Here's a photo of the body tube. I can see why they do not have a shelf in it for the "heat sink". The body was bored for the AA batteries and there wasn't enough meat left to make a shelf. Also, when the final ID was cut for the pill, it was done off center and might have been better if it had been centered.
Seems more hidden flaws are coming out. I was really considering getting one too.
If you go to the other forum selfbuilt has done some graphs and the lux/lumens seem to regulate, so it seems the current setup works. The only time there appears to be a reduction in light due to heat is at the very start before the turbo steps down. If it was properly heatsinked there would probably be no need for a step down on turbo mode.
Man, that really sucks in a huge way! This might be the first light to have worse heat sinking than a P60. Thanks for being so determined in tearing your new light apart to expose nitecores dirty little secrets so the rest of us can avoid them. Im sure you’ll perform your usual magic and come up with something truly amazing. At least they didnt use blue locktite. In practice, Ive found that red seems to release with less heat/torque.
Maybe this will serve until the mod plan comes together . . .
It certainly does look like very poorly thought out heatsinking… One thing I can think of to put a good spin on it is that perhaps it is actually well thought out heatsinking and that they have done computer modelling/testing to ensure that that contact area is in fact enough to get heat out. It’s quite a wide circumference so may appear smaller overall than it is.
This is selfbuilt’s runtime graph, and it looks like that there isn’t any output loss over the long period after the heatsink would be saturated. So maybe heatsinking is adequate afterall.
That's why I included the suggestion that maybe we just get too worked up over cooling on these lights. I, for one have no means of testing how well a light gets rid of heat, so the way I do them may very well be total overkill. Maybe Nitecore did a bunch of engineering on it, maybe not. Possibly it ended up being the only way they could do it and make the light the way they wanted as far as size and weight, so they accepted what they could do with the design they had. I don't know, I'm not an engineer, just an old guy playing around with lights. It's up to y'all to figure out what is right and wrong and draw your own conclusions from it, as many of you have already and it's good to see the opinions of others.
Whatever the engineering intent was behind the light, its still very bold of you to be the one to crack it open. IMO, you took some great risks to your wallet in doing so. Again, THANK YOU for sharing! :bigsmile:
I never liked that light because it uses stack of AA batteries but THIS, this is just sad and disappointing and all that from company that was giving as crap here about prices, Nitecore shame on you, I was eyeballing TM26 but after this I wouldn't give a 100 bucks for it...
Thanks for this revealing Old-Lumens, I hope you will repost this on CPF also, people have a right to know what are the paying for...
perhaps you can talk pilot into doing a thermal analysis on it, but i would assume even if its adequate as is the lumen sag would be huge, or the circuitry just adds more power to compensate for the poor design
why do you think nitecore put all that lock tite on there - they didnt want us to see this!
I briefly considered that, but then of course the circuit can’t measure light output itself but only current to the emitter, so it would be practically impossible.
Remember that all the heat from the LED has to get out from the tiny center pad on its base at the first thermal junction, I’m quite sure that the contact area between the heatsink and body is at least as large overall as that… I agree that the design is certainly less than optimal and imo disappointing too, but I really think the only possibility is that heat dissipation is adequate enough to prevent lumen sag at the post-stepdown levels.
I guess it just means that they could’ve driven it harder if they’d made a better job of it.
not so impossible, the voltage goes down as the chip gets hotter, and that can be measured and compensated for, also they may have calculated the lumen drop over time and have pre-programmed the driver to ramp up the juice
However both seem to be an over elaborate solution to this problem
Thanks Old-Lumens for doing this teardown for us.
I have the EA4 NW and I love it, but I haven't used it yet in anger for any sustained runtime. Now I'm kind of afraid to. 
The UI was actually OK for me and I was considering getting the EA8.
No way in hell I'd buy it now!
Regardless of speculation about thermal engineering tests that may or may not have been done by Nitecore, I think your first impression "Simpy put, it sucks" is a pretty good gut reaction from someone who knows a bit about the subject. No need to second guess yourself here.
Otherwise, why on earth would so many manufacturers and modders have put so much work into designing and improving thermal paths over the years. Simply to raise the prices and trick us into thinking we are getting something we need? I don't think so!
This is not what most people would regard as a cheap clone light. I really cannot imagine what is going on with the engineering / marketing / sales team at Nitecore that they would let this "almost great" light go out in a state like that. It's very hard not to conclude that the fact that it was so very difficult to get apart is that they really don't want us seeing what is inside.
My very uneducated guess would be that perhaps the driver has a thermal stepdown protection to compensate for the crappy build in case anyone actually does decide to run it on high for an extended period with decent NiMH cells. But I know nothing of drivers so others may be better equipped to comment based on your detailed photos.
I'm going to reference this thread in another post soon. Hope that's OK
Ha ha those are the two possibilities I had considered too, why I put ‘practically’ before impossible. I came to the same conclusion as you though, that it was way over-complicating things when they could instead have made a slightly wider heatsink to fit in better 
I suppose it’s also true that even if the temperature of the heatsink (and therefore LED) stabilises at a certain reasonably safe point with the current set-up, that it would still be a lower value if there was better heat transfer, making room for better efficiency.
i am surprised at the low level of heatsinking though, and the high lumen claim, getting 900 lumen OTF from an xm-l is not easy, and maintaining it is even harder, yet those ea4 graphs show maintenance is being done
perhaps their lumen count is emitter, but how is it maintained (for the ea4, and assuming ea8)…
I was pretty disappointed too, when I saw the guts of this thing. It seems like it would have been so easy to create a better thermal path to the outside, yet they didn’t. I bought one, when they first came out, and the crazy thing is….I still like this one. Maybe the newer, more efficient circuits produce less waste heat, and there was no point driving the emitter harder because of the balance between output and runtime, which would be perfect for my needs if I didn’t know what I know now. Maybe I’m just naieve too. I have a pretty decent size collection of lights, and I like them all for one reason or another. As much as I try to convince my wife otherwise, I will not truly NEED any light I will ever buy again (and the collector in me will never want to stop buying lights). Part of me just wants to run this on high all night to see what happens. If it survives, I’ll know that it’s a good product. If not, what am I really out? I just exposed a crappy product that is no longer worth having in the collection. I’ll probably never do this, because there is so much to like about it. I like the form factor (to me, not too big, not too small), the throwy beam, the fact that it runs on AA’s (I have run it on 4, & 8 cells), and the UI. All in all, I guess it’s a near miss, but I’m still glad I picked it up, and I’ll probably never push it hard enough to find out whether or not it really will fry itself.
My vote is for an MTG2
Can’t wait to see the modded light after Old Lumens works his magic on it! :bigsmile:
I just ran a quick thermal test on my EA4W. I'll note that nothing melted or got disfigured, including the black plastic centering ring around the LED. Each time it dropped out of Turbo, I put it back into Turbo. Tested with Turnigy 2400 LSDs, fully charged.
| Time | Temperature (Deg C) |
| 0 | 19.6 |
| 30s | 22.4 |
| 60s | 24.0 |
| 90s | 25.6 |
| 2m | 27.2 |
| 3m | 30.0 |
| 4m | 32.2 |
| 5m | 34.8 |
| 6m | 36.2 |
| 7m | 38.0 |
| 8m | 40.0 |
| 9m | 42.0 |
| 10m | 43.6 |
Body temp at 10m: 39.0 (measured about 1cm above tailcap)
Cell temp at 10m: 35C to 38C
I do not have an EA8 to test. Anyone really disappointed in theirs can send it to me ;)
In hindsight, I should have monitored lumen output at the same time. It was still bright, but no way to visually determine if it had dropped out significantly. I may run it again sometime when I have fully charged cells again.
I noticed the battery tube milling is not centered on my light either. One of the cell tubes is cut so far into the body wall that the tailcap edge is almost sharp. Here is the thickness measured at the top of each battery 'tube': 0.37, 0.52, 0.95, 0.74 (mm)
I still like the EA4W for what it is, but I am disappointed in the build quality, and the heat sinking (if the EA4 shares the EA8 design). The thermal test indicates adequate heat dissipation to the body.
I think I'll have to run this test again from a power supply and measure lumen drop along with temperature.
I’ll lay down the challenge to solve the heat issue. Miniature water cooling set up on the led.