If you leave anything plugged in it will drain your battery. I did a similar mod by just jumping the 12v outlet fuse with add a fuse and jumped to an always on fuse spot and it drained my battery after a few days just having my tablet plugged in the whole time. I drove the car daily but Im guessing there's a power draw from all sockets when on even though you don't have anything plugged in.
I just did the "add a fuse" method someone posted previously for 5thngens. I connected 2 add a fuses together. Unplug the 15a "ACC" fuse. Plug in 1 add a fuse. Plug the other end of the connected add a fuse to the black spot (no fuses currently in space) on the other side, 4 down. It worked! Unfortunately my headunit and radio turned on too. Perfect for the drive in we were at. Not great for camping where I just want awning lights and phone chargers.