AGM battery’ s complete name is Absorbed Glass Mat battery. In AGM sealed batteries, the acid is absorbed between the plates and immobilized by a very fine fiberglass mat. This glass mat absorbs and immobilizes the acid while still keeping the acid available to the plates. This allows a fast reaction between acid and plate material and avoid the electrolyte spilt out the battery. And also AGM battery is the basic battery of Valve regulated lead acid battery in now days. The design life is 5-8years.