2014 Transit Connect, XLT, LWB wagon.
Bought new in 2017 and because it sat for 3 years got a new battery. Now, the van will not hold a charge: After sitting for 15 to 20 hours the vehicle always needs a jump to start. Dealer checked the alternator and it was fine. They checked/tested the system and found no power drain. After 8 hours the battery was still at full charge, so I brought it home, let it sit for a day and you guessed it, it needed a jump to start. The dealer is clueless as to the cause. Anybody...?

 

I have read that late model F150s will run the battery down if you leave the key inserted. I guess it would have to be something you are doing different than what the dealer did.