I do believe there is a protection circuit. If lights are left on for 20 minutes they are cutoff automatically. When you unlocked the car or opened the door the circuit reapplied power to the lights. It would be hard not to run your battery down leaving the lights on all night. I have done the same.
Any lights that are left on will turn off automatically after so many minutes. The headlights, or interior lights. When you start the car the lights will come back on if you left them in the on position.
I wish my wife's Kia Sportage did the same. I left my lights on at work yesterday, arrived at 8:00 a and left work at 10:00 p. Needles to say I was in need of jumper cables and another car on a deserted end of a college campus.
Called Law Enforcement and they didn't have a jump box. They argue that the Maintenence Office handles that, which was closed.
Long story short. I actually had jumper cables in the spare tire compartment :embarrese and a campus police cruiser helped me jump it.
The whole ride home I was thinking that this would never happen in my Charger.