Over time batteries naturally lose power and, if allowed to, can go flat. Renogy's 5W solar trickle charger will help you maintain a healthy battery by converting solar energy into a usable 12V DC current to keep your battery topped off at a stable level. With a quick SAE connection and 3 options for ring terminals, alligator clips, and cigarette lighters, our solar trickle charger is sure to be a great fit no matter what your application needs. It works great with boats, SUVs, RVs, electric fences, accessory batteries, and much more! Maintain a healthy battery and never be caught flat ever again! Note: For some makes or models of vehicles, the cigarette lighter port may not operate when the ignition is turned off. In such cases, please connect the trickle charger maintainer to the battery directly. The trickle charger maintainer must be disconnected from the battery or cigarette lighter port when starting the engine or driving the vehicle. Electric surges from the alternator when starting and running may damage the trickle charger maintainer.