The AGM technology for the production of batteries implies that the entire electrolyte is in a bound state – absorbed into the fiberglass matrix – and is not present anywhere else, except for the space between the plates, in the volume of the battery.
This fact largely determines the operational properties and features of AGM batteries.
A necessary condition for the efficient operation of an AGM Battery is good electrolyte wet-ability of the surface of the positive and negative plates. This condition can be met due to the tight contact of the plates and the separator and is possible only with the use of flat spreading plates of both negative and positive polarity.
Design Features Of AGM Battery
The design of AGM batteries provides high values of discharge power per unit volume. This fact is determined by the type of plates used (flat spread), their dense packing, and a relatively small amount of electrolyte.
This feature of AGM batteries allows you to assemble powerful battery systems in confined spaces, which is especially important when equipping UPS AC with uninterruptible power systems.
AGM batteries do not require maintenance during the entire service life. They are characterized by the effect of internal recombination of the gas in the process of charging with the formation of water.
The recombination channels in the matrix electrolyte are formed by the fibers of the porous separator.
The pores of the glass fiber separator are relatively large, due to this AGM batteries are characterized by the highest possible recombination coefficient of water decomposed during the electrolysis process – 99%.
AGM technology batteries are reliable and easy-to-use self-contained power sources designed for a wide range of applications.
To realize the expected battery life and all the features and benefits provided by the AGM design, follow all instructions of the battery manufacturer during installation and operation.
Before ordering batteries, please consult with GNB Industrial Power to calculate and select the most optimal series and battery capacity, taking into account the work in given conditions.
General AGM Technology Battery Device
AGM, short for Absorbent Glass Mat, is a fiberglass material that performs a dual function: an electrolyte reservoir and at the same time a separator that electrically separates the positive and negative plates.
AGM Technology Battery Design Features
The AGM battery consists of positive and negative plate packs separated by a glass fiber separator. The plates in each of the packages are connected to a common down conductor (bridge).
In block batteries, plate packs are connected by welding in series through special holes in the inner walls of the case, which makes it possible to obtain an assembly voltage of 4 to 12 V. A lead (boron) is welded to the extreme bridges of block batteries.
The plate packs are housed in an opaque impact-resistant polypropylene casing. The battery cover is hermetically connected to the body, the electrical outlets are also hermetically sealed.
The design of the terminal and the way it is sealed depends on the type of battery and the size of the cell or block.
The cover has one or more (depending on the capacity and total voltage of the battery) holes through which the battery is filled with electrolyte during the production process. Then an overpressure valve is installed in the filling hole.
Separator
Separator consisting of glass fibers of variable length and thickness, under magnification
A distinctive feature of the AGM technology is the use of glass fiber separators, which not only perform the function of separating plates of opposite signs but also serve as a reservoir for the electrolyte.
The figure shows a microfiber separator under magnification. It consists of the finest glass fibers of various diameters and lengths; synthetic fiber inclusions can be used for reinforcement.
The liquid electrolyte in the porous separator is retained by the capillary effect. All the electrolyte in the AGM battery is absorbed into the separator and is not in the free space inside the tank.
Overpressure Valve
The valve is installed in each filling hole and is designed to maintain excess pressure inside the accumulator, which is required for the optimal passage of the gas recombination process.
Schematically, one of the designs of the overpressure valve for AGM accumulators is shown in the figure.
Concern Exide Technologies uses in the production of sealed accumulators only its own overpressure valves, paying special attention to the importance of this element for the reliability of the accumulator.
The opening pressure of the valve is about 200 millibars different from atmospheric pressure. Battery valves are made of non-combustible material, which additionally prevents flames from penetrating into the battery and igniting the gas mixture located there.