A while back I ran some tests to optimize the most reliable and fastest way to upload & download DCS files from an engine. I found that DC power did make a slight improvement in both upload & download speeds.
A couple years ago I experienced very interesting situation at a show where the power went out. Obviously no power means no running trains right? Not really. I disconnected my AC power supplies and rigged up my Milwaukee 18v cordless batteries to keep the layout running. At the time these were the XC batteries which were about 5AH. The fully charged batteries easily ran my 4 trains for the two and half hours the power was out and still were at 50% juice when I switch the power back. At the time I wasn't sure how long or how well this would work, so I took some precautions to extend battery life like not running smoke and removing a few of the lighted cars to conserve power usage.
During the above situation I didn't notice if the trains communicated any better or worse, but I do know that I had a mix of PS2 and PS3 engines running that all worked well on DC power. Those batteries saved the day, and for two hours I had the most popular layout that still worked!
