[edit]Absorbent glass mat (AGM)

Absorbent glass mat (AGM) is a class of VRLA battery in which the electrolyte is absorbed into a mat of fine glass fibers. The plates in an AGM battery may be flat like a wet cell lead-acid battery in a rectangular case. In cylindrical AGMs, the plates are thin and wound, like most consumer disposable and rechargeable cells, into spirals so they are also sometimes referred to as spiral wound. Their unique (for lead acid chemistries) construction also allows for the lead in their plates to be purer as they no longer need to support their own weight as in traditional cells. Their internal resistance is lower than traditional cells due to plate proximity and the pure lead plates have lower resistivity, they handle higher temperatures better, and self discharge more slowly.[citation needed]
Their specific power is very good and they can be charged and discharged quite rapidly, however their specific energy tends to be lower than traditional flooded batteries. They are often used in high performance electric vehicles due to their high power density.