OptiMate 1 DUO delivers precise micro processor controlled charging and long term maintenance. Maintain any type of 12 volt lead-acid battery without overcharging, filler cap / wet cell, sealed AGM (MF) or GEL and 12.8/13.2V lithium (LiFePO4) batteries. Ideal for vehicles that are seldom or seasonally used, or in storage. The OptiMate maintenance program delivers only what the battery needs, never overcharges, never undercharges.