Pretty sure it would exceed what a dynamo would put into a battery. And even at that, there’s going to be more than three hours a day when you’re not riding - doesn’t have to produce power when you’re on the bike and moving like a dynamo has to. The cost-benefit is likely considerably better. I’m thinking about getting one of these to test.

But either way, I think for modern electronics it just makes sense to get the right charger and look for an outlet. There are some crazy small but high power chargers around now based on some of this new GaN tech. I have a usb-c 45W charger I got off of Indiegogo than is slightly bigger than the 5W apple iPhone charger and smaller than the size of the Apple 18W charger. That would put my daily capacity back into the battery in something less than an hour. Perfect for touring with such a high power density.

Here’s the Indiegogo link. They have both a 65W and a 45W charger.

https://www.indiegogo.com/projects/s...5w-gan-adapter

There’s a 100W charger now over on Kickstarter that is about the size of a deck of cars with two USB-C PD ports and two USB-A high current ports. There are a number of batteries now coming out that support USB-C PD input at pretty high powers. Omnicharge has a 13,000mAh battery that is USB-C in at 30W, for example. Right charger with the right battery can mean fast charging at pretty high capacity.