I think the alt's going bad, but would just like someone to confirm it... Voltage dropped down to 11.4 at one point while in drive, with the brakes down at a light (AC on high). Lights were off as it was daytime. The laptop was hooked up to an inverter as well which is the part im not sure about...
11.4 is too low, but I don't know how much draw the inverter (plugged into the lighter) has and if it should be 12-13v even with all that stuff runnig.

Is it time to replace the alternator??