The Coleman 6 Watt Solar Battery Trickle Charger Twin Pack is the ideal solution for maintaining 12 Volt batteries for your cars, RVs, tractors, ATVs, electric fences, deer feeders, boats, and more. These units are completely weatherproof and charge in all daylight conditions, even in the shade. The built-in blocking diode protects battery discharge at night. A perfect solution for battery maintenance, these units are completely maintenance free and easy to install. It has a maximum power output of 6 Watt, 400 mAh.