i used to run a 1200 watt amp and 2 12's constanly. never had a single problem with my battery. i would also do it with my car not running. i would say as well alternator or battery __________________ -Josh Sold-1995 318ti, Club Sport, Hellrot Sold-1996 318ti, Active Model, Boston Green Current- 1995 318ti, sport model, schwartz |