I really like that this thing is serviceable. I have an idea worth sharing: If the old battery dies you could take it out and just replace it ( if available ) or take the old connector off the dead battery and rig an external battery. You would have to drill a small hole in the body but that shouldn't be too hard to do. Yep, one of these running off of a single 18650 ( or two 14500 cells in parallel ) would triple to double the run time.