Schumacher SE-1555A 12V Automatic Wheeled Battery Charger with Engine Start High amperage for cranking an engine with a weak or run-down battery Charges standard, AGM, sealed lead-acid, deep-cycle, and spiral-cell batteries Microprocessor controlled, automatically adjusts the amperage rate to charge and maintain Multi-stage charging for added precision, safety, and battery life.If no reading on amps digital display then Check for poor connection at battery.Make sure clamps and posts are clean. Reverse hook-up protectionensures charger will not operate if clamps are reversed