jalbam, you cannot run 3 cells or 4 cells with the Sky Ray. Anyway i doubt it will push out any more lumens that way.
Can't it run 2 or 3 cells with that WF-500 body?
Well, the designed seem regulated properly on 2cells. Someone can (should?) try 3, but not sure it would be any brighter.
Thank you :) I wonder how much will last with the standard configuration of 2 cells. I can't wait until mine arrive! Is it safe to use AW IMR cells or should I use only "normal" Li-ions?
The regulations is pretty good if your battery can take it. With a Panasonic 2900 @ 3.41V in the UF-980L in direct drive, its only capable of of delivering 1.6A. In the Sky Ray 3 x T6 2-cell, its able to ramp up to 3.3A with cell voltage at 3.41V. So that's still 22W approx. The current is going to rise further.
So do not think that...hey you got 3.9A at the tailcap, its going to burn the light up fast. @ 2.8V per cell voltage its gonna be too low anyway and you risk damaging the cell if you push further.
Jalbam, if you are gonna use it in 180mm long config, you can use IMR 18500 x 2. With 2x18650, good cells like Panasonic/LG/Sanyo 18650 or Hi Max/Xtar/Solarforce cells is good enough.
Is it going to rise? more than 22w later? why? :o
I have 18650 IMR AW but not 18500 :( Which one would be the best in 2x18650 configuration, IMR or others? :o
Where do you buy Panasonic, LG and Sanyo? I just have Trustfire, Soshine...
This light intrigues me, but the drop in sold separately is even more enticing. I have a 3D mag that needs some love ( it had an SST-90 DD on 3x12000mah nimh cells sitting on a big C101 heatsink that is now in a 4D mag with a 10amp driver 
). Has anyone seen this dropin available? I have been keeping my eyes open at manafont, DX etc but haven’t had any luck.
I just got a Skyray 3800! BRIGHT BRIGHT BRIGHT! I would estimate a real 1500 OTF lumen! For just $52 too!!! It is now the brightest light in my collection among S12, M3C4 XML, BC40, Scorpion V2, TDX15...
No, it'll keep the constant power. current rises as voltage drops. You can buy the better loose cells on ebay, but they're kind of pricey. See if you can get in on the xtar 2600 group buy deal.
Thank you very much :)
What about the 18650 IMR? Are they not good enough for this triple XM-L?
Please, someone post beamshots and comparisons with other flashlights, they are so interesting!! :D
No, IMR is of course better, but they aren't really necessary for 2-3A draw and they don't have protection which this light would fit (since it will draw your batteries dead).
vinhnguyen54, nice to know that it is even brighter than the M3C4 which is 1011 OTF manufacturer rated. 
Ford Perfect, the drop in is not available seperately. In fact its securedly very tightly to the host, not easy to get it out even with some force.
Jalbam, the IMR 18500 config is when you take out the extension to save 40mm length. That's not a lot so don't do this if length is not critical. (just that some do not like the 220-240mm length of 2 x 18650 and will do absolutely anything to make it shorter).
You can get 2x Panasonics NCR18650 2900mah for usd19.99 shipped from hkequipment.net, get it from their web store as their Ebay store is quite a bit more expensive. These are worth it, they are amongst the best. Or you can go to Ebay and get the Hi-Max 2600mAH, available from Pingyi (shenzhen) on Ebay only. 6 is the most worth it, 2 is like usd15 shipped to US. They are usd17 shipped to my country, not sure why even though its closer, so it's not that worth it if i do not get the 6-pack. Just bite the bullet and get the Panasonic 2900mAH. Or if you have a purchase from Solarforce-sales you can include and tag on to the shipment (coz they will require $2 for registered shipment per purchase), get their Solarforce blue lettering 2400mAH 18650, $7 a piece. They also are very very closely matched, ended with exactly the same voltage. Very very safe once determined that they are matched, till several tens of discharges later then would they require testing for voltage again.
You can get the AW Protected 18500 since IMR are not really needed..... Too bad they do not have Panasonic 18500s. (AW Protected are pretty over-priced for the performance, CPFM is actually the cheapest already)
Or you can try the Trustfire, cheap enough to just try if you are not too particular about the capacity...8.28 shipped.
PS. Seriously, just bite the bullet and go for the Panasonics. Really really good, you are not only paying for the Made in Japan cells, but also the quality of the protection circuit. Not only do they cut in during discharging consistenly and well, they are also the only 2 cells which terminate consistently time after time at 4.22V on my DMM on my Ultrafire WF-188 charger, which my other cells will terminate at different voltages (My DMM reads slightly higher, with my experience with my other cells like SLA etc.). They are so crazy consistent that they both charge and terminate within 0.01v. Literally idiot-proof and safe for everyone's use. HK equipment also gives you FOC a nice 18650 plastic storage box, useful for taking backup batteries out to field.
Due to the fact that the drop in is tightly secured, I have a feeling that this is a well heat-sinked light. I will confirm that and post photos.
You can confirm with your unit (therr might be unit-to-unit variations) by unscrewing the bezel and checking if the 52.7mm drop runs much hotter than the surrounding metal, esp the part near the fins. With P60s the drop in always run quite a fair bit hotter first before the body will catch up, even assisted with alu foil. Do if you can help it, use some heatsink compound, or wrap the foil very tightly and slightly thicker and jam it in so that it cannot even pop out....it helps if you push and screw it in rather than just pushing it in.
The Sky Ray is pretty good, overheat is due to the host heat saturating. If you really wanna run it cool for extended periods, you'll need serious fins, like the Trustfire X6 designnd size, which is too big for most guys anyway.... This is why TK35 limits in hardware the runtime to 20 mins in Turbo mode. (even then it is more for safety, not performance....its gonna be crazy hot by 20 mins). Heck, even a XR-E drop-in @ 0.9A with good heatsinking is going to warm a P60 host to "too hot to hold" at 20mins mark.
Yeah, I think I will have to wait a bit for a 3x XML dropin in the 52mm size ala the 5xR2 or 5xQ5 for the WF1200 etc that mod nicely into a mag d.
Nice beamshots, thanks for posting them.
Wow! Thank you very much 2100, a lot of useful information about cells and such, maybe I will buy some Panasonic :D (although I am hesitant since it's from a Chinese supplier and I am afraid they could be fake ones).
inhnguyen54, did you mean the single XM-L or the triple XM-L version of the EagleTac M3C4? http://www.lighthound.com/EagleTac-M3C4-Flashlight-820-Lumens-max-output-with-Filters_p_3833.html or http://goinggear.com/index.php?main_page=product_info&products_id=2965
Finally, will this Sky ray triple XM-L beat Olight SR91 and Trustfire X6 with SST-90?
They are surely not fake ones, going by their discharge performance.
The Trustfire X6 is measured to be 2.98A at the tail (with charged IMR) and 3-cell operation, so that's like 10W more or 9A. A single SST-90 itself is going to be limited by heat at the junction. Lots of heat to conduct away fast and its not going to happen if the heatsink is no copper. No biggie, just that the luminous flux suffers a bit.
http://www.luminus.com/products/datasheets/Luminus_SST-90-W_Datasheet.pdf
~ 2026 emitter lumens best case on paper driven at 9A.
The 3 x T6 is 2.55A with fully charged good cells (Panasonic/Solarforce V2). So that's 5A to the driver, but we'll just take 5A to the 3 emitters ignoring driver efficiency as also done above for the SST-90. That's 1.7A per emitter.
Spreadsheet for calculating light levels of XM-L
https://budgetlightforum.com/t/-/2525
That's 629lm cold and 533lm warmed up. So that's 1887lm cold and 1600lm warm for 3 emitters.
So 1887lm for 3xT6 vs 2026lm for the SST-90. That's 7% difference. We can talk about "percentages" and be quite close/accurate. That's why we can do away with emitter efficiency and still not mess up, unless one of them is super inefficient. But throw of Trustfire X6 is going to be much better.
Price, usd52 shipped vs $139 shipped (and remember you need to add $10 for additional price of 1 more cell and you need 2 chargers else its a nice waiting game). So that's 3X difference.
SR91 is going to be expensive, and is a 3 x T6 animal with a bigger head as well likely to be much better heatsinked.
In reality, you are definitely not going to see the difference between a light having 10% more lumens than another with 10% less unless compared side-by-side. Pupils dilation is always continuously variable in real-time even with the same light, shine a light onto the ceiling and check out your wife's pupil's dilation.
When you talk about the 'quality of the protection circuit' on the Panasonic NCR18650 cells, what do you mean? Which cells are you referring to? The $19.99 ones on hkequipment and all other 'Panasonic' badged cells are unprotected.
RedForest UK, looks like you are correct. The bottom part of the Panasonic NCR18650 don't have that PCB kink in the wrapping...and the literature on the web shows unprotected.
But then again, I was running the 3 x T6 and it hit a very hard stop, the light just switches off immediately. Tried to change modes, can't do. Took out the cells to measure because I wanted to see whether both are discharge matched, both showed 0.0V. So far all the budget lights that I purchased never have any under-voltage protection. Maybe I made a mistake...that's why I said PCB protected.
Anyway, to confirm things, I am doing another full bore run (with active cooling under the tap, 1 drop per second). I need to cycle the new cells anyway...
I have good news for those afraid of the light overheating. As mentioned in the previous post, I am doing a full bore discharge test on HIGH with running water as active cooling. The head and driver area is cool to touch. Now its already 30 mins, I switched off the light and took out the front bezel. The reflector/drop-in is just barely warm, like 35 deg C. The heatsink area is probably 30 deg C. So the light has EXCELLENT heatsinking. I am impressed. So during winter below freezing, you guys can gun in high mode continuously.