PJ Trailers offers a 2 watt solar charger to help maintain your battery for dump trailers and tilt trailers. These work well in conjunction with our integrated battery charger. The panel is protected by a clear polyurethane coating that makes them extremely durable and weather proof. This panel has a 5 year limited warranty.
https://parts.pjtrailers.com/solar-battery-charger-12v-2w-170407s.html