So this light really gets you respect. I call it the commuter cuz it really doesn't put light down on the ground like the other light. ..But the visibality is great. Perfect for in the city when you need to be seen. A car driver sees you coming and they can't figure out if your a motorcycle or scooter..or a car with a headlight out.. even a train (sez my friend)and it (the light) can be made for under 5 bucks at Home Cheapo. The battery pack is still gonna run you a bit 20 to 30 bucks(use the same battery pack as last light) 10 AA Ni-MH at 1.2 volts thats 12 volts 2500 mAh in the cute little plastic holder from Radio shack or some other electronic place.
This light is 11 watts so on this battery pack it should run just under 3 hours. I did a late night city ride last Friday night and it held strong for the 2 1/2 hours we rode.
Another of my bike lights http://www.instructables.com/ex/i/9129E65EFFBE102880EC001143E7E506/edit.jsp