Eckcan here, since installing a solar panel on the roof, and having a 12 volt leisure battery installed in my eriba, i fitted a triple socket that would normally be fitted to the cigarrette lighter socket. I snipped the ends and worked out what was positive and negative and connected up the cable it then just feed up to front seat area. I am also am installing a new socket with usb connections wired into my inverter just as an extra. Hope this gives some ideas. eckcan😃