Battery, Alternator, both or other?

[Qu4ttroS4]

K so i was driving the other night, battery light comes on, I didnt want to get towed so i kept going as far as i could, lights started going out, then ebc light etc, then critical failure, everything died. I took my battery to get tested and it said it was bad, so i got a new one. Put it in, and it was fine, drove for an hour or 2, then the battery light came on again, this time i made it home. The voltage dropped down to 11.5v instead of 14, which is what it's usually at on the gauge. I tried starting the car and disconnecting the battery, and it stays running. Makes me think the alternator is fine. No i'm stumped, is there a controller that works with the alternator and battery that could be gone? Or could it be something else?

I can take any vag-com readings if needed.

Thanks

[infinkc]

sounds like the alternator, mine did the same thing, even when i brought it in to be tested it passed. Changed it out and never had a problem since. Its probably the brushes making contact 50% of the time.

[Tormented]

do you have any sort of aftermarket speakers? I.E subs or anything of that sort? And yes your issue is the alternator, Because if you put a brand new battery in there and it died again then thats the issue. I am assuming that there was allot of stop and go traffic in that 2 hours right?

[Qu4ttroS4]

It was mostly highway, but towards the end when i was dropping people off it was stop and go. I guess it's time to order a new alternator.
I do also have an aftermarket amp, but it is not connected at all at the moment. Thanks for the responses, i'm gonna change it and hopefully it will solve the problem.

[Tormented]

Are the wires from the factory amp still connected to something? And a way to tell that its a bad alternator is if the car dies and wont start without a jump. If you try to jump it and it still wont start then it is the batt that is bad. If it does start then its the alt. Keeping the vehicle at higher RPM's causes the alternator to keep pumping the battery. When the RPM's drop and are stopping and going then the car will die because there is nothing pushing the power if that makes sense. If not pm me and i am more than welcome to explain more.