Mailint,
Sorry I didn't respond sooner since my last post in that other thread. It has been one of those crazy weeks were I was working a bit later, and as a result, I was dead tired. Well, I have been giving this a lot of thinking. For an extreme light, I keep thinking back to using li-ion. Lithium ion cells are just great due to their high power capacity, convenient voltage, and variety of sizes.
I came up with a couple of battery and circuit combinations (with stuff easily and cheaply available) that could be used to power 3 or 4 of the new tiny rebels with those new 11mm diameter reflectors by McGizmo at a high enough current to be stunning. Sure this is a custom light, but it will be so unique and so bad-***! The entire diameter of the flashlight shouldn't too much bigger than 22mm for three Rebels and 25mm for four Rebels.
I considered how you just want extreme light in small size, also considering that you do not care about battery life (run time) or total life time of the LED (let's push it). Well, unfortunately, I could not promise 5 minutes of runtime, but instead, 30 minutes to 90 minutes (depending on battery used and LED configuration). The
only thing that may be limiting this light from offering more than 10 minutes of on time is heat. Holding this light in your hand is most recommended, but if you let it heat up too much, then I guess the LED life would decrease a few 1000 hours (far from hitting your 2 hour goal).
Expect at least twice the output than your Rebel 0100 Fenix. These lights will be taxing your li-ion cell, but within limits so it should be safe. As long as the batteries can provide the power, then the driver circuits will send enough current to the LED.
So, what are these ideas? In all these examples, I speak of using 18650 cells due to their good capacity, and decently small size. Any li-ion cell used must be a protected one (with integrated protection circuitry). The current of these cells will be within 1C and 2C of the 18650 li-ion cell. 1C means running a cell at a current equal to it's capacity in amps (a 2400mAh cell at 2.4A is 1C). I hear that you should not run a cell at over 2C (~4.8A for the 2400mAh cell) due to the possibilities of thermal runaway. Some protection circuitry cuts the power at so many amps, so then the protection circuitry will be the limiting factor. Where shall I start?
Single emitter lights:
1. This idea was proven in that concept I spoke of a while back in that other thread. It features a singe Rebel 0100 or Cree XR-E Q5 bin (Q2 bin may work better), but the emitter will be running at around 1.5A amps to 2.0 amps. The emitters will be direct driven from the Li-ion cell, but Georges80's D2Dim circuitry allows you to vary the brightness from very low to max power. The circuitry does not regulate current, but uses a PWM to dim the light. It will save you power when you need to find that keyhole or read a book, but can then be set to "stun" mode. It is a pretty tough circuit, too! Low Vf is needed here, so the Rebel may be the best choice. The Q5 could be great if you can find one with a low enough of a Vf (Q4s and Q5s are known to have oddly high Vf). A Q2 supposed to have pretty low Vf, and they are still very bright. With a decent 17mm or 19mm reflector, you will get a decent balance of throw and spill. The beam should be like that of your Fenix, but the intensity will be amazing.
You will be blown away by the brightness! Using evan9162's measurements (
https://www.candlepowerforums.com/threads/169547), I have calculated that the Rebel 0100 will produce ~335 lumens, and according to evan's measurements of the Q4 (
https://www.candlepowerforums.com/threads/172379), the XR-E will produce somewhere around 341 lumens. After losses, expect about 300 lumens. Does that sound about right? Again, as long as the Vf is low, and the flashlight does not have too thin of aluminum walls, then the thing should not get very hot in your hand (I have found).
Multiple LED lights:
2. The design I think that will be the most promising is this one. It uses a single Shark boost circuit to provide either 3 or 4 Rebel 0100s with 980mA of current. You can turn down the current with the trimpot if desired. You can turn down the current and still get amazing brightness. Firstly, if you deliver 980mA to three series connected Rebel 0100s, you will get 702 lumens (minus any losses). With four Rebel 0100s, expect up to 936 lumens! Heat is a limiting issue, but so is the power the li-ion cell can dish out.
With the efficiency of the Shark driver considered, the Shark will draw from 3.62A to 4.01A from the li-ion cell when using 4 Rebel emitters and the Shark will draw from 2.66A to 2.95A from the li-ion cell when using 3 Rebel emitters. The 18650 li-ion cell should be able to handle those loads. Beam shape, according to McGizmo, should be similar to Surefire SL4 (or a Luxeon V mated with an IMS20 reflector). I will discuss McGizmo and the beamshots later.
So, there is a hell of a mini monster. Even if you turn down the current to 500mA going to each LED, 3 Rebels will produce 435 lumens while the driver draws 1.24A to 1.38A from the battery and the 4 Rebels will produce 580 lumens while the driver will draw 1.66A to 1.84A.
3. Finally, you can use two smaller li-ion cells (RCR123 sized) in series to power 4 Rebels using the newer SOB buck circuit. You will need two of these SOB circuits to power 2 series connected Rebel emitters. There is no real advantage of using this design. You get similar brightness as the Shark design for 4 Rebel 0100s, but you just draw half of the current from the batteries. This design is if you prefer using the smaller cells. Unfortunately, you have to pay for the two SOBs and squeeze 2 of those tiny circuits in the flashlight now.
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Okay, what do you think? I had more ideas, but they were using a different boost circuit than the Shark driver (George80's Fatman). It had a limiting factor (you can only draw less than 2A on the input side), so this meant using two in the same light. They were also slightly larger in diameter than the Shark (the Shark is a bit thicker though). I had multiple other designs because of the Fatman's input current limits.
As for McGizmo, check out this link:
https://www.candlepowerforums.com/threads/174089
In that link, McGizmo showed some prototypes using his McR-10R reflectors. One light uses 3 Rebels and reflectors, the other uses 7. Both are just beautiful looking and the really performed well! This thread solidified my confidence in the multi- Rebel and McR-10R reflector combination. I probably would not have thrown out those ideas if it weren't for him!
BTW, I am not sure what percentage of light is lost due to the reflector and lens efficiencies, so I did not account for any losses in with those lumen figures given. Also, brightness will vary a bit by several percent depending on the binning of the LED (flux, forward voltage, and tint). There are numbers out there (percentages) for the losses to expect, but I do not know them. I will be getting a lux meter soon, so I can finally take some somewhat accurate measurements of my flashlights. This will help make comparisons between flashlights, atleast.
Oh, and I gave the input currents to give you an idea how long that li-ion cell will last. You can take the mAh ratings from the cell and determine the runtimes. I give a range of current draws because as the voltage of the li-ion cell drops, the current draw will increase to make up for the power needed by the LEDs and driver circuits. The first current draw is based on a cell voltage (under load) of 4.1V, while the last is based on a cell voltage of 3.7V.
I see that you learned about V*I=P and how Pin=Pout and how the buck or boost driver would function with different cells. I hope you understand that your AAA would not be able to handle the load if you want a light with far more brightness than the Fenix. AAAs is great mostly for tiny lights. Hopefully you do not mind using an 18650, 18500, or 17670 li-ion cells. They will make the flashlight have a diameter of 20mm to 22mm, but they are still pretty compact, and the cells pack quite a punch (in power). The light can be a bit past 100mm long, but that length will vary depending on the cells used. All you have to find is a decent host that the stuff will fit in. You never know, you may be able to find someone here that can turn out a flashlight body for you with a lathe. Local machine shops may be willing to make something for you, too.
So, there are my ideas. If I had the funds and the time right now, I would make a light like this for myself. Besides, I have a slew of other projects in front of me, from a pair of LED headlights (a revision of a previous pair I made), to a tiny Rebel 0100 based Maglite Solitare that uses a 10440 li-ion cell (AAA sized). If interested, I can discuss this stuff in more detail during this weekend. I may mess around in SolidWorks (3D cad program) and draw up a light that uses three or four Rebels, or a single Rebel or XR-E.
What are this Modamag Draco and the Surefire Titan lights? I am a bit out of the loop with these nicer premium flashlights. I saw the Orb Wee, though. Will these lights be any brighter than the Fenix lights like you wanted? Just wondering…
Finally, I was thinking about your green laser. I believe that there are constant current drivers that can feed the right current and voltage to the laser using a higher battery voltage (li-ion cells), right? This way you may be able to add the laser to the flashlight, or maybe just share the battery. If not, you could probably just have the two separate in your pockets. Do you like holsters for things like flashlights? Since you like to EDC stuff, maybe that will be a good idea. The EDC forums would have you covered in this area. Later...
-Tony
? Besides, to a non-flashaholic or person that is aware of some of the latest technologies, the Draco would be pretty damn impressive. Many may try to pull out their mini-maglite to beat you 
. That is a common thing that us CPF members face. There are pockets that work for 1AA and single CR123 lights, like cargo pants (rather large), side pockets on carpenter pants, or just the change pocket (often plenty deep and easy to pull lights out of). Those tri- and quad- Rebel lights are neat and really ultra-small for their power, but since they are a little fatter, they would work better in a small pocket on your side (change pocket or leg pockets on carpenter jeans) or a holster. Thinking about that light, I may have to attempt it myself and put it on my to do list...
