These Chargers are often known as ''taper chargers'' since charging current lowers step by step, as being the battery gets charged. This design is made for use with 6- or twelve-volt batteries. It can be securely applied on maritime, powersport, RV, and deep-cycle batteries, which makes it a versatile alternative. https://www.diigo.com/item/note/b6s4m/5vrn?k=26e14948e52f8f7a77b64a986892670f