Glad you installed the USB port and it works, and there is little reason to complain about this price. But for other readers let me propose a different solution, one without installation at all. Buy an "Olight" RN 800 (or similar) from ebay. When you mount this little thing to your handle bar (in under 2 minutes) it provides for
- an autonomous USB charger (large LiIon battery),
- a very powerful (spare) head light,
- a flasher to use in daylight (similar to what a Kisan modulator does, different modes).
And all this without splicing the motorcycle's harness, without any risk that connections made may later corrode.
And for those of us riding in Europe it comes with another advantage over the Kisan modulator, it is entirely legal.
The good's enemy is the better