Minnikota 1821060 Marine MK-106 On-Board Charger Fully automatic 3- stage charging (bulk, absorption and maintenance) Automatic temperature compensation delivers fast charging recovery, even in extreme temperatures, while protecting your batteries from overcharging. Waterproof, shock-and vibration-resistant construction Short circuit, reverse polarity and ignition protected For use with 12v /6-cell batteries. (50-130 amp hour rating) that are flooded/wetcell, maintenance free or starved electrolyte [AGM] only