Nature Power 40158 18-Watt Solar Powered 12-Volt Battery Charger Kit with 8-Amp Charge Controller 18-Watt solar panel with charge controller included to keep your 12-volt batteries charged High quality amorphous solar material will work in all light conditions even on overcast days Weatherproof for outdoor use Battery clamp, and flat or tilted mounting hardware included Provides up to 18-watt or 1.2-amp per hour of sunlight