I can charge my battery all night long, take it off, start the car, go for a 10-15min cruise come back shut it off, then its dead as a doorknob 15 minutes later. And yet if you stick a test light between the battery cable and post just after a charging, nothing. wtf? Is the battery just totally shot?

Most likely.

Autozone can test it for you. You need a load test on the battery. I bet it has a dead cell.

But after driving it if I disconnect the battery, then reconnect it next time I go to drive it, starts right up. So wtf?! I guess I just got a huge battery drain out of nowhere. There's nothing abnormal with the car. Nothing stays on. I dont get it.

go get it tested, and have the alternator tested while you are there.

i work at autozone actually, bring it in, we'll pull the battery FOR YOU, and then test it, and if you buy a new one, we'll even put it in for you :P

and we can test the alternator on the car, or more accurately, on our tester, and pulling the alt on a firebird/camaro is cake.

If both test out fine, start checking for bulbs that stay on, your stereo, anything that doesnt turn off.

To drain a fresh battery in 15 minutes requires something like 240 Amps. That translates to 2800 Watts. Something big would be glowing red..
If not I believe it's one of those quirky cracks in the lead beneath one of the battery posts. I guess it makes a (short lived) connection by the movement of the post when you hook up the battery. The connection would quickly be degraded when stationary. This is just a theory based on my own experience with smaller batteries, but you could try to observe the interior light after you shut off the car, and if it goes out you could try to just move the battery posts as if you were hooking it up again and see if the power returns..

Or he should just get a new battery. After all that recharging, the battery is going to get worn out real quick. New battery, replace the clamps or whatever, **** i cant think of the name of the wire ends that go on the battery, brain fart .

And also test the alternator.

My girlfriend had a problem similar in her Ford Explorer.

Turned out it wasnt the battery or alternator at all, but one of the terminals was cracked, causing it to not grip the battery post as good as it should. If I were you I would check to make sure that is all in order. Check to make sure the terminals on the post are tight, and the ground connection (other end of negative cable) is tight.

Do that and test your battery at autozone before you go buying anything new. She had to pay 90$ for a new battery (because her dumbass dad told her that was the problem) and it wasn't even related to that.

I've currently got the battery from my cutlass swapped into it. We'll see if it drains down. If not, then ill get a new battery. The one that was in it is just over a year old (still under full replacement warranty). The alternator is good, in fact, i just swapped back to the serpentine setup from the vbelt, so ive had this same problem with both alternators.