voltage issue

[LiL PiNoY]

Having problems with my voltage dropping from about 13.8-14.1 to 13 when warm at idle when i have my headlights on and the air off. Then I accelerate and it goes back to normal until I stop at a light again. With headlights on and air on its fine. also it doesn't happen when I am parked and the car is still on. Replaced the front battery with and acid because of the cold weather used to have a kinetik 2000 up front and kept the kinetik 2400 in the back. Big 3 is done and I have an HO ohio alternator. Could this problem be the battery dying because I beat on it to hard or is the alternator failing?

[hotshot27]

watch you RPMS. in my car, at 750rpms' i'm lucky to get 12.5v but at around 850rpm's im sitting at a solid 14. some cars/alternators need to idle a little higher to put out power.(when im in drive i idle about 100rpms less than when in park.)

[kmalinich]

yeah, the alternator just can't produce enough amps at idle. it's just physics

[LiL PiNoY]

Well I usually idle at 600rpm and when the lights are off it sits at 14 but when they are on it will go to 13 if I have the air on I idle at 700rpm and then it will sit at 14 does that mean the alternator produces next to nothing when there is a load on the alternator because its supposed to idle at 105 amps

[Gotloud555]

Could be that alternator you have doesn't put out that power you looking for. You should got find a shop that bench tests that alternator, and see if doing what it really say..