A true multi-tasker, the DEWALT DXAEC100 Professional 30-Amp Battery Charger and Battery Maintainer is the high-efficiency solution for 12-volt WET, GEL and AGM batteries. It provides a powerful 100-amp engine start, 30 amps of charging, and 3 amps as a maintainer. The alternator check tests the vehicle's alternator to indicate if it is operating properly. Electric pulse technology can help reverse sulfate buildup on battery plates to improve charge capacity and extend battery life. It also has built-in reverse polarity protection for safety. It includes both clamps and O-rings.