Absorbed Glass Mat, or AGM, batteries are a sealed battery technology that was developed in 1980 by Concorde Battery for non-military commercial use. AGM sealed batteries are characterized by the inclusion in the design of a thin fiberglass mat, inserted between the plates, that absorbs and immobilizes the acid without separating it from the plates, allowing for faster reaction between the acid and plates. Due to this internal construction as well as its subtantial internal electrical resistance, AGM batteries are able to deliver and absorb higher rates of amperage during discharging and charging than other battery types.
AGM batteries can be charged at the same charging voltage as flooded lead-acid batteries and are interchangeable with flooded batteries without the need for system calibration adjustments or other equipment. AGM batteries ruggedly-constructed with a tight configuration of its internal construction results in a resistance to vibration. AGM batteries can be frozen without compromising the case and, although they do not work while frozen, they are able to resume normal operation when returned to nominal operating temperature. These features, combined with other safety and design standards established by Concorde and as a result of on-going engineering development, make sealed AGM batteries a logical choice for many applications including: