Battery power on Synergy 2i?

Anyone who can tell me in what way Battery power improve the sound of this pre?
Quite simply, it eliminates the grunge and crap that your local electric utility sends you along with your a/c, which all the motors and noise producing devices along the way further muck up. The battery sends nice, clean d/c to the audio section, making the noise level very low, the background quiet and the sound much cleaner and grain-free.
Thanks for pointing out the benefits. But I am also intrested in hearing from someone who actually has experince with this pre with and without battery.