Charging the battery: how many amps to put and how long to charge?
Charging the battery: how many amps to put and how long to charge?

To properly charge the battery of your car, it is not necessary to have deep knowledge and special skills. The basic knowledge of physics that the school gives us will be enough. Therefore, to put everything into practice is within the power of any driver. At the same time, you should not neglect the instructions, because it is not just included in the package for the battery. This will allow you to decide how many amps to charge the battery.

About what affects the battery charge

Although most batteries are maintenance free, they still need to be charged. And it largely depends on the operating conditions of the vehicle. If you make trips over short distances with frequent stops, turning off the engine and starting it again, then this negatively affects the actual capacity of the battery - it decreases.

car battery
car battery

On top of everything else, the key role is given to the generator, or rather its mode of operation. This is especially true for cars.old years of release. The bottom line is that the generator gives out its optimal characteristics only when it reaches 2,000 rpm. In other words, the idle mode of the power unit is not able to ensure proper battery charging, especially if powerful consumers are involved.

Know how many amps you need to charge the battery, should in any case. And from time to time (at least before the onset of winter) it is necessary to charge the battery from another power source. And in this case, special devices are used.

Battery Charging Overview

Charging itself is usually done with direct current, alternating voltage is not good. Therefore, most chargers (chargers) contain the necessary rectifiers. But even here there may be nuances. At the same time, you can use any other device that gives the desired voltage value with the ability to adjust the output parameters.

It should be noted right away that the recommendations given in the article apply only to acid batteries. For alkaline analogues, the rules are slightly different. But since mostly acid batteries are installed on cars, we will analyze the question of how many amperes are needed to charge the battery in the future, starting from them.

Preparing for charging

Before starting the process, it is worth taking a number of additional and necessary steps. First you need to remove the battery from the car, not forgetting to unscrew its terminals. It is believed that the battery can be charged without removing the batteries, and even leaving the terminals ontheir places. However, it is better not to do this. The battery is a relatively heavy thing, but it's better to work hard and remove the battery.

How long does it take to charge a car battery
How long does it take to charge a car battery

Now you should clean the battery from contamination. While she was under the hood, she could hardly stay clean. In addition, any battery (even a maintenance-free one) has a special valve through which the electrolyte evaporates (it then condenses on the lid). It is worth adding other negative effects: adhering dust, dirt, oil. Ultimately, a conductive layer may form, leading to an increase in the self-discharge of the battery.

Knowing how many amps to charge the car battery, of course, is necessary (more on this later), but preliminary preparation should not be ignored. Therefore, in order to avoid many troubles, the battery must be well cleaned before charging, and possibly after. To get rid of many contaminants, during the operation of the battery, you can purchase a special case for it.

Battery Charging Options

Many drivers are interested in such a logical question, how much time should be taken to charge a car battery? To answer it, you should know that there are four main ways:

  • Using direct current.
  • Charging with constant voltage.
  • Combination.
  • Fast process.

It is worth considering them in more detail, since each option has its own characteristics. In addition to everything else, notDon't forget about safety! The electrolyte contains sulfuric acid. Therefore, care must be taken and it is better to work with gloves and goggles.

How many amps do you need for a car battery
How many amps do you need for a car battery

And it is not so important how many amperes to put to charge a car battery, but to take into account that the procedure itself should be carried out in a well-ventilated area. This is due to the release of hydrogen. In this connection, any work related to an open flame and the formation of sparks (welding, cutting) is prohibited near this place.


This technique is ideal when the battery is very low. Then he will receive a more complete and uniform charge. The process itself, although long, can restore the battery capacity to the maximum. The bottom line is that the manipulation consists of several stages, while the current itself is maintained at a constant level.

This option is not very convenient because it is necessary to constantly monitor the charging process, as well as change the voltage and adjust the current strength. In other words, just turn it on and leave everything for a while will not work. The principle of "turn on and forget" is not appropriate here! In addition, the charger should be purchased with the ability to adjust the current.

The charging procedure itself

Now it's actually time to get acquainted with how much to set the ampere when charging the battery. Only for the process you will still have to arm yourself with a multimeter.

In the future, act on suchpattern:

  • Stage I. The current strength is set to 0, 1 from the battery capacity (60 Ah - 6 A, 40 Ah - 4 A). It should be maintained until the voltage reaches 14.4 V. This is where the multimeter is needed.
  • Stage II. The voltage of 14.4 volts was not chosen by chance - in this case, the electrolysis of water increases, and sharply. As a result, the molecules break down into oxygen and hydrogen. The current should be halved. That is, for 60 Ah - 3 A, 40 Ah - 2 A.
  • Step III. When the battery reaches 15 volts, the current must be reduced two more times (1, 5 and 1 amperes, respectively). And here you should control the voltage every hour or two. And when it becomes constant, and active gas emission is observed in the banks, the procedure can be considered completed.

As you can see, with this method of charging the battery, it is very difficult to say exactly how long it may take. Everything mainly depends on the degree of discharge, sulfation of the battery, its age.

special device
special device

How many amps are needed to charge the battery, we now know with this method. As for the sedimentation of calcium s alts on the plates, this phenomenon simply cannot be avoided. Because of it, part of the battery capacity is lost. Accordingly, the smaller this parameter, the faster the battery is charged.

Constant voltage

The process using constant voltage is relevant in the case of a small recharge. Many devices with a similar mode of operation function automatically - thismuch easier and faster than the method described above. In this case, you can already roughly estimate how much the battery will charge, since the process is affected by the applied voltage:

  • 14, 4V - 12 volt battery will be charged to 80% within 24 hours.
  • 15 V - the battery can charge up to 90% in a day.
  • 16V - Charge percentage can reach 95%.
  • 16, 3 V - in this case, the battery is fully charged.

How many amps should be when charging the battery in this case? The bottom line here is that throughout the process the value of the current changes. Initially, when the battery is discharged, the value can reach several tens of amperes, but subsequently the current decreases. At the same time, the internal resistance of the battery increases.

The convenience of this method is that there is no need to control the current strength, the charger is able to do this on its own. And when the battery is charged, the device also spontaneously stops the process.

Combined version

This technique is the most gentle and effective, because it combines the possibilities of the first two methods. At the beginning of the process, the current remains constant, while the voltage changes. At the end of charging, everything happens the other way around - now the potential difference is set constant, and the current gradually decreases. If you use an automatic device, then you don’t even have to think about how many amps to charge the battery.

The process of charging a car battery
The process of charging a car battery

Besidesthis technique is optimal from the point of view of conducting a qualitative process. It allows you to increase the life of the battery itself. At the end of the procedure, the current is almost 0.

Fast process

This method is good in cases where it is necessary to restore the capacity of the battery for at least one engine start. To this end, some chargers have a corresponding Boost mode. In this case, charging is performed under the influence of increased current for 20 minutes.

If the device does not have such a mode, but there is an adjustment of the current strength, then the overcharge can be set independently. Only its value should not exceed 30% of the value during normal charging. How many amps to give when charging a battery? For example, if it is usually 4 A, then the current in accelerated mode should not exceed 5.5 A. Otherwise, it will negatively affect the battery plates.

It is also worth noting that the boost charging mode should only be used in emergency situations when you need to urgently start the engine. But after the trip, it is imperative to fully charge the battery in the normal mode.

GEL batteries

Recently, gel batteries have become popular. Their main advantage is the fact that, despite the degree of discharge, the battery is capable of delivering increased current. This quality is simply indispensable in case of starting the engine in winter.

Gel battery for car
Gel battery for car

Another distinct benefit is that the battery is capable of supplying the vehicle's entire electrical grid until the battery is reduced to 25% of full charge.

Gel batteries have the same standard capacity - 60 Ah. As is known, this parameter decreases for almost all lead-acid batteries due to repeated charging, which is due to their design features. Gel batteries are more resistant to this procedure. Modern batteries can withstand up to 1,000 charges. But at the same time, you should know how many amperes to put the battery on charge. And this is exactly what will be discussed further.

GEL battery charging features

Since gel analogues of lead-acid batteries are still in the stage of gaining popularity, not every service center can charge them. In addition, there is another difference from lead batteries, which can be charged with a voltage in the range of 14-16 V. You should be extremely careful with modern gel power supplies, since they are characterized by a certain voltage threshold, which in no case should be set above 14 Volt.

Battery charge control

Monitoring the process of charging the battery with a multimeter, you can get only a mediocre idea of what exactly is happening. Of course, it is necessary to know how many amperes to charge the battery, however, to obtain more accurate information, it is worth measuring the density of the electrolyte. And for this you can not do without another device, whichA must have for every driver. This is a hydrometer.

The density of the electrolyte must be measured in each bank, and the degree of charge is estimated by the average value obtained. Moreover, this characteristic itself should be approximately the same in all containers. However, slight deviations may be present, which is normal.

The need for each of the ways to charge the battery

Now you can imagine how long the whole charging procedure will take. Specifically, everything is determined by the state of the battery, the type of procedure used. Finally, a good recommendation can be made. How many amperes to put the battery on charge, we now know. There are no problems with the automatic charger at all.

How many amps do you need to charge a car battery
How many amps do you need to charge a car battery

But it is worth noting one more interesting point - when the charger is turned off, the battery can be left in this mode for storage. And while the battery is idle, the leakage current will contribute to a gradual discharge and, as a result, its internal resistance will decrease.

As needed, the charger will turn on and make up for electrical losses. As a result, the battery will always be fully charged and ready for further use.