Why not get a Euro light? I have a B&M 4D toplight .. 2AA batteries, last a long time.
in senso mode it (if that version) even turns itself on when you ride thru tunnels,
then off again in the daylight..
whole big lens lights up 2 central + 2 diodes face sideways..
also made is another AA powered light flatter, 1 diode , line reflection lenses spread it out.