Review and disassembly: Sofirn SF36

Hello.

This is my first ever flashlight review so I will try my best :)

Flashlight was provided from Sofirn with 99% discount. My review won't be affected by price.

Specification from manufacturer:

LED: Cree XP-L2 V6-2A-D, 1100 Lumen, 5350-5700K, 11200cd
Operating voltage: 2.8-4.2V
Battery: 1x 18650 Battery
Switch: backward tail clicky
Size: 13.2cm length, 2.5 / 3.2cm diameter, 118g (without battery)
Material: 6063 Aircraft aluminum with Type III anodization
Reflector: smooth
Battery warning: Blinks every 2 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)
PWM frequency: 20kHz
Strobe: 6 / 12Hz
5 Mode: High 1100lm 1h28min; Mid 300lm 4h15min; Low 50lm 18h; Firefly 1lm 147h; Strobe 1100lm 2h56min;
Mode Memory: yes
Tail-stand: yes

Package:
Sofirn SF36, 18650 2800mAh battery, USB charger with 70cm cable, manual, belt clip, 2x o-ring, lanyard

Flashlight has nice feel and looks good quality.

Threads are square but little thin. They are anodised and came well lubricated.

Tube is not reversable.

Tail switch is reverse clicky mounted on 17mm board. It has nice click, but maybe little soft feeling (very easy to press, compared to others)

Flashlight can tailstand, but was not perfect na was wobbly. I cut 1mm from center of rubber tailcap and now perfect.

Driver is 19mm, but you could put 21mm with no problem. It's fixed with retaining ring.

Wires to LED are 24AWG

It has 4 modes with memory and strobe on double click. Modes are nicely spread.

Head has SS bezel. Glass is 27x2mm AR coated and reflector is SMO. AR coating is very light, but it's there.

There is o-ring between glass nad reflector and reflector has groove for o-ring to sit nicely.

LED is XP-L2 and is on 17x1,6mm copper 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.

Flashlight is 132mm long, diameter is 25,5mm at tail and 32,5mm at head.

Beam has some rings in it, not sure what is the reason.

Charger is Thorfire branded, with micro USB input.

It charges to 4.19V (if my multimeter is correct).

Battery is Sofirn branded, with protection. It came with protection sticker on + side.

Tested capacity with Lii-500 is 2628mAh so not that bad.

Some comparison pictures with Thorefire VG10 and Convoy S2+

Current measurements:

Cheap dmm, not sure how accurate it is so I made measurements on some other flashlights to compare.

Used ICR18650-26C battery

SF36 VG10S VG10 S2+ 6*7135
Moon 0,03A 0,01A 0,01A
Low 0,16A 0,15A 0,09A 0,18A
Med 0,98A 0,93A 0,77A 0,92A
High 3,20A 3,10A 2,51A 2,13A

XXX-Man,

Thanks for the time and effort you made in sharing this with us.

Just ordered some Sofirn AA Lights (same as Thorfire), so looking forward to more reviews and views like this.

Cheers,
Splott-Light :slight_smile:

Thank you for a great review, nice looking flashlight, I think the rings in the beam comes from the XP-L2 emitter.

Thanks for sharing :beer:

Thank you for nice words.
This is my first review so I try to do my best.

I believe this is the way review is supposed to be, just text and some personal opinion never matered to me when looking at reviews.

Hope I get time to post more like this.

Great review :+1:

I am also testing this light for a review, and I can confirm the greenish outer ring on the beam. But it is only very noticeable indoors and on clear walls. Not really disturbing when using the light outdoors.

Good teardown :beer:

Driver is primitive direct drive with PWM and without stabilisation :frowning:

Do you mean the light gets dimmer as the battery voltage goes down?

nice review!
thanks
I have to do the exact same light, but you done an excellent job, maybe I should just send mine back :slight_smile:

Added current measurements, but I’m sure they are not completely accurate.

Thank you for nice words, you just made me do another review (VG10S), will post it soon.

SF36: Non constant Current output

Great review, does the battery tube interchange between the sofirn and the thorefire?

Exactly. No constant output at all. FET, PWM 21 kHz.

Replace my sf36 then, I want constant output when voltage > 3.7 V :wink:

You SP-series have stabilisation when voltage > 3.7V, but SF-series (SF36, SF31)- NO.

No, it doesn’t.
It’s very different design on the part conecting the head, you can see in my VG10S review.

Good review.
_8502 sot23-6 on board :slight_smile:
You can safely use non-protected batteries. Protection already exists in the driver._

That’s good to know.

I got mine and checked it.
Unfortunately this does not work.
The flashlight starts flashing when the voltage drops below 2.7V
edit: power off after 2 min

Some of my photos in the album Светодиодные фонари и световые приборы. Всё о светотехнике. - Альбом MSS: Sofirn SF36

I need to double-check with my SF36 but I think the light turned off when testing with an unprotected battery.

When the LVP starts blinking you should change battery ASAP anyway.

EDIT
So I did :

at 2.78V the LVP blinking started, then after ~1min the light turned off.

But if I turn it on again, it will do another blinking cycle, then turn off after ~1min again. Etc, etc.

Maybe you got a faulty driver.

About 2.7 is turn off for mine too.
Can’t remember exact number but that’s close enough.