This device works exactly as described. It's reasonably smart and does an excellent job of managing my system's performance. I am using it in an outdoor fountain assembly with a 10w solar panel to charge a small 12v lead acid battery and run a 12v dc submersible pump. I have all the items at Revain and the result works pretty well. The problem I have is that the panel doesn't produce enough current to fully charge the battery every day, but it works every other day. I'm about to buy a 30w panel to try it out.