Citycat YEE-Lic Compact 2.8A 1x18650 CREE XM-L T6 LED Flashlight

Hi, Eggpattern and welcome to BLF. HKJ's battery summary will probably answer your question or at least let you compare different battery lengths:

http://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html

Thanks betweenrides! That is a very useful research tool.

Do you happen to have another link with inner battery tube dimensions? Or has anyone measured this one to know which batteries it can or cannot support?

It may be a bit late now, but here is my experience with this light.
I tried protected Trustfire Flames 2400 in Citycat and they fitted. I had to unscrew the tailcap a bit to “lengthen” the battery compartment (by 1 mm or so). The battery is inserted without any force but there is no extra space left between it and battery tube. If you wrap it with one layer of thin paper it won’t fit. Some edges inside the battery tube were sharp and could easily scratch or tear the battery wrapping. I blunted them and now it seems to be fine. Trustfire Flames are in the list given by BetweenRides so you can compare them to your battery.