Output: 6/12V 3A. Battery Range: 3-50 Ah. Fully automatic microprocessor controlled battery charger & maintainer. Patented Speed Charge technology actively monitors the charge acceptance & constantly modifies the charge output. Charges the battery up to 3 times faster than conventional battery chargers without damaging the battery. Heavy-duty sturdy case, no-nonsense controls, bright, clear, easy-to-read LED status lights & LCD scrolling digital messaging display screen gives step-by-step instructions. Charges conventional Calcium, AGM/ Gel, leisure, stop/start batteries & the next generation Lithium vehicle batteries. Fully automatic float mode ensures that the battery is kept fully charged & ready to use, for extended periods of time. Automatic voltage detection determines if the charger is connected to a 6V or 12V battery. Reverse polarity protection, thermal runaway protection & automatic shut-off are included as standard. Model No. SPI3S