The Nitecore Ci2 is a dual-slot smart charger compatible with Li-ion and Ni-MH/Ni-Cd batteries. It automatically detects battery power level and capacity to then determine the charging mode with the appropriate voltage and current. With each slot controlled independently, you can mix and match batteries so you have less waiting on standby. A lineup of safety features back this chargers reliability with over-discharge, reverse polarity, and short-circuit protection.