battery drainage time to ask the experts for help

Im having problems with my car battery. I changed out the alternator and battery. When in idle for minute battery gauge hits in red until i punch gas on pedal. Im wondering how is the charging systems (or batt. gauges) look at idle, and what the idle rpm is

you should idle around 800-900 RPM. the battery should stay above the halfway mark at idle unless it's low. And you shouldn't have to punch the gas to get it to go to that point.

Could be real simple like corroded connections or even loose ones.

like wires connected to the alternator or battery? could it be any other reason? like a short or ground?

at idle my battery goes below half it gets to beginiing of red

I had battery connections that looked clean but there was a film that looked dull that keep it from making a good connection. I would go over everything you can check.

i will Thanks