This 15 Amp Black and Decker battery charger features one touch automatic charging to charge and maintain AGM, GEL , WET automotive or marine 12 volt batteries. An engine start timer starts most vehicles in up to 8 minutes and a patented alternator check indicates the condition of the alternator. Battery reconditioning helps reverse sulfate build-up on battery plates to improve charging carrying capability and extend battery life and reverse polarity protection warns against improper battery connection.