Originally posted: October 8, 2008
Last revised: July 24, 2010

Reviewer's Note: This is a review of the Olight M20 Warrior Premium R2 light (2xCR123A/RCR, 1x18650). The M20 was provided for review by MattK from www.batteryjunction.com.

UPDATE 4/25/2009: The Olight diffuser and red/green filter covers for the M20 have been added to the end of review

The M20 "Warrior" is Olight's new high-end 2xCR123A build light, designed for tactical uses.

Olight M20 Warrior Features (consolidate from multiple sources):

Light comes with an attached anodized steel pocket clip and aluminum grip ring (both are removable), high-end holster, plastic battery magazine (to prevent CR123A rattle, but use not required), manual, good quality wrist lanyard, extra o-rings and extra GITD plastic tailcap boot cover (looks clear, but glows a blue-teal colour). A good package.

From left to right: CR123A, 18650, Olight M20, T20, JetBeam Jet-III PRO ST, Jet-III PRO IBS, Romisen RC-M4.

As you can see, size is bit larger than the more compact general-purpose 2xCR123A lights, but still quite comfortable in the hand. Certainly much smaller than the dedicated thrower lights - the M20 is actually a bit smaller overall than I expected for a light with all these build features.

Weight: 120.0g
Length: 144.0mm
Width: 35.7mm (head, widest portion), 24.8mm (tailcap)

The M20 is a well made, high quality light. All components feel very sturdy and well built. Everything fits together well, with double o-rings and smooth screws threads at all openings (tailcap threads are anodized, allowing tailcap lockout). Tailcap spring is not exposed, but encased within an assembly with a button top. There is a spring mounted on the positive contact board in the head.

Battery magazine works well to prevent rattle with 2xCR123A. My only concern here is the thin plastic screw threads on the magazine cap might not stand up to a lot of abuse. But the magazine is optional anyway - the spring in the head provides enough resistance to prevent any noticeable rattle.

Machining and anodizing of the light are top-notch on my sample. The raised checkered portions help with grip. While not as "grippy" as aggressive knurling, it seems to work pretty well with my hands. The attached anodized clip and grip ring also help enhance grip, and both are removable. Overall, I would have to say hand feel is excellent in all configurations.

The light can't tailstand - but that's not uncommon for "tactical" lights, since tailstanding rings tend to obstruct easy access to the clicky switch. Light comes with a forward tactical clicky with good tactile feel (momentary on, click for lock-on).

The light features a scalloped stainless steel bezel ring, which could serve as a strike bezel. The reflector is fairly deep, with what I would describe as a medium orange-peel texturing (MOP) - optional smooth reflectors are also available for even greater throw.

Since mine is the premium R2 model, tint is the expected warm greenish tint (WH tint bin). This is fine for me, since I actually like warmer tints - but if you like yours more cool, you should stick with the Q5 bin (WC tint). The relatively deep reflector should translate into decent throw.

For beamshots, below is a comparison to the Solarforce T7 (which is very similar to a Fenix P3D) and JetBeam Jet-III PRO IBS (which is a good mid-range thrower). All lights on max on AW 18650/14670 (pics taken ~0.5 m from a white wall).

As you see in the pics, the M20 beam pattern is close to the original Jet-III PRO IBS, which has a roughly similar sized OP reflector. This means you get pretty decent throw, while minimzing Cree rings in the beam. For a more detailed throw/output comparison, see my Summary chart below.

UPDATE: Some additional long-distance beamshots, to show you how the light compares to others in its class.

Please see my recent 100-yard Outdoor Beamshot review for more details (and additional lights).

User Interace:

UI is straight-forward - press the forward clicky for momentary on, click for lock-on.

Light moves between brightness/mode states by a simple switch of the head - loose/tighten the bezel to move to the next state. Sequence is: Lo - Med - Hi - Strobe, repeated in an endless loop.

This switching mechanism is similar to all other Olights, but the selection of states is different on the M20. Most Olight models switch between 5 output states with no strobe mode, in a Hi to Lo sequence. The revised M20 sequence (i.e. Lo to Hi) and better spacing between the levels (i.e. Lo mode is lower than other Olights) is an improvement, IMO.

Testing Method: All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. 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 the extended run Lo/Min modes which are done without cooling.

Throw values are the square-root of lux measurements taken at 1 meter from the lens, using a light meter.

For the runtime/output comparisons below, I've included the following lights:

From left to right: Olight M20, Solarforce T7, ITP C6, Regalight WT-1. Not shown, Fenix T1.

Throw/Output Summary Chart:

As suggested by the beamshots, throw on the M20 is very good - slightly better than the Jet-III PRO IBS in fact. I would expect even better throw with the smooth reflector (not tested).

Overall output is excellent - for initial output, it beats all the other 2xCR123A/RCR or 1x18650 lights included in this round-up comparison (although some only by a small margin, on certain batteries). Definitely an excellent performer, but see my runtimes for more info.

Output/Runtime Comparison:

Before all the detailed runtimes, here is a comparison of the different batteries on max on the M20:

As you can see, rock-solid regulation on RCR and CR123A. And as expected, the light runs in only semi-regulated fashion on 1x18650 Li-ion. This is hardly surprising, since any multi-power light that can handle >8V input in a regulated fashion is going to have trouble providing the same regulation for 3.7V Li-ion.

But how does it compare to the competition?

A few comments on Max output:

Honestly, I haven't had time to do anything more than the RCR lo mode runtime test - for the simple reason that performance is outstanding at this level:
Potential Issues

I have no qualms about the build quality of this light so far - no signs of any problem in my testing to date.

My only potential concern is the low battery warning flash. As you can see in the runtimes, this gets triggered on 18650 and primaries almost as soon as the light falls out of regulation. Personally, I have always found these warnings to be superfluous, since the lower output is itself an excellent indicator that the battery is running low. Moreover, these warning flashes are actually annoying if you need to run the light for the several hours it is capable of at these low levels (i.e. in an emergency).

But the greater concern is that (inevitably) some batteries in some lights will trigger an erroneous low voltage flash even when the cells are still relatively fully charged. This mistaken voltage sensor effect has been reported for every model light that I've seen with such a high trigger-level. And a quick perusal here at CPF confirms several members reporting exactly this problem for their M20s. Note that I have not experienced any problem with my M20 - but IMO, it's better to just dispense with this feature altogether to avoid the potential risk (especially since there is really no benefit).

FYI, ITP had a similar trigger-level for the warning flash on their multi-power lights (as you can tell in the traces above). I am happy to report that based on customer feedback, they have removed it completely on their latest batch of C7/C8/C9 lights. I hope Olight will consider doing the same.

UPDATE: MattK informs me that upon further investigation, it seems the issue for most of the M20 owners who have reported a problem with the low voltage flash have been attributed to over-lubrification (i.e. migration affecting the current path). That sounds believable to me, as I have observed that excess lube can wreck havoc on lights with complex circuits. That said, Olight appears to be listening to feedback as they have told Matt they are removing the feature from future production runs. Good job!

General Observations

The M20 is a quality light. Build is top notch, with lots of signs that care and consideration went into its design and construction.

The regular Olights are all well made lights, but I find the M20 definitely ratchets things up a notch or two. Although bulkier than the slimmer design lights in this class, the M20 is still smaller than I expected - and smaller than all my dedicated thrower lights.

I particularly like the new sequence of Lo > Med > Hi > Strobe (compared to the Hi to Lo sequence on regular Olights). Personally, I would prefer to have Strobe hidden off somewhere other than the main sequence, but this arrangement is certainly not bad.

But the inclusion of a true Lo output level is an extremely welcome addition. Typically, current-controlled lights that are optimized for specific output levels (like Fenix and Olight) are more output/runtime efficient than continuously-variable PWM lights. But PWM-based lights are capable of much lower output levels, thus having the ultimate low output runtime advantage. The M20 definitely has the best performing low mode I've seen on a classic circuit (>3.5 days on 2xRCR - at that performance level, I'd expect a good week on 18650!).

I am also quite impressed with 18650 performance on max. Simply put, the M20 is the brightest multi-power light on 18650 that I've tested to date. Coupled with its decent semi-regulation - maintaining at least 80% of its initial output before falling out of regulation - this makes the M20 a clear winner (see the first runtime chart again for a comparison of all batteries on max).

Although many decry the lack of completely flat regulation on 18650 in multi-power lights, this is the apparent trade-off required to bring higher voltage level support. If you want perfectly flat regulation on 18650, you are going to have forgo 2xRCR (and potentially even 2xCR123A). Besides, semi-regulated 18650 performance is typically more efficient than full regulation, and provides a long "moon-mode" before triggering the built-in battery protection circuit. The M20 is great performer on all batteries, IMO.

With its evident build quality, well-spaced output levels, and excellent runtime performance, the M20 is a strong contender in the "tactical" 2xCR123A/RCR/1x18650 class. As always, it all depends on what feature set matters the most to you - but the output/runtime performance of the M20 is certainly excellent so far in my testing.


UPDATE 4/25/2009: Matt at Battery Junction has provided me with the new Olight filters for the M20.

First thing I noticed is that these are not cheap colored pieces of plastic. They appear to be actual ground glass, and have an anti-reflective coating that gives them a strong complementary pink/green hue when looked at from an angle. To illustrate my point, here's a flash effect from a steep angle:

No, I have not reverse the filters - red is still in the middle and green is at the end. The AR coating gives you this complementary shine.

Olight has released separate filters for the M20 and the small T-series light, but I believe construction is equivalent.

Note the soft-plastic filter cap has grooves specially cut to fit the scalloped edges of the M20's stainless steel bezel ring. The filter/diffuer covers are a good snug fit, as there is some give in the rubberized material of cover. Very little light sneaks back out around the head.

Here's how they look against a white wall. All pics are at 1/25sec, f3.2, white balance locked to daylight, M20 on max on 1x18650.

Control shot of the M20 (note the slightly greenish hue of the R2-WH tint):

Now with the diffuser:

Green filter:

Red filter:

As you can see, the red filter seems to block a lot more light overall. This is likely due to the fact that LEDs output a lot less in the red wavelengths than they do in the blue and yellows (so there is less light overall once filtered for those wavelengths).

Interestingly, there is a complementary color effect right around the bezel with the filters (likely due to the dual AR coating). Here's some close-ups to show you what I mean - lights are lying on top of a white cardboard box:

Final word: I'm very impressed with the qualiy of these filters and diffusers. They are well-made, and certainly well suited for the M20. Good job.

To follow the online discussions for this review, please see the full review thread at CPF.

Return to the master review list (at flashlightreviews.ca).

For a list of all my CPF flashlight reviews in chronological order by battery type (direct link to CPF), please see here:
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