15-Watt Solar Panel with built-in Battery Tender®3-step automatic microprocessor controller. 100% portable battery charging and maintenance. Perfect for storage space without power access! BATTERY TENDER SOLAR PANELS ARE THE ONLY PANELS AVAILABLE WITH A BUILT-IN CHARGE CONTROLLER TO PREVENT OVERCHARGING!Product Specifications:38" x 16" x 0.875"8 lbs12 V Nominal Voltage 830 mAmpsTemperature Compensation SensorSparkproof5 Year Warranty