A 12vdc power socket, aka a cigar lighter socket.  Since I don't have the tool kit, I figure the chrome would be just fine for a weather capable socket.  Direct the battery, no fuse, but does have a 2-wire polarized connector so I can remove the battery cover if I need to.
 

id run it through a fuse. with it position and unless garage kept that hole will be wide open to fill up and connect contacts on the first good rain. but looks great in the positioning