An idea for doing 12V power from the bygone (hippy era) sailboat cruisers. They (we) used 1/4" mono headphone jacks as 12V plugs. They are still readily available, easy to wire up and handle the current really well. The trick for reliability was to buy professional quality parts (Switchcraft).Not today but this weekend! Setup and went camping in the low country of South Carolina
Here's my setup I took with me.
I still have my boat wired up with 1/4" headphone jack outlets. When I get a piece of 12V gear I just chop off the silly cigarette lighter plugin and wire on a headphone jack. Power at tip, ground to the the body.