3x XP-G mod, with 1x18650 MTE, advice needed

Hi there, swiss first time poster here, glad to be here. How is everyone?


I'm sitting in front of my 18650 ME P7 flashlight (DX: sku 12060) with a driver that gave up yesterday, so I soldered for DD and measured the tailcap 1.5A @ 3.49V on a fresh 2600mah ultrafire.
I don't like DD, so I thought: why not mod the flashlight with 3x XP-G's on 20mm MCPCB and carclo optics from cutter, AW 18650 and a driver.

My question is: How can I get the most lumens out of the light and still be efficient? What driver would you suggest? The existing one has about 17mm diameter and is mounted in the heatsink, with a spring on it. I'd like to have at least 2 modes in order to have the option of longer runtime. I would only be on high for very short periods (i.e. for showing off), so I don't care about heat and runtime on high.

3x XP-G 20mm round is wired in series, so the driver should put out about 11.1V and 1A on high?
Or would you suggest 3x XP-G's on star, soldered parallel and drive at 3.7V 3A? would be easier to find a driver I guess
note: I'm confused if the driver should really put out 3.7v, cause Vf at 1000mA for one XP-G is around 3.26V.

eah die at 1000mA would give around 350lumen without temp. losses, so theoretically 1050 emitter lumens!


Please forgive if I made some mistakes, your help is very appreciated!

Achim

:welcome:

If you want it cheap and simple, you can use 3xXPG connected parallel (which means 3.5V @ 3A). The driver can be bought at shiningbeam.com HERE. It's 17mm in diameter, so should fit nicely. It suppose to deliver 2.5A on high mode, as long as battery voltage under load is higher than Vf of LEDs + 0,15V. It's not the best regulation, but for impressing non-flashaholics folks is more than enough.

The idea with LEDs in series, as you mentioned - 11V@1A is not a good idea for this kind of host (which allows 1x18650). You would need a big boost driver, which would be very inefficient (too much difference between Vin and Vout). Besides, I have no idea if such driver even exists.

Good Luck !

ps. The LED drivers are current regulated. It doesn't matter if the LED Vf is lower. Extra voltage will be converted into heat (in case of linear regulation, such as this AMC7135 based, Shiningbeam driver) or longer runtime (in case of proper step-down circut - but this requires much higher Vin, i.e. 2xLi-Ions).

This is a really good idea. At 2.5A, each LED would see 833 mA, the XP-Gs each producing around 300 emitter lumens for a total of 900. Multiply by .7 for a conservative estimate of OTF lumens, and a 600+ OTF light seems possible.

I build a Mag 1C tri XPG R5 driven by
a Tri-Flupic board

10 brightness levels + burst at 1200mA per emitter

A very verstile UI perfect for a single li-ion

Do a search on threads started by me and also Tri Flupic

I would give you links but I am using my cellphone
right now


EDIT My tri-XPG build

https://www.candlepowerforums.com/threads/251030


Info on the Tri Flupic

https://www.candlepowerforums.com/threads/174715

https://www.candlepowerforums.com/threads/213329

Thanks for the replies so far. That Mag looks really nice txt101!
The tri-flupic is sophisticated, but 40$ is a little steep, not too much for what you get though.
I just ordered the driver coolperl suggested, thanks for the advice! I'm eager to see how much juice the AW battery can give! Might try it DD before mounting the driver.

I will post pics and measurements once I get everything.

Achim

I wired up the triple star in parralell. It's a few extra wires but allows optimal drive from a single 18650.

Yup, that's what I had in mind.