How to properly charge maintenance-free car batteries?

Maintenance-free batteries have been sold on the automotive market for a long time, since they do not require topping up with distilled water and electrolyte during operation. At the same time, the service life of a maintenance-free battery without adding fluids is no less than five years.

A maintenance-free car battery does not have plugs that provide access to the banks. These include only calcium batteries, but there is not too much information on how to charge this kind of maintenance-free battery. However, such a battery should be charged correctly and quite regularly, as it can quickly fail.

How to recharge a partially discharged maintenance-free battery

If the maintenance-free battery is partially discharged, then

It should be charged correctly. To do this, you should use the method of continuously sending voltage to the battery terminals, while choosing a high-quality charger that allows you to control the current yourself.

Find out the charging time of your battery

Charging the battery

In this case, charging a battery that is not completely discharged will occur many times faster. This will be possible if at least 14.5 Volts are supplied from the charger to the terminals, however, already at the beginning of the charging process, the current should not exceed twenty-six amperes.

It will take two to four hours to charge a maintenance-free car battery that is not completely discharged. But if the voltage rises above fifteen amperes, then you can completely lose your maintenance-free car battery. You will need to turn off the charger immediately when the current drops to approximately 0.2 or 0.4 Amperes.

Description of maintenance-free batteries

What does a maintenance-free battery mean, what is the service life of such devices and can such batteries be charged? First, let's figure out what it is. The fundamental difference between maintenance-free devices is that they allow you to work much longer without the need to add an electrolyte solution to the jars. Unlike serviced devices, distilled water practically does not evaporate in unserviced devices, that is, their electrolyte consumption is very low. Thanks to this, there are no holes for cans in the design of the device.

Since there are no technological holes, the battery cover itself is soldered to the body without the possibility of further removal. Ultimately, this became the reason that this type of battery became more difficult to maintain, in particular when it comes to charging. Accordingly, the owners of such devices cannot monitor and check the level of distillate in the jars. If boiling off of the electrolyte does occur, the service life of the device will decrease due to the inability to add liquid.

What are the disadvantages of maintenance-free batteries:

• when compared with serviced devices, their cost is higher;
• extreme cold and low negative temperatures actually have a significant impact on the functionality and service life of batteries;
• If the car uses faulty energy consumers, then such a battery can fail much faster.

But despite these disadvantages, this type of battery has a whole list of advantages, otherwise maintenance-free devices would never have become so popular among domestic consumers:

• the device can work in absolutely any position, tilted, etc.;
• maintenance-free batteries make it possible to provide a higher starting current;
• As for maintenance, in this case we are only talking about periodic charging of the device;
• if you comply with all the requirements and rules of use, the battery life will be longer (the author of the video is the Battery Manager channel).

Varieties

Let's briefly consider the main types of maintenance-free devices:

1. Calcium batteries. In such devices, lead-calcium alloys, aluminum and other elements are used in manufacturing.
2. Lead acid devices. The main components in this case are lead; the plates located inside are made from it.
3. Nickel-cadmium. The working fluid solution in such batteries is based on potassium, as well as lithium monohydrate.
4. Hybrid devices. These batteries also use calcium, the purpose of which is to provide a negative type of electrode. In addition, lead with a small addition of antimony can be used - this makes it possible to obtain positive electrodes.

Photo gallery “Battery malfunctions”

Charging a maintenance-free battery that is 100% discharged

Charged battery

It is worth noting that it is almost impossible to discharge a maintenance-free car battery to one hundred percent if you charge it correctly. However, a faulty generator can completely discharge the battery, but it is possible to charge it, although it will take longer.

First, you should correctly adjust the charger by setting the correct voltage, equal to ten percent of the capacity of the maintenance-free battery. In order to effectively charge the battery to 95%, it will take no more than 24 hours. A maintenance-free battery is characterized by the fact that it does not have open cans, from which toxic and explosive vapors are released, so you will have to strictly monitor the charging time.

Charging serviceable batteries

This process is the simplest, even starting with the choice of charger. You can even charge a serviced battery with improvised means - even in the Soviet magazines “Behind the Wheel” they published advice in the style of “how to quickly charge a battery using a socket, a light bulb and a diode.”

Video: How to properly charge the battery

Of course, this option should only be used if absolutely necessary. Ideally, the charger should provide a current numerically equal to 10% of the battery capacity - that is, for a 45-amp battery the normal charging current will be 4.5 A, for a 65-amp battery - 6.5 A. A slight excess of the charging current for serviced batteries It’s not scary - it will only increase the rate of electrolysis of water in the electrolyte, that is, it will have to be added faster.

How to calculate charging time

Charging the battery

Before charging a maintenance-free battery, you need to calculate how long this process will take. This is because a maintenance-free battery can be permanently damaged if it is undercharged or overcharged. In the event that you need to charge a maintenance-free car battery designed for 12 Volts or 60 Ah to 95 or 98%, you will have to spend at least a day and a couple of hours on this. By the way, a lot will depend on how powerful the charger is, since then the car battery will remain on charge for at least two days.

Correctly charging a maintenance-free battery manufactured by Varta or Bosch is a very labor-intensive and time-consuming task, so many owners think several times before installing such a battery on a car.

Features of charging a maintenance-free battery

Charging while driving a car is taken for granted, but charging a maintenance-free battery at home can be questionable. The following problems may occur:

• there is no way to see whether the electrolyte has boiled. This is how things usually happen: when the electrolyte boils, it means that charging is complete. But since the jar in a maintenance-free battery is closed, it is not so easy to see what is happening inside;
• there is no way to measure the density of the electrolyte. If you can unscrew the plugs in a battery being serviced and use a hydrometer to measure the density, in our case this cannot be done;
• sealing of a maintenance-free battery. There is a fear that when the electrolyte boils, the vapors will have nowhere to go and the casing will rupture.

How to charge a maintenance-free battery

Before installing a maintenance-free Varta or Bosch battery into your car, you need to understand how to charge it correctly, best by watching the corresponding video.

The car battery should be recharged at home monthly. In this case, not a simple additional charge is performed, but a run through the full “charge-hold-discharge” cycle at least two or three times. The fact is that these procedures will reduce the sulfation of the plates, and also greatly increase the completeness of the resulting charge.

It is strictly forbidden to charge a maintenance-free battery with cheap Chinese chargers or homemade options, since the unit will be irretrievably lost.

In order for the car to move stably, it is worth charging the battery with original chargers or those purchased during the Soviet Union. Ideally, in order not to keep track of how much time will have to be spent on a full cycle, the charger should be equipped with automatic stabilization of the specified voltage. In order to properly charge a maintenance-free battery, you need to:

battery

• accurately connect the charger clamps to the terminals;
• check the residual voltage on the battery;
• set the voltage to 12.6 Volts;
• change the voltage to the charger to 14.4 Volts;
• make sure that the current decreases, and then gradually increases and decreases its values;
• after this there is a break for two or three hours;
• after the break, charging will drop to one ampere;
• The last time the voltage in the battery is measured is only after it has cooled down.

How long does it take to charge a car battery?

A car battery is considered fully charged if the electrolyte begins to boil. On average, the battery takes about 9 hours to charge. However, this is considered an approximate value. As a rule, the charging time for a car varies and it depends on the current battery charge.

Experts do not recommend heavy overcharging, since scale appears on the lead plate, after which the battery can no longer be restored. To prevent this from happening, it is necessary to periodically measure the electrolyte density, especially in winter. In summer, recharging is carried out when the battery capacity is 50%; in winter, this value is 25%.

After charging is completed, the battery should be washed and dried, as acid or dirt sometimes drips onto the case. These defects must be corrected quickly, otherwise they can cause the car battery to discharge because the housing allows voltage to pass through. In this case, the battery must be washed with soda solution. Do this carefully so that water does not get into the battery jars.

As you can see, this process is not difficult, you just need to follow safety rules, then the device will serve for a long time and smoothly.

Some charging nuances

Charging a maintenance-free battery involves some difficulties and nuances, including:

• if the voltage at the charger is up to 11 Volts, then the battery cannot be revived;
• if the readings on the ammeter of the charger are unstable, then a short circuit occurs in a separate battery bank;
• you need to decide how long you need to charge the battery to prevent it from overcharging;
• in the event that steam flows or gas is intensely released, the charging process should be stopped immediately;
• The battery must be charged at temperatures above ten degrees in a ventilated area.

At the same time, to the question of whether it is possible to charge a maintenance-free battery with devices that provide a voltage of 14.6 - 15.6 Volts, we say a categorical no, since the battery is guaranteed to fail.

Charged Battery

The opinion that a car's generator and relay regulator can keep a maintenance-free car battery in a charged state all the time is not always correct.

Many reasons affect the condition of the battery, for example, driving mode and many, many other reasons.

Therefore, to the question of whether to charge a maintenance-free car battery or not, there is only one answer - a maintenance-free car battery must be periodically charged.

Is it possible to charge a maintenance-free battery?

Of course you can - it’s a battery and everything inherent in a regular battery also applies to a maintenance-free battery.

But how to charge a maintenance-free car battery - there are some peculiarities in this issue.

Although the principle of charging maintenance-free batteries is almost the same for all maintenance-free batteries, each manufacturer recommends something different. Therefore, it is necessary, first of all, to familiarize yourself with the manufacturer’s recommendations.

Unlike conventional maintenance-free batteries, maintenance-free lead-acid

When charging car batteries, the charge voltage must be monitored. And do not allow the voltage at the battery terminals to exceed 14.4 Volts. Only for some battery models it may be higher, and then no more than 16 V.

It is necessary to control the voltage because at high voltage, the water in the electrolyte will begin to decompose into hydrogen and oxygen, and as a result, the level of electrolyte in the battery will decrease and the electrolyte will become more dense. You cannot add water to a maintenance-free battery.

In connection with the above, charging maintenance-free batteries requires a charger, which must automatically maintain the specified voltage. If the device can automatically maintain a given current value, then this will be even better.

Charging of maintenance-free batteries can be carried out either removed from the car or on the car.

If a maintenance-free car battery is removed from the car for charging. Then you need to connect the plus (+) terminal of the charger to the (+) terminal of the battery, and the minus (-) terminal of the charger to the (-) terminal of the battery.

Set the voltage regulator knob on the charger to the minimum voltage position and only then turn on the charger. Then set the charge voltage to 14.4 Volts and the charging process will begin.

How long it will take to charge the battery depends on many reasons, including how discharged the battery is.

An indicator that the charging process is complete will be the value of the charging current. When the voltage at the battery terminals is 14.4 V, the charging current drops to 200 mA, the charging of the maintenance-free battery can be considered complete.

Under no circumstances should the charging current be allowed to exceed one-fifth of the battery capacity. This charging current is dangerous for maintenance-free batteries.

If the battery is very deeply discharged, you should start charging the battery at a voltage of 12 V, and when the charging current rises to 0.1 of the capacity of the battery being charged, increase the voltage to 14.4 V and continue as described above.

If the battery is recharged in a car, then special care must be taken. It is necessary to turn off or put into sleep mode the ignition and all possible electrical appliances, and only then connect the charger and start charging, as described above.