Thanks for the additional discussion.

Regarding the comment - would people pay for more power, since there are a few people that do bike touring that bring along lots of electronics, there are some that bought the Forumslader (spell?) USB charger. But here in USA they are a small minority. I have found that when bike touring that the Sinewave Revolution with a pass through cache battery was adequate to keep all my toys charged on a two week bike tour. While rolling, I usually have one taillight and one GPS turned on. Phone off, camera frequently used but off when I am riding, headlamp (for my head) in the campsite and tent, etc. And when touring, 99 percent of the time the headlight (on bike) is off, instead just charging batteries. Touring I use battery powered taillights instead of dyno powered in part because during daytime I would prefer a flashing light. I mostly keep internet useage to checking e-mails and weather forecasts, nothing more. I use NiMH rechargeable AA and AAA batteries for GPS, taillight, headlamp (for my head), I charge those off of USB power too.

A few that have used the Forumslader USB charger commented on feeling the additional drag while riding, but I can't recall anyone else commenting that they could feel the additional drag with other chargers. I know I can't feel the additional drag when my USB charger (Sinewave Revolution) is pushing 600 milliamps into one of my devices. And I can't feel any additional drag with a headlight turned on.