Which headlight are you talking about?

If you use lights with replacable batteries, carry extra. I use some that use 18650 rechargables, and just carry one or two extra. Also, in well-lit areas, I just use a bright blinky, saving the flamethrowers for the descents and pitch-black zones.

I'm thinking of getting another flamethrower here: http://www.fasttech.com/products/160...00-lumen-led-b

The mtbr reviews say the headlamp is really nice quality, more of a spot than a flood (better for the road or helmet than handlebar-mount dirt), and maybe 1000 true lumen. The battery pack is of unknown quality, but can be replaced with a known high quality one.