2012
Porsche 991.1
/ ~68,500 miles/ Over-voltage issue – 15.3v at 2500rpm
Had a disturbing drive this morning – driving out to a
Porsche
shop in Ashburn to discuss some issues on my 1980 911SC – I noticed that the voltage gauge was climbing – past 13.5v…. past 14v.. up to 15.3v. NOT GOOD.
After discussions I drove back home – voltage stayed in the 15v range and I parked it. Started to troubleshoot the issue. Pulled up Pelican – then ******** – and all I could find are issues of undervoltage – nothing about overvoltage.
As noted car has ~68k on the clock and still has the original battery as far as I know = 8 years old. I am third owner – got it in Mar 2019.
Car starts just fine – but after a brief period – maybe couple of minutes voltage climbs from the 13v range – to 14v to 15v. I understand that it really should not go past ~14.7v in normal mode – [I don’t use sport mode that often].
I checked the battery with a
multimeter
after car had cooled down some – it was 12.45 at rest cranked it up and it went to 13.4 immediately and quickly rose to 14.7v within 2 minutes.
Battery is
Duralast
Platinum. No external signs of swelling or battery acid overflow.
?? Question: Is the voltage regulator for the 991.1 similar to that of the 996? 997? – where the voltage regulator is a separate sub-component? Or is it more integrated into the
alternator
?
I have no warning lights – just the reading of the voltage on the instruments.
What do you think?
thanks
kgl
I'd say first of all is that you should get a new battery. Also, what was the OAT when you were driving? The 991 and
981
charging system will charge 'harder' or to a higher voltage in colder temps. Your battery is way past due to be replaced!
outside air temp was in the high 40sF - I checke dthe battery this morn - and when cold it registered at 12.12v - which indicates battery is at 50% of its power. I'll do some more tests - but it looks like new battery time
My '14 CS charges at approx. 14.9 to 15.0 at those temps . I am using a new 70AH
lithium battery
and the battery type has been coded as lithium during the install. I'm pretty sure your only issue is the need for a new battery. BTW, 12.12 v definitely indicates a week battery. You got very good service life at 8 years.
!
I had a similar issue with my 2009
Boxster
(base). I realize it is not the same vehicle.
At first, I was very concerned (freaked out?) about the high voltage.
When this occurred I found a few articles about "un-needed
alternator
replacement" and "
porsche
over charging
alternator
"... or similar.
I am not saying you should not replace your battery, I'm just sharing what I had found when this happened to me.
Charging System - Unnecessary Alternator Replacement Service 2 26/10 ENU 2722
The present document was valid at the time of print. A later version may be available online Generator Replaced Unnecessarily (26/10) Model year: as of 2007 Vehicle Type: Boxster (987)/Boxster S (987) Cayman/Cayman S Concerns: Modified charge voltage range. Information: Generator replaced...
porsche-panamera-turbo-worldzzz.blogspot.com
