KR101080597B1 - Lead storage battery charging method - Google Patents

Abstract

PURPOSE: A lead storage battery charging method is provided to perform rapid charging by gradually reducing a charge current according as a battery charge voltage is reached to a gas generation voltage. CONSTITUTION: In a lead storage battery charging method, a current source(10) generates a charge current to charge a battery with a constant current. A detection unit(20) detects the terminal voltage of a battery which is charged according to a charge current supplied from the current source. A voltage comparative part(30) sets the gas generation voltage of the battery by a predetermined voltage in advance. A voltage comparison unit compares a battery voltage with a reference voltage. A charge current controller gradually reduces total current supplied from the current source to the battery according to a corresponding signal.

Description

Battery storage device {Lead storage battery charging method}

The present invention relates to an apparatus for charging a battery used as an electric bicycle, an electric scooter, an electric vehicle, a golf car, an electric forklift, other transportation equipment or an emergency power supply, a spare power supply of equipment, and more particularly, a battery is prescribed. The present invention relates to a battery charger configured to improve charging efficiency of a battery by gradually decreasing a charging current value as a voltage (for example, gas generated voltage by electrolysis) is reached.

In general, a lead acid battery (hereinafter, referred to as a battery) is a battery which performs a battery function through a discharge cycle that converts chemical energy into electrical energy and a charge cycle that converts electrical energy into chemical energy. The closed circuit is made of metal (+,-pole) and liquid (electrolyte) to generate electrical energy by chemical reaction between two metals and electrolyte.

Here, the metal is a conductor through which electrons move, and the solution is a path through which ions move. Both electrons and ions have electrical properties, so a reaction occurs due to a potential. The reaction is caused by a potential difference between two metals, so that one reaction is oxidized and the other is reduced.

On the other hand, looking at the reaction process in the lead acid battery,

Discharge: At the anode, lead peroxide is combined with sulfuric acid group (SO4-) to form lead sulfate. At the cathode, lead sponge is combined with sulfuric acid group (SO4-) to form lead sulfate, and hydrogen (H +) groups in the electrolyte Reacting with the (O-) group, the electrolyte solution becomes dilute. Such a reaction causes hardening of the electrode plate and a change in the concentration of the electrolyte, which in turn causes a decrease in battery performance.

Filling: In the anode plate, sulfuric acid of lead sulfate returns to electrolyte solution and becomes lead peroxide. In the cathode plate, sulfuric acid of lead sulfate returns to electrolyte solution, and it becomes lead, which is lead sponge.

Here, the charging of the battery as described above is usually performed by a constant voltage charging method or a constant current charging method, or a method of constant voltage charging after the constant current charging is used.

In the constant voltage charging method, the AC power is rectified and then converted into a rated voltage of the battery and supplied to the charging power of the battery, and the supply of the charging power is controlled according to the charging state of the battery.

On the other hand, the constant current charging method is a method of charging while supplying a constant current at all times irrespective of the increase of the terminal voltage of the battery that increases as the battery charging operation proceeds. This constant current charging method can always charge the battery with a constant current, thereby reducing the charging time required for the battery to reach the charging voltage and allowing sufficient charging, while continuously charging current to the battery when the charging voltage is reached. When supplied, there are problems such as deterioration of the battery due to generation of gas due to electrolysis along with overcharge.

Here, the voltage range in which gas is generated during charging in a general battery varies according to the type of battery, for example, 2.15V to 2.8V, and gas is most commonly generated at 2.2V to 2.4V.

The present invention has been invented in view of the above situation, and the battery used as an electric bicycle, electric scooter, electric vehicle, golf car, electric forklift, other transportation equipment or emergency power, reserve power of equipment, etc. constant current and constant voltage In charging, it is determined whether the battery during charging has reached the gas generating voltage, and whenever the battery reaches the gas generating voltage, the battery current is kept below the gas generating voltage by decreasing the charging current value. Since it is possible to charge, it is an object of the present invention to provide a battery charging device to improve the charging efficiency.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

In order to achieve the above object, the present invention provides a current source for generating a charging current for constant current charging the battery, a detection unit for detecting the terminal voltage of the battery charged in accordance with the charging current supplied from the current source; A voltage comparator for comparing the battery voltage increasing with the charging current supply with a preset reference voltage, and a charging current for gradually reducing the charging current supplied from the current source to the battery according to a match signal from the voltage comparator It provides a battery charging device comprising a control unit.

In addition, the present invention provides a battery charging apparatus, characterized in that the reference voltage is set to a voltage that can generate gas by electrolysis from the battery in accordance with the application of the charging current to the battery.

In addition, the present invention, the detection unit detects the terminal voltage of the battery in real time, and transmits to the voltage comparison unit, the voltage comparison unit is matched to the charging current control unit whenever the reference voltage and the terminal voltage match A signal is transmitted, and the charging current control unit provides a battery charging device, which reduces the charging current supplied from the current source to the battery every time the matching signal is transmitted.

In addition, the present invention is configured to further include a voltage source for applying a constant voltage, the battery charging, characterized in that to supply a constant voltage for charging from the voltage source to the battery after the gradual reduction of the charging current by the charging current control unit Provide the device.

The present invention further includes a counter for counting the coincidence signal, wherein the charging current controller is configured to provide a stepwise supply of current from the current source to the battery as the counter counts a predetermined number of coincidence signals. After stopping, it provides a battery charging device to supply a constant voltage for charging from the voltage source to the battery.

The present invention may further include a battery current value measuring unit for detecting a current value change of the battery according to the constant voltage supply, and when the current value change rate measured from the battery current value measuring unit is 0, Provides a battery charger, characterized in that to cut off the constant voltage supply.

In addition, the present invention provides a battery charger, characterized in that further comprising a display device that is lit in accordance with the transmission of the match signal.

In addition, the present invention, the step of setting the gas generating voltage of the battery to be charged to the reference voltage (Vr) (S51), detecting the terminal voltage (Vb) of the battery in real time (S52), the reference voltage value Vr and the battery Comparing the terminal voltage Vb in real time (S53), and when the reference voltage value Vr and the battery terminal voltage value Vb coincide with each other, decreasing the charging current value Ich supplied from the current source to the battery (S54); And repeating the steps S52 to S54 a plurality of times (S55), and applying a constant voltage from the voltage source to the battery (S56) while interrupting the supply of the constant current from the current source. Provide a method.

In addition, the present invention, by detecting the change in the current value of the battery according to the application of the constant voltage, if the current value change rate is 0, further comprising the step of terminating the battery charging (S57) characterized in that the battery charging method to provide.

According to the above configuration, in the battery charging apparatus of the constant current and constant voltage charging method, it is easily determined whether the battery has reached a preset gas generating voltage, and whenever the battery charging voltage reaches the gas generating voltage, the battery is charged. By decreasing the current value step by step, the effect of enabling rapid charging is obtained.

In addition, during the constant current charging, the charging time can be shortened by initially charging with high rate charging or large current. In addition, by suppressing the increase in the internal resistance due to the polarization phenomenon, it is possible to prevent the physical and chemical degradation of the battery to extend the battery life as possible.

In addition, the user can easily sense the state of charge of the battery sensibly.

1 is a block diagram showing a schematic configuration of a battery charging apparatus according to Embodiment 1 of the present invention;
2 is a graph showing a state in which the charging current and the terminal voltage is gradually changed by the battery charger according to the present invention,
3 is a block diagram showing a schematic configuration of a battery charging apparatus according to a second embodiment of the present invention;
4 is a block diagram showing a schematic configuration of a battery charging apparatus according to a third embodiment of the present invention;
5 is a flowchart illustrating a charging method by the battery charger according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. First, the battery described in the present invention means a battery that can be charged and discharged to be used as an electric bicycle, an electric scooter, an electric vehicle, a golf car, an electric forklift, other transportation equipment or an emergency power source, or a spare power source for equipment.

Example 1

1 is a schematic configuration diagram of a battery charging apparatus according to Embodiment 1 of the present invention.

The battery charging device according to the present invention is configured to detect a current source 10 for generating a charging current for charging a battery and a battery terminal voltage Vb of the battery 100 charged with the charging current Ich supplied from the current source. The battery voltage detection unit 20, the voltage comparison unit 30 comparing the battery voltage Vb that increases according to the supply of the charging current with a predetermined reference voltage Vr, and the result of the comparison between the voltage comparison unit 30, the battery voltage When Vb and the reference voltage Vr coincide with each other, the charging current controller 40 controls the charging current Ich supplied from the current source to the battery, and the voltage for driving the charging device and the constant voltage Vch for charging the battery 100. It is further provided with a power source 50 to provide. On the other hand, the above and below components of the battery charging apparatus according to the present invention are controlled by an apparatus not shown, which may be implemented by a microcomputer and a program accompanying the microcomputer.

Here, the power source 50 is a normal AC power source, and is rectified and rectified through the rectifying and transformer circuits, and then supplied to the current source 10 to generate a charging current. Further, a reference voltage Vr is generated and supplied to the voltage comparison section 30. In addition, a charge voltage Vch of the battery 100 is generated and supplied to the battery 100.

Here, the current source 10 generates a constant current Ich for charging according to the voltage supplied from the power source 50 and supplies it to the battery 100.

In addition, the battery 100 has its terminal voltage increased by a constant current charging operation in response to the supply of current from the current source 10. On the other hand, the reference voltage Vr supplied from the power supply 50 to the voltage comparison unit 30 for comparison, considering that the voltage range that the gas is generated in the battery is 2.15V ~ 2.8V, for example For example, 2.5V may be set as the reference voltage, but as the gas generation voltage range is set in various ways according to the battery type, the reference voltage may be set in various ways.

The battery voltage detector 20 may be implemented as a voltmeter including a variable resistor and a terminal resistor connected in parallel with the battery to detect a battery terminal voltage in real time.

In addition, the voltage comparator 30 may be implemented as a circuit unit or an AND logic circuit including an OP amplifier, and is preset from the terminal voltage Vb of the battery input from the voltage detector 20 and the power supply 50. The reference voltages Vr are compared to compare voltages (Vb = Vr).

For example, when Vb = Vr, the voltage comparator 30 generates an offset value of 0, and transmits the value to the charging current controller 40.

Here, the charging current control unit 40 gradually reduces the current supply from the current source 10 in accordance with the signal S (= 0) indicating Vb = Vr of the voltage comparing unit 30. On the other hand, after the step-by-step current supply of the current source 10 by the charging current control unit 40, the apparatus control unit not shown controls the power supply 50, the charging voltage Vch is applied to the battery 100 Be sure to

Specifically, as shown in Fig. 2, in the initial stages t0 to t1 of charging, control is performed so that the charging current Ich1 from the current source 10 is supplied. Accordingly, the voltage Vb of the terminal portion of the battery 100 sequentially rises from the reference voltage or less, and reaches the reference voltage Vr at time t1 in accordance with the continuous supply of current to the battery 100.

In this case, the voltage comparing unit 30 compares the battery terminal voltage Vb and the reference voltage Vr, and transmits a S1 signal having Vb = Vr to the charging current controller.

Upon receiving the signal S1, the charging current controller 40 reduces the charging current of the current source 10 by a predetermined level to generate the charging current Ich2. As the charging current decreases, the charging voltage of the battery temporarily decreases. As the continuous supply of current Ich2 is supplied, the battery terminal voltage rises and coincides with the reference voltage again at time t2 (steps t1 to t2).

Here, the voltage comparator 30 compares the battery terminal voltage Vb and the reference voltage Vr again, and transmits an S2 signal indicating Vb = Vr to the charging current controller 40 again. 40 again decreases the charging current of the current source 10 by a predetermined level to generate the charging current Ich3. Meanwhile, as the charging current Ich2 decreases, the charging voltage of the battery drops again. As the continuous charging current Ich3 is supplied, the terminal voltage rises again to coincide with the reference voltage at time t3 (steps t2 to t3).

Accordingly, the voltage comparing unit 30 transmits the S3 signal indicating that the battery terminal voltage Vb and the reference voltage Vr match to the charging current controller 40 again, and the charging current controller 40 transmits the current source 10. Constant current charge is performed by applying a constant voltage to the battery from the power supply 50, while reducing the current supply from the power supply 50 to the level of the constant voltage charge holding current Ich4 smaller than the Ich3 and larger than 0 (step t3 to t4). . Here, the charging current Ich4 may be set to 0 by opening the current source 10 and the battery.

On the other hand, the end of the constant voltage charging associated with the constant current charging measures the current value of the battery 100 and ends when the change rate approaches zero. To this end, the charging device according to the present invention, the battery current value measuring unit (for example, implemented with an ammeter) for measuring the current value of the battery 100, and the rate of change of the measured battery current value is close to zero. In this case, it may be configured to further include an opening and closing circuit unit for blocking (opening) the connection between the power source and the current source and the battery.

In addition, the battery current value may fluctuate within a fine range in accordance with the supply of the electrostatic source, so that the signal of "1" and "0" may be present with and without the change rate of the current value for accurate end point determination. By employing a conventional Schmitt trigger circuit for generating a, it is also possible to clearly determine when the change rate is zero.

Therefore, according to the above-described charging method, as the battery terminal voltage Vb decreases the charging current Ich supplied to the battery terminal at the time points t1, t2, and t3 coinciding with the reference voltage Vr where gas is generated, the battery is It is possible to prevent overcharging, and moreover, to prevent the occurrence of electrolysis in the battery due to the overcurrent supply to the battery, thereby preventing generation of gas during charging from the battery.

Meanwhile, the charging currents Ich1 to Ich3 of the constant current charging steps t0 to t1, t1 to t2, and t2 to t3 may be set to any size. The number of the constant current charging stages may also be set arbitrarily other than three (for example, two to five stages).

Here, Ich1 to Ich4 are obtained from a relational expression of Ich = k · I _h (k is a charge factor according to battery type, I _h is a magnitude of current corresponding to h time rate), and the value thereof depends on the type of battery. May be set in various ways.

As an example, when the Ich value is set to 2 to 3, the Ich1 is determined at a rate of 4 to 8 hours. For example, when k = 3 and h = 5 in a gel type battery, it is determined that Ich1 = 3 · (0.2C) = 0.6C (where C (capacity) is the battery capacity). .

In addition, the Ich2 may be determined at an 8-10 hour rate, the Ich3 may be determined at 10 hour or less, and the Ich4 may be set at a value between 1-5% of the initial current Ich.

Example 2

3 is a schematic configuration diagram of a battery charger according to a second exemplary embodiment of the present invention. In the battery charger according to the second exemplary embodiment, a signal S (transmitted from the voltage comparator 30 to the charging current controller 40 is provided. A counter 60 for counting the number of = Vb = Vr = S1, S2, ... is further provided.

Here, the counter 60 may be configured to transmit the constant current charging stop signal O to the charging current controller 40 when, for example, the number of occurrences of the signal S is greater than or equal to a predetermined number (set value). According to the constant current charging stop signal O transmission, the charging current control unit 40 causes the current Ich4 to be supplied from the current source 10 to the battery. Meanwhile, the stop signal O is transmitted to the device controller, and the device controller receiving the stop signal O controls to apply a constant voltage charging voltage from the power source 50 to the battery.

On the other hand, in the embodiment according to FIG. 3, as the counter 60 counts 3, the constant current charging using the current source is stopped, and the constant voltage charging using the power source is performed.

Example 3

4 is a schematic configuration diagram of a battery charging apparatus according to Embodiment 3 of the present invention. The battery charging apparatus according to Embodiment 3 may be implemented as an LED or the like that lights up according to a constant current charging stop signal input from the counter. A display device 70 is further provided.

As the display device 70 is further provided, the user of the battery charger may clearly check the charge of the battery 100 as the LED is turned on.

On the other hand, the signal transmitted from the counter 60 to the display device 70 can transmit the signals of S1 to Sn in addition to the stop signal O, and the display device 70 according to the transmission of the signals S1 to Sn Can be configured to flash.

Accordingly, the charging device user can clearly check the constant current charging state of the battery 100 as the LED is turned on.

Other Examples

Hereinafter, a charging method by the battery charger according to the present invention will be described with reference to FIG. 5.

First, the device controller sets the gas generation voltage of the battery 100 to be charged to the reference voltage Vr (S51).

According to the reference voltage Vr setting, the device controller controls to input the reference voltage value Vr from the power supply 50 to the voltage comparator 30.

Subsequently, the device controller supplies a charging current Ich from the current source to the battery 100.

Subsequently, the device controller drives the battery voltage detector 20. Accordingly, the voltage detector detects the terminal voltage Vb of the battery 100 increasing in accordance with the charging current supply in real time, and this value Vb is input to the voltage comparator 30 in real time (S52).

Here, the voltage comparison unit 30 compares the reference voltage value Vr with the terminal voltage Vb of the battery in real time, and detects Vr = Vb (S53).

Subsequently, when Vr = Vb in the comparing step, the voltage comparator 30 inputs a matching signal to the charging current controller 40, and according to this input, the charging current controller 40 is configured to supply the current source ( 10), the charging current value Ich supplied from the current source to the battery is reduced (S54).

As the charge current value decreases, the battery terminal voltage drops again, and the steps S52 to S54 are repeated a plurality of times, for example, three times (S55).

Here, the number of repetitions in step S55 is counted by the counter 60, and ends as a predetermined set value, for example, 3 is counted.

On the other hand, upon completion of the count, the charging current control unit 40 cuts off the supply of current from the current source. At the same time, the device controller applies a constant voltage from the battery from the power source to charge the battery at constant voltage (S56).

Subsequently, the device controller detects a change in the current value of the battery, and terminates charging of the battery when the current value change rate is 0 (S57).

10: current source, 20: battery voltage detector,
30: voltage comparison section, 40: charging current control section.

Claims (9)

A current source for generating a charging current for constant current charging the battery,
A detector for detecting a terminal voltage of the battery charged according to the charging current supplied from the current source;
A voltage comparison unit which presets a gas generation voltage of the battery to be charged as a reference voltage and compares the battery voltage and the reference voltage which increase with supply of the charging current;
And a charging current control unit configured to gradually reduce the charging current supplied from the current source to the battery according to the matching signal from the voltage comparing unit.
delete The method of claim 1,
The detection unit detects the terminal voltage of the battery in real time, and transmits to the voltage comparison unit,
The voltage comparison unit transmits the matching signal to the charging current controller whenever the reference voltage and the terminal voltage match each other.
The charging current controller decreases the charging current supplied from the current source to the battery each time the coincidence signal is transmitted.
The method of claim 3, wherein
It further comprises a voltage source for applying a constant voltage,
And after the stepwise reduction of the charging current by the charging current controller, supplying a constant voltage for charging the battery from the voltage source.
The method of claim 4, wherein
And a counter for counting the coincidence signal,
The charging current controller stops the stepwise supply of current from the current source to the battery as the counter counts a predetermined number of coincidence signals, and then supplies the charging constant voltage to the battery from the voltage source. Battery charger.
The method of claim 5, wherein
It further comprises a battery current value measuring unit for detecting a change in the current value of the battery according to the constant voltage supply,
And a constant voltage supply to the battery when the change rate of the current value measured from the battery current value measuring unit is 0.
The method of claim 5, wherein
And a display device which is lit according to the coincidence signal transmission.
Setting a gas generating voltage of the battery to be charged as the reference voltage Vr (S51);
Detecting the terminal voltage Vb of the battery in real time (S52);
Comparing the reference voltage value Vr with the terminal voltage Vb of the battery in real time (S53);
When the reference voltage value Vr and the battery terminal voltage value Vb coincide with each other, decreasing the charging current value Ich supplied from the current source to the battery (S54);
Repeating the steps S52 to S54 a plurality of times (S55),
And interrupting the supply of the constant current from the current source and applying a constant voltage from the voltage source to the battery (S56). The method of claim 8,
And a step (S57) of detecting a change in the current value of the battery according to the application of the constant voltage and terminating the battery charging when the current value change rate is 0.

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