AGM batteries

Absorbed electrolyte (glass mat)

— a type of lead-acid battery, also known by the abbreviation AGM (Absorbent Glass Mat). The main feature of the design is described by the name itself: in these batteries, the space between the plates is filled not with liquid but with glass mat—a microporous plastic impregnated with the electrolyte (an aqueous solution of sulfuric acid). This design has several advantages over the classic type: AGM batteries are maintenance-free (see "Maintenance") and almost do not emit gases during charging (the oxygen and hydrogen produced recombine within the battery itself), they are resistant to vibrations, and are well-suited for start-stop systems (see "Start/Stop Support"). Their drawbacks include high sensitivity to increased charging voltage, the need for a special charger (standard ones are not suitable), and relatively high cost.