everything twin and allnighter said!!!
besides, charging for 30 hours might not be enough to crank the starter... if you have some friend close by with another BMW or MB, or a heavy duty truck, try to jump the car. a honda or toyota will not do - my sister in law once got battery drained (playing loud music in a parking lot with bunch of guys in Civics), and could not get jumped (i mean, the battery!!!), so she called me... i got there, saw little civic trying to jump an E36... connected the E34, a minute later it fired up...
in other words, you need a car with potent alternator to jump your X... then drive 100 miles, and charge it...