Hi.

991.1 4S. 2014.

Car usually indicates 14.2 right after start and drops to 13.7 or 13.2 after 30/40 minute drive.

Today it went to 14.7 and didn’t drop. Granted I just drove 30 minutes. Weather was 75f instead of 100f.

Is the starting at 14.7 an indication of something “no bueno”? Thanks.

 

Model year, please?

 

Recent thread on this.

Your car has an AGM battery and the charge levels might be a bit higher than you're used to seeing on a oldschool flooded lead acid battery. Temperature has a part in this. Battery health also has a part in this. Finally, the instrumentation might not be accurate, which could play a similarly large role.

https://rennlist.com/forums/991/1223...age-15-3v.html

 

OK.....2014. My 2014 battery only lasted 4 years.

**the factory batter was replaced in summer 2015 under warranty, then I replaced that battery in Fall 2019 before winter hibernation**

 

Great info. Seems the 14.2 to 14.7 may be mostly due to cooler weather. Cheers.

 

Based on 19 C4GTS, I would say voltage seems normal but you 911.1 so my info might not carry over.

 

2014 C2. Battery always at 14.7-14.8 when driving.

 

When speaking with an SA the other day, they said normal to operate up to about the 14.8 range or so (will see higher numbers as temps drop). Over that or particularly above 15 and you’d get a message which would require them to take a look. 991.1 GTS and typically in the 14.4-14.7 range at start but after 30-45 min or so of driving (and when not in sport / sport+) will drop into the mid-13s.

 

I'm curious what sport/sport+ has to do with battery voltage, any idea?

 

This thread has some additional insights on the additional draw. Oil temps also drop 15-20 degrees for me as well in sport / sport+ so seems more draw to power certain components.

https://rennlist.com/forums/991/9896...e-reading.html

 

Yeah I remember reading about the oil temps in the tech book for the 991.2. Sport/sport+ alters something about the rate, location, or direction that oil circulates.. can't remember specifics.

The voltage thing is news to me. My .2 doesn't exhibit this behaviour, or at least didn't when I initially monitored it. I'll have to check again next time I drive.

Unfortunately the linked thread contains only conjecture on the subject. The most plausible idea seems to be the fuel efficiency one. Guess we'll never know, unless someone finds some Porsche literature explaining it in the future!