Works GREAT as a trickle charger for 2 70Ah lead acid batteries powering my sailboat's electrical system. I leave my boat docked and had to run the engine for a while over the weekend to keep the batteries charged. This completely solves this problem. Now when I get to the boat the batteries are always charged, the engine doesn't need to be started at all. VERY easy to install as this application does not require a controller. The service was great.