Is there anything sucha s an xbox battary, lets say i was goiing for a long drive, how could i play the xbox is there a power supply thing, if i used a pwer backup unit it would be to short of time, i heard someone once say they did somthing like this with a car battary. .. please help

You'd probably be better off getting an AC adapter for your car's cigarette lighter.

if you have a UPS, you can hook it up to the cigarette lighter and it will work
(remove UPS batt and make a lighter cord)