991.1 Overvoltage - 15.3v

[kimlangley7]

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 Rennlist – 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?

kgl

[JFP in PA]

If you have the car in the chrono sport or sport plus mode, take to out and see if the voltage drops. Both of those modes can run the alternator at 1.5-2 V higher than normal.

[991gts6s]

Ive seen 15V on mine since new... think its normal ...

[Rapewta]

I think you are OK. 14.7 with the engine running is normal and plus or minus a few tenths
of a volt shouldn't be anything to worry about.