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 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
Specification:
Product name: IMALENT DM21TW 2016 XPL HI Neutral White LED Flashlight
Brand: IMALENT
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
P.S.
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
Modding:
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
vs.
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
Conclusion
Positive:
- 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
Neutral:
- 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
Negative:
- 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