Hmmm...I was actually considering the Urban 500, but now you've got me wondering. How far off for you are the run/charge times from the manufacturer claims? The other usb light I was considering is the Lezyne Super Drive http://www.lezyne.com/led-lights#panel-1 , which might work better for you regarding the run times, because you can carry an extra battery and change it out if you need to.