Black and Decker 40/20/10/2 Amp Charge Rate Battery Charger Fully Automatic/High Frequency 12V Smart Battery Charger Product features: 4 Charging rates: 2 Amps, 10 Amps, 20 Amps, or 40 Amps Automatic temperature compensation Battery type selection Alternator and battery voltage check Digital display shows charge rate 1 minute engine start (Bulk charge/Rapid start) 3 stage high-frequency automatic, rapid charge, and float mode Spark resistant reverse polarity and short circuit protection Built in battery reconditioning (Desulfate) Battery equalization Microprocessor control (Digital Smart Control) Compensates for low A/C from extension cord use High frequency power conversion technology Lightweight, high efficiency design 400 Amp rated clamps Weight: 12 lbs Warranty: 2 years limited by manufacturer