AGMs are batteries that come with a lead-acid battery. They do not use, as usual, plates of two-electric material. For the separator, a fine glass wool pad is inserted between the six plates, absorbing the electrolyte, holding it in close proximity to the electrolytes. However, the absorbent wool does not allow it to spill, which makes the batteries more reliable for mechanical movement, splashing or leakage of the electrolyte. The good sealing of the wool to the parallel plates guarantees, in addition to accelerating the reaction between acid and material. It also makes the construction more secure and optimally reduces material losses.
Absorbent Glass Mat batteries have very little internal resistance and can output very high starting current. It is much more efficient at freezing temperatures than the standard lead-acid battery, and allows for deeper dilutions. In addition, they have a longer life.
These types of batteries are placed in vehicles of the highest class, which are characterized by higher electricity use due to the fact that they are equipped with a large number of systems - airbeg system, security system, audio and video system, control panel control, etc. Their advantages, which have necessitated them, are reliable in sulphation, in sharp turns they cannot flow and their security to strong vibrations and can last longer without being charged. Because of their resistance to bends, they are also preferred in motorcycles. again, keep in mind that the battery leveling charge should not exceed 2.25-2.30 volts / cell.
In summer heat it is desirable that the charging voltage be less. Charging systems designed to charge standard lead-acid batteries typically have a voltage of 14.40 volts, equivalent to 2.4 volts / cell. If you directly replace a standard battery with an AGM-type battery, this would damage the AGM battery and significantly reduce its service life, as a result of the prolonged charging with unreasonably higher voltage.
The heat of the warm season does not affect AGM batteries in any way, and for this reason in many modern cars these batteries are positioned as far away from the engine as possible. Charging the processor, which carefully regulates the charging process, stops charging at temperatures above 45 degrees Celsius.