[Shop-talk] Solar battery maintainer

[Robert Nogueirao]

I’ve have an Isetta which is kept in its own small garage separate from my shop. There is no power to the small garage but I need to come up with a way to keep the battery of the Isetta charged.
 Any recommendations on a solar car battery maintainer?    It will need to be weather proof since it will be mounted on the roof of the little garage.
Thanks in advance for recommendations 
Bob