7x XM-L T6 Flashlight!

So I ordered this flashlight a few weeks ago off eBay: 8500Lm 7x CREE XM-L XML T6 LED Flashlight Torch KEYGOS 7T6 18650 26650 | eBay
And here's a little review!

First impressions:
This thing is epic! It's big, heavy, and pretty bright.

Brightness:
Very bright, but not 8500 Lumens!
7 T6's can do 70w, this out of the box does maybe 20. That's being generous.

Heat sinking:
Not bad, could be better. There's a decent chunk of aluminum around the LEDs and the whole thing screws into a big chunk with fins on it. I added some thermal paste to the threads.

Construction:
VERY good! It's solid, all the pieces fit together nicely.

Now, here's what I did to make it better:

I don't have a replacement driver so I just fiddled with the one it came with. I found the current sense resistor (R068, 68mOhm) and put three 0.1 Ohm resistors in parallel with it. This brought the input current up to about 4 amps. At about 11.5V (3x 26650), which gives us 46W input. So I'm guessing about 40W to the LEDs.
Now these LEDs output about 100 lumens per watt. So that's 4000 lumens. Still just a little under half what it claims. I'll be happy if I get 7000 lumen.

The driver was definitely not designed to output this much current as it gets incredibly hot. At one point it started smoking... So I won't be running it for too long.
Now the search for a new driver begins...

Here's a problem:
There is no where near enough heatsinking for 70W. This thing already gets pretty warm with the 40W. But if you've seen my laser build thread you'll know that I don't care! So we'll see what happens...

Now, PICTURES!











And here's my modification: two big resistors (third hidden)


KaiDomain has this driver: http://kaidomain.com/product/details.S020166
But it's too way big for the flashlight. I might be able to make it work by replacing the inductor and cap with smaller versions (same ratings, don't worry!)

quite a beast. Make sure you have proper source of power for that :eg:

I would personally go with the KD driver, and maybe reduce the battery tube to 3 x 26500....that driver would also work on 2 26650s

I have got the 5x T6 edition.

I think 7x of T6's is too much.
Wear sunglasses when using this monster.

BShanahan14rulz said:

quite a beast. Make sure you have proper source of power for that :eg:

Click to expand...

3x 26650? Haha plenty of power.

cilegray said:

I would personally go with the KD driver, and maybe reduce the battery tube to 3 x 26500....that driver would also work on 2 26650s

Click to expand...

The KD driver is just too big, and there's not really any way to mount it with shorter batteries... I already ordered it so we'll see what I can do.

I've KDs quality rather sub-par.

I order 5 drivers, and only 2 of them actually worked. They seem to be built on re-used PCBs and only appear as partial devices.

Well the driver I got works...

Anywho, I made it fit in the space I had. It's a very tight fit and I had to replace the inductor with a smaller one, but the same rating so it's all good.

It pulls 7.5A at the tail cap with moderately charged Panasonic 18650s.
On my power supply it pulls 8A at 11.6V. My 26650 batteries can barely keep up!

I didn't take any pictures of the guts because it was hard enough getting it all together. But if/when I take it apart I will.

I'm trying to figure out whether or not the 470uF cap is part of the switching circuit of if it's just a filtering cap... I don't have the schematic so I can't check

More issues... the driver starts over heating and turning down the current in less than a minute... I gotta figure out how to cool it... Maybe fill the pill with mineral oil? Thermal paste? There is pretty much no extra room for anything.

Thanks for the post I ordered this flashlight as well last week so thanks for all the advise from everyone!

AutoItKing said:

More issues... the driver starts over heating and turning down the current in less than a minute... I gotta figure out how to cool it... Maybe fill the pill with mineral oil? Thermal paste? There is pretty much no extra room for anything.

Click to expand...

You should probably use potting compound if you're going to fill the whole void... I got some rather large tubes on FocalPrice for 2-3$ a piece.

cilegray said:

You should probably use potting compound if you're going to fill the whole void... I got some rather large tubes on FocalPrice for 2-3$ a piece.

Click to expand...

Hmm not a bad idea.

Killed my driver.... whoops

I think a better idea would be to find the source of the heat, usually a large mosfet, and heatsink it to the case with some scrap aluminum or something like that. In the end, you may end up with something that has horrible heat transfer properties, but it is likely better than air....

Good luck finding a driver to drive all those with a healthy current :`(

AutoItKing

Hi Sir: I bought this flashlight about 3 months ago, for some reason it stopped working, I took it to about 3 electronic repair shops and all of them said the same thing. Get a new one. The said the driver is burned out and they can’t find a new one. I’m really not very technically knowledgeable but I can solder and at least test the led’s to make sure they work. I use this light for law enforcement so I would like to save it, could you please provide me with a driver model and were to buy it and some instructions on how to fix the light. I tested the led’s and they all work. Thanks!

Hi Sir: I bought this flashlight about 3 months ago, for some reason it stopped working, I took it to about 3 electronic repair shops and all of them said the same thing. Get a new one. The said the driver is burned out and they can’t find a new one. I’m really not very technically knowledgeable but I can solder and at least test the led’s to make sure they work. I use this light for law enforcement so I would like to save it, could you please provide me with a driver model and were to buy it and some instructions on how to fix the light. I tested the led’s and they all work. Thanks!

He posted a link to a driver that would work with some modification at the very end of the original post

http://kaidomain.com/product/details.S020166