On Fri, 2 Dec 2016 16:47:51 -0800 (PST), Tim
wrote:

I know some construction machinery mechanics that use them on both 12 and 24v systems.

I'd I need to do anything to my bikes, I'd change out the tail lights first. Brighter and quicker response time...

Lights like this have an internal "wide mouth" switcher power supply.
Without that they would be very sensitive to voltage. I am not sure
about these days but back when I was a bike guy, motorcycle charging
systems were pretty primitive. Triumphs used a big zener diode and
Harleys had 2 windings in the generator, one was adjustable. You tuned
the field winding to tune the voltage for the number of lights you
ran.