Sealed Absorbed Glass Mat (AGM) batteries like OPTIMA® Batteries do not spill, sulfate or degrade as flooded batteries do. AGM design holds the electrolyte in suspension while keeping it in constant contact with the active lead material on the plates. This results in higher efficiency when both discharging and recharging.AGM design offers lower internal resistance and greater plate area, which provides superior starting power, the ability to recharge much faster and higher voltage characteristics during discharge.