Bad alternator causing rough idle?

[95GrandPrixGTP]

My car has had the battery light on the dash for about a week now, and after a long period of driving (30 minutes or so) the light goes off. When I start the car the dummy light is always on, but my battery is...for the most part, charged, but it loses its charge if I let the car sit for more than a day without driving it. Also, when I start the car there is a very loud squeek like a pulley is griding metal, or a belt is slipping....I guess I should have checked to see if the alternator belt was slipping (didnt even occur to me until I just thought about this..). I'll go check that out, but if the belt is fine, could my problem be my alternator?...and would this cause a rough idle? (The idle was fine until the battery started losing charge)

*Edit: I also wanted to add that the cars idle sits just fine....in the area of 600-800, and does not surge. When I step on the gas the car goes fine, and doesnt have a problem, it seems as though the problem is only noticable when there isnt enough power being built up to support the car and charge the battery.

 

[JKGMotosports]

Check if your alternator is charging properly, if its not, than you know the problem

 

[blcknspo0ln]

do you have anything indash [like an apexi TT] that tells you voltage? My turbo timer tells me voltage and you know if you start your car, and you're running below <12.5V then it's your alternator.

 

[speedy13]

yeah,check your battery's charge,and check the alternator with everything on,lights,radio,ac, everything,check your battery as well,it may be kaput and it's just not holding your charge.Don't forget your car is controlled by a computer,if that computer doesn't have 12 volts going to it,it will act up or turn off your engine.

 

[fn8uup]

dont advance and autozone offer free battery and alternator testing

if so i think thats what id do