i have the same issue with my 2009 6cyl gas journey had the battery changed 4 time by dealership and just pick the car up after dealership having it 3days and them not even looking at it.
i have found by moving the batery cables it will start but it's the stalling while your driving it that makes this an unsafe car to be on the road.
this time the dealership let it slip that they have had trouble with the grounding on them but when i asked about it they refused to tell me with what part of the car and that only a dealership can fix it. any one that has found the problem plz contact me so i can keep it running long enough to get an ok trade in amount for it towards a chevy