The wall-wart is there so that you can see the LEDs which tell you if the unit needs inflating. You don't need to have it on all the time; some units have slow losses of air, some never seem to lose air (I have one that is always in need of a pump-up every 3 weeks, but two that have never needed to be reinflated). The light will flash until it reaches proper inflation, then glow steady till it needs more air. Use it to be sure you have the right amount of air at setup; after that, you can unplug it if you worry about stray electrical interference, but plug it in from time to time to make sure you don't need to reinflate.
