REVIEW: Nightwatch NI40 Stalker [26650, dedomed 3V XHP50.2, beefy C8], with SST70 mod

This is my review of the Nightwatch NI40 Stalker with a dedomed 3V XHP50.2 led. I purchased this flashlight at the Nightwatch Taobao Store with Taobao agent Superbuy. I wanted to share my thoughts on this flashlight as it is special in many ways.


The Nightwatch NI40 caught my interest because it has a dedomed 3V XHP50.2. There are no other flashlights offering a factory dedomed led as the process is difficult, has to be done manually and can easily go wrong. For more throw but less lumens you can order the Nightwatch NI40 with a dedomed SST40. The Osram S2WP is a quad die led (four 2mm² white flat dies) which gives the same lumen as the XHP50.2 but more throw. Available are also the SST40 and XHP50.2 untouched with dome. The two dedomed variants are almost neutral white while all others are cold white. If this are not the right choices for you, just order the flashlight as a host and put in your favourite led.

Purchase links (non-affiliate)

Nealsgadgets: NIGHTWATCH NI40 Stalker 3800lm 26650 Thrower LED Flashlight – Nealsgadgets


My recommendation is to purchase the NI40 at Nealsgadgets as the Taobao system is a bit difficult and the NI40 is sold out there already. The Nightwatch NI40 is a special flashlight and as such not available to purchase on Banggood or Aliexpress.

Edit: Banggood:

First impressions

As far as I can judge Nightwatch has done a good job with dedoming. BLF’s modders would call this led ‘sliced and diced’ as the dome of the led has been cut off with a razor blade and the excessive phosphor around the led die has been removed, reducing the yellow corona and giving a clean beam. It is important to have skilful people doing this because cutting the dome too low or not cleanly will burn the led and removing too much phosphor at the edges will lead to blue in the beam.

The flashlight itself is special as well. It is like a beefed up C8 with 26650 battery, bigger reflector and deep cooling fins. The anodization is matte black, the threads are square cut and greased. Don’t point the flashlight anywhere near you when you turn it on because it will literally FLASH you. Turbo is always the first mode and there is no mode memory so be prepared that with a full battery it will feel like a L6 on full blast. Despite being relatively big it the XHP50 heats the flashlight up fast. It is nice that they include a spare 50mm coated glass lens as this size might be difficult to get in case it breaks.

What is included

- Nightwatch NI40 Stalker

- thin lanyard and thick lanyard

- two spare o-rings for tube, one spare o-ring for lens

  • spare AR-coated lens


These are the specs, mostly copied from Nealsgadgets. Refer to the purchase link above for the table with the comparison of the lumen and throw of the different versions

- LED: CREE XHP50.2 Dedomed 3800lm, Luminus SST40 CW 2400lm, Luminus SST40 NW Dedomed 2000lm

- Max output: 3800lm

- Color temperature: 5000 – 5500K

- Battery: 26650

- Stainless steel bezel, AR-coated glass lens, black Type III hard-coat anodizing

- Switch: 20mm,10A reverse switch

- Waterproofness: IP68, underwater 2 meters

- Weight: 254g without battery

- Dimensions: 53 mm head x 153mm length

- Reverse polarity protection, temperature control (50°C step down), low voltage protection

  • Modes: Turbo – High – Med – Low, triple click for strobe


Length: 153,7mm
Head diameter: 53,0mm
Head height: 70,3mm
Battery tube length: 70,9mm
Battery tube ID: 27,1mm
Battery tube OD: 32,0mm
Diameter at threads: 30,8mm
Tailcap diameter: 35,8mm
Tailcap height: 32,0mm
Reflector diameter: 47,8mm
Reflector height: 36,0mm
Reflector inner diameter: 44,9mm
Glass lens diameter: 49,7mm
Glass lens thickness: 2,0mm
Driver retaining ring: 22,6mm
Depth driver cavity: 12,0mm
Switch PCB: 19,9mm
Switch retaining ring: 21,8mm
Spring wire diameter tail: 1,50mm
Spring wire diameter head: 1,20mm

User interface

The flashlight has an easy and straightforward user interface. There are four modes and with a triple click you can have strobe as well. The Nightwatch NI40 has no mode memory and will always turn on on Turbo. From Turbo you can cycle with a half press on the reverse clicky switch through High, Medium and Low. There is no true moonlight as the low mode is still rather bright and medium still heats up the flashlight. So the modes are all on the higher side while the lower end of the brightness scale is not covered well.


Front view

Rear view

Different side perspectives

The three parts of the flashlight: head, battery tube and tailcap

The back of the driver with a thick 1.2mm spring and 8 AMC7135 (crappy sailboats, not the raptor claws)

Another fat spring in the tailcap

Here is a close look at the square cut, anodized threads with quite a bit of grease

Led and reflector seen from the front

The cooling fins are not like the ordinary ones. There are many deep fins, a part of them has a knurling on them and they have an anti-rolling function as well.

There are also holes in the cooling fins to further increase the surface and air circulation.

Curious thing here: When I removed the bezel, the o-ring was like melted onto the glass. You can see the white residue of the o-ring on the glass where I peeled it of. Not sure if the high output and heat of the XHP50.2 can cause this?!

I’m reluctant to tell you that there will be no moonlight shoots of the led this time. The low mode is still to bright to look at the led directly as I like to do with a true moonlight or a very low mode.

Comparison pictures

Flashlights with the C8 form factor (from left to right): Nightwatch NI40 Stalker, Manta Ray C8.2, Sofirn C8F, Convoy C8+

All four C8 sized flashlights from the front: NI40 Stalker with dedomed XHP50.2, MantaRay C8.2 (equivalent to Nightwatch NI01L) with XHP70.2, Convoy C8+ with XPL HD, Sofirn C8F with XPL2

A few different 26650 flashlights (from left to right): Nightwatch NI40 Stalker, MantaRay C8.2, Haikelite SC04, CPF Italia Cometa 2016 (Jaxman Z1 clone), Haikelite SC26, Emisar D4S, 26650 battery

Famous flashlights (from left to right): Nightwatch NI40 Stalker, Fireflies E07, Emisar D4S, Emisar D4

Soda can flashlights (from left to right): Nightwatch NI40 Stalker, BLF Q8, Haikelite Q30

Side to side comparison of the Convoy C8+ with the NI40 Stalker

I would like to show you a little side by side comparison of the NI40 Stalker and the Convoy C8. The NI40 has similar proportions but it seems like an enlarged and beefed up version of the C8. Personally, I was astonished by how small the C8+ looked when I held it next to the NI40 Stalker. So, these are the two flashlights and their different parts compared.

Nightwatch NI40 left, Convoy C8+ with SS bezel right

The reflectors

The battery tubes

Flashlight heads

Heads and reflectors from above and frontally

The tailcaps

Bezel, glass and o-ring

Comparison with the MantaRay C8.2 (equivalent to Nightwatch IRA NI01L)

I chose to compare the Nightwatch NI40 also to the MantaRay C8.2 which apart from the name seems to be identical to the Nightwatch NI01L. There are a few versions of this flashlight around with different names. You can see that the design of the NI40 derived from the NI01L. They both have deep cooling fins, 26650 battery tube, big tailcap, SS bezel and the cuts in the fins of the C8.2 were converted to holes on the NI40. The NI40 is aesthetically nicer, though. The SS bezel is crenelated, the cooling fins serve as anti-rolling, the knurling on the battery tube is made better and the head is slightly bigger. The reflector is better for throw and the direct driven XHP50 has the same output as the XHP70 with a boost driver while being smaller and thus able to throw further.


Whitewall beam comparison (from left to right): Nightwatch NI40, Convoy C8+ with XPL V6 5000K, Convoy L6 with XHP70.2 4000K All flashlights on turbo, about 30cm from the wall, the white balance is set to 5000K.

Whitewall beam comparison: Nightwatch NI40, Emisar D4S 219C, Emisar D4 XPG2

Whitewall beam comparison: Nightwatch NI40, Sofirn SP31 V2.0 with XPL HI 5300K, Convoy S2+ with Luxeon V 4000K

Tint comparison on a white wall: left Nightwatch NI40 with dd XHP50.2 5200K, middle Fireflies E07 with 6500K SST20, right Astrolux S43S with Nichia 219C 5000K; The S43S has some very rosy 219C leds which makes it almost pink next to the other two. The NI40 has a hint of yellow and green but warmer color than the SST20 6500K.

Outdoor beamshot of the Nightwatch NI40 Stalker on Turbo (3.2s, F7.1, ISO400) The big tree in the background is about 150m away.

Comparison of the Nightwatch NI40 (first pic) with the Convoy L6 4000K XHP70.2 resistor mod (second) and the Emisar D4S 219C (third)

Teardown and internals

Here is a quick teardown with some pictures of the internals. I suggest you not to try a teardown unless you know what you are doing and want to mod something. For detailed measurements see ‚Dimensions‘.

The PCB and led with bezel and reflector removed

The 25mm copper MCPCB

A close look at the dedomed XHP50.2

Big Omten 250V 1.5A switch on the 20mm switch PCB

All parts of the tailcap with 16mm button

The driver with FET, eight AMC7135 and a strange MCU


On overall it can be said that the Nightwatch NI40 is a high-end flashlight with a budget price. You get almost the same output as bigger and more expensive flashlight in a more pocketable format. Of course, with the XHP50 drawing 18 A from a single 26650 on Turbo the runtime and sustainable output are limited. The handling of the NI40 is good with the smooth square cut and well lubed threads with optional lockout, a sturdy matte black anodising and an ergonomic format. The throw from the big reflector is amazing. The negative aspect on this flashlight is the driver where many things could be improved. The flashlight has no mode memory and will always start on Turbo which is an extremely limiting factor for the practical use. At night in a building or outdoors the bright blast at start-up will ruin your night vision and disturb all others around you. The modes are not spaced evenly, as a result the second and third mode will still make the flashlight hot. It may be possible to hold it for long on medium but the whole body gets noticeably warm and I doubt the battery will last for long. The lowest mode produces little if any heat, but it is quite bright. Improving the driver with even modes in low to high order, optional mode memory and maybe double click to Turbo and long click to reverse modes would make the NI40 much more practical and usable. The XHP50 has a clean white beam without too much yellow but for my personal preference it could be slightly warmer and less green. As far as the name is concerned, I would want something with a less negative connotation than ‘Stalker’. The Nightwatch NI40 with dedomed XHP50.2 3V is a flashlight for showing off or for who needs to light up a target as bright as possible for a short time, so more for giggles than for severe practical use.

What I like

- Really bright beam that throws rather far and has a wow-effect at turn on

- Deeply cut cooling fins with anti-roll function

- Square cut threads with enough grease, screw nice and smoothly

- Dedomed XHP50 3V stock, sliced and diced cleanly to remove beam artefacts

- Matte black anodising, also on the threads to allow lockout

- Bigger reflector than a C8+, good for throw

- Thick springs which can handle the current without bypassing

  • Brightness is similar to BLF Q8 or Convoy L6 with smaller body

What could be improved

- The mode order with Turbo first is a no-go in a flashlight of this brightness

- The XHP50 is a bit greenish and on the cold side

  • The driver has no mode memory, the modes are not spaced evenly and there is no real low.

Many thanks to everyone for reading! If you have any questions or need further information please feel free to ask and comment below.

PS.: I’m planning on dedoming a new SST70 and use it together with a XHP70 boost driver in the NI40. If it works out well, I may add the mod below later.

Edit: SST70 mod added to post below

Nightwatch NI40 modded with SST70 6500K dedomed and XHP70 boost driver

Recently I have swapped the dedomed 3V XHP50.2 in my Nightwatch NI40 for a dedomed SST70 6500K. As the SST70 is a 6V led, I had to use a XHP70 boost driver. The boost driver is from MantaRay, has four modes and delivers 5A. In comparison to the dedomed XHP50.2, the shaved SST70 has a smaller hotspot with more throw, produces less heat on turbo and is maybe slightly less bright.

I shaved the SST70 6500K close to the phosphor with a razor blade to get more throw and more neutral white light color. It is a bit above 5000K, maybe around 5500K and has some green in the beam. Below some fotos:

Close look at the shaved SST70

If you shine a light from the side at the led you can see that the bonding wires on the phosphor are soldered to a shiny dark green pad.

Some whitewall beamshot comparisons (all at 5000K, 30cm from wall, flashlights from left to right):

Nightwatch NI40 SST70 shaved ~5500K, Sofirn SP31 V2.0 5300K, Wildtrail BLF D80V2 SST40 5000K

Nightwatch NI40 SST70 shaved ~5500K, Astrolux FT03 SST40 5000K, Convoy C8+ SST40 5000K

Nightwatch NI40 SST70 shaved ~5500K, Sofirn C8F XPL HD 5200K, Emisar D4S Nichia 219C 5000K

Nightwatch NI40 SST70 shaved ~5500K, Sofirn SP70 XHP70.2 5000K, Convoy L6 XHP70.2 4000K and resistor mod

Outdoor beamshots

Comparison of the dedomed XHP50.2 and the dedomed SST70 in the Nightwatch NI40 (3.2s, F7.1, ISO 400, different seasons as you see, tree at 150m). The different sizes make a comparison a bit difficult. The XHP50.2 has a bigger hotspot while the SST70 is more concentrated.

This is the FT03 SST40 5000K at 150m.

The tower you can see in the following pictures is at 700m distance.


Nightwatch NI40 with dedomed SST70

Astrolux FT03 with SST40 5000K

Astrolux MF02 with XHP35 HI 4000K


As you can see the Nightwatch NI40 with the dedomed SST70 led has a bit less throw than the Astrolux FT03 SST40 but it is pretty comparable. The throw is decent for the smaller reflector. With the XHP50.2 the NI40 barely reached the tower at 700m. I don’t have comparison fotos at 700m as the XHP50.2 is no longer in the NI40. Maybe the difference would be more noticeable if I would mod the driver to deliver 6A current.

EDIT: The previous beamshots of the NI40 have been replaced with fotos of the actual turbo mode that is hidden and can be activated only with a fast double click.

New sst70 as in the round led? And if so can you provide a link?

I bought the new Luminus SST70 on Taobao. It is still in the chinese warehouse and this mod will have to wait until next year. The Taobao link is:

Thanks, and btw nice review :+1:

Nice review!

As promised I have added the SST70 mod.

Outdoor shots? Comparison to XHP50.2DD?

I have added the outdoor beamshots now.

I have replaced the previous outdoor beamshots with new ones that show the actual turbo. I noticed that the turbo is hidden and can be activated only with a fast double click. The NI40 gets hot faster and throws further with turbo.

Do bare 21700 cells fit without being crushed in this light?

I would not risk it because the springs in the NI40 are very stiff and made of thick wire.

The 21700 battery sticks out and would pretty sure be crushed because with the anodized threads on both sides you have to screw on the head and tailcap fully to make contact. Here are two pictures, 21700 Samsung 30T and 26650 Liitokala. Mind that the tailcap spring has almost no tolerance as it is 1.6mm thick.

I’m not too sure how battery protections work but I saw you mention that the Stalker has a built-in PCB, does that mean the battery does not have to be protected? I see you barely fit the unprotected and mention that the spring has very little flex. I assumed a protected battery in such a beast was a no brainer but now I’m not sure what I need and it seems it wouldn’t even fit. Am I correct to assume that with a PCB built-in, that a flat-top unprotected is the correct battery and likely the one the manufacturer intended to be used?.

I have one on the way and want to make sure I don’t order the wrong cells. Thank you for the great review.

The Nightwatch NI40 Stalker claims to have a low voltage protection. I did not test it but most flashlights have it, meaning that they turn off when the battery voltage goes below 3.0V.

I tried a protected battery and it looks much like the 21700 cell above. I don’t think it will fit as protected 26650 cells easily reach 70mm in length. The NI40 seems to be designed for 65mm long cells. Also, protected cells have certain currents when the protection trips. With the current getting over 10-15A (depends on the cell, maybe even 5A) the flashlight will simply turn off. The 3V XHP50 draws around 18A and you will not get a Turbo mode with a protected cell.

I would recommend you to use a flat-top unprotected 26650 from well-known reputable brands. If you use a flashlight with low voltage protection and a decent charger you will not have problems even with unprotected cells. If you are not sure how to handle Li-Ion batteries adequately look for Lithium Ion battery guides here on BLF.

Thank you so much for the info, I guess I’m going with the Shockli. Actually, what brand do you like for this light?

In the flashlight description it only asks for a 26650 Battery and thats it. So is it safe to assume generally speaking that if a manufacturer just gives a battery size without mentioning button top or protected that means a regular unprotected flat top is ok?

I’m waiting on the Sofirn Sp36 to arrive and that one says it needs 3x18650’s only so I’m guessing any flats will be fine. Then I’m waiting for the Haikelite MT09R and that manual says 18650 Button tops with anti-reverse & anti-discharge protection. So that light likely has no protections built in and I MUST use protected buttontops at all times?

Sorry, don’t mean to veer you off course too much, you just seem knowledgable about this.

Edit: Actually I just checked Amazon’s listing of the Sp36 BLF and it says button tops are required and flat tops cannot be used. Sofirn doesn’t say tht at all but Amazon make this very clear. Does that mean I could also use the protected buttontops I’m buying for the Haikelite? Or can protected batteries be used only on flashlights that explicitly say Protected?

You’re welcome. Most of my knowledge about flashlights and batteries comes from reading a lot on BLF. I’ll try to explain you a few things about batteries.

In my NI40 I use mostly Liitokala 26650 batteries. They are rather cheap with an acceptable performance. Those who have the best performance and top notch cells are certainly Vapcell, Shockli, Keeppower and some others. Here is a list of the reputable sellers where you can buy good batteries: Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123

Flat top unprotected batteries will fit almost all single cell flashlights. It depends on how long the battery tube is and on the spring tolerances if a protected cell is suitable or not. Sometimes the description tells to use batteries with more than 10A continious discharge. Then they mean unprotected high drain cells.

The Emisar D4 or the Lumintop FW3A for example fit only unprotected flat top batteries. Flat top is how they are sold by the manufacturer.

Other sellers will add a protection or a button top. A protected battery is not the same as a button top battery. Most protected batteries have a button top but not all button top batteries are protected. Many flashlights with 3 or 4 batteries and battery carriers require unprotected button top cells.

In the SP36 there are 3 18650 batteries. They need to be unprotected because protected cells would be too long. They also have to be button top because there is a brass ring at the head where flat tips would not make contact because usually the positive pole is slightly lower than the surrounding shell of the battery.

You should use unprotected button tops also in the Haikelite MT09R. It has plastic rings around the positive button that prevent contact on flat tops and are a mechanical reverse polarity protection. The MT09R is a high power flashlight with 3 XHP70.2 that need a lot of current in direct drive. With protected cells it would flicker and simply turn off in turbo mode. It has all necessary protections because it uses the NarsilM firmware and the BLF members who developed this firmware and the corresponding drivers are true experts.

Generally speaking, all high power flashlights that use the XHP70, XHP50, SBT90.2 and multiple emitters need unprotected batteries These flashlights also have low voltage and reverse polarity protection. If you see lumen values over 3000 lumen you can be certain that these flashlights use unprotected cells. You can find out if flat top or button top by reading the description or reviews.

For more information about batteries, leds, drivers and flashlights in general check out this reference guide: LEDs & Other Stuff - (Reference Guide)
There are the battery tests by HKJ, the safety guide and links to useful information about batteries.

Hope I could help you. The Sofirn SP36 and the Haikelite MT09R are two great choices.

You helped me tremendously. I was really confused about all this and now I feel far more informed so I thank you sincerely.

If you don’t mind, allow me to give it one crack to see if I’m learning. I’ll very likely be buying the Nightwatch NSX3 NS53A. Since it’s over 3k Lumen, def no protection, and since it’s not in a battery carrier, a flat top is correct. So for that one I’d buy a 21700 unprotected flat top. Is that correct?

Thank you again so much for taking the time to help me with this.

I’m glad I could help you.

Yes, that is correct. The Nightwatch NSX3 NS53A uses 3x Xhp50 3V which is a very current hungry led. For the maximum brightness the best high discharge 21700 is the Samsung 30T. It will heat and stepdown fast. If it doesn’t matter for you to reach the declared 9900 lumens a Samsung 40T or a Molicel P42A should be enough and give more runtime.

Let me remind you to treat these high discharge batteries well. Never risk to short circuit them, store and transport them in plastic cases, use a good charger and be careful not to heat or puncture the cells.

There are only these few basic rules to follow and your unprotected batteries will work fine. In the category of the 3x Xhp50 3V flashlights there are also the new Lumintop FW21 Pro and the about to come out Astrolux EC03.

Have fun with your flashlights! May BLF always be a source of knowledge and inspiration for you.

Thank you once again… Following the battery rules is very important from what I see in all the websites that sell them. They have hefty warnings and even require acknowledgments to make sure you understand. I appreciate the quick rundown.

I sure wish I would waited for your response. I bought 3 40T’s thinking those would be the better ones. I should have researched first. Live and learn.

Anyway, I did consider the FW21 Pro but ultimately didn’t like all the complaints others had about possible quality concerns. I also liked that Nightwatch took heat dispersion a bit more seriously than Lumintop did on such beasts. Ultimately since the lumens were similar, I chose my preferred host which was easily to me the NSX3. I will be checking out the AstroluxEC03, hadn’t heard about it.

I absolutely have received inspiration and have been bestowed a tremendous amount of knowledge in my short time here at BLF, I can’t imagine how that would be changing anytime soon.

Thank you again sincerely.

Yes, lithium ion batteries have a high energy density, a low internal resistance and can release high current in short time. That is why short circuit would be dangerous. However, you have lithium ion batteries in almost any device today, notebook, smartphone, e-bike …

The 40T’s are a good choice. They are rated for 30A discharge, the 30T’s are rated for 35A. You will not notice any difference in startup turbo brightness because a difference of 10000 lumens to 8000 - 9000 lumens can only be measured but not seen. After a few seconds the 30T’s voltage will sag and the current will be reduced anyway. Also, a flashlight of this size will get scorching hot in less than a minute. Additionally, the 40T gives you more runtime.

You are starting a nice flashlight collection I see. :sunglasses:

You’re welcome. :slight_smile: