The Sunforce 5 Watt Solar Battery Trickle Charger (twin pack) will help keep your vehicle s battery charged anywhere anytime! Maintenance free and easy to install this solar charger offers an ideal way to maintain and charge 12 Volt batteries for your car boat RV electric fence deer feeder and more! Made with a durable aluminum frame and amorphous solar cells this solar panel operates in all daylight conditions even in shaded or cloudy environments. With a lightweight and compact design this unit is fully weatherproof for superior durability.