[Review] Nitefox UT20 single 18650 flashlight

The light was supplied by Nitefox and can be bought on Amazon, no compensation other than the light itself was received for this review

They have a website http://www.nite-fox.com/ which is loading a bit slowly

Manufactory specification:

LED: CREE XM-L2 with 50 000 hours life span
Battery: one 18650 Li-Ion battery
Reflector: aluminum alloy smooth reflector
Lens: Anti-reflection coating tempered optical lens
Body: Aerospace grade aluminum alloy with durable Type Ⅲ hard anodize coating
Mode: Outdoor mode 4 output levels(moon-low-medium-high-strobe), tactical mode 2 output levels(High-Strobe-low)
Circuit: High efficient constant current circuit, constant output, more brightness and longer run time
Reverser polarity protection to prevent damage from improper battery installation
Waterproof: IPX8 waterproof, works in rain or shallow water
Included accessory: 1* Tactical Flashlight, 1* USB Charging Cable, 1* Charging Port Cover, 1* Tactical Ring, 1* Clip, 1* Lanyard, 2* O Ring, 1* Switch Cover
Size: 139 mm (length) *25mm (body diameter)
Net weight: 93 gram, light weight and easy carry

NITEFOX UT20 is a max output 1080 LM USB rechargeable flashlight which have tactical and outdoor two modes. Outdoor mode can access by side switch and have 5 output levels while fast change to tactical mode of strobe, turbo and low output by one hand click tail switch. It is easy, flexible to provide different illumination for law enforcement like soldiers, policemen and outdoor enthusiasts. Besides this, UT20 also comes with build in smart remaining power indicator and pocket clip, lanyard for convenient use and carry. UT20 is a compact but powerful all round lighting tool for outdoor activities and law enforcement in most environments.


Package and content:

The lights box came in a bubble wrap envelope

The light comes in a package of thick card box
In the box is a foam inlay with the light and accessories

It comes with:

- 2600mA protected battery

- 2 spare o-rings

- lanyard

- pocket clip

- USB cable

- tactical ring

- tail switch cover

- spare charge port cover

  • manual and extra special note


Photos of the light

The anodisation of this light is shiny and smooth it has no visible defects
The knurling is not too agressive.

Comparism and teardown:

Size compared to other 18650 lights the UT20 looks quite similar sized like other tail and side switch lights
Nitefox UT20, Nitecore P12, Imalent DM21TW, Klarus XT11GT

Beam color is cool around 6500K with a Cree XM-L2 , the beam has no artifacts and a good hotspot and some spill

The LED is very good reflowed and the 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 MCPCB is tested to be DTP

The reflector is well machined and is perfectly coated with no flakes
It is almost free of dust particles that can be seen when the light is off, just one tiny dust particle that I could remove with compressed air

from left to right the lights get warmer, picture taken @5000K camera setting
left Imalent DM21tW XPL-HI 4500K, Jetbeam Jet1-MK Nichia 5000K, Klarus XT11GT XPL HI V3-3C 5000K, Nitecore P12 XML2 U3-3D 5000K, Nitefox UT20

LEDs luminance under 365nm UV light
left Nitefox 6500K, XPL W2-2B 5700K, Nichia 219C 5000K, XPL HI V3-3C, XML U3-3C, XPL HI 4300K

The light is partially glued with white epoxy and the Bezel came loose with no tools, but to get the driver out a little more force was necessary sticking a rod through the LED wire hole and pocking on it

The light has a tail cap with holes for a lanyard

The light stands on the tail, but the surface is small so it is not very stable

The lens is well AR coated and is perfectly clear, you may think they missed the lens

The light runs with one 18650 battery

The driver is the hardest thing to get to, it is glued at the bottom

The driver has a charge circuit and a buck driver on separate boards


The Head

The light has a typical 1 inch head diameter and 18mm visible reflector, so the throw with a domed XML2 is not very high

The reflector is screwed in the head

The driver board has a switch has a green and red LED

The shelf is 1.8mm thick and the 16mm big 1.8mm thick DTP copper MCPCB does a good job spreading the heat


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

The LED is perfectly centered, but it has a big dirt particle on it most likely from burned flux on it

The light is waterproof, the tail cap, head and bezel threads are lubed with a good amount of lubricant and have o-rings
Only thing is they could have added some lubricant to the bezel o-ring

The lens is hardened AR coated glass

The USB cover sits pretty tight and seals the light, it can’t come loose by accident

The switch is kind of annoying you press it over 1mm and nothing happens, press it further then it clicks, it’s a bit strange the retaining ring can be screwed in deeper then the switch feeling gets better, but still the button does not sit centered on the switch so the switch tilts


Tube and Tail

The tail cap is anodized and the inner section is machined, the tail PBC contains a switch and stiff thick steel spring

The retaining ring is smaller that the tube, so it can’t get loose when you screw the tail cap often loose and tight, to prevent from accidently shorts with the spring there is a o-ring around it

Both ends have a spring made from steel and gold plated
the light uses a short soft spring on the driver and a long stiff in the tail cap

the tube is build for 1 18650 battery protected or unprotected
with unprotected flat tops the spring force is good, no rattling

The tube threads are square cut and fit nicely

When reassembling the light it sheared the LED wires off


Driver and Battery

MCU switch and green+red LEDs

The inductor of the buck converter

The light has a some mass to absorb and spread heat, it gets 46°C hot when turned on at highest mode, it has unfortionately a timed stepdown, which ramps the brightness down to medium mode
with DTP star this light could run constantly on highest level without a problem

The mode spacing is good, the moonlight has about 0.25 lumen


Battery current and lux measurement

measured 480 Lux @5m

12000 Lux @1m

Moonlight 10mA 25 Lux

10mA is with the green side switch LED on, if its turned off it goes down to 7mA, still that is not a very accurate measurement with a clamp meter

low 163mA 10,600 Lux

mid 0.8A 34,400 Lux

high 3.25A 109,400 Lux

LED current:

Moon 1mA
Low 200mA
Med 0.98A
High 3.25A

The side switch status LED shows the battery level greater than 20%
red when 10-20%
flash red below10%

The battery has a PCB on the positive end, so no conductor needed to go at the side of the battery

the positive button top is gold plated

the PCBs LVP trips at 2.65V

The supplied battery has 2626mAh with 1.5A discharge to 3V and shows 117mOhms


First thing was to bypass the springs on the driver and tail cap

After the LED wires sheared off assembling the light again I cut a thread and used a screw to stop the MCPCB from rotating

Beam shots

about 2m from Light to ceiling

Nitefox UT20

Nitecore P12 XML U3-3D NW

Imalent DM21TW

Klarus XT11GT

User Interface

The light has 2 different settings, hold side switch 3 seconds to switch between them

1. is tactical, you operate the light only with the tail switch

the light came with this setting active and I thought it has some error, but when read the special note I changed the light to normal operation
the light always come on in high mode, half press the switch changes modes
High —> strobe —> low

2. is outdoor mode

Tail switch turns the light on
it has 4 modes with hidden strobe
Moon —> low —> med —> High
Strobe is activated press and hold 2 seconds, but it starts to strobe in the lower modes with low strobe, only after you release the button the strobe turns to max brightness, if you hold 1 sec longer it changes between the 2 major settings


The light is build well, and the supplied battery is a good one.


- mechanical very good production and engineering

- solid head, DTP MCPCB on 1.8mm shelf

- AR coated glass lens

- good hotspot and beam profile

- proper LVP and low battery warnings

  • supplied battery is good


- the side button has an odd feeling, gets better when the retaining ring screwed in more

  • QC should see such a large dark spot on the LED dome, that can be cleaned before assembly


- the throw rating in the manual is way off it is more than double what I have measured

  • steps down after a minute

This light has Thrunite DNA.

25% discount code

Awesome review Lexel! I also have one on the way to make a review, but yours is pretty complete! Thanks for it :wink:
1 question for you (while I wait for mine): does the side switch has lockout mode? If not, is it easy to get it ON inside a pocket?
Thanks in advance!!

The lights need to be shut down always with tailswitch

Oops, sorry, I guess I missed that :FACEPALM: Thanks for the answer :THUMBS-UP:

Lexel, I have 2 questions in which you may help, because of this light.

1 - You mentioned that the High mode “steps down after a minute”. While I was making my review I tried to see that on my flashlight, but I couldn’t see it! Is it a significant step down? I was using a freshly charged Sony VTC6, counted +1 minute after getting High ON, but couldn’t perceive that change…

2 - I would like to mod the Nitefox LED. I was thinking about getting a XHP 35 HI, as it produces (potentially) an output bigger than XPL-HI. Do you think the driver of this flashlight would be able to “extract” that output from the XHP 35 HI? (https://www.aliexpress.com/item/2016-Newset-High-Power-CREE-XHP35-HI-White-6500K-Neutral-White-5000K-Warm-White-3000K-LED/32756531809.html?spm=a2g0s.13010208.99999999.262.2lNGEc)

Thanks in advance!! :THUMBS-UP:


The light ramps down, no hard stepdown
Also the temperature tops at 46°C then falls slowly to 39°C

XHP35 is a 12V LED and XPL, XML 3V LEDs you need a boost driver to run XHPs

Perfect review with great detail! Exactly what I want to know about a light :slight_smile: Thanks.

Thank you very much for both explanations Lexel :wink: :THUMBS-UP:

So how do I replace the USB cover? It looks like either the old anchor will be left inside and I force the new one in or I will have to disassemble the light, possibly shearing off the wires. Thank you for some insight if there's another way to do it.