Thanks for the replies, I don’t need a light to charge from the USB port, just be powered by it, it does not have to be a powerful light as it’s just secondary to my Cateye Volt 1200, so a low power flashing one would be fine, I like to have a constant light and a flashing light front and rear for when I commute on dark country lanes.
Anyway, if a small flashing light cannot be run of the USB port I’ll keep using my little AA battery powered one.