I was under the impression that the 2012 Jeeps do not have a steering lock. If this is true, there is no need to leave the ignition in the ON or ACCESSORY position, so there should be no battery drain.
My '06 has an "OFF, not locked" switch position, so I have to leave the key in the switch, but nothing is on.
Put your front axle on jack stands, turn the ignition OFF, and try to turn the wheel lock to lock. If you can, there is no steering lock, and you do not have to leave the switch on. If the steering locks, then you probably have to get a battery disconnect. You can find them at any auto parts store.
Good luck.