One of my winter projects is to install a solar power system to keep the batteries charged. I've seen this subject come up on this forum several times in the past.Well, during my research I came across a fabulous website. It explains in plain english using pictures and diagrams (very helpful in my case) how these systems work, how to wire them, and even has a design center page. The best part is that it's free.http://www.freesunpower.com/designtools.phpJust wanted to share.