Dead battery back, from the dead.
 

Parked the FD the other day with the park lights on. Totally forgot about it, from 5pm- 11am the next day. Got in the car and everything was dead.
Had some guy push start the car and ran drove around for an hour. Shut down and it started again and again. BTW I have a pretty new yellow top optima batt. I was thinking that it shouldn't have went dead like it did with just the park lights on.
So good thing I don't have to buy a new batt. And also nothing else was on except for the park lights.

18 hours of running probably 120+ combined watts of lights?

Probably not tooo many batterys will do that, and start your car after that.