2001 4.6 l v8 Ford mustang?

It's been 6 months since I got the car and my new battery is draining, and we've gone through 4 alternators.

Putting in 4 alternators and a battery in 6 months with no change in the problem, is crazy. Take it down to Autozone or somewhere that can run a charging system diagnostic for you before you spend another nickel.

You have a system parasitic draw causing the battery to drain, or a worn/stretched belt causing low alternator output. Or if this car has an external alternator regulator maybe an issue with that