery, a battery voltage V is detected by the voltage detecting means 8 at regular intervals in S1.
It is determined whether it is the first time (S2).
Transferring detected this time and the voltage V to V _a at 3, transferring the zero peak value V _peak. Next, in S4, the voltage V detected this time is transferred to _Vb . Then, the average value calculating means 6 in S5, calculates the average of the voltage V _b detected this time and the voltage V _a detected last time. Average value V _ave = (V _a + V _b ) / 2. Next, in step S6, V _ave and V _peak are compared. If V _peak is larger, the process proceeds to S9. Otherwise, V _ave determined to be larger is transferred to V _peak (S7). In this way, the highest value among the voltages V _ave calculated one after another is stored in the peak value storage means 9 as V _peak . And
In S9, the voltage drop of V _peak and V _ave is checked. V
_{If peak−} V _ave ≧ ΔV is satisfied, charging control is performed in the voltage drop detecting means 7 and charging is stopped in S10. In S9, if still small drop voltage than [Delta] V, the V _a at S8, sets the voltage V detected this time, the process is repeated from S1. -ΔV according to Example 1
Since the detection control method takes the average value of the voltage, it is improved from the conventional method so as not to be erroneously detected. FIG. 3 shows a specific example.
Shown in When detecting erroneously high voltage as V _4, although the conventional methods it takes a long charge control as it detects -ΔV when detecting the V _5, according to the present invention V
_{ave (4) −Vave (5)} <ΔV, and it is not determined that −ΔV is detected. Similarly, when detecting erroneously low voltage such as V ₅ in FIG. _{4, V ave (4) -V} ave (5) < not determine that the full charge because the [Delta] V.

Embodiment 2 FIG. FIG. 5 is a flowchart of Embodiment 2 of the present invention . In the figure, S101 to S108 are the same as S1 to S8 in FIG. 2, respectively, and thus description thereof will be omitted. S106,
In S107, the highest value of V _ave is put into V _peak and stored in the peak value storage means 9. Next, in S110, the average value calculated this time is stored in V _{ave (b)} , and in S111, the previous average value V _{ave (a)} and in S112, the current average value V _{ave (b)} and V _peak are compared. A comparison is performed, and charging is stopped if V _peak −V _{ave (a)} ≧ ΔV and V _peak −V _{ave (b)} ≧ ΔV, that is, if V _peak −V _ave exceeds ΔV twice in a row. Has become. Also, S
If V _peak −V _ave does not exceed ΔV in _steps 111 and S112, the average value V _{ave (a)} is _{added to} V _{ave (a)} in step S109.
_{ave (b)} is stored, and the processing is repeated from S101. As described above, this embodiment is characterized in that the current average value and the previous average value are stored and used for comparison. According to the second embodiment, full charge is performed when −ΔV is continuously detected, so that erroneous detection is alleviated.

Embodiment 3 FIG. In the same manner as in the above-described embodiment, the charging may be stopped when V _peak -V _ave exceeds ΔV for three consecutive times. By increasing the number of result counts, more accurate detection of full charge can be performed.

Embodiment 4 FIG. In the above embodiment, an average of the voltage V _b detected this time and the voltage V _a of the previously detected average value of the voltage was calculated, had made the detection of the peak value and the voltage drop, in Example 4, followed by the detection The same operation is performed with the average of the three voltages obtained. The _{V ave (V a + V b} + V c) / 3
Is assigned. By increasing the number of averaged voltages,
If there is an erroneous detection, the error in the detected value of the voltage is reduced.

Embodiment 5 FIG. FIG. 6 is a diagram showing a flowchart of the fifth embodiment. In the figure, the processing of S201 to S203 is the same as S1 to S3 of FIG. 2, respectively. In S204, the detected voltage V is compared with the maximum value _{Vpeak. When Vpeak} is not large, the voltage V detected in S205 is compared with _Vpeak.
And the highest value of the voltage detected one after another is always stored in V _peak . Next, in step S207, V _peak is compared with the previously detected V _a , and in step S208, V _peak is compared with the _currently detected V. If the difference exceeds ΔV, charging is stopped in step S209. As described above, in this embodiment, by comparing the voltages a plurality of times, it is possible to more accurately determine the full charge.

[0019]

According to the present invention, the type and capacity of the battery
It can flexibly respond to different cases and accurately determine full charge.
Therefore, a highly accurate charger can be provided.

In addition, full charge is performed using an average value of a plurality of voltages.
If so, can the full charge be determined more accurately?
Thus, a more accurate charger can be provided.

[0021]

[Brief description of the drawings]

FIG. 1 is a diagram showing a −ΔV detection control device of the present invention.

FIG. 2 is a flowchart of a −ΔV detection control method according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a first embodiment of the present invention.

FIG. 4 is a diagram illustrating a first embodiment of the present invention.

FIG. 5 is a flowchart of a −ΔV detection control method according to a second embodiment of the present invention.

FIG. 6 is a flowchart of a −ΔV detection control method according to a fifth embodiment of the present invention.

FIG. 7 is a diagram showing charging characteristics of a conventional NiCd battery.

FIG. 8 is a flowchart of a conventional -ΔV detection control method.

FIG. 9 is a diagram illustrating a conventional example of erroneous detection .

FIG. 10 is a diagram illustrating an example of a conventional erroneous detection .

[Explanation of symbols]

Reference Signs List 1 constant current power supply 2 control section 3 control section input 4 control section output 5 switching circuit 6 average value calculation means 7 voltage drop detection means 8 voltage detection means 9 peak value storage means ΔV drop of battery voltage, predetermined value V charge mean value V _{ave (b)} V _ave of the battery voltage V _a last detected voltage V _b average value V _{ave (a)} voltage detected after the peak value stored in the currently detected voltage V _ave detected voltage detected in _{(a )} Average value of the voltage detected immediately after V) V _peak Maximum value of the detected voltage V ₁ Voltage detected for the first time V ₂ Voltage detected for the second time V ₃ Voltage detected for the third time V ₄ Voltage detected for the fourth time V 5 ₅ th to the detected voltage V 6 ₆ th voltage detected in the voltage V 7 ₇ th detected in V _{ave (1)} V ₁ and the mean V _{ave (2)} of the V ₂ voltage voltage V ₂ and V ₃ mean V _{ave (3)} average V _ave of the voltage of V ₃ and V _{4 (4)} of the voltage V ₄ and V ₅ of the The average of the average V _{ave (6)} voltage V ₆ and V ₇ isothermal V _{ave (5)} the voltage of V ₅ and V ₆

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-58471 (JP, A) JP-A-5-56575 (JP, A) JP-A-3-36935 (JP, A) JP-A-60-1985 20478 (JP, A) JP-B 61-59048 (JP, B2)

Claims (2)

(57) [Claims] 1. A full charge detection method for a battery, which detects a full charge of the battery by utilizing a voltage drop characteristic during charging, comprising the following elements . (a) voltage detection means for detecting a battery voltage at regular intervals during charging; (b) peak value storage means for storing a peak value of the battery voltage detected by the voltage detection means; (c) the voltage detection Means during voltage drop
Voltage drop detecting means for determining that the battery voltage detected at regular time intervals becomes equal to or less than a predetermined value from the peak value stored in the peak value storing means for a predetermined plurality of times consecutively as full charge. . 2. A full charge detection method for a battery, which detects a full charge of a battery by utilizing a voltage drop characteristic during charging, comprising the following elements . (a) voltage detection means for detecting a battery voltage at regular time intervals during charging; and (b) average value calculation means for computing an average value of a plurality of voltages continuously detected by the voltage detection means at regular time intervals. (C) peak value storage means for storing the peak value of the average value calculated by the average value calculation means; and (d) the peak value during the voltage drop by the average value calculation means.
Voltage drop detecting means for determining that the battery has been fully charged when a plurality of consecutive detections that the average value calculated every predetermined time becomes equal to or less than a predetermined value from the peak value stored in the peak value storing means are performed. .