Names? Hmm. How bout the TriForce? TripleTripleTorch? The 3x2? Yardsweeper? LumenBlaster?
JonnyC, you lost me. There are drivers for using 2 lithium-ions in series with a single XM-L, so I don't get what you mean. I'm not trying to figure on Rich's exact build running on 2 Lithium Ions, just trying to get a feel for NiMh mods vs. Lithium-ion builds.
Garry
Just so's you know, the Tenergy premiums deliver 10.8A just fine.
I didn't consider li-ion because of voltage issues with the drivers. Otherwise you get into CPF prices for drivers.
Don't know anything about runtime yet.
Rich
Sorry, I thought you were referring to this build. The 7135 constant current drivers are cheap and easy to understand, but the downside is that they can't handle high voltage battery configurations (well, unless you do the Poorman's Multi-lux setup).
Ok, well at least I know that going the NiMh route is reasonable and I don't have to be "stuck" with the idea of using lithium-ions. Can we figure an approximate runtime on this particular setup going on the mAh rating of the batteries and the current draw?
Garry
Already did... I call it the Neutralizer!
I have not, and don't know how, to figure runtime-no good at numbers. All I do know is that I took it on some dog walks and I got an hour on med and low; batteries didn't need to be charged after that. High is for WOW. Like having a big engine in a small car-power in reserve for when you need it!
Rich
Based on 5000mah batteries, and running maybe 10amps (8.4 w/ just the 3 XMLs), you might get 30 mins on high. Pushing that much current through, I think the batteries' capacity is reduced (or something like that), so it will probably be more around 20 mins (just a guess?).
So I'm researching batteries, and the subc NiMH batteries seem to be awesome for this setup. High discharge rate, with actually really good capacity. Not sure why only the sub-C and not C batteries are capable of that type of output.
What about a single high capacity LiFePo4? I've stayed away from those and never tried understanding them because I thought you had to be more careful with them than Li-Ion (maybe because of the high discharge amps?).
EDIT: I think I meant IMR cells, like a 26650. I'm going to research going down that route, since it would give me what I think would be an ideal voltage for this setup.
EDIT once again: Just ordered a 4000mah IMR 26650 from Tactical HID :) Will have to have my 3C cut down and bored.
You won't get the amps... I did up another light, same configuration in a 2C and with a 26650 I get 5.6A out of it. The voltage just isn't high enough, but still damn bright!
Strip the outer shrink covering from the battery and it'll fit fine, BTW, as long as it has no circuit protection board, and IMR's don't have one.
Rich
You keep crushing my dreams Rich! :P
According to the data sheet, the XM-L's forward voltage is 3.3 at 2.8amps. It seems like the IMR's 3.7v would be perfect then, factoring in resistance of wiring, springs, etc. I run 3 x Eneloops (3.6 nominal voltage) and pull 2.8 amps with the XML. According to the specs of the 26650's (http://mymnke.com/en/Mnke_App/Tpl/default/Public/images/DM/26650-H-e.jpg), they remain above 3.6v until they reach about half capacity.
Well, all I can do is give it a shot.
Oh, believe me, it'll still work fine with a single 26650-you'll get at least 5A out of it and it'll be bloody bright, so don't let me sway you. 
Like I said, I just did the same setup with a 2C host using a 26650 to try it in a smaller size light, and it still lights up the world! If you wanna do it up really nice though, use a 2C host, make a spacer for the battery and you'll have the same setup in a smaller package-and you'll still be pleased!
Rich
Well, you were right. The IMR only pushes it to about 5 amps. Even less with the 3 x Nimh C's. Running 4 C's get me to 8.4 amps. Voltage at idle is around 5v, at full load they sag to 4.5v. The only thing I can think is that with all of the wiring and drivers, there is a good amount of voltage drop. I don't really know the best way to measure the voltage that's making it to the 7135s. They don't seem to get hot, so maybe things will be fine.
Don't even worry about it... with 8.4A you're doing good.Why risk blowing something up fooling around with test leads on those tiny parts?
You got this far-how about some pics?
Rich
Alright, I finally took the time to upload my pics. It's not done yet, but here's how I went about building it so far.
I bought one board with the microcontroller, then 4 4x7135 slave boards. I sandwiched two of those together to make a 8x7135. Takes up more space, but it worked. Here's how the wiring looked before I sandwiched everything together.
Here are the stars mounted in the PES2 heatsink. I drilled a larger hole in the center to allow for the wiring to fit. Following Rich's suggestion, I filed down the contacts that were not used in order for the reflectors to sit flush. See those metal pieces on the side? Those are just random parts from a Maglite that I use to cover the emitter dome when I solder the connections. This way any splattering of solder or heat from the iron doesn't mess up the dome.
Blurry picture, but here it is wired up. I just run one 20 gauge positive wire basically directly from the Maglite switch. Then three separate negative wires each to a 8x7135 board.
It's hard to see, but the reflectors had to be filed down quite a bit to fit with the wiring in place.
And there it is with the reflectors on. I used normal Krazy Glue and was sure that it did not touch the emitter dome. However, it really did dry instantly, so it's a really poor centering job. Oh well, these reflectors don't throw anyways, it's really all spill.
I'll get pictures up later once I get the light completed. I want to do the same thing to the bezel that Rich did, and I'll hopefully get some beamshots up for comparison to some of my other lights.
- Jon
Looks good! Good idea on covering the domes... I've screwed up a few.
Krazy glue isn't the permanent holder it's made out to be. I popped my reflectors off and reglued them when the centering was off. Just scraped off the old glue first with a wrist slicer. (X-Acto #11)
Rich
I finally got the light done and created my own thread...
https://budgetlightforum.com/t/-/5765
Thanks again Rich for the help and inspiration!
Any time! Feels good to have helped. Nice birthday present-I'm fast approaching old-fartdom today. (57)
And this bumps this up so others can see it!
Rich
Happy Bday, Rich !!!!!!!!
Thanks! Like that website BTW... we have 3 dogs.
first post here, but figured this might be useful info. If you want more throw from the XM-Ls (or XP-Gs) the Regina reflector gives a very "flashlight" beam and it fits the XM-L if you drill the hole out to 7mm. I prefer optics for the smoother beam (I make my own mtb lights) and good round ones are the LXP-RS (narrow flood, if that makes sense) and LC1 (not tried yet, but others rate it), all available from digikey. The optics are a bit fiddlier as you have to modify the holders to fit them over the solder tabs. I also like the Laura-RS a lot, but it's a 21.6mm square optic.