I'm mystified at the multitude of "this is great" comments on an essentially unspec'd and implausible product. Is this elaborate joke that everyone's in on?
HN has been an engineering-oriented forum and bicycles are "real engineering". Every kind of modern bike is engineered for it's intended use and the idea you can add power and weight without consequences should be suspicious to the engineering mind.
Note: The video shows a USB cable for a charger, which couldn't charge a large-ish battery in an acceptable period, at one point it seems to show power imparted direct to the tire (which would lose a lot of power) but really, how this thing works at all is hard to tell, it's kind of silly to take seriously, even but jeesh.
If you were as attentive as you might think you are, you would have noticed that the USB plug being inserted was the host side, so it's the side generally which charges the connected device.
HN has been an engineering-oriented forum and bicycles are "real engineering". Every kind of modern bike is engineered for it's intended use and the idea you can add power and weight without consequences should be suspicious to the engineering mind.
Note: The video shows a USB cable for a charger, which couldn't charge a large-ish battery in an acceptable period, at one point it seems to show power imparted direct to the tire (which would lose a lot of power) but really, how this thing works at all is hard to tell, it's kind of silly to take seriously, even but jeesh.