As differently powered lights were mentioned, let me venture into the power source area for IQ-Cyo and IQ-X. Even though B&M said that IQ-Cyo is for dynamo systems only, I have powered them fine with DC, specifically with a couple of lithium cells in series. USB output worked fine too, in my memory. I have moved these lamps freely between bikes, on some powered by dynamo and on other by DC and even rectified AC. However, IQ-X seems to have finicky electronics that does not tolerate variations in the delivered power. Can anyone thrown in any practical experiences around that?