Since about two weeks ago I have noticed my battery does not charge to a full 14.2 Volts anymore. This morning I had to get a jump start. 35,000 Miles.

Here are my symptoms if anyone has recommendations.

These are the voltages I get:
- Engine running, warmed up, at idle: 13.2 volts
- Engine Running at high RPM: 13.7 volts maximum
- Battery voltage after resting overnight: 12.1 volts

 

I replaced the battery. Car till idles at 13.5 volts. A shop says it's the voltage regulator which is built into the Alternator.