The Black and Decker Battery Maintainer/Charger keeps your 6 Volt and 12 Volt batteries at optimal capacity with fully automatic high frequency charging and reverse polarity protection. It s perfect for vehicles that only see seasonal use including RVs specialty vehicles antique & classic cars marine deep cycle batteries motorcycles ATVs snowmobiles personal watercraft and more. Keep it plugged in during the off-season ensuring your batteries will stay topped off without ever being overcharged or damaged. It comes with two different connector sets including battery clips and battery terminal rings. The BLACK + DECKER BM3B is also sealed for protection against moisture dust and oil so it s perfect for your garage shop or shed.