Car battery, desulphation: recovery methods

A modern car battery, as a rule, serves from five to seven years. After having fulfilled the put period, he loses the properties of accumulation of electric power and can fail at the most inopportune moment.

The best solution in this situation is the purchase of a new battery. But if for some reason you do not have such an opportunity, you can try to reanimate the old battery. Restoring the battery, of course, does not return her previous abilities, and it will not last as long as we would like, but as temporary or spare, such a battery is quite suitable.

In this article we will consider what is the desulphation of car batteries and how to do it at home. But first let's look at the reasons why the battery "grows old".

Sulphation

The basis of the design of lead-acid batteries is made up of lattice plates. Some of them are made of pure lead, others - from its oxide. The entire space between the plates is filled with an electrolyte - sulfuric acid solution. When the battery works on the discharge, a chemical reaction takes place inside it, resulting in water and lead sulfate precipitating on the grids with the smallest particles. This process is called sulphation. It is he who leads the AKB to "aging".

When the battery goes into charging mode, the reaction proceeds in the opposite direction, but it is never complete. In other words, the sulphate particles that have not entered the process, gradually, layer by layer, cover the electrodes, disabling the battery.

What causes sulphation

Naturally, the settling of salt particles on the gratings does not at first affect the operation of the battery, because all this occurs at the molecular level. But over time, molecules begin to form crystals that grow continuously. And now, after several years of active operation, the cells of the grids are clogged by them, and the electrolyte no longer has the ability to fully circulate. The result of sulphation is:

• Reduction of the working area of the grids;
• Increasing their electrical resistance;
• Decreased battery capacity.

It's impossible to avoid this destructive process, but you should know that it happens much faster and more efficiently when the battery does not get recharged for a long time.

What is desulphation?

Is it possible to extend the life of the battery? The only way to save the battery is desulphation. This is the reverse process, of which we have already spoken. It happens by itself, when the energy source gets charging. But in the accumulator, which has already been worked out, desulfatation does not occur under the influence of the current that the generator gives it. It can be implemented only by radical methods, of which we will talk later.

Ways of battery desulphation

How can you get rid of the salts of sulfuric acid at home? Desulphation of the battery by one's own hands can be carried out in two ways: with the help of electricity, and with the help of chemically active substances. In the first case, electrical appliances are used, which are capable of delivering a different current to the battery and in different modes. Chemical desulphation occurs due to the reaction of lead sulfate with alkaline solutions of industrial or domestic manufacture.

Multiple charging method

This method can be applied to any types of lead-acid batteries, regardless of their condition. He does not require any special knowledge in electrical engineering and chemistry. To do this, it's enough to have a car charger on hand.

Before starting work, check the level and quality (density) of the electrolyte. Better, of course, to fill in a new solution to somehow "revive" the battery. Desulphation by the method of multiple charging implies the supply of low-current current to the battery terminals with short time intervals. The cycle consists of 5-8 stages, during which the battery receives a current, the value of which is one tenth of its capacity. During each of the charge, the voltage at the battery terminals increases and it stops charging. In the interval, the electrical potential between the electrodes is equalized. At the same time, a denser electrolyte separates from the plates. This leads to a decrease in the battery voltage. At the end of the cycle, the electrolyte acquires the required density, and the battery is fully charged.

Recharging method

The next way, with which you can try to restore the battery - is recharging desulphation. It implies the use of a powerful power source capable of delivering current up to 80 A and more, as well as a voltage within 20 V. For these purposes, a welding machine (not an inverter) is perfect. The procedure is as follows. The battery is disconnected from the vehicle's on-board network and removed. Install the battery on a flat surface, unscrew the plugs. We connect the terminals of our improvised charger to its terminals in the reverse order, i.e. To minus - plus, to plus - minus, and turn on for 30 minutes. During this process, the electrolyte will inevitably boil, but it's not scary, because we will change it.

As a result of such shock therapy, not only desulphation of the battery plates occurs, but also a change in its polarity. In other words, the minus becomes a plus and vice versa.

After half an hour of charging, the old electrolyte must be drained. After that, we pour hot water into each jar and so we wash out the sediment formed as a result of desulfation. Fill the new electrolyte, put the battery on the charge, using a normal charger, tuned to a current of 10-15 A. The duration of the procedure is 24 hours.

Important: when charging the battery, observe the reverse polarity, because our battery has changed it forever!

Desulphation with baking soda

If the AKB still shows signs of life, you can try a softer method of its recovery. For this we need clean water, preferably soft (with minimum salt content), capacity and heat source for its heating, as well as ordinary baking soda and a charger.

Remove the battery removed to a level surface, unscrew the plugs and drain the old electrolyte. Next, make a solution for desulphation at the rate of 3 teaspoons of soda per 100 g of water and heat it to a boil. Fill the hot mixture in the jars and let it "work" 30-40 minutes. After this, drain the solution and wash the battery three times with hot water.

Gulf new electrolyte, we charge the battery. Desulphation with soda, as it may seem at first glance, gives a very weak effect, but if you follow the rules of charging, then the battery will have a real chance for a second life.

At the initial stage, we charge the battery with a current of 10 A at a voltage of 14-16 V during the day. Then repeat the procedure every day, reducing the time to six hours. The cycle of the charge should be exactly 10 days.

Desulphation with Trilon-B

Desulphation of the battery by one's own hands can be carried out with the help of a special device designed specifically for these purposes. This means - ammonia solution ethylenediaminetetraacetic acid sodium (trialon-B). You can buy it in any car dealer or in the car market. It is poured into the banks of the battery for an hour, before charging it and draining the old electrolyte. The process of desulphation with trialon is accompanied by abundant gas evolution and the appearance of small bubbles on the surface of the liquid. The termination of these two phenomena indicates that the reaction is over and the procedure can be stopped. The final stage of desulphation is washing the cans with distilled water and filling them with a new electrolyte. The battery is charged in the usual way with a current equal to a tenth of the capacity of the battery.

Desulphation of the battery with a charger

Today, on sale there are special devices that allow you to charge the battery and conduct its desulphation. They cost, of course, not cheap, so buying them specifically in order to restore one battery is more than inexpedient. But if one of your acquaintances has such a device for desulfating batteries, then it's silly not to take advantage of this opportunity. The principle of operation of this device is based on the method of multiple charging, which we discussed earlier. First, the battery is charged for some time with a current of a certain value, and after it is discharged. Then comes a new stage, followed by one more, and so on, until the battery is recharged.

Desulphation of the battery with a charger having this function is the most reliable and safe method of its recovery. In addition, it does not require any control - everything happens in automatic mode. The user only needs to connect the battery to the device, select the desired mode and wait for the result.