If anyone is interested, you could purchase the Magic Shine light as the light head only for $45 and create your own battery pack by using one of these:
http://www.hvwtech.com/products_view.asp?ProductID=1206&utm_source=Google&utm_medium=Product+Search&utm_campaign=Product+Search+(Apr10)Just add the connector you desire to mate the battery to the light and your own rechargeable AA batteries. You will then have a light with the only limit being how many batteries you carry or purchase on the way. I also don't have any idea of burn time... but if I guessed, it would be 1.5 hours on high depending on the cell. Lithium cells would last much longer.
Be aware - there is no bar mount, helmet mount, or anything else -- it is just a light head and you have to provide for the rest.
It takes the same helmet mount as Lupine and Dinotte... which I have one... so for me it's really easy to mount to my helmet....
Just another option.
I like the idea because of the long distances I ride without support. for those of you that just do laps at a local trail and don't spend more than an hour or two in the dark, I would think the $89 kit with battery and charger is more convenient.