What voltage to charge a car battery at home
What voltage to charge a car battery at home

While the car's power unit is idle, the entire on-board network is powered by voltage from the battery. In addition, her duties include starting the engine. At the same time, if you use this device incorrectly, or charge it not according to the instructions, its service life will begin to decrease. In addition, the need to purchase a new battery will arise much faster. Does every owner of his vehicle know what voltage to charge a car battery with? After all, this seemingly simple case has its own peculiarities.

Features of battery operation

The battery of any vehicle cannot generate the required amount of electricity to start the power unit and the needs of on-board consumers. She can only store it in herself and give it away as needed. For recoverythe charge during the operation of the power plant is answered by the generator, which, in turn, functions due to the operation of the engine.

What voltage to charge a car battery
What voltage to charge a car battery

The charge-discharge cycle does not benefit the battery itself, and over time, the amount of charge decreases, up to its complete loss. The maximum number of complete discharge and charge cycles is about 60. After that, the battery is destroyed and cannot hold a charge. And a generator alone is often not enough to restore electrical energy. Eventually, there may come a time when the car battery will not be enough to start the engine. Then it becomes necessary to charge it.

Battery types

There are several types of car batteries:

  • acid;
  • alkaline;
  • gel.

In addition, there are also lithium-ion batteries, but due to their design features, they are not able to start the engine. For this reason, they can only act as an additional source of electricity.

Probably those motorists who are interested in what voltage to charge a 12 Volt car battery already know that there are other types of batteries - serviced and maintenance-free.

The first includes only acid batteries. This is due to the fact that during the course of a chemical reaction, some part of the water in the electrolyte evaporates, which results in a decrease in its density. Therefore, periodicallycheck its condition by adding the missing part of the liquid. For this, only distilled water is used. Some motorists add electrolyte, but this is not recommended.

As for maintenance-free batteries, they are mostly gel batteries. They have a sealed case, and during a chemical reaction there is simply nothing to evaporate. As a result, there is no need to add water. Although some batteries can be restored by adding some distillate to the cells.

As for the device, all batteries are similar to each other - there is a set of plates that are electrodes. Some of them are positive, others are negative. In order for a chemical reaction to proceed between them, the entire space of the monoblock in which these plates are located is filled with electrolyte. It can be different solutions: acid or alkali with water.

Acid batteries

Before figuring out what current and voltage to charge a car battery, at least briefly consider the main types of batteries. In this type of battery, the electrodes are lead plates with additional impurities. The use of lead is justified due to the fact that this material has a good energy capacity. In addition, it has another irreplaceable quality - the ability to deliver a higher current in a short period of time.

Car battery device
Car battery device

The electrolyte used here is an acid solution. This is the most common option that is used in many vehicles. This is especially true for technology.commercial use, since the cost of such batteries is the lowest.

Alkaline batteries

These batteries differ from alkaline counterparts in that the electrodes are no longer lead plates, but nickel-cadmium or nickel-iron counterparts. And all the space between them is filled with a solution of caustic potassium. At the same time, this type of batteries is not used as often as acid batteries. This is mainly due to the fact that alkaline batteries produce less current. But they have a high capacity, so they are used in golf carts, forklifts, where long work is required. They are rarely used as starter batteries.

CA/CA batteries

And what voltage to charge a car battery CA / CA? About this a little later and it is worth noting, there are some subtleties of the charging process. But what is hidden under the calcium battery? In fact, this is the same acid battery with conventional lead plates, which at the same time are alloyed with calcium. Moreover, this metal contains not so much - about 0.1%. But even this amount is quite enough to obtain higher performance in terms of energy storage.

In addition to calcium, the plates can be coated with silver, which as a result raises the cost of such batteries. However, at the same time, their service life is noticeably increased. And all due to the fact that due to the inclusion of silver, it is possible to significantly reduce the percentage of sulfate formation on the surface of lead plates.

Gel analogues

This technology can be considered asstill new, since such batteries appeared not so long ago. This is another version of an improved version of the acid battery. Only now the electrolyte is used in a different way - it is a jelly-like substance that has its own significant advantages.

Gel battery device
Gel battery device

About what voltage to charge a maintenance-free car battery, it will also be said, but also a little later. It is worth noting that this is a more promising version of the batteries. At the same time, a number of technological features do not allow them to be widely used. In addition, their cost is not so affordable.

How do you know if the battery is low?

A car battery almost never suddenly discharges because it is constantly being recharged by the alternator. But again, this is with good electrical equipment. However, sometimes this may not be enough. It largely depends on the nature of the operation of the car. If the trips are frequent and short, then the electricity consumption will always be large and the generator is simply not able to make up for the losses.

Sooner or later, the charge drops to a critical level. In addition, low and negative temperatures act as a catalyst - the discharge time in cold weather is noticeably reduced. For this reason, the need for recharging occurs more often. But how to understand that the battery has lost its charge? A number of symptoms may indicate this:

  • When the ignition is on, all indicator lights go out.
  • When the engine is idle,lighting fixtures are dim than usual.
  • When turning the key, you can hear the starter giving a few turns and notice that it is difficult for him to turn the crankshaft. In addition, there are loud clicks.
  • If the discharge is deep, then the triggering device does not turn on at all. The same can be said about the retractor mechanism.

It is important not only to know to what voltage you need to charge a car battery, but to be able to recognize its discharge in time. Do not allow deep discharge of the battery! Otherwise, sulfation of the plates cannot be avoided, this lowers the battery capacity.

Typically, the appearance of these signs may be due to oxidized terminals or poor tightening of the contacts. Checking the charge is easy with a multimeter or hydrometer. Readings of 12.6-12.8 Volts will indicate that the battery is fully charged, but if the display shows 11.8 V or less, it means that the battery is completely discharged. When using a hydrometer, the positive capacitance value is 1.27 g/cm3.

Choosing a charger

In order to properly charge the battery, you should choose the appropriate device. In fact, this is an electricity converter and the simplest circuit consists of a step-down transformer and a diode bridge. The principle of operation is simple - the incoming alternating voltage (220 V) passes through the listed elements and is converted into direct current with a nominal value of 14-16 V. Actually, this is how much is needed to charge the battery.

Car battery charger
Car battery charger

Manybeginners often think about the question of what voltage to charge a car battery. Moreover, you need to know the answer in advance, as this will allow you to select the desired device. In addition, there are two charging schemes:

  • at DC;
  • at constant voltage.

However, each type has its own advantages and disadvantages. Devices of the first type are able to fully charge the battery (already a plus), but overheating of the electrolyte may occur. This negatively affects battery life.

Using constant current charging, the problem mentioned above can be avoided. At the same time, at the end of the cycle, the current value decreases. As a result, it will not be possible to fully charge the battery (this can already be considered a disadvantage).

Suitable option

But there is no reason to despair, as you can find combo chargers in many car shops. The battery is charged at a constant current value. At the same time, the voltage varies within reasonable limits, which avoids many unpleasant nuances. However, such devices are quite expensive.

In addition, many motorists are interested not only in what voltage a car battery can be charged to, but also ask another equally important question. We are talking about what is better to choose - a transformer or a pulse charger?

The first device has a higher degree of reliability, but has large dimensions and weight. The second type has a compact size, but its reliabilitytotally depends on the manufacturer. Therefore, there are certain risks of running into a low-quality device.

Preparatory stage

For many car enthusiasts, the charging process will not seem difficult. You should carefully read the instructions, which are mandatory attached to any charger.

What voltage should a car battery be charged to?
What voltage should a car battery be charged to?

But at the same time it is necessary to take into account a number of nuances:

  • Caution and attentiveness. When removing a battery with liquid electrolyte, you need to ensure that it does not spill from plugs or necks. Otherwise, the surface should be treated with a 10% solution of caustic soda, although ordinary food is also suitable.
  • Non-residential premises. The battery is charged only in non-residential premises, since during this process the electrolyte heats up and boils, forming an oxygen-hydrogen mixture. Its harmful vapors, if inhaled, can cause serious harm to he alth. In addition, an open source of fire will inevitably lead to fire and even an explosion.
  • Checking the battery. It is not so important to understand what voltage to charge a car battery, the main thing is to make sure that it is working. In most cases, the cause of battery malfunction lies in a short circuit in one of the cans or several at once. This can be understood by the signs of electrolyte boiling when the charger is turned on. If the battery starts to heat up quickly at the set current, this is a symptom of sulfation of the plates.
  • Electrolyte level control. Hisbefore charging the battery, also check and top up with disciplined water if necessary.

After that, you can go directly to the procedure itself. She also has her own characteristics, which will be discussed later.

Features of battery charging at home

When the preparatory stage is completed, you can start connecting the charger to the battery. But for the correct procedure, some features should be taken into account. And first of all, it concerns the choice of the optimal current strength, so the information below will also help you choose the right charger.

The optimal value is 10% of the battery capacity. In other words, for a battery with 55 A / h, the charging current should not exceed 5.5 A. By analogy, you can calculate the current for other capacity values \u200b\u200b- 60, 65, 75 A / h. For such batteries, the indicators will be 6, 0, 6, 5 and 7.5 A, respectively.

What is the voltage on a fully charged car battery
What is the voltage on a fully charged car battery

As for another parameter, the same 10% appear here, only from the voltage on a fully charged car battery (they should be added). For example, for a battery, it is 12.6 V, then 10% will be 1.26 V. In the end, we get the optimal voltage for charging - 12.6 + 1, 26=13.86 V.

In some cases, the process can go much faster with a much higher current - from 20 to 30 A. However, in this case, the battery can be damaged and for this reason it is better to refuse this method.

Charging gelmaintenance-free batteries, care must be taken to ensure that the voltage does not reach a critical level of more than 14.2 V. Based on these criteria, the battery will be charged correctly.

Charging the battery correctly

As we now know, there are two constant value battery charging schemes:

  • voltage;
  • current.

At the same time, the constant voltage method is quite simple to implement. All that is required is to set the optimal current value (as we remember, 10% of the battery capacity). As the battery charges, the current will decrease. The signal for the end of the process will be the lowering of the arrow of the device to "0". As a rule, the entire procedure can take from 10 to 13 hours.

What voltage to charge a car battery with the second method? Everything is a little more complicated here. First, you need to set the same 10% of the battery capacity and at this current value, charging will continue until the battery voltage reaches 14 V. After that, you need to halve the current so that the voltage readings increase to 15 V. Then you should reduce the current by half again. A fully charged battery will be indicated by the fact that within an hour the voltage readings will not change.

Calcium car battery

Charging calcium batteries is slightly different from the traditional options that we have already considered - here the allowable voltage is from 16.1 to 16.5 V. For these purposes, you need a good device, such as "Orion VIMPEL 55", containing several programs andcharging algorithms. It is only worth noting that the device is quite expensive - about 3-3, 5 thousand rubles. But if there were funds to buy an equally expensive branded calcium battery (their price can reach up to 10,000 rubles), then it makes sense to purchase a good charger.

Process started
Process started

The process itself is performed in the following order:

  • Stage I. The voltage is set to 16.1 V, and the current according to the already known scheme is 10% of the battery capacity. In this mode, the battery is charged until a current of 0.5 A is reached. This completes the first cycle. This may take several hours.
  • Stage II. This charging mode is characterized by periodic changes in voltage and current. The device sets "Algorithm 1" (voltage - 16.1 V, current - 3 A) and "Algorithm 3" (voltage - 13.2, current - 0 A).

Here it is important to grasp the essence of what voltage to charge a calcium car battery. At stage II, charging is carried out in waves: that is, the voltage from 12.7 V will increase to 16.1 V. After that, the current drops to 0, and the voltage decreases to 13.2 V. To return to the original value (16.1 V), it takes time (about 20-30 minutes). In this case, the entire process is displayed on the device display.

When the voltage reaches 13.2 V, "Algorithm 1" is connected again. Each time reaching a value of 16.1 V will be faster and faster. At some point, it will take several tens of seconds to reach the maximum threshold, and a few minutes for the minimum threshold. This will be an indication that the battery is ready for use and charging can be completed.