Derived from the term BHC (Banging Hot Chicks). Not to say that the two terms cannot overlap. BAC is a subdivision of BHC. Popularized at universities with a proportionately large number of asian chicks on campus.
Person 2: You know, I got that yellow fever. It will be more of BAC for me tonight.
When you wake up an hour late to school because u were so tired that u bashed the shit out of your alarm clock to the point where it broke.
"*yawns* dude i got BACS"
"oh u should get a new alarm clock then"