Battery light is on, volts are low, but things checkout?

We have a 2000 Chevy Astro with just at 100k and I’m having some issues with the battery light being on and the volts reading low just after firing up. Seems to go away after drive down the street a bit. Just replaced the battery with 100 plus month unit and check the alternator, but starting the motor and pulling the battery cables with no sign of volts reduction or overall engine strain or idle change. I don’t know what it could be. In older V8’s there use to be voltage regulators on the firewall that would need changing from time to time, but what about these new cars?


Thanks for any input.

Ed