Review: Imalent DM21TW supplied by Banggood [picture heavy]

Review of the Imalent DM21TW light availiable in Banggood shop

the light was supplied by Banggood, no compensation other than the light itself was received for this review

The light can be bought here

The price can be lowered to US$41.81 with the code 4BLF,
for BLF members there is a non public code I can give with PN lowering the price to $34.95

This is my 2. light that was supplied for a review, I am honest and will judge the light as it is with its pros and cons


Product name: IMALENT DM21TW 2016 XPL HI Neutral White LED Flashlight
Model: DM21TW 2016
Emitter Type: XPL HI
Light Tint: Neutral White
Material: Aluminum
Total Emitters: 1
Mode: infinity brighness adjust
Max Lumens: 1000LM
Max Runtime: 80h
Battery Configurations: 1 x 18650 / 2 x CR123 Batteries (Not included)
Switch Type: Clicky
Switch Location: Tail cap
Beam Intensity: 16200cd
Impact Resistant 1.5m
Range: 268m
Waterproof: IPX-8
Weight: 89g (Without battery)
Size: 138mm(L) x 25.4mm(Body) x 27.5(Head)

for Product pictures go the the manufactors web site or a shopping site like Banggood

the parcel arrived after 11 days shipping with priority line to Germany which is a good time from China.

Package and content:

It came packed well with a 1cm bubble wrap and in a plastic bag

The light comes in a card box which looks professional

The light sits in a plastic inlay

It comes with a holster, 2 spare o-rings, USB cable and manual
due to the rotary brightness selection there is no way to attach a lanyard

The light has 2 holes on its back maybe its possible to drive a small screw in there for a lanyard

Comparism and teardown:

Size compared to other 18650 and AA lights

Beam color is on the warm side of neutral
from left to right the lights get warmer, picture taken @5000K camera setting

The Imalent LED is most likely a U6-5A2 at 4000K as it is warm er and the CRI is better than on the 3C tint ones

The tail cap got this nice rotary section to adjust brightness
it is usaable with one hand operation

The light can be taken apart, the head is not glued

But on the tail it looks like the section with the e-switch and the USB charging port is glued with transparent silicone on the middle section, so it holds the rotary ring for brightness adjust in place

the transparent silicone also covers the holes for the status indicator LEDs
Because of that I can’t remove the driver completely because the wires are too short

The head has no driver just a plate wired with the LED
It is press fit and I can’t get it out, but on the other side has to be some Diode or electronics to allow the head to charge from the USB port in the tail cap

The threads are smooth and square cut, good quality
The light can be locked out by twisting the tailcap a bit

the reflector is smooth, got some imperfections but that won’t affect the beam at all
the XPL HI LED is perfectly centered

the reflector is 22.5mm wide and 18mm deep

When opening the light i noticed the spring in tail cap is not soldered flat to the driver
it looks even worse after removing the driver retaining ring

I tried to pull out the driver, but the solder joint was poor and came apart

I guess this light was produced on Monday morning or Friday evening, by an unmotivated employee with too low soldering iron temperature
the spring has a centering pin what is really nice and first time I have seen this, very good

soldered a bolt on the driver to pull it carefully out, this is as far as I can go without ripping the cabled of the back as they are soldered and glued in the tail cap

The driver retaining ring in the tail cap has a hole with a plastic insulator for the spring

The tail cap and head threads have an oring and are lubed for water tightness

The light is build for protected button top batteries, no button or too short wont fit
Left the 18650B fits perfectly, middle a Sanyo 18650GA fits only with a magnet on its tail or top, right a Samsung 18650-30Q makes no contact to the spring or head

The thermal paste is applied in a big quanrity and is perdfectly spread and a very thin layer due to good machining

I checked the MCPCM to be a true copper DTP one, very nice

The MCPCBs back is perfectly flat I sanded it with 2500 and the whole area gets sanded

The USB charge port cover is badly designed, it won’t be waterproof here, but it is internally sealed

if you look close you see the middle part of the cover which connects to the switch cover cant seal with the body at all, as it does not go to the bottom of the tail cap

P.S. disassembled the tail cap after driver died, the switch/USB board may be get wet, but the internal of the light seems sealed from it

I disassembled the tailcap.

Here are all pasrts of it, you can see the grey silicone which seals the internal of the flashlight.

The first part to open is glued, under it there is a contact board, which can get wet.

Here you see the rotating wheel

The internals of the light are protected from water with silicone covewring all holes, I did remove it so getting the cables back is easier.

Here you can see how the rotating brightness wheel is assembled.

The back of the driver has a charging IC and an inductor and some diodes probably to generate the current for the MCU

Driver and Battery

The light has a pretty slow PWM visible in all modes
Picture taken with 1/50s 10 spots = 500Hz

The lights runs a decent time on highest level I cant see a significant drop in brightness
The max temperature seems to be at about 60 degree Celsius

The light has a parasitic drain of 0,025mA @4.05V which is lower than the battery self discharge

I could measure 2.6A tail cap current on brightest level
couldnt take a picture as I needed both hands as the driver is in the tailcap
P.S. driver died, Imalent says driver should deliver more current

on brightest level this means about 894 LED lumens from a XPL HI U6 and about 830 OTF at 25°C Tj with the DTP star I estimate the OTF lumens after 30 seconds more like 780 lumens but I can’t measure it

The USB port chages the battery with 1.07A @5.2V droppes to 0.9A at 5.0V, charge takes 3h 19m cell rests at 4.15V after charge and is missing a bit of max capacity measured 2978 in the light and added 68mAh in my Charger to 4.21V

As the battery gets past 90% discharge the brightness has dropped a lot as the LED cant get enough voltage
The light gets very dim, but it lets adjust its brightness at any state of discharge

Unfortionall the light has no Low Volatge Protection, as the light is designed to work with only protected cells its not too bad
It may be the problem, that the driver in the tailcap has simply no access to the battery voltage, but they could easily realize a LVP over the LED current
I stopped the discharge test at 2.5V battery level with 2.28V measuring on the LED
With a old test cell I let the light unattended for 12 hours the light was compleetly dark and the battery dead at 1.47V, it is very likely that the bleeder resistor drain to the tailcap driver would discharge the cell even further over time

A test with a protected battery will be running tomorrow and I will get some trash Ultrafire battery to see how far the light discharges an unprotected cell

There is no intelligent ramping down to preserve longer runtimes with almost depleeted battery this is consistent with the missing LVP


I did solder the spring in right angle and added a spring bypass

Cleaned the old thermal paste

Cut the wires a bit shorter

added a bit of lubricant to the centering ring as the LED MCPCB has no screws or other secure to rotate when twisting the head to prevent the MCPCB from getting grip and rotate, which may lead to a short cutting in the wires

removed old ceramic thermal paste and added arctic silver 5

Also did the LED wires cut a bit in length and soldered them so that they prevent the MCPCP from rotating

Beam shots

left side Nitecore P12 @1050 lumens modded with DTP star and XML U3-3D NW LED running at 3A
the Imalent DM21T with about 800 lumens running at 2.6A on the right side

Both lights are neutral white, even if the Nitecore P12 looks here cool white

Nitecore left and Imalent right, the Imalent DM21T is more neutral-warm white, not sure which color bin they use most likely U6-5A2

you can see the domeless emitter throws better with a smaller hotspot, both lights have about the same reflector size but the Imalent reflector is deeper

Klarus XT12GT XHP35 E4-3C 1.38A @1900 lumens next to Imalent DM21T

The manual says it can drive with 2 CR123A, but i am pretty sure it has no buck converter so operating with 2 16350 will most likely kill the driver

User Interface

The light has an e-switch and a rotary wheel in the tail cap to control the light
Short tap switches the light on and off

if the light is on or off hold the switch for a medium press will go directly to strobe

Plug in the USB cable to charge, the LED will blink red and turn solid green when full



- very good production quality

- solid body with Military Grade Specification hard anodized HA Type III

- infinite brightness control with the rotary wheel

- Strobe ready from OFF and ON with >0.3s press

- LED has a nice neutral-warm white tint CRI seems to be >80 without any hints of bad tint, it’s warmer than XPL 3C tint

- relative deep reflector with domeless LED gives a really good throw out of this size

- scratch proof hardened AR coated glass lens

- optional hard plastic holster with battery compartment

- good beam profile

  • USB chargeable


- the NW LED seems to be not highest flux bin for a XPL but its CRI seems >80

- minor spots on the reflector coating, but does not affect beam quality at all

- no moonlight mode lowest brightness about 30 lumens

- due to the rotary brightness design no lanyard attachable

- my light had the spring not soldered good to the driver, I guess it was just a tired employee not a design problem

  • can only accept button top batteries, raised top or flat top unprotected won’t fit without magnets or spacers, but its not recommend to use unprotected ones as the light has no LVP
    claims IP X8 waterproof, but the design of the USB port cover is really weak and won’t be even close to be waterproof
    P.S. the tailcap board with USB and switch is not waterproof, but internally to the driver it is sealed


- does not have a low voltage protection, I guess due to driver in Tailcap not easy acces to Battery voltage, the light discharged a test cell to 1.47V within 12 hours

- relative slow PWM with 500Hz

  • quality control issues, light died running over night
    advertized 1000 lumens can’t be met with XPL U6 @2.6A current on my light
    My driver died Imalent says the light should run with more current

after 12 hours test with a crapfire cell I measured 1.47V battery voltage so this light needs definately a protected cell if run unattended
you have to switch batteries when the light gets down to about 10 lumens to be safe with unprotected cells

still the light got an awesome tint if you can live with 500Hz PWM and about 800 lumens

Thanks Lexel! Excellent review!

I just received this light and will add my observations…

I ordered it from Banggood and the shipping was surprisingly fast - received 10 days after ordering with Banggood’s regular shipping. I got the white DM21T (non neutral) version. The tint is as expected - cool white but not too blue.

I didn’t try to take mine apart so I can’t comment on the internal assembly quality. I agree 100% with Lexel that there is no way this thing is waterproof. The USB cover on mine just flops down over the port and there is nothing to keep the rubber cover pressed against the port. Usually there is some type of friction fit that will hold the cover in place - but not on the DM21T.

The biggest negative that I observed is the sloppy operation of the control wheel. It isn’t a “premium” feel. There is some slop in the fit and the control wheel has some wobble. The amount of play is fairly small, but enough to make it feel cheap. If I shake the light, I can hear the wheel rattle. There is also a bit of grittiness felt when turning the wheel - which I would guess is anodized aluminum rubbing against anodized aluminum. Would have been nice if they put some type of bearing (nylon, Lexan, etc) in there to give it a smoother feel and less play.
The low level is inconsistent. If I turn mine fully counterclockwise and wiggle it a bit, the light will go to different lowest dim levels. They specify the dimmest is 30 lumens, but with some wiggling I can definitely get mine to go lower than that. I don’t have a way to measure it, but comparing it to my other lights, I would guess it goes dimmer than 10 lumens. It would be a plus if it consistently went down to this low level, but it doesn’t (without some wiggling). The high end seems pretty consistent.
The wheel does not control the brightness in a “visually” linear way. The wheel has about 120 degrees of rotation. The full brightness range is almost reached within the first 40 degrees (1/3) of rotation, leaving very little perceived brightness change over the remaining 2/3 of the wheel travel. Ideally, this would have been the other way around.
The last thing I noticed about the control ring is there is sometimes a lag in the response. On several occasions, when I turned the brightness down (turning wheel counter-clockwise), it would take several seconds for the light to respond - but it did eventually ramp down. I also see a little bit of lag on increasing brightness (turning wheel clockwise), but not the multi second I saw when decreasing.

Also beware that the charging circuit has an undesirable behavior. Just for kicks, I unscrewed the head when it was charging to see what happens. The charging LED indicator turns green! So if the head or tail happens to come loose when you are charging, then the light will indicate it is fully charged - leaving you with a dead battery when you might need it. The charging indicator will also turn green upon plugging in a charger if either the head or tail isn’t connected.

I’m not sure if I got a lemon, but I would be hesitant to recommend this light unless you really wanted a light with a brightness control ring. That is basically why I bought it and I have to say I’m somewhat disappointed.

Very interesting torch!

There is a non public code for BLF members for this light lowering the price to $34.95

contact me for it.

I did disassemble the tail cap
The contact board seems to be non waterproof but the inner driver is sealed waterproof

My driver died and Imalent says the driver should deliver more than 2.6A

The NW LED Imalent claims to be a V2, its definately warmer than 3C tint

Nice review Lexel. Appreciate the heads up on this.

Heads up! Oh no wait… head’s falling apart… :frowning:

Lol, exactly… Lexel did a very nice job pointing out the features

IPahleaaaaseX-8 waterproof as well.

So I add some pictures here and in OP

I disassembled the tailcap.

Here are all pasrts of it, you can see the grey silicone which seals the internal of the flashlight.

The first part to open is glued, under it there is a contact board, which can get wet.

Here you see the rotating wheel

The internals of the light are protected from water with silicone covewring all holes, I did remove it so getting the cables back is easier.

Here you can see how the rotating brightness wheel is assembled.

The back of the driver has a charging IC and an inductor and some diodes probably to generate the current for the MCU

I got here now a idea from Easy B, who wants to build a S2+ with rotary tailcap
So I came up with the idea that it may be possible that the Imalent tailcap of my dead driver fits the S2+
and it fits

even better the S2+ tail cap fits the Imalent light as well

Now as I got the news I get a full replacement light as Imalent cant provide the tailcap, which contains the driver, as spare part
I need to get me a S2+ tail cap

I opened up the press fit contact board of my Imalent DM21TW
as i expected there is a diode for the charging from the tailcap driver
and bleeder resistor on that contact board

So with a S2+ tail cap I could get this light back to life getting a Bistro TA driver

from this thread

I may help you with your rotary S2 triple
I got here a defective Imalent light
The tailcap fits the S2+ body, just the tube needs to be shortened 2mm so the tail cap gets over the oring
When the replacement light arrives here I can send you that tail cap

Thanks for you review. I almost wanted to get one just one. XD

The light is on flash sale with 27.99$ now

I did DM21 review back in 2015. Initially, I was a bit curious if there were any improvements for DM21TW. Seems like half-baked design, think i will skip this model. Haha.