The battery has lost capacity how to recover. How to repair a lead acid battery. Polarity reversal is the last chance in a hopeless situation

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The performance of a car is highly dependent on technical condition battery... As soon as it is discharged or out of order, it becomes very difficult to operate the car. Constantly pushing or pulling the vehicle in tow is not an option. Since replacing a power source is not cheap, a natural question arises as to how to restore a car battery in a conventional garage. Life extension is often quite feasible.

About the design of acid batteries

On the vehicles 3 types of batteries are used - gel, alkaline and lead-acid. The former are considered relatively new, are used infrequently, and have not yet developed sufficient resources to speak of recovery. Alkaline batteries are found in commercial vehicles, electric forklifts, and carts. Overwhelming majority passenger cars equipped with acid batteries, therefore, their resuscitation is worth considering in more detail.

A lead-acid battery is a sealed plastic case containing the following elements:

positive electrodes (anodes) in the form of lead plates with an active filler, assembled in blocks (in jargon - cans);
negative electrodes (cathodes) of identical design;
separators - insulating partitions made of polymeric materials or fiberglass;
connecting busbars ending with two terminals for connecting the battery to the vehicle power supply;
electrolyte - sulfuric acid solution.

Negative and positive electrodes are installed alternately, separators are placed between them to avoid short circuits. In the process of charging the battery, a chemical reaction takes place, which is why lead dioxide is deposited on the surface of the anodes - energy is accumulated.

After connecting consumers, the dioxide reacts with the lead of the cathodes, forming a layer of lead sulfate on the negative electrodes - energy is released. The gases evolved by the reaction are discharged to the outside through the valve and vent.

Common battery problems

Car battery recovery is not always possible and depends on the type of malfunction. The type of battery also plays a role:

the serviced battery is equipped with plugs installed above each bank;
The maintenance-free power supply features a one-piece plastic casing - a monoblock without plugs.

If there are screw caps, you can check and correct or drain the fluid for repair. The sealed monoblock is reanimated in one way - by charging according to a specific algorithm, but a positive result is not guaranteed.

Battery faults are conventionally divided into 2 groups - external and internal. Each variety should be disassembled separately.

Elimination of external defects

During the operation of batteries, motorists have to deal with two external faults: oxidation of lead terminals and cracks in the case. The latter arise for the following reasons:

the case has burst as a result of mechanical damage (for example, a drop of the battery);
swelling of a discharged battery in severe frost;
plastic has become brittle with age.

Oxidation of the terminals prevents reliable contact of the source with the on-board network and often causes starter failure. The defect is "treated" by simple cleaning with coarse sandpaper, in advanced cases - a fine file. Likewise, the oxide layer is removed from the contacts that are pushed onto the terminals and screwed down.

If a crack has formed in the housing, repair maintenance-free battery will not come out - there are no holes for draining and filling the electrolyte. A battery equipped with plugs is repaired as follows:

Drain the electrolytic liquid from all cans and rinse the body from the inside with distilled water so that the hot tool does not come into contact with acid during soldering.
Dry the case from the side of the crack, then carefully solder it along its entire length.
Cut out a plastic patch and weld it over the crack, sealing the seams without gaps.
Another option is to use a glue gun. The defect needs to be slightly widened, filled with a polymer composition, and then patched.

At the end, check the battery for leaks by filling it with distilled water to the top. If there are no leaks, fill the battery with electrolyte and try charging. If the plate assemblies are not damaged, the battery will "take" charge and continue to serve in the vehicle.

Note. If the case is cracked from swelling or the old age of the product, then it is unlikely that it will be possible to revive the battery by soldering the defect. The exact result will only show the charging performed after the crack has been filled.

Internal problems

Most internal faults will definitely render the battery unusable if the problem is discovered too late. In the early stages, resuscitation is quite possible. The list of common problems looks like this:

sulfation of electrodes - deposition of a thick layer of lead sulfate on the plates, which does not allow the electrolytic liquid to contact normally with the active filler;
shedding filler from lead gratings;
closure of electrodes and blocks with each other.

Reference. The short circuit of the plates is a consequence of a large amount of active filler falling off the gratings. The defect is critical - the battery cannot be repaired.

The reasons for these malfunctions are as follows:

multiple full discharge of the lead-acid battery "to zero";
operation of the power supply with a low level of charge due to malfunctions of the generator or the electrical part of the car;
long-term storage in a discharged state.

If the problem is detected at the last stage - deep sulfation, total crumbling - it will not be possible to reanimate the car battery. An irreparable defect is diagnosed simply - the battery absolutely does not perceive charging, the electrolyte is constantly boiling. In other cases, try to implement the methods of battery restoration described below.

How to get rid of sulfation?

The first remedy is only suitable for serviceable batteries. For implementation, you will need a charger, a device - an electrolyte density meter (hydrometer), a multimeter and a light bulb - a 12 V consumer.

Important! The power of the lamp is taken according to this calculation: the battery capacity (for example, 45 Ah) is multiplied by a factor of 0.1 and by the voltage value (12 volts). In this case, the power was 45 x 0.1 x 12 = 54 W.

The restoration of a faulty battery is carried out in the following order:

Fully charge the battery at 10% of the power supply capacity.
Check the density value in all jars with a hydrometer, it should be 1.27 units. If the density "does not reach" the indicated figure, add electrolyte and charge the battery for 30 minutes.
Connect a lamp to the terminals and discharge the battery by periodically measuring the voltage. Do not forget to time the discharge start.
When the voltage drops to 10.2 volts (full discharge), turn off the light bulb. If the process took more than 8 hours, the battery is in an acceptable condition (the discharge rate of a new battery is approximately 10 hours).
When finished, charge the battery again to 100% and put it on the car. Do not keep the power supply completely discharged.

The procedure allows you to partially or completely return the lost battery capacity. To restore a battery with a maintenance-free housing, use another method:

Look for a charger capable of delivering low currents - from 0.5 to 2 A with a periodic shutdown function.
Charge the battery for at least 2 days by periodically measuring the voltage.
Unplug the charger and check the voltage for 2 hours. If it does not fall, try to put the battery on the car, otherwise charge further.

To achieve a positive result, the charging time can be 50 hours or more. It is preferable to use a charger in which the desulfation function is provided - it will supply a current of 2 A at regular intervals.

Chemical washing method

This procedure is used to eliminate sulfation and quickly rebuild a serviced battery at home. You will need 2 commercially available reagents - "Trilon B" and ammonia solution. The procedure is as follows:

Try to fully charge the battery, then drain all the electrolyte.
Rinse the battery with distilled water.
Prepare a solution by adding 5% ammonia and 2% Trilon B (by volume of water) to the distillate.
Gently pour the solution into the jars - a violent reaction will begin, accompanied by boiling and splashing.
When the liquid stops boiling, drain it and flush the battery again.

After flushing, fill in electrolyte and recharge the battery to the end. Flushing removes the excess lead sulphate layer, so the battery's capacity should be restored.

The last way to remove lead sulfate is to replace the electrolytic liquid with distilled water and charge it for a long time at 14 volts. In the first stage, the battery is brought to a boil, then the voltage is reduced. The goal is to slowly dissolve the sulfate with water. In the second step, the distillate is changed and the voltage and charging current are set to a minimum. The operation is considered successful if the density of the solution does not drop within 2-3 days. In terms of duration, the procedure can take 3-4 weeks.

Modern storage batteries remain one of the biggest challenges for both manufacturers and consumers. And it's not so much about the potential risk of fire, but about the gradual depletion of the power source itself. Therefore, you should not be surprised that with daily charging, the batteries can withstand a year or two of active use, after which their capacity drops dramatically and it becomes problematic to use your favorite gadget. You cannot completely reanimate a deceased battery, but you can extend the period of active use while you are looking for a replacement. We will talk about this today.

The recommendations below are designed for a technically trained user, therefore, if you do not know which side to approach the soldering iron, it is better to either contact the services of a service center, or immediately go to the store for a new battery.

Method number 1

He will be able to help in cases where, due to prolonged work, gases begin to accumulate inside, as a result of which the battery swells and does not hold a charge well.

Required tools and materials: a soldering iron, some epoxy, a thin needle, a flat, heavy leveling object.

Disconnect the battery case from the upper block with the sensor as carefully as possible.

We separate the electronic sensor.

There should be a cap under it, inside which the control electronics are hidden. We carefully pierce it, for which a thin needle is well suited. Remember that it will be impossible to reanimate the battery with a damaged filling.

The most crucial moment. We put the battery on the table and press it down with a press. Keep in mind: excessive force can render the battery unusable, and a lack of it, on the contrary, will not lead to the desired result. It is also categorically not recommended to use a vice or a device similar in purpose for repairs.

When you're done, put a drop of epoxy on the hole and solder the sensor.

Method number 2

He is not able to reanimate a battery with a significantly reduced resource, but it can slightly extend its life. You shouldn't count on much, but a reanimated battery will be able to provide power to a modern smartphone while you are looking for a replacement.

Required tools and materials: any power supply unit (5–12 V, current not less than 0.1 A), voltmeter or tester for voltage control, resistor (power not less than 500 mW, resistance from 330 to 1000 Ohm).

If you do not have a spare power supply, almost any complete one from active network equipment (switches, routers, modems) will do. First, you should make sure that the parameters of the current output by them correspond to the required ones.

We release the contacts of the power supply and connect them to the dead battery: "minus" of the power supply with "minus" of the battery, and add a resistor to the "positive" line. Be sure to check the correct polarity with a multimeter.

When everything is done, plug the power supply into the mains. The procedure time is no more than 2-3 minutes. If possible, control the process with a tester: the maximum allowable voltage is no more than 3.3 V.

A few important notes

Do not leave a problem battery unattended during repairs. Cases of spontaneous combustion are not a theory, but a harsh reality.

Periodically check the temperature of the "client" with an external thermocouple, electronic thermometer, or simply by hand. If the surface feels hot and not just warm to you, stop repairing immediately.

Excessive charging currents should not be used. The most you can afford is 50mAh. This parameter is calculated as follows: the power supply voltage of the power supply is divided by the capacity of the resistor. For example, if the first parameter is 12 V, and the second is 500 Ohm, then the charging current will be 24 mAh.

You can use a standard 80mm computer fan instead of a resistor.

It is also recommended to monitor the initial charging of a remanufactured battery to avoid spontaneous combustion.

Method number 3

The technique is controversial and questionable, but, according to reviews on specialized forums, it helps some users, because the responsibility for possible negative consequences lies with you.

Required tools and materials: working refrigerator.

Remove the battery, which does not show signs of life, from the smartphone and put a plastic bag, which should be put in the freezer for 20-30 minutes.

Remove it from the device, let it warm up to room temperature, and then charge it in the usual way.

Method number 4

A harmless but ineffective resuscitation technique. But if it seems to you that the battery in your smartphone is completely out of order, then why not give it a try?

Required tools and materials: Smartphone with standard charger.

Bring the battery to full discharge (when the phone no longer turns on). Any resource-intensive game or AnTuTu utility can help with this.

Fully charge the battery to the 100% mark.

Repeat steps 1 and 2 several times.

Method number 5

Almost all professional electricians will consider the following procedure sacrilege, but many users of old batteries have been helped by it.

Required tools and materials: razor blade, thin screwdriver, moment glue.

We remove the battery from the phone.

Peel off the sticker with technical characteristics.

Cut off the top plastic cover as much as possible, behind which the control electronics is hidden.

We find the main contacts.

We short them for a moment with any metal object.

Glue top cover and let it dry.

We remind you once again that none of the above methods of resuscitation does not guarantee a 100% result, and all responsibility rests entirely on your shoulders. But if the battery has turned off completely, and the purchase of a new one is postponed for several days, it's worth a try. But if you rarely pick up a soldering iron and consider yourself a humanitarian, it is better to seek help from a friend who understands the topic.

Video instruction

Every motorist knows how important the correct operation of the battery is for the functioning of the entire mechanism. Exactly lead acid batteries used as starter devices for passenger cars.

In this article, we will talk about the device and the principle of operation of the battery, we will also talk about diagnosing the battery, the most common problems and how to restore it.

The device and principle of operation of the battery

The body of the product was expelled from propylene, this material was chosen for two main reasons:

Does not conduct current
Not destroyed by acid

One device includes six interconnected batteries. A separate battery combines negative and positive electrodes (lead alloy is used for their manufacture, lead-calcium composition for negative electrodes) filled with active mass.

Insulation of layers of opposite charge is provided by a plastic separator. In order to improve corrosion resistance, lead-calcium electrode alloy can be diluted with silver or tin.

The active mass of the negative electrodes consists of spongy lead, the positive ones of lead dioxide.

There are two types of battery:

With liquid electrolyte.
With special material pre-impregnated with non-liquid electrolyte.

Today, the most common batteries with liquid electrolyte.

The principle of operation is based on the conversion of electrical energy into chemical energy during charging, during discharge, the opposite effect occurs - chemical energy is converted into electrical energy.

The battery discharge occurs as a result of connecting consumers: the active mass of the electrodes (negative and positive) interacts with the electrolyte.

As a result, lead sulfate is generated with water and the density level of the electrolyte drops. When the alternator is working properly, it charges the battery while the engine is running.

Also, the battery can be charged with a special device, as a result of the charge, lead sulfate and water are converted into lead, lead dioxide and sulfuric acid, thus, the density level increases.

Note! Charging must be carried out taking into account the recommended electrical voltage, in the event of a violation of this rule operation, the service life of the device may become significantly less than the specified one.
As a result of high voltage, the electrolyte level drops, low voltage may cause incomplete charging of the battery. In general, the battery life is about five years, it all depends on the conditions in which the device is used.

Device parameters:

Rated capacity. This indicator is measured in ampere-hours (Ah), depending on the energy output of the charged device during discharge (20 hours). For example, a device with a volume of 50 Ah for twenty hours gives a current of 2.5 A.
The nominal voltage consists of the voltages of the individual batteries, at passenger car is 12 V.
The cold cranking current indicates the vehicle's ability to start during cold periods. The higher the indicator, the easier it is for the engine to start in cold weather.

Battery malfunctions

The rechargeable battery, like any mechanism, can fail, as a result of which it will malfunction or stop working altogether. Below we will consider the most common system problems and teach you how to fix them.

Very often, car owners are faced with the problem of oxidation of the leads, as a result of which the supply of current stops and the resistance in the circuit increases, thus the entire electrical system fails.

To solve the problem you need:

Remove the terminals.
Clean the battery terminals and leads.
Now we put everything in place, check the correctness and reliability of the fasteners - the terminal should not move or move away from the output.
It is recommended to grease the top of the terminal with technical vaseline.

Many drivers complain about the rapid discharge of the battery.

There can be two reasons for this:

Contamination of the electrolyte inside the device.
Contamination of the device itself.

In this case, it is necessary to remove the battery and wipe all contacts well, pay attention to the device should not be left wet. Next, you need to check the purity and level of the electrolyte; if necessary, you should replace the fluid with a new one.

How to diagnose a car battery

Before proceeding with the diagnostics of the device, it is necessary to remove it.

Note! The negative terminal is removed first. However, when installed, it connects last.

Electrolyte level

It is recommended to check the level and density of the battery solution at least once every three months. The level is checked using a glass tube (internal diameter should be 4-5 mm) through the filling holes.

The tube should be lowered to the end, the outer glade should be well plugged with a finger and removed. The permissible electrolyte level in the storage battery should be 12-15 mm.

If there is a tube in the battery, the level may be 3-5 mm higher.

Electrolyte density

The second indicator - the density of the electrolyte - plays an equally important role, so it also needs to be monitored.

During operation, the density of the liquid can fluctuate, a full discharge is a full charge, the indicators can change by 0.15-0.16 units.

A high level of density can cause rapid deterioration of the device; at a low level of density, starting the engine will take a long time and will be problematic.

Battery charge level

To check the charge indicator of the car battery, use load fork... This device has a voltmeter, load resistor switch, handle and two contacts.

Also, the charge can be determined by starting from the output voltage, for this you will need a multimeter and a voltmeter (it is important to disconnect the negative terminal).

Modern devices are equipped with an indicator showing the battery charge. If the device is charged, the indicator is on in green, discharged - white or red.

To charge car battery it is necessary to use a charger, which is a source of current: connect the positive contact to the positive terminal, the negative one to the negative terminal.

Battery recovery methods

Every motorist is interested in the question of how to extend the life of the battery or how to restore its work.

And yet, if you missed or ignored some tips regarding the operation of the device, do not despair, below we will tell you what are the ways to restore the functioning of this device.

Use of CTZ

CTC (control and training cycle), this procedure helps to restore capacity and avoid the process of sulfation. The KTC procedure consists of several stages of discharging and charging the battery.

For this we need:

Charger.
Voltage monitoring device - voltmeter.
A device for monitoring the level of electrolyte density - a hydrometer.
Bulb.

So, first, fully charge the battery. It is important that the covers are removed from the cans while charging. The battery should be charged for 6 to 8 hours.

Upon completion of the procedure, using a hydrometer, it is necessary to check the level of electrolyte density in each jar separately - the indicator should be equal to 1.27 g / cm. cub. If necessary, distilled water or sulfuric acid is added to the cans, after which the battery is put on charge for another half hour.

Multiple charging mode

No less simple method restoration of the correct operation of the battery, offered by the auto business specialists, is to carry out several stages of charging the device with interruptions. Initially, it is necessary to set the current level to 0.04 of the nominal volume of the battery. After 8 hours of charging, you must take a 12-hour break (no more than 16 hours).

A break is necessary to equalize the internal potential and external lead plates, diffusion of dense electrolyte into the gaps between the electrodes is performed.

After a break, the battery charging procedure resumes. It is recommended to carry out at least 5 such procedures. In the course of increasing the volume, the level of density of the electrolyte will increase, as a result of which it must be diluted with distilled water and the level indicator must be controlled; it is important to keep it within the normal range.

Chemicals

So, first you need to fully charge the battery device, after which it is important to drain all the electrolyte. Now you need to rinse the container with distilled water, at least three times.

For the next stage of washing, we take a solution of 5% (wt.) Ammonia and 2% (wt.) Trilon V. Pour it into a container previously purified with distilled water, from which the electrolyte was poured, and leave it for an hour.

Splashes and active gas evolution will be observed inside, this is the process of desulfation. Upon completion of gas evolution, the procedure can be considered completed. Now we drain the liquid from the battery and rinse the container again with distilled water (2-3 times). Now we fill the battery with new electrolyte and carry out a full charge.

If strong sulfation is observed, then the battery can be restored with such a solution a couple of times. However, we note that such a solution cannot be prepared on your own, it is recommended to contact a specialist.

Impulse current

This method will help to solve the problem of a short circuit in the battery bank, many do not know about this method or do not risk using it, however, according to reviews of many motorists, it is safe to say that the method of burning out using a pulsed current is quite effective.

We connect the battery to a source that generates a large current (in this case, it is at least 100 amperes). Very often, a welding machine is used for this purpose. A short circuit in the bank is burned out as a result of a two-second passage of such a current.

An uninterruptible power supply and feeds all our hardware when the external network is turned off. But these batteries, alas, are not eternal, they degrade, their capacity decreases, and with it the battery life. Down to zero.

Unfortunately, this process is often not controlled by anyone, the owner is confident that he is protected, and at this time the battery is no longer quite a battery, but a dummy.

Why do batteries degrade?

There are many reasons. From intensive use, sulfation of the plates occurs, from overloads, active substances crumble, and so on. V UPS there is a maintenance-free battery, but it still has electrolyte and this electrolyte is based on water. Being constantly in the buffer mode, in the slow charging mode, this water gradually evaporates and the electrolyte no longer fulfills its functions... The battery becomes unusable.

How can premature battery failure be avoided?

This can be avoided by correct mechanisms for charging the battery, monitoring its characteristics, but this is the lot of UPS manufacturers.

It so happened that the Internet in my places is only wireless, for its operation a frightening antenna is installed on the roof, and to reduce signal loss in the cable, its length is minimized. The server that then distributes the Internet (one more server and a switch) is installed in the attic. This small bundle needs uninterrupted power. Even without taking into account the loss of data - running to load the server at the slightest sneeze (and we often have them) - little pleasure. Continuity should be and preferably more.

I bought a 1100VA uninterruptible power supply, not new (a new one costs more than those servers) and of course I did not rely on batteries - they are often worn out. In the UPS control panel, they cheerfully showed me about almost an hour of battery life (the load was about 70 VA). I decided to check it out. He turned off the power and after two minutes, approximately, everything turned off safely. The batteries are "dead". This is exactly the case with false protection. Nothing to do, you have to buy new batteries. I installed backup batteries (it so happened that there is an electric bike and they are inactive), 12VA. And he brought his dead relatives down.

I have heard that the electrolyte in UPS batteries often dries up. That it is not sulfation, not chipping of the plates, the cause of death of the UPS batteries, namely the drying out of the electrolyte. An attempt, as they say, is not torture. The accumulators are still to be thrown away, and the craving for picking did not give a chance.

To conduct experiments, I needed:

Distilled water (NOT electrolyte at all!). Sold at a car dealership.
- A syringe, preferably with a needle - it is easier to dose with a needle. Sold in a pharmacy.
- Knife for picking, stronger.
- Scotch tape for assembly (for aesthetes, of course ONLY blue duct tape should be!).
- Flashlight.
- The battery itself.)

The battery has a lid that closes the cans. Gently pry off with a knife. I had to walk in a circle - it was glued in several places.

Under the lid are jars covered with rubber caps. These caps are probably needed to release water vapors, hydrogen and other things that can create excess pressure in the bank during battery operation. A kind of nipple that releases gas outside, but does not let anything inside.

We pour water. Better to use a flashlight and look. The main thing is not to overflow.

After filling the water, I covered the jars with rubber lids and set the battery to charge. And I charged it separately, with a large charger, but I think it's not necessary - you can just charge it in an uninterruptible power supply. If the batteries are discharged below 10V, then they cannot be charged in this way. There is information that such batteries can also be "shaken", but for this it is necessary at the initial stages to supply them with high voltage (about 35V for a 12V battery) with current control. I haven’t tried it, I can’t say anything concrete. I also cannot recommend this method.

The first moment - if you poured water - it will come back from under the lid. It must be collected with a syringe and poured down the drain.

The second point - if you covered the jars with lids, then during the charging process the pressure in the jar rises slightly and the lids will fly with a characteristic pop throughout the room. It's funny, but only once. I checked twice - the second time is no longer fun :) I covered the lids with my own plastic cover, and put a load on it.

After charging, I slightly discharged the batteries with a car "carrying", about half an hour, measured the residual voltage, estimated the capacity. I charged it again and again discharged it a little.

I did the same with the second battery - there is a pair of them in the uninterruptible power supply. After all, I sealed the uncovered covers with tape, put the batteries back in place.

The results are as follows:

In 10 minutes with a load of 110VA, the batteries were discharged to 79 percent. The battery life changed a little, at the end the software spoke of almost 29 minutes + 10 already passed, it comes out almost 40 minutes. This state of affairs suits me. Enough to go and start the generator. When will I have it :). And on the way to make some tea. And drink it.
Based on 79%, that's 21% in 10 minutes or 47 minutes of battery life. Somewhere in the area of what the software promises.
Another calculation option is the full capacity of the batteries 12V * 7Ah * 2pcs = 168 Watt / hour. This is the ideal. With a load of 110W, the charge should be enough for 1.5 hours. But in reality, even with new batteries, there will be no such operating time - the discharge current is too large and the given capacity will be lower. It is difficult to say for sure how much the capacity has recovered, but it is very likely that up to 80 percent of the nominal. In my opinion - not bad at all for one syringe, a can of distillate and an hour of time.

The moral of this fable is this:
- Check the battery life periodically. They can put a pig on you at the most unpleasant moment.
- At your own peril and risk, even well-worn batteries can be restored with little blood... But no, it will always have time to buy new ones.

Car battery life is limited. When it fails, many simply buy a new one. And almost every battery can be rebuilt to make it last longer.

1 Battery malfunctions - disease symptoms

In a closed plastic container, there are positive and negative plates. A solution of hydrochloric acid, called an electrolyte, is poured inside, which forms a galvanic pair with lead plates. The terminals are supplied with current from a charger or generator. When enough of it has accumulated, the car's battery becomes a source of electricity. It is spent on starting the engine, operating instruments and lighting.

The generator replenishes energy losses, but over time, for various reasons, the accumulated reserve is not enough for a normal engine start. At correct operation the time factor acts: the plates age. Under certain conditions, you can restore the battery, breathe new life into it. There are several methods of resuscitation. To choose the most suitable one, we first determine the reason for the inoperability.

The most common cause of death is sulfation of lead electrodes. The discharge is accompanied by the formation of plaque on the plates. If critical discharges are avoided, the crystals will dissolve during charging. But the causes of sulfation are not only deep discharges. It is also caused by other circumstances: constant undercharging, long storage in a discharged state.

Sulfation is fairly easy to identify visually. We unscrew the plugs and inspect the plates. A light white-brown bloom indicates the presence of a process. Other signs, including for maintenance-free acid batteries:

when charging, it begins to boil very quickly;
a fully charged battery does not turn the motor, it sits down in a few minutes from a regular light bulb;
white bloom on the body.

The second common malfunction is the destroyed plates, their crumbling. It is easily identified by the black color of the battery acid. If many gratings have crumbled, it is unlikely that it will be possible to revive such a source of tension.

Adjacent plates can be shorted. This occurs as a result of their deformation or shedding and sludge formed at the bottom. Closing occurs, as a rule, in one of the sections. A clear sign Short-circuit - when charging in that bank, the electrolyte does not boil or boils later, and the voltage indicator does not grow or grows very weakly.

Finally, acidic electrolyte can freeze. This happens when storing a highly discharged battery in cold weather. The ability to recover depends on the degree of frost damage. If the formed ice broke the plastic case, then the plates, probably, were warped, and they closed, after defrosting they will begin to crumble. If the case is intact, we defrost it in a warm place, and you can try to restore it.

We start any repairs with cleaning. We remove dirt from the surface, rinse with a solution of soda to neutralize the electrolyte, which is almost always present on the lid. We clean the terminals from plaque with medium-sized sandpaper. By the way, try how a car battery with clean terminals works. Often, their oxidized surface does not allow normal charging and the release of electricity.

2 Simple desulfation - we use a conventional charger

If the battery is sulfated, and the plates did not crumble (the electrolyte is clean), then it can be restored using a simple charger. We need to break up the plaque on the plates. In the serious literature, pulsed charging, alternating with discharging, and strict adherence to modes are recommended. It is rather difficult to do it manually, and special charging device expensive.

In practice, everything can be done much easier. We use the simplest memory with a slight alteration. We throw out the smoothing filters at the output of the step-down transformer. Instead, we install a diode rectifier. Each of the four diodes is rated for 10 A.

A hydrometer is required to monitor the density of the electrolyte. We check it in all banks, recording indicators. If there are 1.20 and below, it's time to act. We look at the level: if insufficient, add electrolyte of standard density so that it covers the plates by 1 cm. Connect the charger, set the current to 10% of the capacity. If we have a 60 Ah battery, then 6 A, maybe less: 3-5 A.

On a simple memory without fixing the parameters, the ammeter will first show a slight increase in current, then it will decrease, and the arrow will freeze in a certain position. From time to time we observe the process so as not to miss the beginning of the boil. After it, the current is reduced to 2 A, we continue to charge until it starts to boil again, and another 2 hours after that.

After the end, we measure the density: it does not grow much. We leave the battery disconnected from the charger for the same time that it was being charged. We measure again - we observe a slight increase in density. If it has not yet returned to normal, we repeat the cycle. It takes one day, usually recovery occurs after 3-4, sometimes you have to repeat 5-6 times.

Never add acid to a sulphated battery: it will only speed up the process and can lead to the death of the unit.

3 The second method is a cyclic charge-discharge

On sale there are automatic chargers such as "Cedar" and the like. During the charging process, they turn off on their own at the right time. We carry out a full charge beforehand to the maximum possible level. Then we turn it on in training mode for 3-5 days. In parallel with the charger, we catch the light bulb from the turning lamp, press the corresponding button. The process goes like this: charging goes on for about a minute, then discharging for 10 seconds. After training, we charge it completely.

Several schemes have been developed homemade devices, which, like the factory ones, give out a short pulsed charge current and conduct a small discharge in between. The figure shows a diagram according to which it is not difficult to create such a device if you have knowledge of radio engineering.

We connect it to the terminals and observe the LEDs. Green light indicates readiness for operation, while yellow and red light indicates the need for desulfation. We carry it out like this:

we connect the device for a while until it is completely discharged (LED D1 goes out);
connect the charger and charge;
repeat desulfation until diodes D7, D8 light up green.

The charge-discharge process may have to be repeated many times. In especially advanced cases, it takes a week or more. The peculiarity of the device is that it consumes only 20 mA, it can be connected to the on-board network. It will constantly maintain the desired state of the battery without affecting the operation of the generator.

If there is no impulse memory, but we cannot do it ourselves, we try to use the manual mode. Let's take a simple charger with fixed settings. We set it to 14 V and 0.8 A, and leave it for 8-10 hours. The voltmeter will show the increased parameters. Be sure to leave it to stand for a day and charge it again, but with a current of 2 A. The voltage with the density will slightly increase.

We start the desulfation process. We connect the light bulb high beam... For 6-8 hours we observe a voltage drop to 9 V, we no longer allow it - this is what we need. We'll have to control it with a voltmeter. We repeat the cycles:

night - we charge with a current of 0.8 A;
a day is worth;
night again - charging with a current of 2 A.

Depending on the degree of neglect, the process takes up to two weeks. A fully discharged battery is restored by 80%, which is enough to start the engine.

4 Change the electrolyte - return to life of short-circuited batteries

If the liquid in the cans has acquired an incomprehensible color: cloudy, black, it will have to be replaced. This happens in very old, unused batteries for a long time and in the event of a short circuit. In general, if the short circuit occurred due to warping of the gratings, then it can only be reanimated by physical intervention.

With old batteries, this was done simply: each can was separate. The short-circuited one was opened and new plates were installed. Now all the individual elements are enclosed in a common body, and such an intervention is difficult, but possible. We will tell you how to do this further, and now how to change the electrolyte.

A short circuit is determined by the black color, as already mentioned, and by charging. All banks begin to emit gas, but this does not happen in the short-circuited one. Then we drain the electrolyte by pulling it out with a pear. It is possible from one container, but better from all - filling with fresh electrolyte will not hurt. Then fill in distilled water, slightly shake the case and carefully drain. Do not turn it over so that the sludge does not get stuck between the plates. Repeat until the water is clear.

In a bank with short circuit, we resort to a more radical method. We drill a small hole 4–5 mm in the bottom of the case, drain the electrolyte and rinse with distilled water. All the sludge goes away, nothing remains. The hole is sealed with plastic using a soldering iron. If the plates are not warped, then it will be enough to change the electrolyte.

The further process is as follows:

Fill with electrolyte with a density of 1.28. It is possible to pre-dissolve a special additive for desulfation in it in two days. Let it stand for a day so that the air comes out.
We charge with a current of 0.1 A up to full recovery density, making sure that there is no violent boiling and strong heating of the case. If necessary, turn it off, let it cool. We charge up to 14-15 V.
We look at the hydrometer readings, reduce the current and leave it for 2 hours. If during this time the density has not changed, stop charging.
We discharge with a current of 0.5 A to 10 Volts. If the indicator has dropped to this mark earlier than 8 hours, the cycle is repeated. If not, just charge up to nominal values.

And now about replacing the plates in a non-separable battery with your own hands. Cut the plastic around it from above. We disconnect the jumpers going to neighboring banks in any way: we unsolder or cut. We take out the bag and rinse well in water to wash off the acid residues. Now we are looking for where it closes. We examine the plates and dielectric. Objective: to find a particle that connects two plates.

Found - good, we remove it. First, you should rinse, removing all the dregs, set the bag in place. We restore the jumpers, glue the lid using glue, epoxy resin or melt it with a soldering iron. Fill with electrolyte and charge. If the plates are warped, you can use them from another old battery by choosing the least damaged package.

All work should be carried out with gloves and in a room with adequate ventilation, and preferably in the air: sulfuric acid and gases can be harmful to health.

5 Polarity reversal is the last chance in a hopeless situation

If a strong voltage drop occurs in one of the six containers, the poles change their value during charging. A chain reaction is provoked, which leads to the same consequences in neighboring banks. The reasons for this situation are:

excessive sulfation, not amenable to recovery;
incorrect connection of the battery to the charging, which does not have protection against polarity reversal;
dirt on the case, causing constant self-discharge;
the discharge is not controlled, a strong discharge has occurred repeatedly;
errors in the operation of the generator and other power supply and consumption devices.

The polarity reversal technique is considered barbaric, but resuscitation is impossible in other ways. If it fails, there is nothing to regret, all the same, the battery had one way - disposal.

To begin with, we select the electrolyte from all the cans with a hydrometer and look at the indicators. We identify completely workers, sick and dead. The dead, as a rule, are few: one or two. To restore capacity, by and large, should only be with them. But the solid body does not allow for disassembly. You can use the technique described above to get to the faulty jar.

We will tell you how to reverse the polarity of all containers at home without resorting to disassembly:

First, we discharge the old battery to zero by connecting some kind of load, for example, a car light bulb. We measure the voltage: if something remains, we close the terminals.
In the gap of the negative terminal of the charger, we include the ballast resistance. A 50K resistor will do. It will protect the plates from short circuiting.
We connect the wires from the charger in reverse polarity. Positive - to the "minus" of the battery, negative - to "plus".
We charge with a current equal to 10% of the capacity. The charge builds up quickly enough, but the case gets very hot.
We lower the current to 2 A and continue charging. Let it boil at a low current for 2 hours and turn it off.

We check the density: in normal containers it decreases, in dead containers it rises. Then we conduct a strong discharge by closing the terminals. We connect to the charger, observing the correct polarity. We charge according to the above scheme. For recovery, it is recommended to reverse the polarity twice.

You should not resort to polarity reversal when the following signs of a malfunction are present:

black electrolyte in cans;
short circuit;
insufficient level of density.

First, we apply the repair methods for a specific case, and if it does not help, we apply a polarity reversal.