Low voltage reading ? Charging issue

[Kenflo]

So just got back from a cruise, and I jotted down some readings taken at the voltage gauge while I was driving around.
before I left on cruise battery tests at 12.66 volts and was charged overnight
-idle 800rpm at red light with brakes on and radio 11.7-11.8 volts
-driving around radio on 1800rpm 11.9 volts
-driving with turn signal and brakes dips down to 11.5-11.7
-driving with lights on 11.8-11.9 volts
When I got back from cruise battery now tests at 12.44
Going to NAPA to buy new voltage regulator I’m thinking

 

[Kenflo]

FIXED!! Thanks fellas FABO rocks!
Switched out the voltage regulator, performed all tests mentioned earlier to rule out alternator, now 13.9 volts on gauge in dash and 14.2 volts at alternator outpost as well as battery + and - while idling

 

[67Dart273]

Just excellent!!

 

[Bewy]

Beers all round!