The STANLEY BM1S high frequency battery charger and maintainer is used to keep batteries in stored vehicles and battery applications at optimal capacity during the off season. With 1 Amp rapid charge, charges 12 volt batteries in most RVs, specialty vehicles, antique and classic cars, marine deep cycle batteries, motorcycles, lawn mowers, ATVs, snowmobiles, and personal watercrafts. Connect the battery charger and maintainer with the included battery clips or battery ring terminals. Charging automatically stops when battery is fully charged or topped off and switches to float mode monitoring to maintain charge. Built-in circuit protection guards against overcharging, reverse polarity, or short circuit. The STANLEY BM1S battery charger and maintainer is sealed for protection against moisture, dust and oil..