9737u50

Very interesting, did not know the battery system was that smart! OK, well I suppose i'm still in the dark. I will read up on this forum about parasitic drain and continue to monitor for anything unusual. Another fact: When I bought the car a year ago it had a brand-new battery installed, old battery was in the boot and seemed fine (reading 12v). Dealer was unsure why new battery had been put in by previous owner.

This is interesting, may explain why im seeing voltage jump from 12v - 14v while driving around

Thanks for this, will check the forum for parasitic drain

sometimes yes, sometimes no

The problem is sporadic - I can go days with no issue, then suddenly it wont start even after a long drive. I have taken to turning off infotainment and turning lights to OFF instead of AUTO when shutting down. First time it happened (after a 30min drive, failed to start) after gutting jump-start, I drove straight to my mechanic. He used this battery diagnostic kit that guided him through steps - at certain points he asked me to turn on lights and heating full blast.. His conclusion that the battery diagnostic seemed fine and battery seemed fresh and of a good brand. He noted that it was running ~13v was a bit odd.

oh yeah, thanks. 2.0 TDI estate

Hi there I have the above problem, sometimes even after a long drive! Had a battery diagnostics done and battery is in good condition (it is an expensive stop/start battery). I’ve been driving around for last week with a voltage display plugged into the cigarette lighter: about half the time it reads 14.8v the other half of the time it reads 13.2v when it reads 13.2v the car automatically disables start/stop. Also I’ve noticed the car idles quite rough when at this lower voltage. one other symptom (might not be related) is a very loud fuel pump noise when starting the car. thanks, any ideas would be much appreciated 👍