20 Watt/12 Volt Amorphous Solar Panel efficiently charges in all weather conditions including cloudy days. Maintenance free operation prevents natural drain of batteries over time. Maximum charge up to 20 watts / 1 Amp per hour; Specifications: 12.0" x 34.75" weighs less than 12 lbs; Kit includes: Solar panel w/5 ft. cable 12V DC adaptor 12V DC socket battery clamps extender cable and mounting hardware; 10 amp charge controller recommended - CYC-SOLC10A (sold separately).