Don't know 'bout VA. but IL. does and what I've done in the past was use a small 9V battery. The + connected to the light wiring, alligator clip connected to the -, clip it to some metal part of the bike, whala.... light works, not long or bright but what's the chance of a LEO checking you out anyway. If you are looking for a way to comply this may help.
"Democracy is two wolves and a lamb voting on what to have for lunch.
Liberty is a well-armed lamb contesting the vote" Ben Franklin
Current bikes F800GS-EXCF350-Versys-690R-RZ350