I too have been having far too much trouble with the battery discharging overnight. Ford dealership in Shrewsbury obviously have no idea what the problem is. I have a B-Max titanium X, 1.6 powershift with heated front seats, front and rear sensors, leather, sat nav etc etc. Lovely car to drive, comfortable BUT crap in-car management software. I'm convinced of that fact. My daughter took delivery of a Nissan Duke and my Sister-in-law a Mini at about the same time in August 2015. They have had no problems whatsoever, despite leaving their vehicles both inside and out side for several days at a time, sometimes leaving their doors unlocked. Their specs are compatible with my B-Max and they both use smart phones with hands free and synced to their in-car management systems.
Reading the forum problems related to this battery discharging problem and the replies and answers from the various Ford dealerships indicates to me that far from the multitude of laughable causes that are spouted by the dealerships, the only plausible and common fault has got to be the car management software. The software sub-routines are not being addressed when inputs like doors not being locked, windows left open, phones being switched off when away from the vehicle could all be catered for in such a way that the battery drain is reduced to a minimum. A really clever subroutine could even report what the root cause of a higher battery drain was...But sadly, not Ford B-Max's Engine management software. In the meantime, I'd advise all B-Max owners with this battery drain problem to worry their dealerships until sheer numbers force the dealerships to, in turn, worry Fords to that fact that a very real problem exists with the B-Max.