Absorbed Glass Mat
Similar Terms: AGM
AGM Batteries are lead-acid batteries but are sealed instead of vented. The electrolyte is held captive in a fibrous glass mat within the battery shell, and therefore cannot be spilled. Due to this innovation, AGM batteries can be mounted on their end, or side depending on space restrictions, and inside your 4X4, Boat, caravan, motorhome as their is no leakage. They can be fully recharged at lower Voltage due to less internal resistance and are also faster to recharge than most standard batteries.
Absorbed Glass Mat Batteries are totally sealed and therefore the best battery to have on board a boat