There were some reports these migh not fit some flashlights. I'm curious what numbers yours are?
Mine are (diameter, length) sticker included:
XTAR 2400 mAh - 18,2mm, 68,1mm
XTAR 2600 mAh - 18,3mm, 68,3mm (by removing the sticker it should be same as others if need be, or so it seems)
XTAR 3100 mAh - 18,2mm, 68,1mm
XTAR 1800 mAh - 18,1mm, 68,1mm
These are all i have in multiples and no other brands in this form factor to compare. Had a few Hi-MAx but never kept any. I find fitting them not an issue but some do, can you take measurements? Just curious. If someone care posting results for other brands might be usefull too.
A word of caution! I used some non conductive foil to measure the batteries length and had the foil thickness subtracted later. It's generally a bad idea to short them even with protection PCB on it. Carefull! :)