A PS2 should have fairly minimal power draw. 79W is what it says on the power tag on the back of mine. If you plan on sitting for a long period of time with the car off playing games, I would be looking at getting another battery and isolating it from the main battery. That small amount of power draw will not drain your battery immediately but eventually any continuous load on the battery will drain it and once you drain a normal car battery, it will never be the same again.