I bought a 2018 AWD V6 Edge three weeks ago. Last week, at 850 miles, I parked the vehicle on Sunday after a four hour drive and left it until Monday night. I opened it to get something out and locked it. On Tuesday night I went to open the car and the battery was completely dead. I was unable to use the key fob or Keyless Entry to open the car, so the tow truck driver had to use the "real" key to open the door. He jump started the Edge and it started right up, but the clock, date, radio stations, etc. were all reset to factory settings. I drove it 50 miles to the nearest Ford dealer who did a complete check of the electrical system: battery check, check for shorts, etc. They said they could find no codes or anything to explain why the battery went dead: no shorts, battery good, etc. They said I must have left a door open or something, but I know I didn't, and anyway, I thought the electrical system would shut off anything automatically after 10-45 minutes.
So, does anyone have an idea what I should do next? My wife doesn't want to drive the car if the battery can go dead in 24-48 hours with no identifiable cause. My local dealer is reluctant to run diagnostics since they say the warranty does not cover it if the car isn't broken.
p.s. if I am posting in the wrong forum, let me know and I'll repost correctly. Thanks.