Excelvan 12V 4.5W Portable Car Solar Battery Charger Panels with Cigarette Lighter Plug Mono Crystalline Silicon Motorcycle Solar Panels Charger Brand: Excelvan (1 year warranty and friendly customer service) Charges in all daylight conditions, even on cloudy days Mono-crystalline silicon solar panel guarantees its high efficiency Supplement power to all your 12V car batteries and creates 4.5 watts of energy Constructed with a built-in blocking diode in its cigarette lighter and clips to prevent reverse discharging