X5 e53 went into failsafe mode on motorway

[X5smw]

... it nearly wiped my wife and child out! 
we were just coming back from our house (we have just moved) and suddenly the car misfires and stops. Car is in gear so quick deceleration and a lorry nearly smashed it up the #####. I was in my van in front and talking to my wife. We managed to limp it to the next junction and the engine is irratic idling and I turned it off, obc states oil level and abs inactive. Starts it up, all clear. Drives it 10 miles to new house and as I get into the village, it dies again. Now stating dsc inactive. 
I don’t have the time to plug the laptop in tonight but what are your thoughts?? 
battery issue?  Sensor issue? 
 

the car hasn’t been used for a few days but never had an issue before. 
it has been travelling 40 miles on motorway and dual carriageway for the last week and starts ok, so I wouldn’t have said battery... but I know they can have a bit of a temper.... anyway, all home safe now. Time for a cuppa and a calm down! 

[X5smw]

Just had chance to plug the computer in. 
looking at the readings, the battery is at 11.5v and goes up to 13.5 when the car is running. I clear the faults and the fault returns straight away. 
What do you guys reckon?

[Greydog]

Morning Stu

Good that you all were OK.

Battery voltage should be 12.5 to 12.8 fully charged engine off 14+ volts engine running, so definitely looks as though your battery could be the culprit.

There is a label on the battery which will show its age, my battery died literally overnight just before Christmas. By the date on the dead battery it was the original !!! Replaced with a Yuasa best deal at the time on a Sunday from Halfords. 

Good Luck stay safe

Oh and hope your al happy in the new house

Dave

[X5smw]

Update. 
got a new battery and changed it. .... reset everything and left the car to charge. 
reset the throttle and bang! 
seems to have solved it. 
 

BUY THE SCANNING SOFTWARE!! Saved me a fortune. 
 

... also while hunting for the battery, I found a genuine 6cd changer in the boot if anyone wants one? Lol