How to properly charge the car battery

It does not matter how the AKB villages: did you forget to pay off the dimensions, got too carried away listening to music in the parking lot, or left for the whole summer on vacation. To charge a battery, you need to have an idea of ​​the theory and follow a few simple rules.

A bit of theory

In cars, mostly lead-acid batteries (WET) are used. Their principle of operation is based on the chemical reaction of lead plates with an electrolyte, which produces electricity. Over time, sulphation and destruction of plates inevitably occur, as well as the boiling away of the electrolyte, which reduces the capacity of the battery. And the battery can be discharged at the most inopportune moment.

How to check the battery

The easiest way to use the built-in charge indicator, which is on most batteries. This is the same “bulb”, which in reality is not a light bulb, but a green float ball moving in a transparent bulb. At a sufficient level and density of electrolyte, the ball rises and we see a green indicator. If the float is not visible, you need to check the electrolyte and recharge the battery.

Another option is a multimeter. With it, you can measure the voltage at the terminals and see if the battery is dead or not. A fully charged battery should be 12.6 V or more. The voltage of 12.42 V corresponds to 80% of the charge, 12.2 V – 60%, 11.9 V – 40%, 11.58 V – 20%, 10.5 V – 0%.

The most reliable way is to check the load plug. It can show the voltage drop under load, that is, the actual level of charge and, accordingly, the capacity. Such a device is available for any auto electrician or in a store where batteries are sold. And for this check with you, most likely, they will not even take money.

How to prepare the battery for charging

Having determined that the battery is really discharged, you can start charging, but first you need to prepare.

1. The battery should be removed from the machine. If there is no time for this, disconnect it from the on-board network by disconnecting the negative lead.
2. After this, the terminals must be cleaned of grease and oxide for good contact.
3. It does not hurt to wipe the surface of the battery with a dry rag, or better – soaked in a 10% solution of ammonia or soda ash.
4. Also, do not forget to remove the plugs on each of the battery cans or remove the plug to ensure that the electrolyte vapor is free and prevent excessive pressure inside.
5. If the level of electrolyte in any of the cans is insufficient, you need to top up the distilled water so that it completely covers the plates.

How to charge the battery

The principle of charging is simple: you only need to connect the wires from the charger to the battery terminals and plug in the plug into a socket. However, to begin with it is necessary to determine the charging method. There are two main methods: charging with DC and charging with DC voltage.

The first is more effective, but takes place in several stages and requires control. The second is simpler, but it provides charging of battery only up to 80%.

There is also the so-called combined method, in which participation by the car owner is minimized. Minus this method in the need for a special charger with a fairly high cost.

DC charging

1. Set the current at 10% of the nominal capacity of the battery and charge until the voltage at the battery terminals rises to 14.3-14.4 V. For example, a battery with a capacity of 60 Ah should be charged with a current of no more than 6 A.
2. Then reduce the current in half (up to 3 A) in order to reduce the intensity of the boiling, and continue charging.
3. As soon as the voltage rises to 15 V, you need to reduce the current again by half and charge the battery until the voltage and current values ​​stop changing.

Charge by constant voltage

Everything is much simpler here. You just need to set the voltage within 14.4-14.5 V and wait. Unlike the first method, with which you can fully charge the battery in a few hours (about 10), charging with a constant voltage lasts about a day and allows you to make up the capacity of the battery only up to 80%.

Precautionary measures

Since charging the battery is a chemical process in which an explosive mixture of hydrogen and oxygen is released, one must be very careful and follow the rules:

1. Charge the battery in a well-ventilated area.
2. Do not use open fire and do not perform any work with the formation of sparks.
3. If it is not possible to remove the battery from the machine, disconnect the negative lead, or both.