Is there such a thing out there? I want to make my m1 throw some serious light, but I am only comfortable doing basic modding, like solder 2 wires to a led star. I wanted to do a xhp50 led, but I think that may only be possible with a boost driver
Putting an XHP-50 in an M1 with 2 18350 cells and a 6V direct driver is what you are looking for, pretty much all a lego build and they come out quite nice. I built one awhile ago and love it.
Hmmm… 18350 are only 700mAh…
I would prefer a boost driver and a 3000mAh VTC6 (or 2600mAh VTC5) battery.
I mean so would I but 17mm boost drivers that have the kind of output you want to really utilize the XHP-50 aren’t exactly easy to find. Really an XP-L2 would probably be a good choice to run it with a single 18650 and still get a nice boost to lumen output.
I wouldn’t know where to find a beefy boost driver either.
But i’m not familiar with the world of LED drivers, so i would open a topic just like this one for some tips. 
More or less they don’t exist, mostly because it’s very hard to build a driver with an inductor small enough to fit in the light and still be able to produce as much power as you want. And even if you could do it the driver would not be very efficient because of the undersized inductor. Boost and buck drivers follow the pick 2 mantra. You can have size, efficiency or power output but you can only pick 2. Also with two 700mah cells remember you have equivalent of 1400mah which while yeah certainly is not the 3000 of a good 18650 it’s not nothing either, depends totally how you use the light. I guess you could say you get the same pick 2 problem with size, output and battery life of a light.
I don’t think one exists, at least not at ~17mm.
Stupid question, With a 6Vf emitter and Vbatt at 4.2… What would happen if you just hot wire the emitter to the cell?.. or do you still need something in there to throttle back the current?
Knowing only rudimentary circuit design (but being very familiar with the 3-way engineer’s compromise in many other walks of life), this is interesting to learn. If you wanted to expand on how/why that compromise works, I’d be willing to listen and learn more.
But this is incorrect, right? Assuming the 2x18350 are running in series (to utilize a 6V driver without boost), they would be 7.2V and still 700mAh.
An LED won’t turn on until it hits some specified voltage, I think generally 1.8-3V (I think - don’t quote me on that). So trying to power a 6V XHP50 LED (which is 2S2P dies in one unit) would need minimum 3.6V to even turn on, which is pretty close to 4.2V fully charged. If the required voltage to turn on an XHP50 is more like 4 or 4.5V, then it may not even light. And if it does turn on, it probably wont stay lit for long because the 18350 voltage will sag quickly.
Yeah, the 17mm would be a problem…
I think what he is saying is the increased Voltage would be accompanied by a reduction in current draw…. Like how with many AA lights Run times with 14500 700mah are not that much more or less than with 2000 mah nimh
But compared to a single 18650 (fits in the Convoy M1) it would be equivalent to 1400mAh
Actually it’s better to translate it to Wh (Watt hours)
For 1x 18650: 3.6 Volts x 3.0 Ah = 10.8 Wh (you can run 10.8 Watts for 1 hour)
For 2x 18350: 7.2 Volts x 0.7 Ah = 5.0 Wh (you can run 5.0 Watts for 1 hour or 10.0 Watts for 30 minutes)
Ah, that makes sense. Yup.
Good point by J that comparing Wh may be the better metric when talking about differing voltages.
To get the simple one out of the way first, your runtime of a light is not based on mah, it’s really based on watt/hr, the total energy your battery has available. You are correct that we really have 700mah at 7.4V, I just was trying to simplify since most lights are single cell and people tend to correlate mah to capacity. So 3.7V times 3ah (3000mah) you get 11.1 watt/hr and with two 18350s you get 7.4V times 0.7ah (700mah) which is 5.18watt/hr. So it has about half the energy stored as the 18650. Edit: well I was beaten to that quickly 
The boost/buck driver comes down to the inductor. The inductor makes a magnetic field that stores and releases energy, and it’s size determines at which point it becomes saturated and is storing it’s maximum magnetic field. I am simplifying a bit here. Operating it near this saturating point means lots of wasted energy in heat. So if you have a big inductor compared to your power output it will be efficient, small it will be inefficient (or at some point just not big enough).
I use it at work, and around the house a lot, 700 ( 5.18 watt hour.) mah does not seem like it will last very long… my armytek wizard uses xhp 50, and a single cell.
Is there another light, roughly the same size, and durability of the m1 I could try and build? if I found a holster, I could even just wear it on my belt instead of back pocket.
I guess it depends how much output you are after, the reason the Armytek Wizard can use an XHP-50 is that it’s only putting out 1200 lumens. The boost driver it uses is only outputting a small amount of power and barely using the full capability of the emitter. The M1 really is a very nice host and if you put in an XP-L and a direct drive driver it would be around 1600 lumens. Still quite a lot of light and you can use a high capacity 3000mah cell.
It has a mtn fet direct driver now.
So an xpl should give me noticeably more light? The springs are already bypassed tail, and driver.
Oh OK that makes sense… thanks.
Light perception is a complex issue. The human eye light response isn’t linear so 10% more lumens doesn’t seem 10% brighter(more like 1-2%). A tighter beam might seem brighter even with a lower lumen output. Different tints produce different levels of contrast in different environments. It’s often the case that side by side is the only way to see a difference and even then be different to each observer.
p. It’s true that at present boost drivers are limited in output by size constraints such that the trade offs favor 3V emitters in single 18650 lights. There’s more power available from a single 18650 than from 2 X 18350’s.
An xhp 50 run from DD from 2 X 18350’s would be noticeably brighter but for one quarter or less the run time. If the additional lumens are necessary along with run time then a 2 X 18650 host is necessary.
At that point you should also contemplate a host with enough head mass to more effectively handle twice the heat load, possibly even up to a 2 X 26650 host.
It’s a growth problem, more of this begets more of that.
Without good boost drivers available to drive the XHP50/70 well, a triple or quad XPL is a good way to get a lot of power from a single cell. The CUTE-3 triple with domed or dedomed XPL is a great combination. ~3500 lumens and 55Kcd (with dedomed XPL V6 1A and 30Q cell).
JakeDjanitor, if you are looking for an alternative light, the CUTE-3 in an Eagle Eye X6 might be a good choice.
Best to get low Vf emitters on a single cell linear driven light.
Otherwise the party is over when the battery is still half full.
(so to speak).
This means Nichia 219C or Cree XP-G3 basically.
high drain cells also help.