Newbie makes C8 with XHP50 (2x18350)

Somehow I wanted to assemble a flashlight with XHP50 diode.

I read BLF for a long time.

Even longer thought and chose.

As a result, ordered the following components (AliExpress and Kaidomain):

Elfeland C8 XM-L T6 $ 4.63
CF-FX-17A 17mm 3V-9V 2.2A 1/2 cells Driver Circuit Board for XM-L XP-L XHP50 MT-G2 $ 5.51
XHP50 5500K 6V Light Emitter with 20 x 1.6mm Copper Base $ 7.99
26 x 13.5mm Copper Driver Pillar Set for C8 $2.36
TOTAL $ 20.49

Additionally was ordered:
Aluminum Alloy Extension Tube for U-F C8/C2/C12 Flashlight - $ 6.11

Further simple:

Threw out a pill and a plastic reflector from the host.
Temporarily used an aluminum reflector from Convoy C8.
Assembled, inserted two 18350 - it works.


I liked the light.
In the middle mode I hear a nasty driver's whistle.
The quality of the host is disgusting - thin metal, bad thread.


Use new Convoy C8 GRAY ($ 14.68) without a pill as a host. (or here)
Try new XHP50.2 Neutral White 4000K ($ 12.21)
Find a different driver.

I like it!!! :+1:
Nice job & thanks for sharing…… :slight_smile:

Which 17mm driver advise for a XHP50.2 ?

looks good!
just look at it:

you are a brave man, placing a XHP50 in a $5 C8
you will like the COnvoy for it has much higher quality

No - $4.63 !!! :slight_smile:

This is a test - I decided not to spend a lot of money.
And I turn it on for 30 seconds max. :partying_face:

The second version should be better.
If you will advise.

With 2 cells the simplest way to go is with an FET driver such as the A6 driver. That and some high drain cells will give you the wow factor. To get a tighter beam which can also appear brighter in the spot you would need to go to a smaller led. The best would be a dedomed xpg-2 in a higher bin but an XPL hi would also be a good choice. Same driver but only one cell for those LEDs.

Rufusbduck, how is that possible? the A6 driver is 2.8-4.35v input, but the 2S cells are 8.4v.

Fin17, did you ever get a new driver for this?

I’ve also been researching for a light I’m building with 2S cells for an XHP50.2…

  • For a FET/DD driver he can use this one, (FET Driver w/zener mod):
    FET Driver - 17mm

However, I was informed the QLITE is more suited for smaller cells such as 2*18350, for the larger cells I was recommended this driver:

Another option, and one I’ve been looking into is the LD-B4HV from led4power:

It has some really great advanced features, one I like is the ability to user program it for either direct drive or constant current for the high mode.
Plus you can also adjust the output current a few amps up or down.

Installation is a bit more complex as it takes a special mcpcb because the mosfet component is externally mounted there.
It also can utilize a temperature sensor that can be mounted on the mcpcb as well.

led4power is a member here: (his thread): : LD-4 CC linear drivers, ILC-0/1 illuminated tailcaps, optics, MOSX, copper DTP MCPCBs...

Anyone have any other suggestions?
I came here when researching for the CF FX-17A driver from KD, because it’s 17mm and I was curious about it.

Fin17, besides the nasty driver’s whistle you’re hearing in the middle mode, is there anything else you didn’t like about the FX-17A?

Those look like 18650s to me… did you use 18350 or 18650? I like the idea of one that uses 18350.

He used 2x18350s in series, meaning 7.4V nominal working with the 17mm buck driver.

IMHO, now that we have the Kaidomain C8.2 XHP50.2, this type of dual 18350 build is not viable anymore, since even 2 1100mAh 18350 cells have less energy than an average high drain 2500mAh cell.

Did he? Not that it makes any difference for the driver but the OP here is confusing, he states he used 2x18350 but also states he used an extension tube, and shows photos of the light with 2x18650 and extension tube. It appears 18350 was a typo when he meant 18650, or maybe he edited in the 2x16350 statement later but didn’t change the photos?


This type of build is still viable if you want to build your own C8 with 6V/12V emitter. (Like the OP) Because there is no capable 17mm boost driver for XHP currently available to buy.

Regular C8’s have a 17mm driver space (Convoy, Thorfire, Sofirn etc)The KDLITKER C8.2 is using 20 and 22mm drivers, so they have a special body/pill that fits them. KD doesn’t even sell the C8.2 host, which I find very odd since they sell every other flashlight parts imaginable.

EDIT: Sofirn and Thorfire make 20mm C8’s (see posts below)


A lot less, running 2 cells in series does not double the energy/capacity/mAh, it stays the same as one cell, (2x1100mAh in series = 1100mAh)

I meant the total energy stored in the cells in terms of Wh.

7.2Vx1.1Ah= 7.92Wh

3.6Vx2.5Ah= 9Wh

Therefore, the 18650 would be a lot of a better choice.

Also, there is a C8 host from Sofirn that fits 20mm drivers. Go on their Aliexpress store, and you will find it.

Edit: Only the mobile link works for some reason:

Ok thanks for explaining.

Thanks, your link doesn’t work BTW, but I found it: Page Not Found -

The 3 Thorfire C8S I have all have a 20.8mm driver.
(probably the same as the Sofirn)

It was strange because after my post about it I began thinking that I vaguely remember reading about a Sofirn 20mm host, but when I searched “Host” in their store it didn’t show up, only the 17mm and C8F.

But after reading your post I searched again and that time it was showing.

I wonder what KD is doing for their XHp35 version, it appears they’re using the 22mm H2-C 5-mode boost driver. Maybe their host is 22mm and they’re using a 22/20mm adapter ring in the XHp50 versions.

I wonder if anyone has tried to fit an H2-C in the Sofirn host.

Thanks, (I edited my post)

2S is still the only option currently for anyone that wants to upgrade their existing 17mm C8
Or (like me) want’s to upgrade a different light with 17mm driver space.

I have used that host (Sofirn C8s in 20.8mm) and although the description doesn’t mention it, it DOES come with a decent copper MCPCB (star) that WILL fit the XHP50 (or my SST-40 I used in my build along with Lexel’s Bistro TA driver). Also includes the centering plastic washer (mating with the refector’s rear where it seats perfectly around the LED after floating it on) and the usual extra rubber o-rings (and I think also a lanyard). Sofirn does a good job here I think, and I also am pretty sure the glass is now AR coated (although it is not near as noticeable as say KD’s coated glass).

I have thought about running an XP-L2 (higher bin- shaved) in this host as I recently burned out the shaved SST-40 I had on it. The TA Bistro driver delivers up to 8 amps of current, and the SST-40 has a low threshold for failure and so I won’t try it again in any case. I’d LOVE to run the XLP-HI, but I’m concerned it also would fail at 8 amps— so more work needed on that decision (or need to stay with 30Q and below as the SST ran fine with them until I put my 25R’s in last night and smoked it). :person_facepalming:

Zappaman, have you considered an XHP35 HI? (if you can get the 22mm boost driver to fit somehow) looks like you’ll need about 6mm depth in the driver cavity.

I thought about it, but I’d be further ahead to just buy the KDLIKTER C8.2

Yah, I actually have a second host (same 20.8mm) I AM planning to run with a shaved XHP-50.2 when Lexel get’s his boost driver working and available in that size. My C8.2 KD does have a domed XHP50.2 and I agree— for the money it’s hard to go mod, when a factory build works as well as DK’s does. He (KD) sells a driver for that XHP50.2 too (about $10), so there is yet another option driver wise for someone wanting to mod the XHP35 HI/50.2 (shaved in my case).

But as I have the sunken cost in this Bistro driver ($15) and I can put any 20mm star/led in there… I’m thinking I may try a better XP-L2. The damn thing is… the Sofirn C8T and C8A factory lights REALLY do about as good as my SST-40 mod did (and the C8A has a better tint- not SO white). So probably go on the safe side and drop one of my XP-L2 (V6) shaved leds (but not too close like last time) :cry:

I seem to always have an order from DK in the works (as now with 5 weeks waiting so far on the last batch of parts ordered) but maybe I’ll shop LED stars some there (and wait another 6 weeks) :stuck_out_tongue:

Yes the KD H2-C is the 22mm boost driver I was referring to in my post.

I’m curious about the beam of the shaved xhp50.2, I don’t recall reading of anyone doing that before but I suppose it’s been done.

I’m surprised you’re not considering trying the XHP35 HI, it seems to be what the latest high lumen production throwers are using, such as Utorch UT01 and Thrunite Catapult V6. I’m assuming because of its smaller XP size footprint it would have a tighter hot spot than even a shaved xhp50.2?

Lexel did it…

I HAVE definitely thought about the XHP35 HI but the feedback so far favors the XHP50.2 shaved. So I decided on the driver for C8 host #2 will be Lexel’s when it’s ready (which should be any day now) and have the XHP50.2 in the hand.

Always waiting on something :wink: