Car battery, desulfation: recovery methods
A modern car battery likethe rule is from five to seven years. Having worked the time, he loses the properties of the accumulation of electricity and can fail at the most inopportune moment.
The best solution in this situation ispurchase of a new battery. But if for some reason you do not have such an opportunity, you can try to revive the old battery. Restoring the battery, of course, will not restore its previous capabilities, and it will not last as long as we would like, but as a 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 figure out the reasons why the battery "grows old".
The basis of the design of lead-acid batteryconstitute 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 - a solution of sulfuric acid. 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 reactionpasses 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, subsidence of salt particles on the latticesin the first time does not affect the battery performance in any way, because all this happens 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 is no longer able to fully circulate. The result of sulphation is:
- reduction of the working area of the grids;
- increase their electrical resistance;
- decreased battery capacity.
Avoid this destructive process is impossible, but you should know that it happens much faster and more efficiently when the battery does not receive recharging 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 him. It can only be carried out by radical methods, which we will discuss later.
Ways of battery desulphation
How can you get rid of sulfuric acid saltsacid 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 that 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 oflead-acid batteries, regardless of their condition. He does not require any special knowledge in electrical engineering and chemistry. To do this, it is enough to have a car charger on hand.
Before starting work, check the level andthe 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 across the terminalsThe battery rises and it stops charging. In the interval, the electrical potential between the electrodes is equalized. In this case, a denser electrolyte separates from the plates. This causes the battery voltage to drop. At the end of the cycle, the electrolyte acquires the required density, and the battery is fully charged.
The following way, with which you canTry to restore the battery - 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 we remove it. 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 the desulphation of the battery plates takes place, but also the change in its polarity. In other words, the minus becomes a plus and vice versa.
After half an hour of charging, the old electrolyteit is necessary to merge. After that, we pour hot water inside each can and wash away the sediment formed as a result of desulfation.Bay new electrolyte, we 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 cantry a softer method of restoring it. To do this, we need clean water, preferably soft (with a minimum salt content), capacity and heat source for its heating, as well as ordinary baking soda and a charger.
Remove the battery removed horizontallyflat 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 Aat 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 with your own hands canbe carried out with the help of a special tool 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 trialo 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 has ended 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 there are special devices on sale,allowing you to charge the battery, and conduct its desulfation. They are, of course, expensive to stand, 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 battery desulphation, 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 charger,which has such a function, is the most reliable and safe method of its restoration. 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.