[Review] Thorfire BLF Q8 4x18650 flashlight

I bought 2 of those from Banggood

The group buy price was 40$, likely a coupon will come out when 2. batch is shipped

I am honest and will judge the light as it is with its pros and cons


Manufactory specification:
Product name: BLF Q8 4X XP-L 5000LM Professional Super Bright LED Flashlight
Brand: BLF
Model: Q8
Emitter Type: XP-L HD V6 3D
Light temperature: 4750K-5000K
Light color: Neutral White
Mode: Smooth ramping or mode set operation
Material: Aerospace grade aluminum alloy construction
Total Emitters: 4x
Battery Configurations: 4 x 18650 or unprotected button top (not included)
Working Voltage: 3-4.2v
Switch Type: Electronic switch
Switch Location: Body side of the flashlight
Peak Beam Intensity: 50,000+ cd
Impact Resistant 1.2meters
Max Output: 5000+ lumens
Range: 450+ meters (max)
Lens: High transmittance glass
Reflector: Aluminum alloy mirror reflective cup
Waterproof: IPX-8 waterproof
Color: Black
Weight: 400g without battery
Size: 132mm x 59mm x 50mm(length x head x body diameter)

• Compact and lightweight 5000 Lumens flashlight
• Utilizes four XP-L LEDs
• Uses four 18650 batteries for maximum runtime up to 1500hours
• Features advanced temperature regulation (ATR) technology
• Integrated power indicator in side switch indicates remaining battery power
• Flashlight can blink out voltage with 0.1V accuracy
• Intelligent memory function for brightness levels
• Direct access to ultralow and turbo outputs
• High transmittance glass
• Stainless steel bezel ring protects core components from damage
• Constructed from aerospace grade aluminum alloy
• HAIII military grade hard-anodized
• Waterproof in accordance with IPX-8
• Tail stand capability

Package included:
1 x BLF Q8 4X XP-L 5000LM Professional Super Bright LED Flashlight
2 x Flashlight Body Tube O-ring
1 x Flashlight Head Lens O-ring
1 x Switch cover
1 x English Manual
The parcel arrived after 14 days shipping with to Germany which is fast from China.


Package and content:

The light boxes came packed OK with a wrap around the card box and in a plastic bag

The light comes in a package typical for Thorfire

In the box the light is packed in some bubble wrap


It comes with:

- 2 spare o-rings,

- switch cover,

  • cheat sheet and manual

The cheat sheet can be folded and stored in the end of the tube

Photos of the light

it fits pockets but you feel the light you carry


Comparism and teardown:

Size compared to other 3x or 4x18650 lights the Q8 compared to my other lights it is quite small, as it has no battery carrier or deep reflector

Beam color is neutral around 5000K with 4 Cree XPL HD V6-3D, the beam has a nice balance between throw and spill

The LEDs are very good reflowed and the DTP MCPCB is perfectly flat, but not polished or gold plated
The heat paste is applied in a good amount and squeezed in an uniform thin layer

The reflector has some tiny imperfections and is free of dust that can be seen while the light off

Light color is a nice neutral white, at high currents the hotspot has no tint shift I can notice, on very low level the LEDs tint shift towards green/yellow

from left to right the lights get warmer, picture taken @5000K camera setting
left Nitecore P12 XML2 U3-3D 5000K, Thorfire BLF Q8, Astrolux MF01 Nichia 5000K, Klarus XT12GT XHP35 E2-3C 5000K, Nitefox UT20 XML2 1A 6500K

The light can be opened no threads are glued, but it seems the screws have some sort of locktite on them
Some of the screw heads are damaged

The light has a solid tail cap, but no hole for a Lanyard
The light stands on the tail perfectly rock solid

The lens is really big but not AR coated

The head has a diameter of 58.2mm and 44mmm visible reflector, while each LEDs reflector has a diameter of 21mm

The light can be run by one, 2, 3 or 4 18650 batteries in parallel

The driver is easy to access just 2 screws are holding it, the brass ring is a bit dirty and not centered

Unfortunately the screw holes of the driver were not drilled for 3mm, partially the screw head was messed and all the screw threads contain some dirt or glue

The driver has one FET +1*AMC7135 and is running NarsilM on a Attiny85

The light can be physically locked out by twisting the tube 1/4 turn from the head
Also electronic lockout by 4 fast clicks possible


The Head

The big reflector contains for each LED a small reflector
The LEDs from one of my 2 lights were not centered, the reflector was twisted a bit, but nothing serious and easy fixable

The switch is from transparent silicone
The switch cover can be screwed out easily counter clockwise

The slave board for the switch has two green LEDs and a single resistor

The LEDs are often uneven bright, better for each LED a single resistor like I did on the left one

The shelf is 5mm thick and the really big 2mm thick copper MCPCB does a good job spreading the heat

The MCPCB is s true copper DTP, the back of it is bare copper

The MCPCBs back is perfectly flat

However the lubricant is very dirty from black anodisation worn off when the light was assembled

The lens is not coated glass, no fingerprints or dust on it when it came out of the box

Tube and Tail

The tail cap is fully anodized and solid, but has no hole for a Lanyard

The light is waterproof, the tail cap and head threads are lubed with a medium amount of lubricant

the tube is build for 4 batteries, protected and unprotected fit well

The tube threads are square cut and fit nicely


Driver and Battery

The light uses a DD+AMC driver with Attiny85

The light has in ramping and mode sets on most modes PWM, Turbo and 350mA are PWM free

The light has a some mass to absorb and surface to spread heat
some members did already infrared videos, the light runs about 3 minutes on Turbo before the temperature step-down kicks in, depending on which temperatur it is calibrated

The light is build for protected and unprotected batteries, the positive contact ring is from solid brass, but there is some dirt on it that can be cleaned with acetone or steel wool

the light uses double springs from steel, that can be bridged

The mode spacing is good and a lot of modegroups availiable,
the moonlight has less than 1 lumen, in ramping the light can be set to over 100 brightness levels

The side switch status LED can be used with triple click to show the battery level


current Measurements

User Interface

The light uses NarsilM with a very complex UI and settings


First thing was to bypass the springs on the tail cap

Loosening the reflector screw and bezel to center the LEDs to the reflector
Cut all the threads again to get the stuff out of them

Switch PCB added resistor for both LEDs and choose white LEDs
Unsoldered LEDs and switch just holding my temp stabilized iron at 300°C at the other side
also skillet might work well

then cut the trace to one LED and add a resistor

add solder paste

add resistor and wire

2 white LEDs with 19.1kOhms each


Beam shots

Control shot


Klarus G35 with XPL HI

Astrolux MF01

about 2m from Light to ceiling


Klarus G35

Klarus XT12GT

Nitecore P12 XML U3-3D NW


The light is mechanical build very well, just a little issues, most of them are easily fixable
Feedback from first batch hopefully leads to the minor issues fixed with further batches
The light has great potential to be modded.


- mechanical very good production and engineering

- very solid head, DTP MCPCB screwed on the 5mm shelf

- one of the best firmware NarsilM, ramping or modes highly customizable

- good hotspot and throw, still nice amount of spill

- beam in high modes is a very pure white

- proper LVP and low battery warnings

- low resistance wiring in the head

- easy to mod this light everything is accessible within a minute

  • minor production issues are known and the Miller is working to fix em on future batches


- uncoated lens, who likes can upgrade it

- uneven switch LED brightness

- screw heads partially damaged

  • driver holes not wide enough


  • some dirt or glue that can reduce the max output on Turbo on the brass ring and on the tail board mounting area
    this can be fixed cleaning the brass ring and tube

Very nice review Lexel, can you confirm that the driver screws are M3 size?


Thanks Lexel for the review.
@ Smittymojo. Yes the driver is held in with 3mm taper head screws. Some are replacing with 3mm button head screws for even force on the driver in this area.
Edit. There is a mod thread on this light here.

Wow you are fast!
Thanks for the review.
Cool to see the cheat sheet in action!

Nice review Lexel

seemed a bit dirty in there, just curious to know what products you used (eg alchohol) before relubing ?

steel whool needs no additional chemical liquids, its like fine sandpaper, but also can be pushed against uneven surfaced or corners
some said acetone worked wonders on the brass ring

Thanks mate

Nice review Lexel!! Weird bout the rings though. I didn't see anything that bad in 9 Q8's I received. I did though run some 2000 GRIT sandpaper over the ring, and clean with isop. alcohol on the one I fully modded so far - never know what coating or oil/grease, etc. might be left on there. Just can't trust them.

Dunno if any you guys remember, but there was a time that the ThruNite TN31 was the hot light to mod - nice big copper MCPCB. Think AlexGT wrote up a nice mod thread - resistor bypasses, dedomed XM-L2 U2 and can hit 600 kcd. Well it turned out ThruNite shipped least a full batch of them where they left the protective mylar or kapton tape stuck on the back of the copper MCPCB. The better copper MCPCB's are shipped like that, specially when it's uncoated copper to prevent oxidation. So they shipped them all nice with thermal grease, beautiful big thick copper MCPCB, but left the tape on. I was modding them for guys, and sure enough i came across a couple like that.It had to be like a wall for thermal transfer and I'm sure most buyers never noticed a thing.

Man kann deine Anschrift auf dem Paket 2x lesen.

Thank you for the review, very useful and gives me confidence to purchase the light in the future. Seems like one of the best products Thorfire and BLF have created. (not naming anyone because there were so many who worked extremely hard to get this finalized. Big thanks to everyone involved!)

I use a fiberglass cleaning pencil for this kind of cleaning with very good and fast results.

Nice review tks would be nice if anyone can compare beamshot with Noctigon Meteor M43. Looks almost the same am guesing :wink:

Great detailed review, Lexel. Very descriptive with good photos, and plenty of them! :+1: Are you gonna bake your Q8? :smiley:

I know myflashguy has seen these by now, but I’ll post them here in case others haven’t.

This is the Q8 compared to the Noctigon Meteor M43 with 219C emitters:

See details and more beamshots with other flooders in my post in the main Q8 thread.

I can’t wait for my Q8 to show up, I hand-me-downed my klarus g20 to my girlfriend so we can both have high lumen dog walking lights.

I re-ordered one today after I canceled my original 1st batch order because of all the issues like stripped screws and the switch LED’s messing up, etc. This is based on a friend of mine who got his from the second batch recently telling me his is perfect in every way. I also read others having the same experience. I’m really looking forward to it.

Nice Glenn! I got in my 1st of the 2nd batch and I agree, and posted bout it - wayyy better.

Here's my post with details on the batch 2 changes: https://budgetlightforum.com/t/-/39069/15384

The bottom line is with all the tweaks and much better quality of assembly, the improved #'s from the light box don't lie.

Strange if you did not get yours shipped from first 500, you should have automatically got one of the 2. batch, no need to cancel order

I had no idea I was going to get one from the second batch. I didn’t want to take any chances I’d get one from the flawed first batch. I’m sure you understand.

Thanks Tom, I’ll check that thread out now :slight_smile:

The first batches lights were all taken within less than 2 days, whoever ordered after that will get for sure one from 2. batch