NOCO GENIUS1, 1A Fully-Automatic Smart Charger, 6V, and 12V Portable Automotive Car Battery Charger, Battery Maintainer, Trickle Charger, and Battery Desulfator with Temperature Compensation. Designed for 6-volt and 12-volt lead-acid automotive, marine, RV, power sport, and deep-cycle batteries, including flooded, gel, AGM, and maintenance-free, plus lithium-ion batteries. Enjoy precision charging - An integrated thermal sensor detects the ambient temperature and alters the charge to eliminate over-charging in hot climates and under-charging in cold climates. Charges batteries as low as 1 volt. Or use the all-new force mode that allows you to take control and manually begin charging dead batteries down to zero volts. Automatically detects battery sulfation and acid stratification to restore lost battery performance for stronger engine starts and extended battery life.