At the very beginning, I would like to say what a maintenance-free battery is all about. This is not an ordinary lead battery, but a modern power source that does not have holes for adding electrolyte or water. A feature of maintenance-free batteries is that they are operated without adding water to them during the entire service life (4-5 years).
How to charge a maintenance free battery
This question is asked by many motorists who have purchased such a battery. But first you need to decide whether this can be done at all. Of course, if the battery is charged while the car is moving from the generator, then why can’t you use a special charger (charger) and recharge the battery yourself? The only thing to keep in mind is the exclusion of "grandfather" recharging methods. This will simply disable the battery or shorten its life.
Now let's try to answer the question "how to charge a maintenance-free battery." To begin with, it should be noted that this must be done not just carefully, it is worth using personal protective equipment (glasses, gloves). Since we do not know the electrolyte density of our battery, but focus solely on the auto sensor, we only use the memory purchased in the store. You also need to understand that the battery can be fully or partially discharged.
Recharging a partially discharged maintenance-free battery
In this case, the method of continuously supplying voltage to the battery terminals is ideal for us . You can use the memory, which allows you only to control the current strength. Therefore, charging will be an order of magnitude faster than with a fully discharged battery. If we talk about numbers, then on average 14-14.5 Volts should flow from the charger to the battery terminals, and at the very beginning of charging, the current should not exceed 25-26 Amps.
Then it remains only to wait. Depending on the level of the residual charge in the battery, the process can take from 2 to 4 hours. But here you need to remember that if the voltage is higher than 15 Amps, then you risk being left without a battery at all. As for the end of recharging, you need to look at the memory. When the current drops to 0.2-0.4 amperes, this indicates that you can turn off the charger from the network, as the battery is ready for use.
What should I do if the battery is completely empty?
In principle, this should not happen. The only excuse for this is a faulty car generator , which does not provide proper recharge during engine operation. Let's figure out how to charge a maintenance-free battery if it has completely sat down. Immediately, we note that this will take much longer than the situation described above. You will also need more attention.
The first thing you need to do is configure the memory. As a rule, a voltage equal to 10% of the battery capacity of the battery (measured in Ah) is set on it. This way you will not damage the battery. In order to get 90-95% of the charge, it will take a little more than a day, but we'll talk about this a bit later. Here the main difficulty lies in the fact that you need to know when to remove from the terminals of the memory. As a rule, this is done when gas is released from the electrolyte. This is not only poisonous, but also an explosive mixture, and since we have a maintenance-free battery in which there are no openings for the release of vapors, it is necessary to observe the time.
How to charge a maintenance-free battery: keep track of time
As noted above, constant control over time is necessary. This is due to the fact that it is possible not to charge the battery to the end, and vice versa, which is even worse. As an example, take a standard charger with a voltage of 14.0-14.5 Volts, which is optimal for a battery. Let's say we have a 12 V, 60 Ah battery. For it, we must use a nominal voltage of not more than 1-3 V in the event that we need a full charge.
Using simple calculations, we can draw a definite conclusion that using a standard charger and a maintenance-free battery of 12 V and 60 Ah, we need a little more than a day to charge 90-98% (26-27 hours). Of course, the amount of time depends on many factors. For example, if the memory is weak, then you can charge the battery for two or more days. One way or another, but you should already have more or less sorted it out and figured out how to charge a maintenance-free battery and why. It is also worth noting that a conventional battery or low maintenance requires more time to replenish power.
Important points
Not every motorist knows that it is necessary to charge a maintenance-free battery in certain conditions. It is known that the battery discharges much faster in the cold, this applies to all their types. To start a cold engine, a large amount of energy is required, and if several attempts were unsuccessful, then you can completely land the battery. This will not happen if the charge is full.
So, the room where the battery stands should be well ventilated. It is desirable that this was a garage, not an apartment. This is due to the fact that dangerous vapors are released that settle everywhere and adversely affect the body. It is advisable to charge the battery at temperatures above 10 degrees Celsius.
A little bit about how to check the charge level
If we were talking about a regular lead battery, then the question as such would not have arisen, but in our case, everything is much more complicated. It is immediately worth noting that this cannot be done with absolute accuracy. Moreover, the sooner you turn off the engine after checking, the worse the result. It is recommended to proceed only when 7-8 hours have passed.
If the battery is fully charged, the voltage at the terminals will be about 12.7 volts, which corresponds to an electrolyte density of 1.28. Thus, the charge level is 100%, the discharge is 0%. If you saw 11.7 Volts on the sensor, then this indicates a full discharge. At this time, the density of the electrolyte does not exceed 1.1.
Charging maintenance-free batteries from different manufacturers
You can often hear the question: "How to charge a Bosch maintenance-free battery?" In principle, this is a healthy interest, but I would like to note that, regardless of the manufacturer, all batteries of this type are charged equally. The only thing that changes is the current strength and voltage, which depends on the capacity of the battery.
If you are interested in how to charge a maintenance-free Varta battery, which is famous not only for its quality, but also for its high level of reliability and reliability, then the sequence of operations is as follows:
- we check the charge level on the sensor;
- depending on the results and battery capacity, adjust the memory;
- turn on and periodically monitor the voltage;
- turn off the charger when there is 0.2 amperes.
Finally
Every car owner needs to know how to properly charge a maintenance-free battery. Despite the fact that not everyone uses such batteries because of the high price, they gradually replace the serviced batteries every year.
It is strongly recommended not to operate the battery at a voltage below 13.9 volts. Also, you cannot use the battery if it is recharged, that is, the voltage on it is above 14.4 V. It is advisable to check the difference in the density of the electrolyte once every few months, which should be + -0.02. If you plan to leave the battery for the winter, then it must be charged up to 100%, and then placed in a protective case. This ensures that after you can safely start the cold engine.