Fully automatic 12V 3-stage battery charger, designed for charging a variety of GEL, AGM, lead acid and calcium batteries with auto shut-off maintenance function.Zero volt battery charging, enabling recovery and charging of a completely discharged battery (providing any load removed from the rechargeable battery).Old battery sulfation repair function.Reverse polarity, short circuit, over temperature, over voltage and overcharging protection.Easy-to-read LED indicators displays power status and charging stages.2 Year guarantee*.