I'm starting this thread here, mainly due to the many solar trickle chargers used for RV's. However I need a solar trickle charger for my 07 C&C batteries, but I also have a 10W crank case heater installed on my AC compressor. I need the CCH to eliminate the refrigerant from migrating into the compressor during long periods of not running. It was always present with my OEM compressor, and I believe it is what caused it to fail. Testing for the issue proved that it was a problem. I now have to turn on the CCH for at least 12 hours before I start the engine. The heater at 10 watt is a minimal drain on the batteries, but I can't leave it on for more than two days, or it drains the batteries. Even if I don't have it plugged in and I remove all of my parasitic voltage draw, my batteries won't hold enough of a charge past two weeks, and their only 6 months old. So I've decided to install a solar trickle charger that can also keep up with the 10 watt heater. What are the better solar trickle chargers, or what other options/suggestions can anyone recommend?