So last week, I got my ac recharged. It works great nice and cold. But my problem is whenever I come to an idle either in park or in drive the car will have a rough idle. The battery gauge will go down between 12-13 but once I accelerate its normal again. Could it be the iac? serp belt?

 

My suggestion would be the ICV (idle control valve) is lazy to keep track of what is required. The compressor is sensed as "load" and the ICV must compensate for that.

Being as how you are in the States, your car has an EGR system, that I have read reeks havoc with idle until the "valve" is cleaned??. We dont have that system, so I have no hands on with it.

The notorious "black goo" inside the throttle body, and around the throttle disc also gives grief to stable idle.

 

I will check into that thanks

 

I had the same issue. I had previously got my car to the point that the idle was super smooth. A few weeks ago the idle became quite rough and the steering wheel would vibrate at idle. Then the ac compressor died and the idle was super smooth again. New compressor is being installed today.

 

Just got the car back after the new compressor install. The rough idle that was there immediately prior to the failure of the old compressor has not returned.

Hopefully the OP's problem is not a dying compressor.