I have had some weird electrical things going on with my:
2010 997.1 Cab S

I got some great advice earlier on my flakey top. I also have purchased some small USB ports to fit in the lighter, but they keep going bad.

The one I just bought has a volt meter built in. It shows that there is 14.0 to 14.4 while the car is running and about 12.4 +- 0.5 when the car is off.

Is this normal?

Could this be frying my electronics?

Thanks!!

 

14.4 is a touch high, but nothing unusual. Sounds as though your charging system is working properly. But if your battery voltage is fluctuating between 11.9 (basically very dead) and 12.9 (fully charged) with no changes, then you got an issue with that battery

 

Pretty much agree with Quadcammer's description.

 

13.7-14.7 is normal range for a 12V car battery.

 

Thanks to all!

 

Looks normal to me. The typical alternator out is 14.1V so with some cable loss up to the battery your numbers are good.

The car off numbers look good too. When my 997.1 sits for a couple weeks the voltage drops to about 11.7-11.9 but will still start fine.

Most vehicle systems are designed to work between 8-16V and temporarily up to 26V without permanent damage. God only knows how you could get 26V into the car but there are situations where spikes can occur (eg shorts, silly jumper cable usage)