I would stay away from the bicycle generators, because they are not
built to withstand the high rpm and constant high speed that our MB's
create. They will self destruct for sure, you can count on it. I've been
using a 12 volt 4 1/2 amp alarm system battery with a VERY bright
WalMart tractor light for $12.00 and a led tail light $16.00. I only have
to charge the battery once a week, as long as I don't turn on the
Head light. It's very simple to charge. I unplug the wire coming out
of the battery box that is mounted just below my seat and attach
a cheap trickle charger to it over night,no problem!