All batteries have an expiration date, with numerous charge-discharge cycles and many hours worked, the battery loses its capacity and holds a charge less and less.
Over time, the capacity of the battery drops so much that its further operation becomes impossible.
Probably many have already accumulated batteries from uninterruptible power supplies (UPS), alarm systems and emergency lighting.
Lead-acid batteries are found in many household and office equipment, and regardless of the battery brand and manufacturing technology, whether it is a regular serviced car battery, AGM, gel (GEL) or a small flashlight battery, they all have lead plates and an acidic electrolyte.
At the end of operation, such batteries cannot be thrown away because they contain lead, basically they are waiting for the fate of recycling where lead is extracted and processed.
But still, despite the fact that such batteries are mostly "maintenance free", you can try to restore them by returning them to their previous capacity and use them for some more time.
In this article, I will talk about how restore 12v battery from UPSa on 7ah, but the method is suitable for any acid battery. But I want to warn you that these measures should not be taken on a fully working battery, since on a working battery you can only achieve capacity recovery by using the right charging method.
So we take the battery, in this case old and discharged, pry the plastic cover with a screwdriver. Most likely it is point glued to the body.
Lifting the lid, we see six rubber caps, their task is not to maintain the battery, but to bleed the gases formed during charging and operation, but we will use them for our purposes.
We remove the caps and in each hole, using a syringe, pour 3 ml of distilled water, it should be noted that other water is not suitable for this. And distilled water can be easily found in a pharmacy or at a car market, in the most extreme case, melt water from snow or pure rain water can come up.
After we have added water, we put the battery on charge and we will charge it using a laboratory (regulated) power supply.
We select the voltage until some values \u200b\u200bof the charging current appear. If the battery is in poor condition, then the charging current may not be observed, at first, at all.
The voltage must be increased until the charging current appears at least 10-20mA. Having achieved such values of the charging current, you need to be careful, since the current will increase over time and you will have to constantly reduce the voltage.
When the current reaches 100mA, there is no need to reduce the voltage further. And when the charge current reaches 200mA, you need to disconnect the battery for 12 hours.
Then we reconnect the battery for charging, the voltage should be such that the charging current for our 7ah battery is 600mA. Also, constantly observing, we maintain the specified current for 4 hours. But we make sure that the charging voltage, for a 12-volt battery, is no more than 15-16 volts.
After charging, after about an hour, the battery needs to be discharged to 11 volts, this can be done using any 12-volt light bulb (for example, 15 watts).
After discharging, the battery must be charged again with a current of 600mA. It is best to do this procedure several times, that is, several charge-discharge cycles.
Most likely, it will not be possible to return the nominal one, since the sulfation of the plates has already reduced its resource, and besides, there are other harmful processes. But the battery can continue to be used in normal mode and the capacity for this will be enough.
Regarding the rapid wear of batteries in uninterruptible power supplies, the following reasons were noticed. Being in the same case with an uninterruptible power supply, the battery is constantly subject to passive heating from active elements (power transistors), which by the way heat up to 60-70 degrees! Constant heating of the battery leads to rapid evaporation of the electrolyte.
In cheap, and sometimes even some expensive UPS models, there is no charge temperature compensation, that is, the charge voltage is set to 13.8 volts, but this is acceptable for 10-15 degrees, and for 25 degrees, and sometimes much more in the case, the charge voltage should be a maximum of 13.2-13.5 volts!
It's a good idea to move the battery out of the case if you want to extend its life.
It also affects the "constant small under charge" by an uninterruptible power supply, 13.5 volts and a current of 300mA. Such recharging leads to the fact that when the active spongy mass inside the battery ends, a reaction begins in its electrodes, which leads to the fact that the lead of the down conductors on (+) becomes brown (PbO2) and on (-) it becomes "spongy".
Thus, with a constant charge, we get the destruction of current leads and the "boiling" of the electrolyte with the release of hydrogen and oxygen, which leads to an increase in the concentration of the electrolyte, which again contributes to the destruction of the electrodes. It turns out such a closed process that leads to a rapid consumption of battery life.
In addition, such a charge (recharge) with a high voltage and current from which the electrolyte "boils" - converts the lead of the current leads into powdered lead oxide, which crumbles over time and can even close the plates.
With active use (frequent charging), it is recommended to add distilled water to the battery once a year.
Top up only on a fully charged battery with control of both electrolyte level and voltage. In some case, do not overfill, it's better not to pour it because you can’t take it back, because by sucking out the electrolyte, you deprive the battery of sulfuric acid and, as a result, the concentration changes. I think it is clear that sulfuric acid is non-volatile, therefore, in the process of "boiling" during charging, it all remains inside the battery - only hydrogen and oxygen come out.
We connect a digital voltmeter to the terminals and pour 2-3 ml of distilled water into each jar with a 5 ml syringe with a needle, while shining a flashlight inside to stop if the water is no longer absorbed - after pouring 2-3 ml, look into the jar - you will see how the water is quickly absorbed, and the voltage drops on the voltmeter (by fractions of a volt). We repeat topping up for each jar with pauses for soaking for 10-20 seconds (approximately) until you see that the "glass mats" are already wet - that is, the water is no longer absorbed.
After topping up, we inspect whether there is an overflow in each battery bank, wipe the entire case, put the rubber caps in place and glue the lid in place.
Since the battery shows about 50-70% charge after topping up, you need to charge it. But charging must be carried out either with an adjustable power supply or with an uninterruptible power supply or a standard device, but under supervision, that is, during charging it is necessary to observe the condition of the battery (you need to see the top of the battery). In the case of an uninterruptible power supply, for this you will have to make extension cords and bring the battery out of the UPSa case.
Place napkins or plastic bags under the battery, charge up to 100% and see if electrolyte does not leak from any can. If suddenly this happened, stop charging and remove smudges with a napkin. Using a napkin soaked in a soda solution, we clean the case, all the cavities and terminals where the electrolyte has got in order to neutralize the acid.
We find the jar where the "boiling" came from and see if electrolyte is visible in the window, we suck off the excess with a syringe, and then carefully and smoothly fill this electrolyte back into the fiber. It often happens that the electrolyte after topping up is not evenly absorbed and boils up.
When recharging, we observe the battery as described above, and if the "problem" battery bank starts to "poured out" again during charging, excess electrolyte will have to be removed from the bank.
Also, under inspection, at least 2-3 full discharge-charge cycles should be done, if everything went well and there are no smudges, the battery does not heat up (light heating does not count when charging), then the battery can be assembled into a case.
Well, now let's take a closer look cardinal methods of resuscitation of lead-acid batteries
All the electrolyte is drained from the battery, and the insides are washed first a couple of times with hot water, and then with a hot soda solution (3 tsp of soda per 100 ml of water), leaving the solution in the battery for 20 minutes. The process can be repeated several times, and finally thoroughly rinsed from the remnants of the soda solution - a new electrolyte is poured.
Then the battery is charged for a day, and after, for 10 days, for 6 hours a day.
For car batteries with a current of up to 10 amperes and a voltage of 14-16 volts.
The second way is reverse charging, for this procedure you will need a powerful voltage source, for car batteries, for example, a welding machine, the recommended current is 80 amperes with a voltage of 20 volts.
They do a polarity reversal, that is, plus to minus and minus to plus, and for half an hour they “boil” the battery with its native electrolyte, after which the electrolyte is drained and the battery is washed with hot water.
Then a new electrolyte is poured in and, observing the new polarity, they are charged with a current of 10-15 amperes for a day.
But the most effective way is done with the help of chem. substances.
From a fully charged battery, the electrolyte is drained and, after repeated washing with water, an ammonia solution of Trilon B (ETHYLENEDIAMINETETRAACENETIC Sodium) containing 2 weight percent Trilon B and 5 percent ammonia is poured. There is a process of desulfation for 40 - 60 minutes, during which gas is released with small splashes. By the cessation of such gas formation, one can judge the completion of the process. In case of particularly strong sulfation, the ammonia solution of Trilon B should be refilled, removing the spent one before that.
At the end of the procedure, the inside of the battery is thoroughly washed several times with distilled water and a new electrolyte of the desired density is poured. The battery is charged in the standard way to the nominal capacity.
Regarding the ammonia solution of Trilon B, it can be found in chemical laboratories and stored in sealed containers in a dark place.
In general, if you are interested, the electrolyte composition produced by Lighting, Electrol, Blitz, akkumulad, Phonix, Toniolyt and some others is an aqueous solution of sulfuric acid (350-450 g per liter) with the addition of sulfate salts of magnesium, aluminum, sodium, ammonium. Gruconnin's electrolyte also contains potassium alum and copper sulphate.
After recovery, the battery can be charged in the usual way for this type (for example, in UPSe) and not allowed to discharge below 11 volts.
Many uninterruptible power supplies have a "battery calibration" function with which you can carry out discharge-charge cycles. By connecting a load of 50% of the UPS maximum at the output of the uninterruptible power supply, we launch this function and the uninterruptible power supply discharges the battery to 25% and then charges up to 100%
Well, in a very primitive example, charging such a battery looks like this:
A stabilized voltage of 14.5 volts is supplied to the battery, through a high-power variable wire resistor or through a current stabilizer.
The charge current is calculated using a simple formula: divide the battery capacity by 10, for example, for a 7ah battery it will be - 700mA. And on the current stabilizer or using a variable wire resistor, you must set the current to 700mA. Well, in the process of charging, the current will begin to fall and it will be necessary to reduce the resistance of the resistor, over time, the resistor knob will come all the way to its initial position and the resistance of the resistor will be zero. The current will further gradually decrease to zero until the voltage on the battery becomes constant - 14.5 volts. The battery is charged.
For more information on the "correct" charging of batteries, see
light crystals on the plates - this is sulfation
A separate "bank" of the battery was subjected to constant undercharging and, as a result, was covered with sulfates, its internal resistance grew with each deep cycle, so that, during the charge, it began to "boil" before anyone else, due to loss of capacity and removal of electrolyte into insoluble sulfates.
The plus plates and their grids turned into powder in consistency, as a result of constant recharging by an uninterruptible power supply in the "stand-by" mode.
Lead-acid batteries except for cars, motorcycles and various household appliances, where they are not only found in flashlights and watches, and even in the smallest electronics. And if you got into the hands of such a "non-working" unmarked lead-acid battery and you do not know what voltage it should give out in working condition. This can be easily recognized by the number of cans in the battery. Locate the protective cover on the battery housing and remove it. You will see gas bleed caps. by their number it will become clear how many "cans" this battery is.
1 bank - 2 volts (fully charged - 2.17 volts), that is, if cap 2 means a 4 volt battery.
A fully discharged battery bank must be at least 1.8 volts, you can’t discharge it below!
Well, in the end I will give a little idea, for those who do not have enough money to buy new batteries. Find companies in your city that deal with computer equipment and UPSs (uninterruptibles for boilers, batteries for alarm systems), agree with them so that they do not throw away old batteries from uninterruptibles, but give them to you, possibly at a symbolic price.
Practice shows that half of AGM (gel) batteries can be restored if not up to 100% then up to 80-90% for sure! And this is a couple more years of excellent battery life in your device.
Many people have cars, but not everyone knows how to properly restore the battery after a breakdown. A car battery supplies the vehicle with energy, but after a few years it can fail. Under normal operating conditions, the device lasts for five years. If the battery began to show signs of failure, it is not necessary to run to the store and purchase a new one. There are several ways in which you can reanimate the battery.
signs of wear
To understand that the battery will soon fail, you need to have some information - to know the main signs. Without the necessary knowledge, the restoration of car batteries will be difficult. You will need to keep a close eye on your vehicle. Only in this case it will be possible to take the necessary repair measures in time, in particular the battery.
There are several main features:
The battery can be restored in almost all cases if it is not completely run down. The operation can be quite expensive, but it will take much less money than when purchasing a new unit.
You need to be attentive to the operation of the battery and immediately notice various problems. This will depend on the lifespan of the battery. Before proceeding with the direct restoration of the car, you need to find out which parts of the battery are generally subject to resuscitation.
Electrolyte density
The electrolyte is poured into the battery. Usually this substance is a kind of cocktail of acid and water. If the battery is nickel-cadmium or nickel-iron, then in this case an alkaline electrolyte is poured inside.
Before you start repairing the battery, you need to know exactly the density of the electrolyte. To do this, use a device called a hydrometer. You don’t have to spend a lot of money to buy it, it is sold in absolutely any store with auto parts. You can also use a voltmeter to measure the density of an acid solution. It is necessary to turn off the equipment to the terminals of the car.
In the off state, the numbers should be approximately 11.9-12.5 V. After that, turn on the car, dial 2500 rpm and measure again. If the voltage is 13.9-14.4 volts, then the density is within normal limits. In this case, the old battery only needs to be recharged. But, if the indicators are too small, you will need to restore.
Several ways to carry out resuscitation:
Before you restore the acid solution, it is worth trying to simply recharge the equipment. Sometimes it happens that after such a simple procedure, all problems disappear.
If after charging there are problems with the electrolyte, then it is necessary to change the density of the solution in the battery.
Under no circumstances should water be poured into sulfuric acid.. It is very important. Otherwise, you can get very serious damage to the skin in the form of burns. The water will boil and splatter in all directions. Restoring a car battery must be done carefully.
Destruction and closure of plates
If the plates on the battery have collapsed or are just beginning to collapse, then it is necessary to immediately take measures to restore it. If the battery is significantly destroyed, then it will not be possible to restore its parts.
That is why before resuscitation, you need to make sure that this is not a useless exercise. The process of destruction can only be stopped if it has just begun. It makes no sense to reanimate a fairly shabby device.
If you find signs of destruction, you should immediately wash the jars:
- First you need to completely discharge the device by connecting any load to the battery. For this purpose, a conventional light bulb is usually used.
- All damaged solution is removed from the jars. To do this, use a rubber pear. The solution is placed in a glass dish, which was previously prepared.
- Banks are washed with distilled water until completely clean. When cleaning the battery, it is necessary to constantly turn over and shake.
- If there is a lot of dirt inside, and the crumb of coal is still pouring, then the process is already irreversible, since it has gone far. In this version, the battery is no longer subject to recovery.
- When they have achieved complete purity, a new solution must be placed in the jar. Before this, the density of the substance must be checked.
- The battery is put on recharging so that the previous voltage returns to the desired level.
When the cleaning operation is completed and the device is fully charged, you need to check the electrolyte and its density again. If necessary, the indicators will have to be adjusted.
Diagnosis of sulfation
This is one of the most common battery related problems. If normal operating conditions occur, then certain processes occur in the battery during discharging and charging. But when the car starts infrequently, processes will be disrupted.
Lead sulfate crystals may appear on the plates. They are difficult to remove and can lead to the following consequences:
- The battery capacity is decreasing.
- The internal resistance increases.
- The volume of the plates increases.
In most cases, sulfation begins to appear if the car has been idle for a long time, overheated, or critical current conditions are applied to it. You can understand that sulfation has begun by seeing the charge drop.
To determine this indicator, you must use a tester. If a defect is found, you need to think about ways to restore the battery as soon as possible. You need to act quickly while the device can still be restored. For recovery, it is necessary to use a special additive to the electrolyte. A desulfurizer is usually used to dissolve the crystals formed. These were the main faults. After studying them, you can learn how to reanimate a car battery at home.
Chemical recovery methods
The chemical form of battery recovery at home is quite effective. Professionals distinguish three main methods. Recovery options:
Not every degree of sulfation can be restored by hand. That is why it is desirable to notice this process on the car as early as possible.
In order for the battery to work without interruption, it must be constantly and competently looked after and performed. easy tips:
- You will have to regularly monitor the electrolyte and its density. The main cause of boiling is overcharging or overheating of the device. The sooner a problem is detected, the greater the chance of recovery.
- If the car is not used in winter, the battery must be removed and placed in a well-heated room. If the battery freezes, then it will not be possible to restore it.
- Rated current - 0.1 of the capacity of the entire battery. If this threshold rises, the device will not recover.
These are very simple tips for keeping your battery in good condition. They should not be neglected. Only in this case the battery will work for many years without interruption. Restoring a car battery is not difficult, but it will take effort and study the main faults. After studying all the tips, you can understand how to restore a car battery on your own.
Not every car enthusiast knows how to restore a car battery. And this can extend its life by several years and save the car owner from unexpected financial expenses. Today, there are four main ways to extend the life of any battery.
The battery is responsible for the process of continuous supply of the required voltage. Accordingly, they are an indispensable component of the operation of certain mechanisms of the machine and its devices. Everyone knows that nothing lasts forever. As a result, every car needs regular technical inspections in order to identify unusable parts. As a rule, any battery (the most common - acid alkaline and lithium) can be repaired. This option is better than immediately running to the store for a new one.
As for acid-base (they are also called lead-helium), their structure is presented as follows - a pair of plus-minus plates of lead in sulfuric acid. They are most common in the automotive industry and in the production of flashlights. However, such a battery does not last long.
The first way to restore the battery is to use repeated recharging with a small current. In this case, the charging process should provide for time intervals between recharging. Thus, starting from the first charge and ending with the last one, the voltage in the battery gradually increases and as a result, it will cease to perceive the charge itself.
Pauses are necessary so that the potentials of the electrodes, located in the depth of the mass of the plates themselves and on their surface, are aligned, which makes the recovery safer. In parallel, the densest electrolyte begins to flow directly from the pores of the plates themselves into the space located between the electrodes.
Together with the cyclic charge and along with the increase in battery capacity, the density of the electrolyte itself also increases. It is necessary to wait until the section voltage is equal to two and a half volts, and the density indicator reaches a normal level. Only then should the car battery "rest". This cycle should be repeated up to eight times. Also, the charge current itself must be exactly ten times less than the capacity of the battery being charged.
Electrolyte replacement
Direct battery recovery can also be carried out using the replacement method. To do this, completely drain the electrolyte, and then rinse the battery thoroughly with hot water several times. After that, you will need three teaspoons of ordinary soda, which must be diluted in one hundred milliliters of water. 
The resulting liquid must be boiled, poured in instead of the electrolyte, and after twenty minutes - drained. This action must be repeated several times, followed by washing three times with the same hot water.
This method is great for car batteries. The last stage of this process ends with the infusion of a brand new electrolyte and daily charging. After that, the battery is charged for six hours for ten days in a row. The charger must have the following characteristics - the voltage is not more than sixteen volts, but not less than fourteen, and the current strength is not more than ten amperes.
Reverse charge
Recovery by reverse charging is also possible. However, this method provides for the presence of a fairly powerful source of voltage itself (the same welding machine). It must have a voltage of at least twenty volts with a current of at least eighty amperes. Having obtained the necessary device, the next step is to open the corks of the cans and charge them back. To carry out such charging, you need to attach the “plus” of the charger to the “minus” of the battery, and to its “plus” - the “minus” of the charger. And this can extend its life by several years and save the car owner from unexpected financial expenses. 
During the charging process, the battery will boil, but that's okay. Charging itself should last no less and no more than half an hour, after which the old electrolyte is drained, the container is washed with hot water, and only then can new electrolyte be poured in. The next step is to use another charger with a current of up to fifteen amperes. They charge the battery all day long.
Charge recovery in distilled water
Using the last, fourth method, the battery can really be restored in less than one hour. If it is completely discharged, then it should be pre-charged. After that, the electrolyte is also completely drained and washed several times with water. Next, it is necessary to pour an ammonia-type Trilon B solution into the washed battery capacity, which includes two percent of the same Trilon and five percent of ammonia itself. With its help, a process of so-called desulfation is carried out, which lasts up to one hour. During this process, there is a characteristic evolution of gas and the appearance of small splashes on the surface of the poured solution.
After all of the above, it is necessary to rinse the battery several times with plain distilled water, followed by pouring in an electrolyte of acceptable density. Then the battery is charged and it can be considered completely repaired. Summing up, we can say that, in general, the restoration of a car battery can be considered not a very difficult task.
I can say with certainty that the cessation of gas evolution indicates the completion of desulfation. If the sulfation is too strong, then it is necessary to repeat the processing process in order to fully restore the battery.
Video “How to restore the capacity of an old battery”
The recording shows how to charge a lead battery at home.
4 ways to restore a car battery
Batteries are a stable source of constant voltage, they are indispensable in individual designs and devices. But of course there are no eternal things on earth, and with batteries, time passes and they are no longer suitable for use, what should I do? Throw it away and buy a new one? You can of course, but it's better to try to repair them. On the market you can find a sea of batteries of different types of capacities and voltages. Mainly use acid alkaline and lithium batteries. Today we will talk about ways to repair such types of batteries as lead. Acid batteries - more commonly referred to as lead-helium batteries. Two lead plates are immersed in sulfuric acid, one plate is positive, the other is negative. Such batteries are most often used in automotive technology and in flashlights. They have a relatively short lifespan. They can be repaired (restored) in several ways.
The first method of multiple charging with a small current rating with short time intervals between charges. By the end of the first and subsequent charges, the voltage on the battery gradually increases, and it stops accepting a charge. During the break, the electrode potentials on the surface and in the depth of the mass of the plates are equalized, while the denser electrolyte from the pores of the plates flows into the interelectrode space and reduces the voltage on the battery during temporary breaks. During a cyclic charge, as the battery gains capacity, the density of the electrolyte begins to increase. When the density becomes normal, and the voltage on one section reaches 2.5-2.7 volts (the nominal value of each can is 2 volts), the charge is stopped. Repeat this cycle 5-8 times. The charging current is ten times less than the battery capacity, let's say the battery has a capacity of 1000mA / h, then the charge current should be between 80 and 100 milliamps.
The second way to restore acid batteries is to replace the electrolyte. We drain the electrolyte from the battery and rinse the battery with hot water several times. Next, take 3 teaspoons of soda and dilute in 100 ml of water. We boil water and immediately pour boiling water into the battery, wait 20 minutes and drain. This process is repeated several times. Then rinse the battery 3 times with hot water. This recovery method is very convenient to use for car batteries. At the last stage of work, we pour a new electrolyte and charge the battery for 24 hours, the repaired battery is charged once a day for 10 days, the charge lasts 6 hours, the charger parameters are 14-16 volts, the charge current is 10 amperes (no more).
The third way is reverse charging. To do this, you need a powerful voltage source (a welding machine, for example), the voltage of the charger is 20 volts, and the current strength is 80 amperes or more, open the plugs of the cans and charge them only back - we attach the plus of the power source to the minus of the battery, and the minus of the power source to the plus battery. At the same time, the battery will boil, but do not pay attention, we charge for 30 minutes, then drain the electrolyte, rinse with hot water and pour in a new electrolyte. We take an ordinary charger with a current of 10-15 amperes and charge the repaired battery for 24 hours, just do not mix up the polarity, since the factory positive pole will already be negative, and the negative positive pole, we will talk about the repair and restoration of alkaline and lithium batteries in the next article, stay with us - Artur Kasyan (AKA).
Fourth way is highly efficient and fast (the battery is restored in less than an hour). A discharged battery is pre-charged. The electrolyte is drained from a charged battery and washed 2-3 times with water. An ammonia solution of Trilon B (ETHYLENEDIAMINETETRAACETACETE sodium), containing 2 weight percent Trilon B and 5 percent ammonia, is poured into the washed battery. The time of desulfation with a solution is 40-60 minutes. The process of desulfation is accompanied by the evolution of gas and the appearance of small splashes on the surface of the solution. The cessation of gas evolution indicates the completion of the process. In case of strong sulfation, the treatment with the solution should be repeated. After treatment, the battery is washed at least 2-3 times with distilled water, then filled with an electrolyte of normal density. The flooded battery is charged with charging current to the nominal capacity according to the recommendations in the passport. Regarding the preparation of the solution, it is necessary to contact enterprises with chemical laboratories. Store the solution in a dark place in a vessel with a hermetic lid to prevent evaporation of ammonia. http://www.handiman.ru/
December 18, 2012, 09:58
battery repair,
battery recovery
As unfortunate as it may be, everything has its own lifespan. It is believed that the battery has a life of about three years, after which the battery is sent to a landfill, and a new battery takes its place in the car.
However, do not rush to say goodbye to the old battery ahead of time, as there are several ways to resuscitate it. It is with them that I would like to introduce you today.
The most common and favorite methods for resuscitating batteries by most car owners include:
1. Continuous charge of the battery with low current.
2. Battery charge in distilled water.
3. Maximum battery discharges by low currents.
Agree, the names of recovery methods give only superficial ideas about their essence. To achieve an excellent result, you need to get to know these methods of resuscitation of the battery closer.
Continuous battery charging with low current
Using this simple method, you can restore life only to a battery with a slight and not chronic sulfation of the plates.
In order to give a second life to a battery, you need to:
1. Fill the battery with distilled water slightly above the level.
2. Turn on the battery for charging with a current of normal value (0.1 battery capacity).
3. As soon as gas formation in the battery becomes noticeable, the charge should be turned off for 20-30 minutes.
4. After a break, the battery must again be connected to a current, only this time reduced by ten times in comparison with the original, i.e. 0.01 of the battery capacity.
5. Having noticed increased gas formation on the plates of both polarities, it is necessary to disconnect the battery from the current and take a break for 15-20 minutes.
The fourth and fifth battery recovery steps should be repeated several times. Sometimes, in order for the battery to come to full combat readiness, it is necessary to repeat these procedures for several days in a row before starting to operate the battery at full power.
To avoid the inconvenience associated with battery operation, we recommend periodically checking the electrolyte level in the battery (the height of its layer should not be less than 5 mm above the upper edges of the plates), and if necessary, you can add distilled water. Make sure that no foreign matter gets into the battery. Traces of oxidation on battery terminals and wires must be carefully removed.
Battery charge in distilled water
If the sulfation of the battery is deep, but not old, then you can try to restore the battery in the following way.
1. We discharge the battery to a voltage of 9 V.
2. Drain all the electrolyte solution and fill the battery with distilled water. We are waiting for about an hour.
3. After a pause in operation, turn on the battery for a charge. In this case, the voltage at each battery terminal must in no case exceed 11.5 V.
4. Gradually increase the charge. After the specific gravity of the solution has been increased to approximately 1.1-1.12, it is necessary to bring the charging current to a value equal to 0.1 of the battery capacity.
5. The battery should be charged in this way until a uniform gas evolution is noticeable on the plates of both polarities.
6. After that, it is necessary to discharge the battery for one and a half to two hours with a current equal to 0.2 of the discharge current, corresponding to a ten-hour battery discharge mode.
Steps 5 and 6 of battery recovery should be repeated several times. After the specific gravity of the solution does not stop increasing, the electrolyte level should be brought to normal and the battery is ready for use.
It is worth noting that this method is quite time-consuming, it can often take weeks to give the battery a second life.
Resuscitation of the battery by the method of maximum discharges with low currents
The battery recovery method, which will be discussed now, is suitable for batteries with old sulfation. Obviously, the process will be long and laborious, but worth it.
1. First of all, you need to charge the battery with a current equal to 0.2 * Q (where Q is the battery capacity).
2. After the voltage has reached 12V, the charging current should be reduced to the value calculated by the formula 0.05*Q.
3. The charge should be stopped when both the voltage and the weight of the electrolyte have reached stable values.
4. Let the battery rest for half an hour to an hour. Then again charge it with a small current until it “boils”.
This step should be repeated several times. You will understand that it is time to stop the procedure when the electrolyte starts to boil a few minutes after the start of charging.
After that, you should repeat the first stage of work, and after a couple of hours, continue to charge the battery in the indicated way. To restore battery performance, you may need to repeat the entire cycle of work up to 8 times.
Of course, restoring the battery on your own is a rather long and laborious process, but with a little effort you can significantly extend the life of the battery and save a significant amount.
