Review and disassembly: Sofirn C8F

Flashlight was provided from Sofirn for free.

Specifications from manual:
LED: Cree XP-G3, 1955 Lumen, 13600cd, 5350-5700K
Operating voltage: 2.8-4.2V
Power: 20W
Output: 6A
Battery: 1x 18650 Battery
Switch: backward tail clicky
Size: 14.4cm length, 4.46 / 2.45cm diameter, 140g (without battery)
Material: 6063 Aircraft aluminum with Type III anodization
Reflector: smooth
Battery warning: Blinks 2x/sec. And turns off one minute later
Deep discharge protection: yes, at 2.8V
Lens: Hardened glass lance with AR coating
Waterproof: IPX-8 (2 meters for 30 minutes)
5 Mode: High 1955lm 26min; Mid 630lm 1h40min; Low 105lm 9h8min; Moonlight 1lm 800h; Strobe 1300lm 1h26min; SOS 1300lm 1h26min
2 mode groups: moon/low/med/high/SOS; low/med/high; strobe is activated with double tap
Mode Memory: yes

Sofirn C8F, manual, strap, 2x o-ring

Flashlight has nice feel and looks good quality.
Threads are square and look. They are anodized and came well lubricated.
Tube is not reversible.
Threads are compatible with Convoy C8.

Tail switch is reverse clicky mounted on 17mm board, held in place with retaining ring. It has nice click.
Flashlight can tailstand without problems.

Driver is 17mm, bigger driver won’t fit. It’s fixed with retaining ring.
It has 3/4 modes with memory and strobe on double click. Modes are nicely spread.

Glass is 42x2mm without AR coating and reflector is SMO.
There is o-ring between bezel and glass.


LEDa are XP-G3 and is on 30x1,5mm alu board.
There is 1 screw holding board to shelf. Shelf is fixed, so no pill.
There is good amound of thermal paste between board and shelf.

Picture with CC bezel from Convoy

After reassembly it was working for 2 minutes and then turned blue so I quickly turned it off.
After turning on all I get is this, on high.


Any idea what happened??

There could be too small pressure to the pcb from reflector (due slightly different bezel size).

You mean LEDs overheated?

There was even more pressure with SS bezel. It even doesn’t screw all the was down with thick o-ring I used.

I don’t think it could overheat in a minute even with low pressure, but I may be wrong.

maybe the driver can’t handle the current

Mine looked like this when I turned it on first time :

I don’t think the XP-G3 likes the heat, the MCPCB isn’t DTP.

XP-L HD/HI works fine :

With XP-L HI V2 4B it pulls 12.3 A on a VTC6 on high, it does get very hot before the 3 min step down, I have been using it for walking the dog the last two evenings drained two VTC6 batteries so far no problems with XP-L HI

You did reflow yourself? On stock pcb?

Looks like there’s some room for improvement :laughing:

Did you bypass the springs too ?

Yes I re-flowed the emitters on the stock MCPCB myself, the XP-G3 has a low Vf so they pull a lot of amps, if the just used XP-G2 instead it would be fine.

The springs are bypassed from Sofirn.

Ok, looks like I have to order some XP-L HI :smiley:

Can you post some beamshots? I want to know how does it look with XP-L HI.
White wall would be ok :slight_smile:

Sofirn C8F Triple XP-L HI V2 4500K LED

I sent Sofirn a message on Aliexpress trying explain that the XP-G3 is the wrong emitter for the C8F, it’s of course fine if you use a low drain battery, but high drain battery and bypassed springs is not going to end well.

Thank you. Looks great :slight_smile:

Maybe I killed it because I used LG HG2…

If using high drain cells, you may try lowering the cell voltage. You could, for example, start at 3.7V with a 30Q and measure current flow. Maybe the overall Vf off 3 XP-G3 emitters in parallel is a bit low, this way there's a very good chance the emitters will survive by limiting the potential current avalanche.

This looks maybe like design fail and if it is it needs to change.

No battery should cause leds to die in any flashlight.

That is what regulated drivers are for.

Cheers :-)

I guess you are right :slight_smile:

Turning blue means catastrophic levels of current being pushed through the chip.

I had a “3V-22V” drop-in that I wanted to test to make sure it could handle even only 2 cells, so put in 2 18350s. Got really blue and really dim. Didn’t have it that way for more than 1-2sec tops, pulled the plug. 1 cell back in, the bugger survived.

1 cell?? Dunno how a trip could go blue from only 1 cell like that, even if just crowbarred right across the LEDs.

Unless they separated from the mcpcb and were just floating? Could make electrical contact w/o much thermal contact. That might cook ’em.

It was on no more than a second after turning blue but no help. I don’t understand how would they get so hot that fast. I was using it max 2 minutes before they died but it wasn’t constant on as I was playing with modes.
Interesting is moon didn’t work at all (before it died), leds were off in that mode.

It’s before my time here, but I believe OL did pretty much only DD lights: LED and Li cell and switch, that’s the whole circuit. Don’t think they could cook so fast unless there was some serious thermal upset.

’Though now with continuous-38A cells…