Nitecore MH40GTR Flashlight Review

Nitecore keeps dropping lights in the MH series.  This time it’s a thrower, of the 2×18650 variety.  And it has an interesting UI.  Read on to find out more!

Official Specs and Features


There’s only one version of the MH40GTR.

Price and Coupon

This light sells as a kit on for $129, and that’s everything you need to get up and running.  There isn’t a non-kit option, but it’s possible to add a car charger adapter for $5.

Short Review

This light has the beam profile of a thrower, and throws to match.  It’s within 10% of the claim on throw, which for my amateur equipment, is good enough for me.  The UI is unique and simple if you just want a two mode light.  Accessing the other modes quickly takes practice but if this is your main LEO etc light, then it will become second nature quickly.  With non-proprietary cells included and on-board charging, this is a solid package light kit.

Long Review

The Big Table

Nitecore MH40GTR
Emitter: Cree XP-L HI (V3)
Price in USD at publication time: $129.00
Cell: 18650×2
Turbo Runtime High Runtime
LVP? ~
Switch Type: Mechanical and Twisty
On-Board Charging? Yes
Chargetime: <4h10m and <6h
Power off Charge Port with no Cell? No
Claimed Lumens (lm) 1200
Measured Lumens (at 30s) 1094 (91.2% of claim)*
Claimed Throw (m) 1004
Candela (Calculated) in cd (at 30s) 3710lux @ 7.443m = 205528cd
Throw (Calculated) (m) 906.7 (90.3% of claim)*
All my Nitecore reviews!

* Standard measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

  • Nitecore MH40GTR Flashlight
  • Nitecore NL1826 18650 (2) (not pictured here)
  • Wall wart to barrel plug (not pictured here)
  • Spare o-rings (3)
  • Tactical ring
  • Pocket clip
  • Spare switch boot
  • Nylon pouch
  • Lanyard
  • Manual and paperwork

Package and Manual

It’s the standard Nitecore package.  The light is in a plastic tray.

Here’s a direct link to the pdf manual.  It’s a good manual, as most Nitecore manuals are.

Build Quality and Disassembly

The MH40GTR has all the build quality of a Nitecore flashlight.  Externally it’s striking – this is a long, thin light.  The anodizing feels nice and thick.  The light has a nice weight to it, too.

The knurling is my favorite type – diamond pattern with a flat top.  There are a couple of places with knurling – only and exactly where you’d need it.  The tailcap has a little bit of knurling, and the body just where you’ll twist to drop out of turbo has a bigger patch.  The center of the cell tube is free of knurling, but has a couple of rings for added grip.

(At least one of those rings would likely accommodate a “tactical o-ring” quite nicely.)

The head has a number of grooves, likely to deal with the heat.  I didn’t find that much heat makes it out to the edges of the head, anyway.

The bezel also has a bit of gripping – reeding – but the bezel didn’t budge on my copy.  The perfect emitter for this light is installed anyway, so there’s no great reason to get in there (ok, better tints of the XP-L HI than what’s in here stock do exist, I’ll give you that….)

The threads are quite lubed.  Too much for my taste.  Not… that I tasted it.  No who would do such a thing.

The threads are triangle cut and long (lots of twisting).

The switch end parts are held in place by an aluminum retaining ring.  The head end has a similar spring.

The bezel has some fairly dramatic crenelations, which make for great relief as a table light, or probably could be used as strike bezels too.  The bezel isn’t swappable for a non-crenelated version.



Size and Comps


Length 257 mm
Head Size 70 mm
Weight 374 g

Like I said, this is a long light.

And per request, here’s a shot of the light in my extra medium sized hand:

Retention and Carry

A nylon pouch is included, and most likely will be the primary means for carrying this light.  It’s a nice pouch, with bezel-up only carry.  The d-ring on the back is an actual metal ring, and actually a D ring.

There’s also a lanyard, which attaches on the tailcap.

Alternatively, the lanyard may attach on the optional tactical ring.  The tactical ring is not screwed down on this light, so it’ll spin semi-freely.  This is probably the better lanyard attachment point.  The tactical ring feels plastic to me.

And finally, there’s a belt clip.  The belt clip is quite longer than a normal pocket clip, and has a wider shoulder, too.  It should fit thick belts very well.

It’s just a friction fit clip, and can be removed.  It only allows bezel down carry.

Power and Runtime

The MH40GTR is powered by two 18650 cells.  Nitecore includes the required cells – two NL1826 2600mAh protected cells.  I would recommend sticking with these two cells, or buying backups of these cells.  Alternatively, some high drain protected cells will work fine.  Since there’s a spring on both ends, any type cell should work.  Read on to see why I recommend protected cells.

As with most Nitecore cells I’ve handled, these are quite long.  Since the light fits them fine without much slop, unprotected flat top cells will probably be too short for the normal use case with this light (even if they do make the light work just fine).

Here’s a runtime on Turbo.  As you can see, Turbo holds out for a respectable few minutes, only dropping to 80% at around 8 minutes.  Then there’s a dead flat stepdown for another 100+ minutes.  Also note the temperature never blips over 30 degrees C…. not very warm to the touch at all!

When the light is out of juice it doesn’t fade, it just shuts off proper.  It’s a matter of perspective on whether this is good or not.

And here’s a runtime on High.  Again just absolute dead flat output at 400 lumens for over 4 hours.  That is short of the claim (6h15m).

Now why do I recommend protected cells?  In both of those runtimes, protection on just one cell was tripped.  So one cell read 0V and the other (in both cases, actually) read 3.42V.  I am not sure exactly why the protection tripped – immediately after they were brought back from their tripped 0V state, they read 3.42V also.  (ie internally they were all each at the same state, just one cell was tripped and one wasn’t.)  I don’t know if the light leverages this trip as a protection, or what.  I don’t think tripping is bad for the cells (???), so I’ll give this one a pass….

Further to this point – on bench power, the light doesn’t shut off (and remains at near mode-accurate-level output) until the total voltage is 3.7V.  With two cells in series, that’s much too low.  So again, use the included cells.

Fortunately Nitecore includes a charger – indeed the light has a built in charge port.  Normally it’s a terrible idea to charge cells in series, but Nitecore has built this light specifically to do that.  And I’d say it’s safe if you use the included cells.  If you’re not using the included cells, make absolute sure that the cells are matched before using the on-board charging feature!

The wall wart outputs 12V at 1A.  How is a 12V charger used to charge two 4.2V (max) (3.7V nominal) cells in series?  I don’t know – I would have expected a 9V wall wart.

Interestingly (and unfortunately) the plug isn’t the standard 12V size.  It’s much, much smaller.

To access the charge port, part of the head must be unscrewed and pushed back. There’s a charge port, and a hole for viewing a LED that only illuminates Red.

This ins’t inconvenient, but that is a lot of mass to be moving around – the same amount as if you took the cells out of the light and charged them in a charger.

The manual mentions it but I bet most people won’t notice.  The light must be switched to the on position for charging.  That makes perfect sense once you think about the tailswitch being a mechanical switch.  If it’s not on, then no electrical connection is made.  So plug the light on, and then click the switch to on.

I don’t have a way to test these small barrel plugs, but I timed my charging twice.  The first time I caught it right after it stopped, at around 4h10m.  The second time, I caught it “just sometime after it stopped” at around 6h (but likely much less).  When charging is happening, the red LED blinks (at a sauntering pace).  When finished, the red LED is steady.  My cells were at a (low) 4.11V when finished.  If you’re attempting to charge and something’s screwey, the red LED will flash with a “kid on candy” pace.

User Interface and Operation

The on/off switch is mechanical: a forward clicky.  This means it allows momentary on.

The second switch of this two-part UI is a twist option on the body.  Gripping the knurled area below while holding the head and loosening or tightening allows access to a second mode.  The second mode can be a number of things, which the user gets to select.

Here’s a UI table!


State Action Result
Off Click On (If body is tightened: Turbo.  If loosened: User Defined mode)
On Click Off
Off (Loosened to User Defined Mode) Half click HML>SOS>Strobe Selection (Leave in desired mode)

But there’s more to the UI than the table would indicate.  There are five options in the user defined section of the UI.

Basically this should be seen as a two-mode light.  It’s possible to access the rest of the modes fairly easily, but as far as quick access, it can be tricky.  

The twist area for the two modes is generous.  Fully tightened is Turbo.  About a quarter turn switches to the second mode.  The second mode is active in 3/4 to 1 full twist.  It’s possible to confuse the shroud that allows access to the charge port with the twist parts for the UI, but even just a little practice will clear that up.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Turbo 1200 2h 1094 1.37
High 380 6h15m 397 0.34
Mid 100 27h 121 0.08
Low 15 140h 17 ~

LED and Beam

The emitter is a Cree XP-L HI.  The XP-L HI is one of my favorite emitters (ok maybe my singular favorites?).  It’s a perfect choice for this light.  Another reasonable choice would have been a Cree XHP35 HI, especially sensible since the two cells are in series, and the driver seems to regulate the Watts very well anyway.  The reflector is smooth.

On the low modes, there’s little spill.  On the high modes there’s some spill, as you’d expect with this type light.  The thing sneaking into the photos is the light itself – that’s just a construct of being consistent with the beamshots.

Tint vs BLF-348 (Killzone 219b version)

Would love for this to have been a 4000K XP-L HI, but it’s a bit cooler than that.

Random Comparisons and Competitive Options….

Here’s a relevantly filtered link to  There are a couple of other close lights, but nothing else like this that offers everything and integrated charging.  The Acebeam T21 is a similar setup, as is the Olight M3XS-UT Javelot.  Those are likely both good choices too, but the UI on the Nitecore is something very unusual, and could be perfect for your needs.  The addition of charging is a nice bonus.


What I like

  • Very regulated ouptut
  • Full package light
  • Loads of throw

What I don’t like

  • Nonstandard 12V barrel plug
  • Cell protection seems to trip when run low

Up Next

I have a couple more lights this week, including one Fun Fund Friday light I’ve been holding on to for ages, waiting for the right moment.  I think this Friday is that moment!


  • This light was provided by Nitecore for review. I was not paid to write this review.
  • This content originally appeared at  Please visit there for the best experience!
  • Whether or not I have a coupon for this light, I do have a bunch of coupons!!  Have a look at my spreadsheet for those coupons. It’s possible to subscribe and get notifications when the sheet is edited!!

Author: zeroair

Leave a Reply