I have a West Wight Potter 15 with a 12volt battery in it. I want to keep it charged out on the water as I will be listening to music and having a few lights on this summer. What would you recommend for keeping it charged. Solar or wind power? And are there any cost effective ways because solar panels are usually very expensive. I also am wondering how much a solar panel can do considering I may be using the battery a lot. Do you think it could keep up with my use and how many watts would it need to be to do that? Thanks.