One charger to rule them all! The Genius 1 Allround 6 / 12 V Lithium / Gel / Lead Smart Battery Charger, can charge every battery! But is does not stop there! The GENIUS1 is a 6-volt and 12-volt battery charger, battery maintainer, and battery desulfator rated at 1-amp for lead-acid automotive, marine, and deep-cycle batteries, including flooded, gel, AGM, and maintenance-free, plus lithium-ion batteries.