AGM (Absorbent Glass Mat)
Battery with electrolyte absorbed in a glass fibre mat. Lifespan roughly double that of a conventional battery. Required for advanced Start-Stop.
AGM (Absorbent Glass Mat) is a lead-acid battery technology in which the electrolyte is absorbed into a fibreglass mat between the plates. This construction makes the battery sealed (no maintenance of fluid levels required), vibration-resistant and able to handle far more demanding cycling than a flooded SLI. The cycling protocols defined in EN 50342-6/-7 confirm a much longer service life than a conventional battery, especially under Start-Stop use. AGM is mandatory in vehicles with Start-Stop and regenerative braking (present in many European premium models since the late 2000s and in mainstream cars from the mid-2010s) because it tolerates hundreds of microcycles per day.
Typical models: Varta F21 (80 Ah AGM), Tudor TK800, Exide EK800. Usually costs 1.5 to 2 times the price of an equivalent EFB.