So whats the actual charging voltage?

IMO 13-14.5 is the ideal range. I like to see it closer to the high side.


Its a ford alt, but look at the VR set voltage here.

 

Very good test report. I would like to tell the uninitiated that the output rpms on that report are ALTERNATOR rpms, not engine revs.

 

Another example, from the 95 FSM.

 

Thanks for posting that I was beginning to think that I was FOS on my 13.8v post that was burned into my brain for some reason, thought it might have been a GM thing maybe.

 

13.8 to 14.5 is fairly normal voltage output, now add temperature changes to a battery with a failing cell could explain the voltage fluctuations. The regulator will try to increase voltage to overcome the resistance in one or more sub par cells. Load test that battery to find if you have one or more bad cells.