I'm getting a intermittent flat battery issue on my ford cmax it can be fine one minute next time you try to start it , it won't turn over like the battery is flat some times the external temp gauge reads -60 when the batt is flat. I have taken a reading and the battery was down at 11.7v so I jump started it spun over fine run it for 5 min or more and it will be fine for a few days/ weeks but it's happening more often now so becoming a pain. Has anybody else had anything like this ?
Cheers roger

Sounds like you have a dead or dying cell in the battery. Either recondition it with a ctek or the like or time to get a new battery I'd say as 11.7v is to low  FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.