The 021-0128 Battery Tender Plus is a 1.25 amp battery charger designed to fully charge a battery and maintain it at proper storage voltage without the damaging effects caused by trickle chargers. Included with the Battery Tender Plus, is a quick connect harness for hard to reach areas. - Temperature compensated to ensure optimum charge voltage according to ambient temperature. - Automatically switches from full charge to float charging mode. - The Battery Tender Plus at 1.25 amps will charge as fast or faster than any 3 amp charger available. - Reverse Polarity Protection to ensure user safety. - Complete 3-step charging program (Bulk Charge, Absorption Mode, Float Mode). - 10 year Warranty!