The DeWalt 70 amp rolling charger is a jumpstarter, battery charger and maintainer all in one. It features a 70 amp continuous charge or a 210 amp starting charge, and features a alternator check function, two USB outlets, one 120V AC outlet, and a reverse polarity alarm in case the clamps are hooked up incorrectly to the battery. This high-efficiency unit also includes an integrated alternator check and a digital LCD screen for real-time diagnostics.