We use our Mini as a toad behind our RV and need an 'always on' 12 volt accessory socket. I did the same to my FJ Cruiser and that was quite easy but I can't decide how to proceed on my Mini.

Has anyone else added or converted a socket?

 

I would recommend going straight to the battery. Depending on what you need it for, it's the easiest to reach without concern of taping into something that will overload a particular circuit. What are you using it for?

 

Following suggestions from other sources, I simply used the 'add a circuit' fuse adapter with a 10 amp fuse to power an auxiliary braking system for the toad. It uses a peak of 6 amps intermittently depending on how much serious braking is going on which based on my recent trip from Florida to Colorado is minimal. I had thought I needed to supply a charging voltage to the Mini to prevent depletion of the battery but as it turns out, the battery is unfazed over 10 hours a day of driving. At the end of each day, I put a battery maintainer on it and it's able to fully recharge the battery overnight.