Once I receive it, I will try to make a 18650 pack for the back of my head when recquiring longer runtimes, it should also help a bit with the bouncing problem these type of headlamps have with the Kaidomain elastic belt and similar ones.
I am not sure if there will be enough room on the inside even reducing the spring's length, It might be better to do it from the outisde, but will probably look worse:
And by the way a +1 for Manafont, mine has been already shipped, not like DX where it takes ages for that.
Mine just arrived. Puts out light even on a clinically dead AA I'd just pulled from my pager (Didn't have any other AAs around, these are really nasty lightweight alkies from the local pound (dollar) shop.) Produces much more gratifying amounts of light from a 14500 - my flame protected 14500's won't fit, they are too long.
Pictures uploading now. You would almost have to remove the spring completely top get flame Trustfires into it. While doing the beamshots with an IMR cell it got hot enough to melt solder and a small brass nipple fell out. I'll try it with NiZn next, It would seem that my one didn't like 4.2V.
There is a brass nipple about 3mm long soldered to the driver board to make contact with the + end. It might work without it, but mine doesn't appear to be 4.2V capable.
From the smell from it, it's toast. Try an alike. No light.
Try a 14500. No light.
Now to find out how to remove the battery tube. For the moment I'd regard this as a 1.5V device - I'll ask Manafont if it is supposed to work with 4.2V.
Here's the little brass nipple that melted out. Note how generous the assistant has been with her hair. Next job, giving her a very good brushing.
Very shallow reflector
Minus lens and reflector. It definitely is an XP-G.
Where the brass nipple used to be. Not a great shot as I didn't have enough hands to hold the light to illuminate the inside of the tube and hold the camera upside down.
It's easy enough to get the head off - it is just pressed onto the body and is held in place by the two screws for the clip - one of them came undone with a T6 Torx driver and the other with a T7. The head appears to be mostly solid - the driver is in the battery tube. Now to find out how to dig it out. I've just emailed Manafont to see if it is supposed to be able to use a 14500.