Sunwayman M20A (2xAA, XP-G R5) Review: RUNTIMES, BEAMSHOTS and more!

Originally posted: December 16, 2010

Warning: pic heavy, as usual. :whistle:


Although I have reviewed a number of SUNWAYLED lights (now called SUNWAYMAN), this is my first review of a XP-G R5-equipped light – the 2xAA M20A.

Packaging is fairly typical, and the light comes with a reasonable number of extras. Inside the cardboard box with plastic insert is the light, manual, warranty card, spare o-rings, extra boot cap, good quality wrist strap, and pocket clip. I would have liked to have seen a belt holster, though.

From left to right: Duracell alkaline AA, Sunwayman M20A, Nitecore D20, Fenix LD10-R4, Jetbeam Jet-I PRO EX V2, Eagletac P20A2-II.

M20A: Weight: 74.5 g (no battery), Length 151.1mm x Width 23.0mm (bezel)

Overall dimensions are about typical for this class of light.

Build quality is excellent. Note the square-cut threads at both ends of the battery tube. Screw threads are anodized at both the tailcap and head for lock-out. :thumbsup: As before, I would like to see a few more threads at the head region of the battery tube.

The tailcap switch is a typical forward clicky, with good feel. The light can tailstaind.

The magnetic control ring in the head allows you to choose between output levels. The ring has a good feel, although it can be hard to see (i.e. color matches the rest of the body anodizing)

Light feels very solid. Knurling is not very aggressive, but there are a lot of body ridge details to help with grip.

Anodizing is excellent on my sample, no chips in the dark gray natural finish (HA = type III). Note that natural color anodizing is by its nature more variable from sample to sample, and even within the components of a given light.

Lettering is sharp and clear, nice and bright against the black background.

As before, the clip seems to be fairly basic. It holds onto the light well, and can be positioned for bezel-up or bezel-down carry in a number of ways. But with all clips of this sort, there is always a risk the light might catch on something and be pulled off. I recommend you use the wrist lanyard if there is a risk of dropping the light. I am disappointed that a belt holster wasn’t included with the light.

The M20A features the Cree XP-G R5, with a medium textured orange peel (MOP) deep reflector. I am glad to see Sunwayman has made the switch to these newer reflectors.

Which brings us to the requisite white wall hunting ;). All lights are on Hi on 2x Eneloop NiMH, 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.

From now on, all my beamshots will be taken in this standard configuration, to facilitate comparisons.

As you can see, the M20A has a reasonably smooth beam for this class. There are some minor artifacts in the beam, but these are only noticeable on a white wall at really close distances. Scroll down to my Summary Tables for more specifics on output.

User Interface

The M20A has a similar interface to the earlier M20C/M10R and related lights.

As before, on/off is controlled by the tailcap clicky (press for momentary on, click for lock on). Mode switching is still controlled entirely by the magnetic control ring in the head.

The four control ring levels on the M20A are Lo – Med – Hi – Strobe, arranged clockwise if you have the light in hand, bezel pointed away from you. The total traverse of the ring is ~1/3 the circumference of the light, so you can switch back and forth with ease one-handed.

Unlike some control rings, there is no “standby” mode on Sunwayman lights with clicky switches – you turn the light on or off by the tailcap clicky (or by loosening the head to tailcap to lock-out). This is actually a good thing, since standby modes always drain power (i.e. they are electronic switches, and need to have power to operate). Although the standby drain can be minimized, on some lights they are considerable and will drain batteries quickly.

The control ring has a good feel, with noticeable resistance changes when it falls into place at each level (these are typically called “detents”).


There is no sign of PWM flicker by eye or with my sound-card oscilloscope on any level. Sunwayman lights thus seem to be current-controlled. This is particularly impressive, given how low the “Moonlight” Lo mode is.


Strobe was measured at a fairly high “tactical” 17.6 Hz, which is a bit higher than the earlier M20C/M10R.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's 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 any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

Throw/Output Summary Chart:

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see for a description of the terms used in these tables.

The max output and throw of the M20A is typical for this class of light. The Lo mode is quite low compared to other makers (i.e. more of a “Moonlight” mode).

See my runtimes below for info on the relative output levels.

Output/Runtime Comparison:

Note: my original M20A sample failed during testing, with only the Hi output runs completed (identified as #1 in the runtimes below). Sunwayman replaced the light with another sample, used to complete the testing (identified as #2). I have left both samples in the results below.

Output/runtime efficiency is excellent on the M20A, as expected for a good current-controlled light. :thumbsup:

In fact, performance of the replacement M20A sample (#2 above) is simply outstanding on Hi on Eneloop and alkaline batteries. I’ve left the original M20A sample (#1) in the runtimes above, as its performance was more in keeping with a typical light of this class. I would expect a given M20A sample would perform somewhere within this range of performance.

All-in-all, this is very consistent with Olight/4Sevens performance.

Potential Issues

Max output on L91 is lower than NiMH/alkaline. However, all output levels are maintained on L91 lithiums (i.e. many other 2xAA lights loose the lower levels initially).

The control ring lacks obvious visual landmarks, so it may take you a moment to find it when you want to change modes.

The circuit on my first M20A sample failed during testing. The head has been returned, and Sunwayman is investigating the source of the problem.

Preliminary Observations

The M20A is another solid offering from Sunwayman. :)

The physical design and build is similar across the Sunwayman line – and generally excellent. I find their anodizing to be among the best of the Chinese-made lights. The grip is reasonably good, with a lot of ridges and body details, although I could see how some would like more knurling. As before, I consider the clip to be most effective as an anti-roll device – I wouldn’t trust this design to securely hold the light. In that sense, it’s disappointing that no belt holster was included (although a good quality wrist lanyard does come with it).

The implementation of their magnetic control ring technology in the 2xAA form factor is consistent with their other lights. While no ring is perfect, the feel of the detents on their lights are good. I just wish it was a little more obvious where the ring was (i.e. may take you a moment to get the right grip).

I’m glad to see them going with the latest class of emitter (XP-G R5). The beam pattern is good for this class, consistent with other lights.

And of course, performance is excellent – can’t beat current-control for overall efficiency. :thumbsup: I’m particularly impressed to see the ultra-low Lo mode is also current-controlled (that’s not easy to do – few outside of Olight/4Sevens seem able to do this). I like this selection of relative output levels.

A well thought-out and well built light. Certainly another nice offering in the 2xAA class. :)


M20A provided by Sunwayman and for review.

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