This is the second generation of the the BMW X3, this LCI model released in the US market in 2007 featured an updated exterior and interior styling as well as a new engine, the N52B30.
Usually when e90s stall you can fix it with a new battery. But the underline issue could be the alternator, a bad ground(strap under car that connects the chassis to the engine) loose battery or faulty wiring. Start there.