A cheap little add-a-circuit device plugs into your fuse box and provides a single hot wire that you then attach to the red wire on this power socket

I purchased an ATM Add-A-Circuit to attach to the positive wire, and attached the negative wire to a bare bolt

I purchased an ATM Add-A-Circuit to attach to the positive wire, and attached the negative wire to a bare bolt

Had to solder one of the USB connections and it's positive wire back to the board

The wires are only long enough to tie into an existing power source, like a nearby cig lighter plug, using the supplied "fold-over" splices