You may want to have a look at Mike Mickelson's recent review of the Audioquest Sky on Soundstage. Mickelson seems to suggest that the static voltage bias induced by the batteries takes several days to establish after the battery is activated, and several days to drain if the battery is turned off. While Mickelson asserts he has tested the effectiveness of the battery pack by cycling the batteries on/off for several days per cycle, he should have sourced two identical sets of cables and interconnects: one set with batteries and one set without. This would have enabled him to make quick swaps for a more accurate/reliable audio comparison. Please see:
http://www.soundstage.com/revequip/audioquest_sky_volcano.htm
Guido
http://www.soundstage.com/revequip/audioquest_sky_volcano.htm
Guido