Howdy all! I have limited experience with modding lights and have only done a few simple led swaps in the past. I was looking at the nitecore ea4 and was curious if a xp-g2 swap would work. I have the ea4 now and would like to get some higher lux numbers out of it and wanted to know if xp-g2 swap would work. From my limited knowledge it looks like it would work but i wanted some expert opinions before i tear into the light.
The heads on these things tend to be glued down with about a gallon of red loctite. Just about impossible to remove without severely damaging the head… see Nitecore EA8 tear down - Modding will be later and in a different thread.
It is easy on the ea4. All you need is a grippy surface such as a rubber pad. Push the light bezel down into it and turn… The bezel pops off nice and easy unlike the ea8 which is almost bomb proof. I figured the xml is pushing about 2.8 amps based on some tables i have seen here related to lumens. If that is the case it seems like the xp-g2 would be a acceptable replacement…
My friend’s EA4 could not be opened… looks like some may be glued.
That is interesting. I bought mine when it first came out. That could make things more difficult if they did glue some of the lights.
Make sure the XP-G2 is copper mounted.
1,5A is typically what is considered max, but you can push it beyond 2A on a aluminium MCPCB… (if you have good heatsinking)
Copper changes the game entirely… 2,8A to aluminium mounted XP-G2 is not something I would have done… Especially not in a light with limited/bad heat sinking!
I cant comment on how the reflector would work, but most seem to report good results when using XP-G in XM-L reflector.
The best thing is always to have a reflector made for that specific emitter though.
Not sure that a copper star will fit because the factory alu one is quite a bit thinner, so the bezel may not screw back down. 
Instead, how about de-doming the existing led?
Every now and then there is discussion about reflectors made for specific leds. But apart from the size of the hole, most reflectors are just simply parabolic shaped, which is the shape that gives the tightest hotspot, and that does not discriminate between led sizes. The hole must be big enough for the led and the led must be in focus, that's all there is to it as far as I can think of.
Am I missing something?
There is no head on the ea4 to come off, just a bezel and tail cap. The bezel might be difficult to come off, but it might take a little elbow grease
You may me 100% correct for all I know. I just shared what several others seem to have said. I have not flipped around on reflectors much myself so I cant really give you a good answer based on my personal experience. I can say that my very limited experience (which I would not draw conclusions by) only says that its best to not have much hole around the reflectors. XP-G reflectors usually have smaller holes for the emitter though. In some reflectors a hole that is too large seem to result in more of a black spot in the middle.
On several occasions I believe to have seen similar sized reflectors6 for various types of emitters. Example here.
According to those pictures, the hole even seems to be the same size. But reflector design on the backside is completely different. Not sure on the inside, but I would assume the XM-L reflector is best suited for XM-L and same with XP-G otherwise those who design them and engineer them would only make XM-L reflectors since XP-G emitters would fit. There would be no need to make anything else than XM-L reflectors if they were just as good for XP-G. But yet we usually see one for both.
Manufacturers would save money if they only had to make XM-L reflectors. Despite the possible saving, they make XP-G reflectors. There is probably a reason for it, otherwise they would not have bothered. (at least that is what I am thinking)
But as I said. Most seem to report good results with XP-G emitters in XM-L reflectors…
Noctigon XP-G boards are 1.6mm (20mm SinkPAD are 2mm thick), so they might fit in the EA4.
I think you’ve summed it up, djozz. A parabolic reflector has just one focal point. The only difference between the XP-G and XM-L to a reflector is that the smaller LED better approximates a point source of light.
Lots of good points brought up. I am going to take some of these suggestions and try it anyway. If it doesn’t work out o well i can always put the xml back in it. I did see the poor heat sinking that the ea4 and ea8 offer or i should say lacking. Dedoming could work as well. Might have to try that just for the fun of it. Looks like a copper mcpcb is a must in this situation. I will see how they compare in thickness and go from there. Thanks for the input!