20W 12V Solar Car Battery Charger is the perfect trickle charger/maintainer for 12V batteries of cars, motorcycles, boats, snowmobiles, etc Please note that the protective plastic film on the panel is supposed to peel off. The plug option only works if it has constant power when the key is out of the ignition. When you start the car, please remove the solar panel from the car battery Charging 12V rechargeable batteries in emergency, suitable for vehicles in outdoor work or travel or camping training. Easy to install and completely maintenance-free design-high quality clips to prevent short circuit Environmental protection and energy saving, built-in blocking diode to prevent reverse discharge, not only maintains the battery but also extends its usage life Max power: 3A Size: 240 x 352 x 2.5 mm Waterproof: IP65 Conversion rate: 19.6-20% Number of USB ports: single colour:Black Material:Monocrystalline silicon Package Contents: 1 x 20W Solar Trickle Charger 1 x Alligator Clip Adapter 1