I know some of the triple builds have to be running high. How high? How hot do they get and how long do you run them hot?
Just built my S2 a few weeks ago with XM-L2 and 7135x12, but the novelty has already worn off. Was ordering for my UF-1504 host and thought maybe I would just order 2 of each and try the same setup in the S2:
FET Driver - 17mm
CREE XM-L2 U4 1C LED on Noctigon 16mm MCPCB
I have a convoy c8 as a host with a fet dd powering an xplv6 and it really through and then I have a c12 with a pure copper pill built by vesture of blood with 12 7135 chips and Iam pretty disapointed in the c12 the difference is extreme I’d guestamates about 30%less bright than the c8 with matching emitter so now I want to try the new xml2-u4 from mountain electronics and see what happens when I mount it on dd.
8+ amps through my triple XP-L S6 build. Can only be run on high for about 60 seconds before it’s HOT. I rarely need light for more than a minute at a time, so it works great for me. It’s the only light I carry all day EVERY day.
DD in the 1504 will only get warm at the most. I just put together a 1405 with a direct drive driver going to an MT-G2. I ran it for 4 minutes before it was as hot on the outside as my S6 at 45 seconds. I’ve never been concerned by the heat coming from any of the DD 1504’s I’ve built.
SWMBO & I EDC 2 of my DIY “S5 Clones” (slightly smaller bodies than yours) with 2.8A NANJG-105c into 3c or 3d XM-L behind 60° TIRs.
On High they get hot enough to strongly encourage us to shift down to Medium or Low after a few minutes on High, but not “burn baby burn” hot. No blisters yet.
They eat all of a 2800mAh battery within a day’s hard use & give such a lovely light, it’s worth carrying a spare 18650 in case the one runs out. As usual, I do wish the batteries would hold up longer…
Using Momentary-ON switches helps mitigate both heat and runtime issues.
Not for spotting Stukkas over Disneyland, but for working in the LAN/WAN infrastructure business or the various construction jobs we do (e.g. pulling an entire spool of Single-Mode fiber through the guts of the biggest building in town), or bathing the whole front yard in delicious, smooth, no-Cree-rings WHITE light they’re darn-near perfect (IMNERHO, of course). Only once have I wished for a tighter TIR, and that wasn’t exactly “necessary”, just “it’d be nice”. If I were to build one for The Great Outdoors I’d probably use a 10°-15° or so TIR for a little more Throw.
I’d opine that 12x 7135 or DD through a FET, in such a wee body, could hurt you.
I have a modified S2+ mini with triple XPL that I run with a FET driver on an IMR 18500.
The head got really hot really fast. So much so that I added an external heatsink around it.
Running 12 chips is roughly 4.4amps and with the new LEDs you’re lucky to hit that for the first 20sec of a full battery they ramp down rather quickly(bummer) with a fet driver you’ll get between 4.6 to 5 amps with the new bin LEDs—the big difference I’m seeing is that the fet will keep you over the 4 amp range longer—In a S series light I would say that translates to very hot in about 60sec
I have single emitter S-series that are stock, 7135*12, and FET with step downs and without, and 2 triples with 7135*12 and FET. To some even a 7135*8 may seem hot but for whatever reason the heat does not bother me or scare me as long as the light does not get to the point of melting down. I have taken all of them on a track inspection at work on run them all on high for several minutes, many times even longer, without issue and no problems holding the light.
It is true that one must be aware of the tool they are using because of heat but I do think that sometimes the heat gets blown out of proportion.
If you have true need for the vast amount light the availability of it outweighs the heat - as long as there is no melt down and you can hold it comfortably :)
Try it...you'll like it :)
I have an S8 with double XP-L at about 6amps, and an S6 with single XP-L at about 4.4amps
The S8 gets hot in about 45 seconds, the S6 takes over a minute.
How long are you able to run/hold a triple with a fet on high—curious
My S8 with warmwhite XHP50, zener-modded FETdriver and 2x18350 batteries runs at 5.8A (initially, going down fast). At 7V, that is 40W of mostly heat. I switch to a lower mode when the head is too hot to hold. It sounds like a freak light, but it has proven very usable already when looking for a grave hill site in the woods at night (during a school camp we did an exciting night walk for the pupils in the school where I work :-) )
Do you have a build thread or any details on the double xp-l build? I’m curious about the optics
It’s actually a triple, but only two of the three are XP-L’s. The other emitter is a deep red XP-E.
here is the thread if you are still interested
Please note the disclaimer of "at your own risk" as the following goes against all conventional recommendations.
Using an LG HE2 I have probably gone as long as 15 minutes, most likely even more. You can see the battery capacity is considerably lower but nowhere near dead and the body will be warmer (warmer towards the front). I do NOT get stupid and grab the lens while it is running but it cools quickly after turning it off. I would assume as the battery depletes so does the wattage.
I have two coworkers using the same setup but with Samsung 26F's (less amperage) with no issues. I do not always need all out brightness for that kind of time (15 min. +) unless I am doing my section of track inspection/walk but a few minutes all out is not an issue I even think about except that I wish they made 18650's with 10,000 mah 
My biggest problem.....after getting used to running these FET's at max I feel like anything less is not enough light. Thank goodness for forward clicky switches an momentary ability. Works well (for me)
Edit: I have changed the springs and braided them on the switch side. (Drivers were already done)
I bought their M1, M2 and S2 lights all with 2.8A 7135x8 boards and that little S2, with a freshly charged ICR gets shut down after only a 4-6 minutes on high.
I couldn’t really imagine going higher. Shorts bursts, fine, but walking around on high for 10 minutes, no way.
Chris