Originally Posted by
adamrice
I do not currently use a dyno hub, but I am planning on building up a bike with one.
I'd look into running a strip of helicopter tape over the wires to protect and retain them. That stuff is robust (it's often used as chainstay protector), would leave no more stray wire exposed than necessary, and would make for a clean-looking install.
K-lite sells a dyno headlight and an inline switch so you're not putting a load on your dyno hub when you don't want to. I've been following
Igaro, which currently sells a dyno-USB converter and is working on a headlight that also has USB-out; when that is released, you'll be able to control the light's parameters via an app.
Almost all dyno powered headlamps have a light switch built in. No need for a second switch. The rare exception is that some lights were built for use with a sidewall tire driven dynamo without a switch but they are quite hard to find.
If you wire a USB charger in parallel with your lights, when you turn on the lights almost all power goes to the lights. Turn off the lights and all power is available to the USB charger. If you are not chaging anything with the USB charger and your lights are off, there is very little drag on the hub. The exception is that some USB chargers have a pass through cache battery, with those you could have some hub drag if your hub is charging up that internal battery.