My 740i bmw will not start only click i get a jump off and drive it for hour or longer soon as i cut it off it does the same thing

One of two things could be the issue. I would drive it to an AutoZone or similar parts store. They will check the battery (under load, as any battery will normally show 12+ volts with a voltmeter) and should be able to determine if it is the battery or the voltage regulator. Unfortunately if it is the regulator you may have to get another battery as well. But since you can drive for an hour or so after a jump, I would say the battery is not holding charge correctly and needs to be changed. Hope this helps