Reviewer's Note: I am very backlogged with lights, so expect somewhat less detail than typical in my upcoming reviews.
Nitecore has updated their MH-series with a new version of the MH20 model, featuring even greater throw – the appropriately-named MH20GT (for Great Throw, presumably). Let's see how it compares.
Manufacturer Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).
- LED: CREE XP-L HI V3
- Battery source: 1 x 18650 or 2 x CR123A (both sold separately)
- Lumen outputs/Run times (1 x 18650): Turbo: 1000 lumens - 1h, High: 410 lumens - 3h, Medium: 230 lumens - 6h 45 min., Low: 50 lumens - 22h, Firefly: 1 lumen - 680h
- Lumen outputs/Run times (2 x CR123A): Turbo: 1000 lumens - 45 min., High: 410 lumens - 2h 30 min., Medium: 230 lumens - 4h 30 min., Low: 50 lumens - 14h 15 min., Firefly: 1 lumen - 340h
- Candela rate/Peak beam intensity: 33,000cd
- Beam/throw distance: 362m
- IPX rating: 8
- Impact resistance: 1.5m
- Easily charged with micro USB cable (not included), because of embedded micro USB port
- HAIII military-standard, aerospace-quality, hard-anodized aluminum for durability
- Strengthened mineral glass lens for smooth light transmission
- Nitecore five-year warranty covers defects and malfunctioning units
- Pocket clip included for secure attachment to a pocket or belt loop.
- Included accessories: USB charging cable, Holster, Pocket clip, Lanyard, Spare USB port cover, Spare O-ring
- MSRP: ~$100
Packaging is the same as before - Nitecore's standard thin cardboard display box, with specs and information printed right on the box. Included with the light is a holster with Velcro closing flap, micro-USB charging cable, spare O-rings, basic wrist lanyard, warranty card, and manual, and spare micro-USB port cover.
All dimensions directly measured, and given with no batteries installed:
Nitecore MH20GT: Weight: 89.4g, Length: 111.6mm, Width (bezel): 31.9mm
Nitecore MH20: Weight: 85.4g, Length: 105.5mm, Width (bezel): 31.8mm
Eagletac TX25C2: Weight 93.6g, Length: 120.4mm, Width (bezel): 31.6mm
Fenix PD35: Weight: 82.7g, Length: 138.1mm, Width (bezel): 25.4mm
Lumintop SDMini: Weight: 91.1g, Length: 108.7mm, Width (bezel): 31.8mm
Nitecore MH10: Weight: 73.6g, Length: 129.5mm, Width (bezel): 25.4mm
Nitecore MH12: Weight: 87.3g, Length: 139.5mm, Width (bezel): 25.4mm
Thrunite TN12-2014: Weight: 80.0g, Length: 140.5mm, Width (bezel): 25.4mm
The MH20 was always particularly short for a 1x18650 light, with a wider bezel/reflector than typical. The MH20GT takes this further with a deeper reflector and longer overall head length. Otherwise, the lights look very similar in external styling.
Anodizing remains a shiny black finish, hard anodized, with no chips or damage on my sample. Body labels are bright white and clear against the black background. The MH-series has a built-in micro-USB port in the head – for in-light charging with the supplied USB cable.
As before, knurling is of moderate aggressiveness on the body tube and tailcap. But when combined all the other grip elements (e.g., side switch cover, fins in the head, pocket clip, etc.), I would describe overall grip as pretty good – especially with the large grippy-textured switch and charger cover. Like before, the light has anti-roll indentations on the body – and these work well to stop roll, along with the rubberized port covers here.
Tailcap is unchanged from before. Tailcap screw threads are standard triangular cut and anodized for lock-out at either end of the body tube. Tailstanding is stable due to the flat tailcap. The lanyard option on the MH20/MH20GT is a small hole for a split-ring or simple lanyard.
The switch is similarly unchanged. As before, the electronic switch in the head controls output selection. Switch is easy to locate by feel, and there are two blue LEDs located under the switch cover. Please see my User Interface section for a discussion.
As before, there is an electronic reverse polarity detection feature in the head, so only true button tops are likely to work on this light. For example, my AW protected 3100mAh ICR work fine in the MH20, but the Samsung 20R INR don't.
The body tubes are wide enough to accommodate all size 18650 cells. Note the MH20/MH20GT has less cell length space than some other models.
The emitter has been upgraded to a XP-L HI emitter on the MH20GT, which should provide greater throw (due to its smaller profile). There is also a deeper smoother reflector now, compared to the MH20. Together, I would expect excellent throw for this class. Scroll down for beamshots.
The MH20GT uses the same interface as the MH20.
To activate, press the switch all the way and release (i.e., a full click). Turn off by a full press and release. The light has memory on this mode, and will retain the last output used (see below). Alternatively, press firmly and hold all the way down for momentary on (in Turbo), with no memory.
Half-pressing the switch for ~1 sec (and then releasing) turns the light on in Lower (Moonlight) mode. There is no memory for this mode – it always comes on in the Lower level.
From either method of activation, simply half-press and release the switch to advance modes. Mode sequence, in repeating order, is Lower > Lo > Med > Hi > Turbo. Turn off by a full press and release.
There is a shortcut to Turbo from On: press-hold at the first level (i.e., a half-press and hold).
Strobe modes can be accessed by fully holding down the switch from On for ~1 sec. To advance strobe modes, simply half-press and release the switch as you would for constant output modes. Mode sequence is Strobe > SOS > Locator Beacon, in repeating sequence. Turn off the light to exit strobe modes (there is no memory for strobe).
As before, there is a double blue LED under the switch to serve as a low voltage indicator. Once the cells are below 50% power (according to Nitecore), this indicator will flash blue every 2 seconds. It will flash faster as the power capacity drops down further.
Note that when first inserting connecting the tailcap, the blue LEDs under the switch will read out the voltage of the battery in a series of flashes (e.g., four flashes, followed by a short pause, with two more flashes would indicate a full charge of 4.2V).
There is also a standby indicator that you can turn on. Simply click the switch the half-way level (i.e., not a full click to turn on, not a sustained press of the half-way level for Lower short-cut). The LEDs under the switch will not flash once every 3 secs, to let you know the light is in standby mode. This feature is not on by default.
For information on the light, including the build and user interface, please see my video overview:
As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.
As before, the light appears to be current-controlled. There was no sign of pulse width modulation (PWM) at any level, on any light.
The strobe, SOS, and locator are unchanged from before (shown below from my MH20 review).
The MH20 has a fast high frequency strobe, at 20 Hz.
A fairly typical SOS mode.
MH20 Beacon is a quick full-power flash, once every 2 secs.
As before, there is a standby drain on the MH20GT, due to the electronic switch.
On the MH20, the standby drain (after the battery read-out) was 27uA. On the MH20GT, it was a comparable 28uA. This would translate into ~13 years before a 3100mAh battery would be drained, and so is not a concern.
Accidental activation can be prevented by a physical lock out of the light – simply do a quick turn of the tailcap (or head) when not in use.
Because the light uses a USB charging cable, I was able to take direct measures of the charging parameters using my Xtar VI01 "USB Detector" (basically a specialized USB current/voltage meter). There are many of these on the market now, and this model was favorably reviewed by HKJ here.
For charging tests, I started with a NCR18650A 3100mAh battery (protection circuit tripped). For all these tests, I left the USB detector in place for all readings. Note that the voltage reading on this device refers to the input voltage (i.e., from the USB port).
Initial charging current and input voltage on the MH20GT was ~0.50A, and ~5.10V. Since this is no different from the MH20, I am showing the charging cycle from that review below:
For the first ~4.5 hours, there was no change in the input voltage or charging current.
By 5 hours, it had become to drop
By 5.5 hours:
By 6 hours:
By 6.5 hours:
By 7.25 hours:
Final resting battery voltage was only ~4.16V.
This pattern is pretty much what I would expect from a typical CC/CV algorithm.
For white-wall beamshots below, all lights are on Max output on an AW protected 18650 battery. Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.
The MH20GT is clearly even more "throwy" than the MH20, thanks to the deeper reflector and smaller profile XP-L HI emitter. A very impressive amount of throw in such a small package! The overall spillbeam width is a bit narrower, due to the deeper reflector.
All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.
I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info.
Throw/Output Summary Chart:
My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).
Max output of the MH20GT is ~10% lower than the original MH20 in my testing, but peak beam intensity has more than doubled. This makes the MH20GT the furthest throwing compact 1x18650 I have tested (outside of those with massive heads, of course).
Let's see how all the levels compare across the two lights on 1x18650, in my lightbox:
The MH20GT's output levels are lower across the board, compared to the MH20.
All my current runtimes are done with protected NCR18650A (3100mAh capacity) batteries. First, a comparison between the Hi/Turbo levels of the three new lights:
Overall runtime patterns are very similar, although the XP-L HI seems to be slightly less efficient than the XM-L2 (i.e., slightly less output and/or runtime). But the difference is not great.
Note that I did some analyses on the original MH20, to see how its thermal regulation worked. Below is the graph from that review.
As you can see, without cooling the MH20 ran for ~6 minutes at Turbo output, before dropping down to a reduced output level that was just below the defined Hi mode level. With some minor fluctuations it stayed at this level for the rest of the run. These results indicate the thermal sensor-mediated drop in output works as expected. I would expect the MH20GT to be unchanged in this regard.
The MH20/MH20GT both use an electronic switch, and therefore have a standby current when connected but not on. But in both cases, this current was negligible - and can easily be broken by a simple twist of the anodized tailcap.
As always, the rubber dust plug covering the micro-USB ports may reduce waterproofness. I recommend you make sure this is securely in place before venturing into any wet conditions.
The two-stage switch interface on the MH20 gives you more versatility in how to control the light. But it also means you will need to take care on the timings/pressure if you have dark-adapted eyes and want to avoid Turbo.
As previously discussed in my earlier round-up review of the Nitecore MH-series, the MH20 was an innovative light for this class. Remarkably short for an 18650 light, it reminded me of some of the early CR123A/RCR "thrower" lights in its overall dimensions and throw (e.g., the Lumapower D-mini). Of course, it managed that feat by skipping a physical clicky tailswitch and using just an electronic switch in the head. But the choice a two-stage switch meant the added functionality of the TM-series was also available now, in a single 18650 build.
What's changed in the MH20GT is the use of the XP-L HI emitter (with its lower profile for better focusing and throw), an extended head with deeper reflector. The net effect is to more than double the peak intensity throw of the MH20 – which was already a leader in the compact 18650 class. Nitecore has managed to re-invent the compact thrower class: the MH20GT is it.
The circuit performance is basically unchanged from the MH20. Instead of the timed step-down on the other MH-series models, the MH20/MH20GT use good thermal management to regulate output at its highest level. Output levels are slightly lower across the board on my MH20GT sample, but the difference isn't noticeable. See the runtimes and tables above for more info on how everything compares.
Beam pattern is generally similar, except that MH20GT has a much more tightly focused hotspot than the MH20 (i.e., brighter and smaller). Before, the MH20 had a large and fairly uniform hotspot that was sharply defined. The MH20GT has a brighter center, with wider surrounding corona. The overall spillbeam width is slightly less on the MH20GT (but it seems a touch brighter).
The real difference in the models comes down to how much throw you want. The MH20 was already an excellent performer in this regard – but the MH20GT really brings it up to the maximum you could expect in this compact size. And all this with only a slight increase in overall length. It’s a very impressive beam pattern for a throw freak.
MH20GT provided by Nitecore for review.