Amazon.com : Ultra Bright 1600 Lumens Rechargeable Mountain Bike Light with Cree XP-G2 Neutral White LED - Bike Headlight - LED Bike Light-Suitable for: Mountain Biking, Downhill, Touring, Commuting - Long Battery Life -7.4V 5.2Ah BAK Rechargeable Li

This is the best deal on a quality package that includes everything you could need. You won't find anything better anywhere for less. Only caveat, the little M4 x8mm screw that holds the plastic mount to the shell is a bit short. I'd recommend replacing it with a 10mm long one and throwing in a #60 O-ring as a washer under the screw head, cost pennies at any big box store and makes a world of difference. In all other regards the NiteFighter BT40S package can't be beat. On sale for only $69.95 right now, fulfilled by Amazon so pretty much risk free.

Yeah you might see what look like good setups on for less, but none of them will be as reliable as the Nitefighter. It's the only one comes with genuine new high quality Li-ion cells (5200mAh BAK pack), will give long run time on each charge and last years.

Enjoy your commute, Wallonthefloor.