Battery Defender 36 Volt 1.2 Amp Battery Charger De-sulfation of battery: The charger will remove loose sulfation and increase the battery life. (Hard sulfation cannot be reversed). One charger for any type of lead acid battery (no switch): Battery Defender charger will charge lead acid and AGM batteries. The charger will adjust itself as the battery gets old. Short circuit and reverse polarity protection: If you touch the output +ve & -ve wires (with AC ON) and there will be no failure (no fuse will blow). If you connect the battery in reverse, there will be no failure (no fuse will blow).The charger will just not work. When the problem is corrected, the charger will operate normally. Low voltage start: Battery Defender charger will start charging from 0.5 volts. This means a very deeply discharged battery can be charged. Other chargers cannot do this. Maintain full charge & no overcharging: Battery Defender charger can be left connected to the battery indefinitely without harming (overcharging) the battery.