Batteries in Bicycle Handlebars?

[Kernal]

I recently got a front light for my bicycle similar to http://www.amazon.com/dp/B005WPXNQ6/?tag=cpf0b6-20 but I find the battery pack to be cumbersome and annoying. I'm considering making my own battery setup in which one or two batteries are held in the hollow at each end of the handlebars and routing the power line underneath the handlebar tape. Has anyone else tried this or anything similar?

Cheers,
Kernal

 

[pdw]

I thought about it, but only got as far as determining that 18650s don't fit.