Content:
Basic methods for restoring and training batteries
Restoring batteries using the method of long-term charging with low currents
This method is successfully used for minor and not old sulfation of battery plates. The battery is connected to charging with a normal current value (10% of the total battery capacity). Charging is carried out until gases begin to form. After which there is a break for 20 minutes. At the second stage, the battery is charged, reducing the current value to 1% of the capacity. Then take a break for 20 minutes. Repeats charging cycles several times
Restoring batteries using the method of deep discharges with low currents
To restore a battery with signs of old sulfation, the battery charging method is used with recharging with currents of normal magnitude and subsequent long-term deep discharge with low current values. By performing several cycles of strong discharge with low currents and normal charging, the battery can be successfully restored.
Restoring batteries using cyclic current charging method
The battery is tested and the internal resistance of the battery is measured. If the actual resistance exceeds the factory-set value, the battery is charged with a low current, after which a break of 5 minutes is taken and the battery begins to discharge. Take a break again and repeat the cycles “charge - break - discharge - break” many times.
Restoring batteries using pulsed currents
The essence of the method is to supply a pulsed current to charge the battery. The amplitude of the current value in pulses is 5 times higher than normal values. Maximum values amplitudes can briefly reach 50 Amps. The pulse duration is short - a few microseconds. With this charging mode, lead sulfate crystals melt and the battery is restored
Restoring batteries using the constant voltage method
The essence of the method is to charge the battery with current DC voltage, while the current strength changes (usually decreases). At the same time, at the first stage of the charging process, the current is 150% of the battery capacity and gradually decreases to low values over time
- professional device for restoring and training batteries
SKAT-UTTV is a modern automatic device for testing, training, recovery, charging and resuscitation of lead-acid batteries various types (sealed and open type). The device makes it possible to determine how long the battery can last in the future, charge it, and restore a battery with a reduced capacity. The device has a convenient user interface; all operating modes and charge and discharge parameters are displayed on digital display
Capabilities of the device for restoring and training batteries
- The device determines the residual capacity of the battery using the test discharge method, normal battery charging, accelerated battery charging, restoration of batteries with sulfated plates, training batteries using alternating charge and discharge cycles, forced charging of a heavily discharged battery.
- The device has effective protection from a short circuit in the circuit, electronic protection from incorrect connection to the battery terminals, reliable protection from the process of overheating of device elements, clear light indication of device operating modes, display of battery parameters and device operating modes.
Methods for restoring and training batteries of the SKAT-UTTV device
The device uses following methods charging, training and restoring batteries:
- charge DC values of 10% of the battery capacity until the voltage threshold is reached;
- charge with direct current 5% of the battery capacity until the voltage threshold is reached;
- constant voltage charge with automatic selection of current value;
- charge with direct current 20% of the battery capacity until the voltage threshold is reached;
- charge with constant voltage until the battery capacity threshold is reached;
- charge asymmetrical current with alternating pulses optimal charge, selected automatically until the battery voltage threshold is reached; discharge with a low-value direct current from 5% of the battery capacity until the minimum voltage threshold is reached.
During the process of charging, training and restoring the battery, the device automatically selects programs for using all methods on various cycles.
It is possible to program custom programs for charging, training and restoring batteries by installing following parameters operating modes: choice of method, number of operating cycles, values of electrical parameters, values of operation limits.
The device is designed for professional battery recovery various types, including car batteries and batteries for uninterruptible power supplies. Using the device makes it possible to significantly increase the life of batteries in various devices.
Many car owners believe that the “life” of a battery depends only on the quality of its manufacture, so they buy imported batteries. Some car magazines even suggest that the battery life should be no more than a century. This is, of course, very beneficial. paniyam - producers.
Practice shows that if you monitor the electrolyte level and perform training cycle (full discharge followed by a full charge), then the battery life can be increased to 9 years while maintaining sufficiently high parameters (capacity and maximum discharge current). Carrying out training cycles not only extends the life of the battery, but also increases the maximum discharge current (reduces internal resistance).
But training cycles (especially eliminating sulfation) take a lot of time. Therefore, many descriptions of automatic chargers have been published in amateur radio literature, each of which has both advantages and disadvantages.
I propose another device, which, with a simple circuit, has wide functionality.
The scheme consists it from a voltage stabilizer (microcircuit DA 1), Schmitt trigger (elements DD 1.1, DD 1.2), counter of discharge-charge cycles (microcircuit DD 2) with a unit indicating the status of this counter(R 8... R 1 3, VT 1... VT 6, VD 4... VD 9), two keys (VT 7, VD 2, K1 and VT 8, VD 3, K2), inverter DD 1.3, power rectifier(HL 2, T1, VD 10.... VD 1 3) and load resistance, the role of which is played by the lamp HL 1.
On-chip voltage stabilizer DA 1 serves to power microcircuits DD 1, DD 2, as well as a reference voltage source for monitoringbattery voltage. Schmitt trigger controls the key VT 7, VD 2, K1. On-chip counter DD 2 counts the number of discharge-charge cycles and controls the key VT 8, VD 3, K2, which turns off the load HL 1 from the battery.
The device works as follows. First you need to connect the battery to the device G.B. 1. At the same time, at the output of the stabilizer DA 1 a voltage of +5 V appears, and the resistor R 15 a short positive voltage pulse is generated, setting the counter DD 2 to zero state. At the same time, its output is 0 high level, which opens the transistor VT 1 . LED lights up VD 4. If the voltage of the connected battery is less than 15 V, then at the trigger output (pin 3 DD 1 .1) - "1", transistor VT 7 is open and relay K1 is on. Relay K2 is also turned on, since pin 5 DD 2 - “O”, respectively, at the output (pin 10) DD 1.3 is "1", and VT 8 is open.
The device is connected to a 220 V network. This starts charging the battery G.B. 1. Charging current flows through the circuit: diodes VD 10....VD 13, closed contacts K1.1, battery GB 1. Magnitude charging current limited by incandescent lamp resistance HL 2, connected to the gap in the primary winding of transformer T1. As the battery charges, the voltage across it and the resistor R 2 increases. When the voltage is on GB 1 reaches 15 V, the Schmitt trigger switches, at pin 3 DD 1.1 - "0", and the transistor VT 7 closes. Relay K1 releases, and its contacts K1.1 switch the battery to discharge (connect a load - a lamp HL 1 ). The battery discharge current is determined by the lamp resistance HL1.
In this case, the voltage drop from the trigger output (pin 4 DD 1.2) goes to pin 14 of the counter DD 2 and switches it to the next state, i.e. "1" at output 1. Then the transistor opens VT 2, and the LED lights up VD 5.
As the battery discharges, the voltage across it (and across the resistor) R 2) decreases. When the tension GB 1 decreases to 10.7 V, the trigger switches again, the transistor VT 7 opens. Relay K1 is activated and switches the battery to charging. After several charge cycles- discharge when the counter is triggered again DD 2 "1" appears on its pin 5,accordingly, at the output DD 1 .thirty". Transistor VT 8 closes, relay K2 releases, and the lamp HL 1 disconnects from the battery. This concludes the battery training. Then both relays are turned off, and the battery is discharged with a small current equal to total current chip consumption DDI,DD 2,DA 1 (total about 4 mA).
The number of battery training cycles can be changed by connecting the inputs (pins 8 and 9) of the element DD 1 .3 to different outputs of the microcircuit DD 2. The charging and discharging current of the battery is regulated by the selection of lamps HL 1 and HL 2 (HL 1 must be designed for a voltage of 12 V, aHL 2 - at 220 V). Using resistors R 2 and R 3 You can widely adjust the battery voltage thresholds at which the trigger switches. Wherein R 3 adjusts the hysteresis width of the trigger characteristic, a R 2 simultaneously and proportionally changes both threshold response voltages.
The described method of training a battery, when it is completely discharged (to a voltage of 10.7 V) and then fully charged (to 15 V), is “classic”. Special literature recommends other training methods, for example, this regimen. The battery is fully charged to a voltage of 15 V and disconnected from the charger. When the voltage dropson it to 12.8 V, the battery is again connected to the charger and its voltage is brought to 15 V. The process is repeated several times. The proposed device allows you to implement this mode. For this lamp HL 1 is excluded from the scheme, and HL 2 such power is selected so that the battery charging current is about 0.05 of its rated capacity. During breaks between charges, the battery will be discharged with a current of approximately 4 mA.
Capacitor C1 suppresses voltage ripple at the trigger input, which improves the clarity of its operation. Diode VD 1 limits the voltage on C1 within 0...5 V (in principle, VD 1 can be excluded). The voltages at which the trigger operates are quite stable, because chip DD 1 is powered by a stabilized voltage.
Replacement of parts must be carried out in accordance with their electrical characteristics. It is advisable to replace the K561 series microcircuits with 564 series microcircuits, because the latter have a wider temperature Range. Headlight switch relays (90.3747-01) from a UAZ car were used as K1 and K2. The power of transformer T1 must be at least 150 W (for charging a 12-volt battery with a current of 6 A). In order for the lamp HL 2 effectively limited and stabilized the charging current, sufficient power should be released on it, so the voltage idle move transformer must be within 19....30 V. Pampu HL 2 can be replaced with a capacitor large capacity, but practically this is inconvenient, because It is difficult to select the right capacitor, and the charging current will not stabilize.
For ease of use, you can add a switch to the circuit that changes the number of charge-discharge cycles. It must alternately connect the inputs DD 1.3 to DD 2 outputs. To increase the efficiency of the device in the off state, you can install toggle switches that turn off the LEDs(VD 6....VD 9).
For example, if you connect the inputs DD 1.3 to pin 7 DD 2, then LED VD 7 must be turned off, otherwise the current consumption will increase from 4 to 15 mA. To reduce current consumption, you can also increase the resistance R 7 up to 3 kOhm, but this will reduce the brightness of the LEDs. The initial (zero) position of the PA1 ammeter needle should be in the middle of the scale, and the current measurement range should be 1.0...10 A.
The device is housed in two metal cases. One contains the power supply(VD 10 ...VD 13, T1, FU 1), in the other - all other elements (except for the lamp H.L. 1). Connecting the elements, as well as connecting the lamp HL 1 and battery connection is carried out using standard plugs and sockets (220-volt) mounted on the housings.
Setting up a properly assembled device consists mainly of setting the threshold trigger voltages. To do this, the device is disconnected from the network, the lamp is disconnected HL 1, and instead of a battery, an adjustable constant voltage source is connected to the device. Changing resistance R 2 and R 3, the required response voltages are set (the response times are determined by the clicks of relay K1).
1. K. Kazmin. Automatic charger. To help the radio amateur. Vol. 87. - M.: DOSAAF, 1978.
2. V. Sosnitsky. Automatic charger. To help the radio amateur. Vol. 92. - M.: DOSAAF, 1986.
3. A. Korobkov. Device for automatic battery training. To help the radio amateur. Vol. 96. - M.: DOSAAF.1987.
4. A. Korobkov. Automatic attachment for the charger. To help the radio amateur. Vol. 100. - M.: DOSAAF, 1988.
5. N. Drobnitsa. Automatic charger. To help the radio amateur. Vol. 77. - M.: DOSAAF, 1982.
Section: [Chargers (for cars)]
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The described device is intended for servicing acid batteries with rated voltage 12 V and capacity from 40 to 100 Ah. The device is powered from the mains alternating current voltage 220 V and consumes no more than 25 W when not charging and no more than 180 W at maximum charging current.
The proposed device uses a pseudo-combined method, in which the battery is discharged to a voltage of 1.7-1.8 V on each battery, and then recharged in cycles. The criterion used to control the charging process is the voltage on the battery, which is functionally related to the degree of its charge. Charging in each cycle ends when the voltage at the battery terminals reaches 14.8-15 V, and resumes when it drops to 12.8-13 V.
To automatically train the battery, the device discharges the battery to a voltage of 10.5 - 10.8 V, automatically switches to charging mode and carries it out in cycles as indicated above.
The device can operate in one of three modes:
- in the first mode “Shch” two options are possible: either charging in cycles, or discharging to a voltage of 10.5 - 10.8 V, and then charging in cycles;
- in the second mode “NC” there is a multiple transition from charging to discharging when the voltage at the battery terminals reaches 14.8 - 15V and from discharging to charging when the voltage at the terminals is 10.5 - 10.8V;
- manual mode “RZ” corresponds to the operation of a conventional charger without automation.
The battery is discharged with a current of 2 - 1.7A, and charged with a current of 2 or 5A (in the first case it varies from 2 to 1.5A, in the second - from 5.8 to 4.5A).
Operation of device components
Step-down transformer T1 provides an alternating voltage of about 19 V on the secondary winding. Using diodes VD1 - VD4, a pulsating voltage with an amplitude of about 27 V is obtained, and after diode VD6, a constant voltage of about 26 V is formed on capacitor C1, which is necessary to power the automation unit. A pulsating voltage is applied to the anode of thyristor VS1. If the appropriate voltage is applied to the control electrode of the thyristor, the thyristor will open and pass current to charge the battery through lamps HL2 - HL6 and switch SA3.
The charging current is limited by incandescent lamps HL2 (in “2A” mode) or HL2 - HL4 (in “5A” mode). The battery is discharged through transistor VT13 and resistors R25, R26.
The thyristor and transistor VT13 are controlled by the automation unit. It contains a reference voltage source (resistor R17, zener diodes VD10, VD11), a discharge threshold switch (transistors VT6, VT7, resistors R19 - R21), a discharge current signal amplifier (transistors VT9, VT11, VT12), a charging threshold switch (transistors VT2 + VT5 with corresponding resistors, including R12, R16), a charging current signal amplifier (transistors VT1, VT8) and charging signal inhibition elements (diode VD12, transistor VT10).
The discharge threshold switch is connected to the output terminals of the device X1 and X2, intended for connecting the battery. The voltage present on them is both the supply voltage and the controlled voltage of the switch.
Radio amateurs know an analogue of a thyristor, consisting of two transistors different structures. The analogue is capable of external signal go to open state and maintain it as long as at least one of the transistors is in saturation. Turning off occurs when the current decreases to a threshold value, when both transistors come out of saturation.
The threshold switch is made with similar connections, but not directly, but through resistors, with the emitter of one of the transistors connected to the reference voltage, and the base to the voltage divider. Thanks to this, the threshold switch has temperature stability of the switching threshold voltage. Set the switch to a threshold voltage of 10.5-10.8V using trimming resistor R19.
The discharge current signal amplifier consists of a chain of transistors with an alternating structure. Transistors operate in switching mode. The operation of one of them (VT11) is made dependent on the presence of a voltage of 26 V. This is done to stop the discharge of the battery in the event of an emergency shutdown of the mains voltage.
The threshold charging switch consists of a transistor amplifier (VT5), a Schmitt trigger (VT2, VTЗ) and a key transistor (VT4). The latter is designed to eliminate the influence of the lower switching threshold (resistor R12) on the upper one (resistor R16).
The charging current amplifier, like the discharge current amplifier, consists of a chain of transistors of different structures operating in switching mode. Wherein collector current transistor VT1 can flow through the base circuit of transistor VT8 when transistor VT10 is closed (i.e., no discharge).
Diode VD12 increases the reliability of closing transistor VT8 when opening transistor VT10 (when the battery is discharging and current should not flow through the control electrode of the thyristor). The VD7 diode protects the thyristor control electrode from reverse current, which could occur when the network is turned off and the battery is connected.
Chain C2, R15, VD9 is needed for charging a deeply discharged or sulfated battery, when a pulsating voltage may occur at its terminals. Thanks to the diode VD9, a smoothed voltage appears on capacitor C2. Without this chain, voltage surges could prematurely bring the threshold switch out of charging mode.
Rice. 1. Schematic diagram of a device for automatic battery training.
Capacitor C3 plays the role of a kind of battery and is used to monitor the health of the device. In the “CONTROL” position of switch SA3, it can only be charged through the diode VD12 and resistor R34, and discharged through the automation unit. Since in the “1C” and “NC” modes the charging and discharging processes occur with a repetition period of about 1 second, the needle oscillations will be observed on the PV1 voltmeter, reflecting the switching threshold voltages and the controllability of all charging circuits and the threshold switch.
Terminals X3 and X4 with a voltage of 12.6 V are intended for connecting a vulcanizer, a backlight lamp, a small-sized soldering iron and other loads with a power of up to 100 W.
Let's take a closer look at the operation of the device in various modes when switch SA3 is set to the “CONTROL” position (the battery is not connected).
In the “1C” mode, after supplying the unit with mains voltage on capacitor C3, the voltage does not increase because there is no base current of transistor VT1. To ensure initial operating conditions, switch SA4 briefly sets the “P3” mode and returns to the “1C” position. After this, the threshold switch begins to work, prohibiting charging when the voltage on the capacitor rises above the set maximum (14.8-15V) and allowing it if it falls below the set minimum (12.8-13V).
When switch SA4 is switched to “NC” mode, voltage is supplied to the collector of transistor VT7 through diode VD8, and the threshold switch is activated, allowing discharge. In this case, the open transistor VT10 prohibits charging, and capacitor C3 is discharged through the automation unit to a voltage of 10.5 4-10.8 V.
After the threshold switch is flipped, transistor VT10 closes, the collector current of transistor VT1 flows through diode VD12 and the base circuit of transistor VT8. This transistor, and after it the thyristor, opens. A charging current flows through capacitor C3, and the voltage across the capacitor rises to 14.8-15V.
During this control, the discharge elements remain unchecked, since defects such as an open circuit in the circuits of transistors VT11 - VT13 will not affect the readings of the voltmeter PV1. To control the operation of these elements, switch SA3 is set to the “CHARGE” position - then in the “NC” mode, capacitor C3 will be discharged mainly through transistor VT13. As a result, the HL7 “DISCHARGE” lamp will begin to blink, indicating that the discharge circuits are working properly.
The device works similarly with a connected battery. In the “1C” mode, charging cycles immediately begins (meaning that the battery voltage does not exceed the threshold voltage of 12.8-13V).
The HL6 lamp lights up at a charging current of 2 A or HL5 at a current of 5 A. By pressing the button switch SB1 “DISCHARGE”, voltage is applied to the triggering input of the threshold switch, causing it to operate. Discharge is indicated by the HL7 lamp.
In the “NC” mode, when the battery is connected, work can begin with both charging and discharging - depending on what mode the threshold switch was in at the time of switching on. If you want to set a specific mode, switch SA1 is first set to the “1C” position, and then to the “NC” position.
In mode manual charging The "P3" switch contacts block the threshold switch, and the thyristor is controlled directly from the DC source.
Device setup
To set up the device you will need an adjustable DC source with maximum voltage 15 V and a load current of at least 0.2 A, a test voltmeter or signal lamp for a voltage of 27 V.
Before setting up, the trimmer resistor sliders are set to the maximum resistance position, a control voltmeter or warning light connect between the VT8 collector and the common wire (clamp X2), and the power source is connected (maintaining polarity) to the output terminals of the device. Switch SA4 is set to the “1C” position, switch SA3 is set to the “CONTROL” position. The output voltage of the DC source should be 14.8 - 15V.
After connecting the device to the network, the control voltmeter should have a voltage of about 26 V. Smoothly move the slider of the trimming resistor R16, ensure that the control voltage drops abruptly to zero.
Set the voltage at the source to 12.8 - 13V and smoothly move the slider of resistor R12 until a voltage surge of 26 V appears on the control voltmeter. Press the SB1 button - the controlled voltage should drop to zero again. Having set the voltage at the source to 10.5-10.8V, move the slider of resistor R21 until a voltage of 26V appears on the control voltmeter.
After this, you should check and, if necessary, select more precisely the levels of operation of the machine when the voltage of the power source changes.
Setting the upper threshold of 15 V does not cause the electrolyte to boil off after fully charged batteries, because in this case the battery is automatically turned on for charging for 8 - 10 minutes and turned off for about 2 hours. Observations have shown that when operating in this mode, even for several months, the electrolyte level in the battery banks does not decrease.
Details
Fixed resistors: R33 - vitrified wire type PEV-20 or two resistors (connected in parallel) of 15 Ohms (type PEV-10), the rest - MLT of the power indicated on the diagram, tuning resistors R12, R16, R21 - type PPZ or others.
In addition to those indicated in the diagram, transistors VT1 VT5 VT6, VT9 can be P307, P307V, P309: VT8 - GT403A, GT403V - GT403Yu; VT2, VTZ, VT7, VT10, VT11 - MP20, MP20A, MP20B, MP21, MP21A - MP21E; VT4, VT12 - KT603A, KT608A, KT608B; VT13 - any of the P214 - P217 series.
Diodes VD1 - VD4 can be, in addition to those indicated in the diagram, D242, D243, D243A, D245, D245A, D246, D246A, D247; VD5, VD7, VD9 - D226V + D226D, D206 - D211; VD6 - KD202B KD202S; VD8, VD12 - D223A, D223B, D219A, D220. Instead of D808 zener diodes, D809 - to D813, D814A - to D814D are suitable.
The thyristor can be KU202A - to KU202N. Capacitors C1, C3 - K50-6; C2 - K50-15. Lamps HL1 t HL3, HL7 - SM28, HL4 HL6 - automotive lamps for voltage 12 V and power 50+40 W (50 W filament is used).
Switch SA1 - toggle switch TV (TP), switches SA2, SA3 - toggle switches VBT, push-button switch SB 1 - KM-1, switch SA - type PKG (ZPZN). Transformer T1 - ready-made, TN-61 -220/127-50 (rated power 190 W). DC voltmeter - type M4200 with a 30 V scale.
The method is based on the restoration of batteries with an “asymmetrical” current. In this case, the ratio of charge and discharge current is selected 10:1 ( best option). This mode allows you to easily restore sulfated batteries, but also carry out a preventive procedure with a working battery.
To restore and train batteries, it is best to set the pulse charging current at 5 A. In this case, the discharge current will be about 0.5 A. It is primarily determined by the resistance value of resistor R4. The circuit is designed in such a way that the battery is charged by current pulses during one half of the mains voltage period, at the moment when the voltage at the device output exceeds the potential level on the battery. During another half-cycle, diodes VD1, VD2 are locked and the battery is discharged through load resistance R4.
The charge current value is adjustable variable resistor R2 by analog ammeter. Considering that during charging, part of the current also flows through resistance R4 (10%), the ammeter reading should be 1.8 A (for a pulse charging current in the region of 5 A), since the analog ammeter shows the average current value over a period of time, and the charge occurs during half the period.
The circuit protects the battery from uncontrolled discharge in the event of an accidental loss of mains voltage. In this scenario, relay K1 with its contacts will break the battery connection circuit.
Relay K1 took the old one Soviet type RPU-0 with an operating winding voltage of 24 V, connected a limiting resistance in series with the winding. For this circuit, almost any transformer with a power of at least 150 W with a voltage in the secondary winding of approximately 22-25 V is suitable.
The technology for restoring car batteries using alternating current allows you to quickly reduce the internal resistance almost to the factory level, with minimal heating of the electrolyte. The positive half-cycle of the current is fully utilized during charging car batteries with minimal operating sulfation when power pulse current The charge is enough to restore the battery plates.
When restoring a battery with long term operation, it is recommended to use both half-cycles of alternating current in comparable quantities: with a charging current of 0.05 C (C - capacity), the discharge current is selected in the range 1/10-1/20 charge outflow. The time interval of the charging current should not be more than 5 ms, i.e. the recovery process should occur at maximum level the voltage of the positive part of the sinusoid, at which the pulse energy is sufficient for the chemical transition of lead sulfate into an amorphous state. The released SO4 residue increases the density of the electrolyte until all the lead sulfate crystals are reduced, and the voltage on the battery increases due to the electrolysis that occurs.
When charging and restoring procedures, it is necessary to use the maximum current amplitude with a minimum duration of its action. The steep leading edge of the current pulse melts sulfate crystals when other methods fail to produce noticeable results. The time between charge and discharge is also required for the cooling of the plates and the recombination of electrons into acid electrolyte. A smooth drop in current in the second half-wave of the sine wave creates the necessary conditions for electron braking when the current passes into the negative half-wave of the sine wave through the zero point. For creating necessary conditions recovery, a thyristor-diode current control circuit is used. During its switching, the thyristor produces a fairly steep leading current edge and is practically not subject to heating during operation, unlike a possible transistor version. Synchronizing the charging current pulse with the supply voltage reduces the likely level of interference.
The moment the battery voltage level rises is controlled by adding a negative voltage to the circuit. feedback by voltage, from the battery to the standby multivibrator on the DA1 timer chip. Also used in the design temperature sensor to protect against overheating of the main power components. The current charge regulator allows you to set First level recovery current, based on the battery capacity parameters. The average charge current is monitored using an analog ammeter with a linear scale and an internal shunt. In its applications, the currents are summed up, so the readings of the average charging current will be underestimated.
Do not do it for a long time supply only a negative current half-wave to the battery - this leads to discharge of the battery with reversal of the polarity of the plates. A charged battery always self-discharges due to different levels density of the upper and lower levels of electrolyte in the jar and other factors.
Part schematic diagram includes a standby multivibrator - a synchronized pulse generator on the widely used timer KR1006VI1, a current pulse amplitude amplifier made on a bipolar transistor VT1, a temperature sensor and a negative feedback voltage amplifier on VT2. The synchronization voltage comes from a full-wave rectifier on diodes VD3, VD4 and is supplied through a resistor voltage divider R13, R14 to the second input of the lower comparator of the DA1 microassembly.
The pulse frequency of the waiting multivibrator is determined by the parameters of resistors R1, R2 and capacitance C1. At the initial moment, there is a high voltage level at the third output DA1 in the absence of a voltage higher than 1/3 U p at the second input DA1, after its appearance the microassembly is triggered with a threshold specified by resistor R14, a pulse is generated at the output with a period of 10 ms and a duration depending on the position of the variable resistance regulator R2, - the charging time of the capacitor C1. Resistance R1 sets the minimum duration of the output pulses. The fifth pin of the microassembly has direct access to point 2/3 U n of the internal voltage divider. As the voltage on the battery increases at the end of the charge, the bipolar transistor VT2 of the negative feedback circuit is unlocked and the voltage at the fifth terminal DA1 drops, with the pulse duration shortening, the operating time of the open thyristor decreases. The pulse from the third pin of the timer goes through resistor R5 to the amplifier input at VT1.
The amplified pulse is supplied through an optocoupler to the control electrode of the thyristor, the thyristor opens and supplies the car battery recovery circuit with a full-wave charging current pulse with a duration depending on the position of the variable resistance motor R2. Resistors R9, R10 protect the optocoupler from possible overloads. The temperature of the power components is controlled by thermistor R11 installed in the negative feedback circuit divider. As the temperature of the thermistor resistance increases, the shunting of the fifth terminal of the microcircuit by transistor VT2 also decreases, the pulse duration decreases, and so does the current.
The power supply of the timer in the circuit is stabilized by a zener diode VD1. The electronic design is powered from the secondary winding of the transformer through VD2-VD4, the ripples are smoothed out by capacitance C3. The thyristor is powered by a full-wave pulsating voltage and performs the function of a switch with an adjustable turn-on time for positive current pulses, a negative pulse follows in car battery from a half-wave rectifier VD5.
There is no gas in gel batteries - helium; in them the electrolyte is simply in a gel state. Therefore, there is no need to worry about depressurization, this type maintenance-free batteries It is quite possible to open it, provided that it cannot be charged, and the voltage on it has dropped below the level of 10 V.
Gel batteries necessarily contain a water-based electrolyte, which is typical consumables The battery, since when it is restored using electrolysis, it is destroyed into a hydroxyl group and hydrogen. And the leakage of the lightest element into ambient air, it is almost impossible to stop, because hydrogen seeps through the rubber valve caps located under the outer plastic cover.
Recovery gel battery it is necessary to tear off the glued top cover, and remove all valve caps. You only need to add a little water - the poured liquid will be absorbed into the filter paper, so after half an hour, check how much distilled water is left in each section of the battery. Its level should slightly cover the surface of the plates, so it is recommended to pump out excess water using a rubber bulb.
To do this, close all battery compartments with valve caps. And also don’t forget to cover them with the outer cover, and press it down with a weight (we’ll glue it a little later). During charging, excess pressure will be released through the caps due to the formation of hydrogen, and the lid will serve as an obstacle for them.
A battery that has lost capacity due to drying out of the electrolyte will not consume current from the charger at the initial moment of charging, so the voltage should be selected around 15 V.
It will take quite a long time to charge until the battery begins to consume current. But if after 15 hours it does not “eat Amps”, then do not wait for sea weather, but increase the voltage of the charger to 20 V and do not leave the battery unattended until current consumption begins.
A good method for “swinging” a battery that does not want to charge is to first let the battery charge and then discharge it - and so on one by one, in short time intervals. The first cycles should be carried out under high voltage- around 30 V, and in subsequent periods the charging voltage should be gradually reduced to 14 V.
You need to discharge a recharged battery with a very small load, such as a light bulb or a 5 or 10 W resistor, while monitoring the voltage on the battery so that it does not drop below 10.5 V.
Once you have managed to get the “problem” battery to consume current, continue to restore it until full charge long-term charging with low current somewhere at the level of 0.05 of the capacity.
The average lifespan of a typical lead-acid battery is approximately 5 years. However, you can extend the life of the battery. To do this, you must follow the battery operating rules and, if necessary, perform battery training. In this article we will look at the basic methods of training and restoring batteries.
Reasons for decreasing battery capacity and voltage
The main reason for the decrease in battery capacity and the decrease in voltage at the battery outputs is sulfation of the plates. Sulfation of plates is chemical process deposition of a layer of lead sulfate on the surface of the plate. The resulting lead sulfate is a poor conductor of electric current, which leads to a decrease in charging efficiency and a gradual decrease in battery capacity.
The main reasons for sulfation of battery plates include:
- long vehicle downtimes, battery non-use long time;
- storing the battery in a discharged state;
- short battery charging time and heavy load on the battery;
- insufficient battery charge current;
- lack of periodic recharging;
- using the battery in conditions low temperatures;
- deep battery discharges.
The main way to reduce sulfation of plates is to expose them to electric shock in various modes. This process is called the battery training or reconditioning process.
Battery training and recovery methods
There are several basic proven methods for training and restoring batteries:
- battery restoration using long-term low-current charging method
- battery restoration using deep discharge method with low currents
- battery restoration using cyclic current charging method
- battery restoration using the constant voltage method
- battery restoration using pulsed currents
Training and restoration of batteries using the method of long-term charging with low currents
The method of long-term charges with low-amplitude currents makes it possible to obtain good results with slight and recent sulfation of battery plates. The battery must be connected to charge with a normal current value (10% of the total battery capacity). The charge must be made before gases begin to form. Next you need to take a break for 20-30 minutes. At the second stage, the battery is charged with a decrease in current value to 1% of the battery capacity. After this, another break is taken for 20-30 minutes. Such charging cycles must be repeated several times.
Training and restoration of batteries using deep discharges with low currents
The method of deep discharges with low currents is effective for training and restoring a battery with signs of old sulfation. The training method consists of charging the battery with recharging with standard currents and a long-term deep discharge with low currents. Performing several cycles of low current discharge and normal battery charging makes it possible to effectively restore the battery.
Training and restoration of batteries using the cyclic current charging method
Another effective method restoring batteries and increasing battery life - the method of charging with cyclic currents. The essence of the method is simple. The battery resistance is measured. If the actual resistance exceeds the standard factory value, the battery is charged with a low current, after which they take a break of 5-10 minutes and begin discharging the battery. After this, take a break and repeat the cycles “charge - break - discharge - break” several times.
Training and restoration of batteries using the constant voltage method
The essence of the method is to charge the battery with a constant voltage current, while the current strength changes (usually decreases). In this case, at the first stage of the charging process, the current strength can be 150% of the battery capacity and over time gradually decrease to small values. It is necessary to take into account the internal resistance and capacity of the battery. Depending on the ratio of these indicators, the current that passes through it at the beginning of charging can exceed 50A. To prevent the battery from burning out, all chargers have a limiter of 20-25A
Training and restoration of batteries using pulsed currents
The essence of the method is to supply a pulsed current to charge the battery. The amplitude of the current value in pulses is 5 times higher than normal values. The maximum amplitude values can briefly reach 50 Amps. The pulse duration is short - a few microseconds. With this charging mode, lead sulfate crystals melt and the battery is restored
Rules for carrying out work on training and restoring batteries
When performing all work, the following rules must be observed:
- Before starting work, you must completely clean the battery.
- Before you start charging the battery, you must check the condition and level of the electrolyte.
- Work on charging batteries should be carried out in a special, well-ventilated room.
- It is prohibited to keep open fire near the battery.
An effective device for restoring and training batteries
SKAT-UTTV is a highly efficient device for automatic testing, training, recovery, charging and remaining capacity determination lead acid batteries various types and types. The device allows for the restoration of open and closed type batteries.
SKAT-UTTV has microprocessor control, which allows you to quickly determine the predicted battery life. The device has various operating modes; a digital display and control buttons are used to control the modes.
Methods for restoring and training batteries of the SKAT-UTTV device
The device uses the following methods for charging, training and restoring batteries:
- charge with direct current 10% of the battery capacity until the voltage threshold is reached;
- charge with direct current 5% of the battery capacity until the voltage threshold is reached;
- charge with constant voltage with automatic selection of current value, charge with constant current of 20% of the battery capacity until the voltage threshold is reached, charge with constant voltage until the threshold for the battery capacity is reached;
- charge with an asymmetric current with alternating pulses of optimal charge, selected automatically until a threshold is reached according to the battery voltage value, discharge with a direct current of low value from 5% of the battery capacity until the minimum voltage threshold is reached.
During the process of charging, training and restoring the battery, the device automatically selects programs for using all methods on various cycles.
