[selfbuilt]

Sunwayman has recently updated their old XM-L continuously variable 1x18650/2xCR123A model – the V20C – with the V25C, a new XM-L2 model with higher output and revised control ring. In this review, I will put the V25C, through its paces … :whistle:

Manufacturer Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).

• LED: CREE XM-L2
• LED: Runs on: 2x CR123A or 1x 18650 (Batteries NOT included)
• Output mode/Runtime: High: 780 lumens / 1hr, Low: 0.1 lumens / 200hrs
• Peak Beam Intensity: 3140cd
• 360° fully-variable output control system
• High quality reflector maintains great throw distance and spread with an ideal beam pattern
• Constant current circuit, constant output
• Effective range of 112 meters
• Ultra-clear tempered glass lens resists scratches and impacts
• Aerospace-grade aluminum alloy body
• Military Specification Type III- hard anodized body
• Waterproof, in accordance with IPX-8 standard
• Included Accessories: Lanyard, O-ring, Rubber cap
• Dimensions: Length: 5.3" (134.5mm), Body Diameter: 1" (25.4mm),
  Bezel Diameter: 1.26" (32mm)
• Weight: 4.1 .oz (116g) (excluding batteries)
• MSRP: ~$66

Packaging is standard Sunwayman, and nothing fancy. Inside, included with the light are spare O-rings, a basic lanyard, spare boot cover, product insert and manual. I must say, I am a little disappointed to not see a holster, pocket clip, or grip ring – this seems to be quite basic packaging.




From left to right: AW Protected 18650 2200mAh; Sunwayman V25C, V20C; Olight M20S-X; Foursevens MMR-X; Fenix TK15; Klarus XT11; Eagletac G25C2-II.

All dimensions directly measured, and given with no batteries installed:

Sunwayman V25C: Weight: 117.3g, Length: 134.9mm, Width (bezel): 32.1mm
Sunwayman V20C: Weight: 117.4g, Length 133.0mm, Width (bezel) 32.2mm
Foursevens MMX: Weight 145.8g, Length: 153.3mm, Width (bezel): 38.7mm
Skilhunt S2: Weight: 133.0g, Length 153.0mm, Width: 36.0mm
Olight M22: Weight: 148.4g, Length: 144.8mm, Width: 41.2mm (bezel)
Olight M21: Weight 119.5g, Length 145.2mm, Width 38.5mm (bezel)
Eagletac G25C2-II (stock): Weight 141.0g, Length: 150.6mm, Width: 39.6mm
Eagletac TX25C2: Weight 93.6g, Length: 120.4mm, Width (bezel): 31.6mm
Klarus XT11: Weight 133.0g, Length: 148.8, Width (bezel) 35.0mm
Nitecore MH25: Weight: 145.4g, Length: 160mm, Width (bezel): 40.0m







As always, anodizing is excellent on Sunwayman – in a matte finish black on my V25C sample. Personally, I miss the older natural finish anodizing (which was a rich dark gray). In any case, there were no blemishes or damage on my V25C black sample. As usual, labels are bright white and exceptionally clear, despite the small font in places.

Overall build is similar to a number of earlier V20C, except for the reduced labels around the control ring, and the lack of a removable grip ring. As before, there is knurling on the tailcap and control ring, of reasonable aggressiveness. Overall grip is certainly ok, but a grip ring or pocket clip would help.

Screw threads are square-cut, but unfortunately no longer anodized (i.e., lock-out is no longer possible). There is some sort of darker coating on the threads of the body portion of the light, but these do not allow for lock-out. This is disappointing, but likely reflects patent/litigation issues with another maker.

There is a spring on the positive contact plate in the head of the V25C, as before. Higher capacity flat-top cells can be used.

The V25C can tailstand, but is wobbly on my sample (loosening the tailcap assembly may help).

There are no longer any detents (or labels) on the magnetic control ring – the ring can freely turn the full circumference of the light. Scroll down to my User Interface section for more info.



Reflector is textured to at least a medium orange peel, and fairly deep. Coupled with the XM-L2 cool white emitter (which was well centered on my sample), I would expect a fairly typical beam for this class. Scroll down for beamshots.

User Interface

As before, the V25C has a forward tailcap clicky - press and release for momentary on, click for locked on.

Mode switching is controlled by the magnetic control ring in the head. The V25C features a continuously-variable interface with full 360 degree rotation. There is no detent or mark to indicate the start or end of the output ramp. Holding the light in front of you, simply turn to the ring to right (i.e. clockwise) to increase output, and turn to the left (counterclockwise) to decrease output). See my ramping analysis below.

There is no strobe mode on the V25C.

Ramping Pattern



The original V20C used what was considered "visually-linear" ramp at that time. As I explained in V20C review, this wasn't a true visually-linear ramp, but rather a variation on the logarithmically-adjusted output ramp. In practice, this meant that the V20C spent a lot of the ring dynamic range at ultralow outputs.

The new V25C features a more consistent "visually-linear" ramp, organized around the well-established Stevens' power relationship for human perception of output (i.e., a cube-root relationship for non-point sources of light). Please see this post in my Sunwayman V10A review a detailed discussion of this power relationship.

To help you visualize this better, below is the ramping pattern plotted on a cube-root scale:



This is roughly how the light will appear to you as you turn the dial.

As you can see, the V25C is more consistently "visually-linear", and doesn't spend as long at the ultra-low levels as the V20C. But it does reach the max output earlier than you might expect for a fully-continuous ring (i.e., less than half the turning range). There is also a small stretch of the ring when no output is presented. If you keep turning pass this point, the ramp will commence again.

In practice, this is reasonable – but I would have preferred a clear detent, as least for Max or the full off position. As it stands now, you have no way to predict where you are in the ramp before turning on the light. And if you turn too far to the right when in Max, the light eventually shuts off without warning.

Video:

For information on the light, including the build and user interface, please see my video overview:

Прямая ссылка на видео YouTube

Video was recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen.

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.

PWM/Strobe

As before, the V25C appears to be current-controlled. There is no PWM that I can detect, on any level of the ramp.

There is no longer a strobe mode on the V25C either.

Standby Drain:

There is no standby drain when the light is clicked Off at the tailcap.

However, there is a standby drain if the light is clicked On but the dial is adjusted to the portion of the ring where no light is produced. I have measured this current as 13mA on an 18650 cell. That would translate into ~10 days before a 3100mAh cell would be fully drained. I note that this is much higher than the "off" standby detent of the original V20C, which was only 70uA.

As an aside, this standby current defines the maximum runtime of the light - it's not possible any of the lowest modes to exceed 10 days runtime, given this limiting circuit overhead.

In any case, I recommend you always leave the light clicked off at the tailcap when not in use.

Beamshots:

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.













As you can see, overall output has increased over the original V20C. Overall throw and output are reasonable for a general purpose light of this size.

Testing Method:

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.flashlightreview... 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).







Overall output for the V25C is very much in keeping with other recent 1x18650, 2xCR123A/RCR lights. Considering the overall smallish size of the V25C, this is a fairly aggressive drive level. The V25C is also capable of extremely low output (i.e., can set the ring so that the emitter barely glows).

Note that while the Sunwayman's ANSI FL-1 max output spec seems very believable to me, their beam distance spec seems very low. :thinking: My measurements are consistent with what you would expect for a light of this size and drive level.

Output/Runtime Graphs:




It is not uncommon for continuously-variable lights controlled by a magnetic ring to show some change in output over time. This is typically gradual enough for you not to notice, and you can always adjust the ring to fine tune your output over time.

But in the case of the V25C, it seems like any medium-to-high level setting (i.e., anything >50% max output) gradually increases in output over a few minutes to max output. :thinking: I don't quite know what to make of that … although I would note that all my runtimes are done on fully charged 18650 (in case that makes any difference)

In any case, overall output/runtime efficiency seems excellent for the V25C (when taking into account the actual light level produced). And as you can see at the lower level, the V25C manages to keep a fairly constant output (with a slight output oscillation that is not visible to the eye).





There is no step-down on Max on 2xCR123A/RCR – the V25C maintains a very high output level from the start. However, I did observe an instance of PTC engagement on my made-in-the-USA CR123A cells (i.e., that unusual looking trace above). I discuss the origin of this behavior in more detail in this thread, as well in my 2013 CR123A round-up review. It simply reflects what happens when you drive CR123A at a high level for too long (in multi-cell setups).

Potential Issues

Range of the magnetic control ring is the full 360 degrees, but less than half of that produces variable light. The rest of the time, the light is either in full Max output, or Off.

You can no longer select your desired output from Off (i.e., if you turn the ring when off you have no idea where you are until after your turn on again).

Similarly, since there is no detent/stop at Max. If you keep turning past the point of Max output, the light eventually shuts off (without warning). Simply turn back the dial slightly to re-engage at Max.

The V25C is heavily-driven on its Max level, without automatic step-down. I therefore suggest you limit runtime when on Max, and don't leave the light unattended.

My sample wouldn't maintain flat regulation at Med-Hi levels, and would instead slowly increase in output back up to Max (and then decrease in a largelly direct-drive-like manner). You would therefore have to continue to adjust the ring to keep a sustained Med-Hi level. At the lower levels, the light maintained consistent regulation.

Light lacks a pocket clip, as before, but also lacks a grip ring or holster now.

Preliminary Observations

The V25C is mainly a refresh of the V20C – but one giving you almost twice the max output. :ooo: The control ring has also been revised, to feature a previously-unseen full 360 degree rotation.

Of course, there may be a reason why we haven't seen that before – it's hard to know where your output will be before your turn on, and at some point along the dial, the light has to go from Max to Off. :shrug: Personally, I would have preferred detents (defined stops) for Max and/or Off. Alternatively, I suppose they could have had the light ramp both up and down from Max along the ring - but then it wouldn't have been clear which way to turn (i.e., at least now, you know clockwise will always increase output from off or low). Again, there is no perfect solution to this issue - and your preferences may vary from mine.

Note also that the ramp has been updated for a true "visually-linear" ramp (based on modern perceptual research), which I consider to be a plus. The ultra-low levels are all still there, albeit over a shorter portion of the ring turn. However, the ring spends almost half of its turn in Max output, which was unexpected. Personally, I'm fine with the dynamic control over less than half the turning range – it makes it convenient for one-handed use (although I still miss the detents). In any case, I suggest you pay close attention to the ramp testing results earlier in the review, to see if this suits your needs. :whistle:

A few other changes that are not so welcome are the increased standby drain in the Off region of the ring (although this may not matter if you are sure to always leave the light clicked off at the tailcap). Screw threads remain square-cut, but are no longer anodized for lockout (likely due to litigation issues). And some of the previous extras like the grip ring and holster are gone now. :shrug:

That said, the overall build remains one of high quality. Annodizing is excellent (black now instead of natural finish), and the light has good hand feel with decent knurling and an overall compact shape. The light remains very comfortable to hold and use.

Output/runtime performance is also excellent, consistent with other good current-controlled lights. This is particularly impressive, given the continuously-variable nature of this light. Regulation was a little peculiar on my sample though - the Med-Hi levels tended to turn back up toward Max over time. :thinking: Something to keep in mind, since there is no automatic step-down feature on Max (i.e., you would need to adjust output yourself).

Overall, the V25C remains a solid light, with a robust implementation of a true "visually-linear" continuously-variable control ring. It addresses the main perceived limitation of the V20C, which was its out-of-date max output level. The new V25C certainly produces a lot of light, although I personally prefer the detents on the original control ring. I hope you found the comparison overview helpful in making your own choice! :wave:

----

V25C provided by Sunwayman and Battery Junction for review.