There was a recent thread here about voltmeters, got me thinking about putting one on and found this:
https://a.co/d/6eE3pYKPO had installed a lighter outlet on LH fork on a bracket ( who uses these now?) plug and play as was already wired to battery.
USB A, USB C smart 3.0, and an on- off switch so no power draw.
$13. Only down side so far is that the LED blanks out when the driving lights are on for some reason.