Trickle Charger ----- It can charge all types of 12V lead-acid batteries, including flooded or sealed maintenance free batteries (AGM & gel cell). It's the best smart charger for car, truck, boat, motorcycle, RV, lawn tractor, or any other vehicle with a 12-volt battery.FULLY AUTOMATIC ----- No need of any manual operation, just plug and leave it for charging and maintaining your batteries automatically for long time. The microprocessor controlled program will monitor the whole charging progress and automatically stop when the battery is fully charged. Then it will monitor the battery voltage and maintain the battery with a float charging current.MICRO-PROCESSOR CONTROLLED PROGRAM ----- No worry about overcharge, short circuit and reverse polarity. Spark-free technology applied. Safer floating charger with maximum voltage up to 14.8 volts.EASY OPERATION ----- Energy Saving design with one LED indicator to display different charging status. Simply hook up the charger to the battery, plug it in and walk away. Note: be care of the clip positive and negative electrode (Red = positive, Black = negative)