JPH0618470B2 - Sealing lead-acid battery charging method and charging device - Google Patents

Description

The present invention relates to a method for charging a sealed lead acid battery and a charging device.

[Prior Art] Conventionally, as a method of charging a sealed lead-acid battery, a normal charging current is supplied until the charging voltage reaches the terminal charging voltage, and when the charging voltage reaches the terminal charging voltage, the charging current is changed to a minute charging current. There is known a charging method (for example, a trickle charging method) for switching to. A schematic configuration of an example of a conventional charging device for carrying out this charging method is as shown in FIG. This conventional device includes a DC power supply DC that rectifies an AC power supply to obtain a DC output, a current value switching circuit 10 that switches the current value of a charging current, and a charging end period that detects that the charging voltage has reached a charging end voltage. A voltage detector 20, and a current value switching control circuit 30 that outputs a current value switching command signal S1 for switching the charging current to a minute charging current to the current value switching circuit 10 when the detection signal S2 is output from the voltage detector 20. Is equipped with.

When attempting to charge a sealed lead-acid battery (hereinafter referred to as an over-discharge abandoned battery) after being left over-discharged by this device, there is a problem that the battery cannot be sufficiently charged if the internal resistance of the over-discharged battery becomes high. This is because when a conventional device charges an over-discharged battery with a high internal resistance, the charging voltage becomes higher than the end-of-charge voltage due to the high internal resistance immediately after starting charging, and the end-of-charge voltage detector 20 operates. This is because the charging current is switched to the minute charging current.

Therefore, in order to solve such a problem, the applicant first carried out charging in the opposite direction to normal charging for a predetermined period immediately after the start of charging of an overdischarged battery until the battery voltage became a negative state. A method has been proposed in which the battery is allowed to flow (hereinafter referred to as reverse charging), and the internal resistance of the over-discharged battery is lowered (Japanese Patent Application No. 61-16196).

[Problems to be Solved by the Invention] Even in an over-discharged battery, the internal resistance varies depending on the length of the standing time. Therefore, some over-discharged batteries have not so high internal resistance and some have relatively low internal resistance. When the internal resistance is relatively low, there is no need to dare to perform the reverse charging that takes time and shortens the battery life, and the normal charging method may be performed to perform the charging.
However, even if the internal resistance of an over-discharged battery is relatively low, the rise of the voltage at the initial stage of charging becomes unstable, and even if the internal resistance is small enough to make reverse charging unnecessary,
There is a problem that the charging voltage at the beginning of charging exceeds the terminal voltage at the end of charging, and unnecessary reverse charging is performed.

An object of the present invention is to provide a charging method and a charging method and apparatus suitable for carrying out the method, which solves the problems of the conventional techniques.

[Means for Solving the Problems] The method of the present invention is a method for charging a sealed lead-acid battery, which performs charging by switching the charging current to a minute charging current when the charging voltage reaches the end-of-charging voltage. The AC voltage component of the charging voltage is detected after the charging current is forcibly supplied for a predetermined period after the charging is started using the DC power supply including the above. When the AC voltage component is larger than the predetermined reference value, the reverse charging voltage is applied to the storage battery until the battery voltage has the reverse polarity, and then the normal charging operation is performed.

Further, in the device of the present invention, the charging voltage of the DC power supply 1 containing the AC voltage component by rectifying the output of the AC power supply AC and the charging voltage of the sealed lead-acid battery B is detected, and when the charging voltage exceeds the charging end voltage, the charging end period is reached. The end-of-charge voltage detector 4 that outputs the voltage detection signal S2, and the current-value switching control circuit 7 that outputs the current-value switching command signal S1 when the end-of-charge voltage detection signal S2 is output.
The above problem is solved in the sealed lead-acid battery charger including the current value switching circuit 2 that switches the charging current to the minute charging current when the current value switching command signal S1 is input. Therefore, in the charging device of the present invention, polarity switching is applied between the current value switching circuit 2 and the storage battery B, and the charging voltage is applied to the storage battery B in reverse polarity only during the period when the voltage polarity switching signal S5 is output. Switch circuit (SW21, SW
22), an AC voltage component detector 5 that detects an AC voltage component of the charging voltage and outputs an AC voltage component detection signal S3 when the AC voltage component is larger than a predetermined reference value, and an AC voltage component detection signal S3. Is output, the voltage polarity switching signal S5 is output to the polarity switching switch circuit for a predetermined period, and the current value switching stop signal S4 is output to the current value switching control circuit 7. A detection operation delay circuit 3 that delays the start of the detection operation of the end-of-charge voltage detector 4 and the AC voltage component detector 5 is provided until a predetermined period elapses. Further, the current value switching control circuit 7 is configured not to output the current value switching command signal S1 when the current value switching stop signal S4 is input.

[Operation of the Invention] It has been found as a result of research that the change in the charging voltage is stabilized to some extent when the charging current is forced to flow for a predetermined period after the start of charging. Particularly, in a battery having a relatively small internal resistance, a certain amount of charging current flows, so that the unstable change of the charging voltage is considerably stabilized, and the charging voltage drops to the final charging voltage or lower. On the other hand, the results of the study revealed that the charging voltage of a battery with a high internal resistance hardly flows, so that the charging voltage is only stabilized to some extent, and the charging voltage is still considerably higher than the terminal charging voltage.

It was also found that the internal resistance of the battery can be detected by detecting the AC voltage component in the charging voltage. However, even when detecting the internal resistance of the battery based on the AC voltage component, it was also found as a result of research that the internal resistance cannot be detected reliably when the charging voltage is unstable, such as at the beginning of charging. .

Therefore, in the method of the present invention, the charging voltage is stabilized to some extent by forcing the charging current to flow for a predetermined period after the start of charging. Then, the AC voltage component of the charging voltage which is stable to some extent is detected, and when this AC voltage component is larger than a predetermined reference value, the reverse polarity voltage is applied to the storage battery until the battery voltage has the reverse polarity, and the reverse charging is performed. To do. When reverse charging is performed, the internal resistance of the battery decreases, so that the charging voltage becomes equal to or lower than the end-of-charging voltage even if normal charging is performed later, and sufficient charging can be performed. Thereafter, as in the conventional case, when the charging voltage exceeds the terminal voltage of the charging, the charging current is switched to the minute charging current.

The apparatus of the present invention can implement the above method with a simple structure and without malfunction.

Embodiments Embodiments of the method and apparatus of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic circuit diagram of an embodiment of the present invention. In the figure, reference numeral 1 is a rectifier circuit that rectifies the output of the AC power supply AC that has been transformed into a predetermined voltage by a transformer T. In this embodiment, this rectifier circuit is a full-wave rectifier circuit with two diodes D11 and D12. It is configured. A current value switching circuit 2 that switches the charging current to a minute charging current when the current value switching command signal S1 is input is connected to the positive output terminal of the rectifier circuit 1. In the current value switching circuit 2, for example, an impedance capable of supplying a normal charging current is inserted into the energizing circuit until the signal S1 is input, and when the signal S1 is input, the charging current becomes a minute charging current or a trickle charging current. The charging current value is switched by inserting the impedance to be switched into the energizing circuit.

The switches SW21 and SW22 are provided between the current value switching circuit 2 and the storage battery B, and constitute a polarity switching switch circuit that applies the charging voltage to the storage battery B in reverse polarity only during the period when the voltage polarity switching signal S5 is output. To do. These switches SW21 and SW22 are electromagnetic switches, and when a current flows through the coil L2 of the electromagnetic relay of the voltage polarity switching circuit 6 which will be described later, these switches make contact from the contact a so as to apply a reverse voltage to the storage battery B. Switch to b. Also switch S
W11 and SW12 are normally open electromagnetic switches, which are closed when a current is applied to the coil L1 of the electromagnetic relay of the detection operation delay circuit 3.

The detection operation delay circuit 3 is a circuit that delays the start of the detection operation of the end-of-charge voltage detector 4 and the AC voltage component detector 5 until a predetermined period elapses from the start of charging. This detection operation delay circuit 3 includes normally open contact switches SW11 and SW.
It has a coil L1 of an electromagnetic relay that drives 12, and when the switch SW is closed to perform charging, time counting is started and a predetermined time period (about 10 minutes in this embodiment).
Is counted, a current is applied to the coil L1. The time limit is set to an appropriate length according to the type of storage battery.

The end-of-charge voltage detector 4 detects the charge voltage of the sealed lead storage battery B when the switch SW11 is closed, and outputs the end-of-charge voltage detection signal S2 when the charge voltage exceeds the end-of-charge voltage. The AC voltage component detector 5 detects the AC voltage component of the charging voltage when the switch SW12 is closed,
When the AC voltage component is equal to or larger than the reference value, the AC voltage component detection signal S3 is output. This detector 5 detects an AC voltage component, that is, a pulsating voltage component, from the charging voltage in order to detect the internal resistance of the storage battery B. Then, when the AC voltage component is detected, the reference value to be compared with the detected AC voltage component corresponds to the internal resistance that requires reverse charging, by previously examining the relationship between the internal resistance of the storage battery and the AC voltage component. The voltage value corresponding to the AC voltage component is used as the reference value.

6 is a polarity changeover switch circuit (switches SW21 and S21) for a predetermined period when the AC voltage component detection signal S3 is input.
The voltage polarity switching circuit outputs a voltage polarity switching signal S5 to W22) and a current value switching stop signal S4 to the current value switching control circuit 7. This voltage polarity switching circuit 6
The voltage polarity switching command signal 6a for outputting the current value switching stop signal S4 and the voltage polarity switching signal S5 and the output of the voltage polarity switching command circuit 6a are output for a predetermined period (about 1 hour in the embodiment).
It is composed of a reverse voltage application stop timer circuit 6b for stopping the reverse voltage application to the storage battery B after a lapse of time.
After the reverse voltage application stop timer circuit 6b outputs the stop signal S6, the output of the signal from the voltage polarity switching command circuit 6a is stopped.

In principle, the current value switching control circuit 7 outputs the current value switching command signal S1 when the terminal charging voltage detector 4 outputs the terminal charging voltage detection signal S2, but the current value switching stop signal S4 is input. Even when the end-of-charge voltage detector 4 outputs the end-of-charge voltage detection signal S2, the current value switching command signal S1 is not output. Therefore, while the reverse voltage is applied to the storage battery B, the charging current is not switched to the minute charging current by the current value switching circuit 2.

Next, the operation of the apparatus shown in FIG. 1 will be described. First, FIG. 2 shows charging characteristics when an over-discharged battery having a high internal resistance was charged according to the present invention. This battery is a HP4-4C type battery having an internal resistance of about 400Ω and was charged at a temperature of 25 ° C. When the switch SW is closed, the detection operation delay circuit 3 starts counting time. Until the detection operation delay circuit 3 completes counting the preset time period, the switches SW11 and SW12 are open, the end-of-charge voltage detector 4 and the AC voltage component detector 5 do not operate, and during this period, the battery is forcibly forced. A charging voltage is applied to B to perform forced charging.

However, when the internal resistance is high, the charging current I hardly flows, and even when the detection operation delay circuit 3 completes counting the time limit and the switches SW11 and SW12 are closed, the charging voltage V remains at the end of charging. It is in a state considerably larger than the voltage Vs. Therefore, when the switch SW11 is closed, the end-of-charge voltage detector 4 immediately outputs the end-of-charge voltage detection signal S2 to the current value switching control circuit 7. The AC voltage component of the charging voltage V at this time is considerably larger than the reference value. Therefore, when the switch SW12 is closed, the AC voltage component detector 5 immediately outputs the AC voltage component detection signal S3, and in response to this, the voltage polarity switching command circuit 6a outputs the current value switching stop signal S4 and the voltage. The polarity switching signal S5 is output. The AC voltage component detector 5 has a reference value that is compared with the detected AC voltage component to detect the internal resistance of the battery. When determining this reference value, the relationship between the internal resistance of the storage battery and the AC voltage component is checked in advance, and the voltage value corresponding to the AC voltage component corresponding to the internal resistance that requires reverse charging is used as the reference value.

The current value switching control circuit 7 does not output the current value switching command signal S1 while the current value switching stop signal S4 is being applied, even if the signal S2 is output from the end-of-charge voltage detector 4. Therefore, the current value switching circuit 2 is maintained as an impedance that allows a normal charging current to flow. When the voltage polarity switching signal S5 is energized from the voltage polarity switching command circuit 6a to the coil L2, the switches SW21 and SW22 are switched to the contact b side, and the battery B is applied with the voltage of the opposite polarity. Even if the switches SW21 and SW22 are switched,
The voltage polarity switching command circuit 6a is configured to continue to output the signals S4 and S5 until the reverse voltage application stop timer circuit 6b completes counting for a preset time period.
In this embodiment, a time limit of about 1 hour is set. This time period is the time required for the battery voltage of the storage battery, that is, the terminal voltage, to have a reverse polarity and the internal resistance of the battery to be sufficiently low when a reverse voltage is applied, and is appropriately set according to the type and temperature of the battery. Adjusted.

When the timer circuit 6b completes the timed counting, the outputs of the signals S4 and S5 are stopped, the switches SW21 and SW22 are switched to the contact a side, and the charging voltage of the regular polarity is applied to the battery B. . At this time, since the internal resistance of the battery B is lowered by the reverse charging, the detection signal S2 is not output from the end-of-charge voltage detector 4 even if the switch SW11 is closed. Therefore, after that, charging is performed in the same manner as normal charging, and when the charging voltage V reaches the end-of-charge voltage Vs, the end-of-charge voltage detector 4 outputs the detection signal S2, and the current value is received in response to this signal S2. The switching control circuit 7 outputs the current value switching signal S1 to the current value switching circuit 2. As a result, the charging current I is switched to the minute charging current,
Enter trickle charging.

Even if the internal resistance of the battery B is not very high and the rising of the charging voltage in the initial stage of charging is unstable, the AC voltage component of the charging voltage should be measured after the charging current is forcibly supplied to stabilize the charging voltage to some extent. For example, it is possible to detect with high accuracy whether or not the internal resistance is high enough to require reverse charging, and therefore the reverse charging operation can be reliably performed.

FIG. 3 shows charging characteristics when an over-discharged battery having a relatively low internal resistance was charged according to the present invention. This battery was a HP4-4C type battery having an internal resistance of about 3.67Ω and was charged at a temperature of 25 ° C. When the internal resistance is as low as this, it is possible to perform sufficiently normal charging, and thus it is not necessary to perform reverse charging. However, even if the internal resistance is low, as shown in the figure,
The rising of the charging voltage at the initial stage of charging may be high. According to the present invention, the charging voltage is stabilized by forcibly flowing the charging current for a predetermined time at the initial stage of charging.
Therefore, when the detection operation delay circuit 3 completes the time counting and closes the switches SW11 and SW12 (time t in FIG. 2).
At the time of 1), the charging voltage of the battery having a small internal resistance is equal to or lower than the terminal charging voltage Vs. In a battery with a small internal resistance, the AC voltage component that is substantially proportional to the magnitude of the internal resistance is also small, and naturally, no detection signal is output from the AC voltage component detector 5 and the end-of-charge voltage detector 4, Normal charging is performed.

(Specific Embodiment) FIG. 4 shows a specific circuit configuration of the embodiment of FIG. 1 excluding the DC power source portion. In the figure, the same parts as those in the configuration of FIG. 1 are designated by the same reference numerals as those shown in FIG. The current value switching means 2 is composed of resistors R1 and R2 and transistors Tr1 and Tr2. The resistance values are in the relationship of R1> R2. Transistor Tr1
When is on, the resistors R2 and R1 are inserted in parallel into the charging circuit to allow a large charging current to flow, and when the transistor Tr1 is cut off, a minute charging current is allowed to flow through the resistor R1. When the transistor Tr1 is turned on, the light emitting diode LED emits light to display the charging state.

The current value switching control circuit 7 is composed of transistors Tr3, Tr4 and Tr5 and resistors R4, R5 and R6. Until the detection operation delay circuit 3 completes counting, a base current is supplied to the transistor Tr3 through the resistor R7, When Tr3 becomes conductive, the current value switching circuit 2
A conduction signal is applied to the transistor Tr1.

The detection operation delay circuit 3 includes a first timer circuit including a resistor R23, a capacitor C5, and a Zener diode ZD3. When charging is started and a charging voltage is applied to the battery B, the capacitor C5 has a predetermined value. When the charging voltage of the capacitor C5 exceeds the zener voltage of the zener diode ZD3, the transistor TR9 becomes conductive and a current flows through the coil L1. As a result, the switches SW11 and SW12 are closed and the detection operation is started.
The power source for charging the capacitor C5 is a constant voltage circuit including a resistor R10 and a zener diode ZD2.

When the switch SW11 is closed, the end-of-charge voltage detector 4
A charging voltage is applied to the Zener diode ZD1. When the charging voltage is equal to or higher than the end-of-charging voltage and the charging voltage exceeds the Zener voltage of the Zener diode ZD1, the Zener diode ZD1 becomes conductive and the thyristor SCR
An ignition signal is supplied to the gate of 1. As a result, the thyristor SCR1 becomes conductive and the transistor Tr3 is cut off. At this time, if the internal resistance of the battery B is low and the AC voltage component detector 5 does not output the AC voltage component detection signal S3, the transistor Tr4 is in a non-conducting state, so that the transistor Tr3 By the cutoff, the transistor Tr1 of the switching circuit 2 is cut off, and the charging is switched to the charging of the minute charging current.

When the internal resistance of the battery B is large, the AC voltage component detector 5 outputs the AC voltage component detection signal S3, so that the transistor Tr4 is in the conductive state and the transistor Tr3 is in the conductive state.
Even if is cut off, the cutoff of the transistor Tr1 is blocked. The AC voltage component detector 5 includes a capacitor C6 and a resistor R.
By subtracting the direct current component from the charging voltage with 25, only the alternating voltage component is input. The AC voltage component amplified to a predetermined value through the operational amplifier OP2 charges the capacitor C7, the terminal voltage of the capacitor C7 is input to the + input terminal of the operational amplifier OP3 that constitutes the comparator, and the resistor R11 and the variable resistor VR1 are used. It is compared with the reference voltage output from the configured first reference voltage setter. This reference voltage is a voltage value corresponding to an AC voltage component corresponding to the internal resistance that needs to be reverse-charged by previously examining the relationship between the internal resistance of the storage battery and the AC voltage component. Therefore, when the internal resistance of the battery is high enough to require reverse charging, the operational amplifier OP3 outputs the detection signal S3.

When the detection signal S3 is output, the thyristor SCR2 of the voltage polarity switching circuit 6 becomes conductive, and as a result, the transistor Tr
7 and the transistor Tr6 become conductive, and the transistor T
When r8 becomes conductive, an exciting current is passed through the coil L2, the switches SW21 and SW22 are switched, and the battery B
A reverse voltage is applied to.

In the voltage polarity switching circuit 6, the resistor R13 and the capacitor C3 compose a second timer circuit, and the capacitor C3 is generated from the reference voltage set by the second reference voltage setting device including the resistor R12 and the variable resistor VR2. When the terminal voltage of is increased, the output is not output from the operational amplifier OP1. The time when the operational amplifier OP1 stops the output is the time when the reverse charging is stopped. Until then, an output is output from the operational amplifier OP1, and when the transistor Tr7 becomes conductive, the transistor Tr6 also becomes conductive immediately. When the AC voltage component detector 5 outputs the signal S3 and the thyristor SCR2 becomes conductive, the transistor Tr7 becomes conductive, the transistor Tr6 becomes conductive, and as a result, the transistor TR8 becomes conductive. Then, when the output from the operational amplifier OP1 is stopped, the transistor TR8 is cut off and the switches SW21 and SW22 are switched to the contact a side.

When the thyristor SCR2 is turned on and the transistor Tr6 is turned on, a conduction signal (current value switching stop signal S is sent to the transistors Tr4 and Tr5 through the resistors R4 and R6).
4) is applied, these transistors become conductive.
The transistor Tr5 keeps the thyristor SC during the reverse charging period.
Thyristor SCR by shorting the anode and cathode of R1
It plays the function of blocking 1. This is to prevent trickle charging due to a minute charging current if the thyristor SCR1 is conducting when the reverse charging is restored to normal charging, and this is prevented. The second timer circuit (R13, C3) completes the counting of the time limit and the operational amplifier O
When the output of P1 disappears, the transistors Tr4 and Tr5
And Tr8 are shut off, and normal charging is resumed.

In the above embodiment, the switches SW11 and the like are composed of electromagnetic switches, but it goes without saying that semiconductor switch circuits may be used as these switches.

[Effects of the Invention] According to the present invention, an overdischarge left battery that requires reverse charging and an overdischarge left battery that does not require reverse charging are clearly distinguished, and overcharge left with high internal resistance that requires reverse charging. Only the battery can be reliably reverse-charged, and the over-discharge left-standing battery with low internal resistance that does not require reverse charging can be quickly charged by the normal charging method without performing reverse charging.

Further, the apparatus of the present invention has an advantage that the method of the present invention can be reliably performed with a simple configuration.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, FIG. 2 is a diagram showing charging characteristics when an over-discharged battery having a high internal resistance is charged in the embodiment of FIG. 1, and FIG. FIG. 4 is a diagram showing charging characteristics when an over-discharged battery having a low resistance is charged in the embodiment of FIG. 1, FIG. 4 is a specific circuit diagram of the embodiment of FIG. 1,
FIG. 5 is a diagram showing a schematic configuration of a conventional charging device. 1 ... Rectifier circuit, 2 ... Current value switching circuit, 3 ... Detection operation delay circuit, 4 ... End-of-charge voltage detector, 5 ... AC voltage component detector, 6 ... Voltage polarity switching circuit, 7 ... ... Current value switching control circuit, SW21, SW22 ... Polarity switching switch circuit, B ... Sealed lead acid battery.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kensuke Hironaka 2-1-1 Nishishinjuku, Shinjuku-ku, Tokyo Inside Shin-Kindo Electric Co., Ltd. (72) Akio Komaki 2-1-1 Nishishinjuku, Shinjuku-ku, Tokyo No. 1 Shinshin Toden Electric Co., Ltd.

Claims (2)

[Claims] 1. A method for charging a sealed lead-acid battery, wherein charging is performed by switching a charging current to a minute charging current when the charging voltage reaches an end-of-charging voltage, and a predetermined value after starting charging by using a DC power supply containing an AC voltage component in its output. The AC voltage component of the charging voltage is detected after the charging current is forcibly supplied for a period of, and when the AC voltage component is larger than a predetermined reference value, a reverse polarity voltage is applied to the storage battery until the battery voltage has a reverse polarity. A method for charging a sealed lead-acid battery, which comprises performing a normal charging operation after applying the voltage. 2. A DC power supply for rectifying the output of an AC power supply AC to output a DC voltage containing an AC voltage component, and a charging voltage of a sealed lead-acid battery B is detected and the charging voltage exceeds a terminal voltage of charging. And an end-of-charge voltage detector 4 that outputs an end-of-charge voltage detection signal S2, a current-value switching control circuit 7 that outputs a current-value switching command signal S1 when the end-of-charge voltage detection signal S2 is output, and the current value In a sealed lead acid battery charging device comprising a current value switching circuit 2 for switching a charging current to a minute charging current when a switching command signal S1 is input, between the current value switching circuit 2 and the storage battery B. And a polarity changeover switch circuit (SW21, SW22) for applying the charging voltage to the storage battery B in reverse polarity only during a period in which the voltage polarity switching signal S5 is output, and an AC voltage component from the charging voltage. An AC voltage component detector 5 which detects and outputs an AC voltage component detection signal S3 when the AC voltage component is larger than a reference value, and the polarity changeover switch only for a predetermined period when the AC voltage component detection signal S3 is output. The voltage polarity switching circuit 6 that outputs the voltage polarity switching signal S5 to the circuit and outputs the current value switching stop signal S4 to the current value switching control circuit 7.
And a detection operation delay circuit 3 that delays the start of the detection operation of the end-of-charge voltage detector 4 and the AC voltage component detector 5 from the start of charging until a predetermined period of time elapses. 7 is the current value switching stop signal S
4 is input, the current value switching command signal S
A sealed lead-acid battery charging device, which is configured so as not to output 1.