Our Automotive Solar Battery Chargers or Solar Trickle Chargers Keep your 12 Volt Battery full charged. Sunforce Products makes the small solar battery maintainers to keep your batteries fully charged. When you park your car at the Airport for extened periods plug in a Solar Trickle Chargers and your battery will be full of power when you return. If your car or 12 volt batteries are in long term storage hook up a solar trickle charger and your 12 volt battery will stay fully charged. If you don't maintain your battery you will end up buying a new one which is hard on the pocket book and the environment. The SunForce 50022 12 Volt Solar Panel Battery Trickle Charger 5 Watts, is waterproof and rfect for maintaining larger Trucks, Boats, RVs and Heavy Equipment with Deep Cylce Batteries. The Sunforce 50012 12 Volt Solar Panel Battery Maintainer 1.8 Watts is designed for smaller cars. Solar Trickle Chargers are great for Deer Feeders and many other applications that don't require a lot of power and are away from electrical power. These Sunforce Solar Trickle Chargers have built in diode protection to prevent overcharging your battery.