Review: Sunwayman C21C (XM-L2 | 1 x 18650)

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_the_'s picture
Last seen: 2 months 3 weeks ago
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Posts: 3647
Location: Finland
Review: Sunwayman C21C (XM-L2 | 1 x 18650)

Sunwayman C21C (XM-L2 | 1 x 18650)

This flashlight was provided for review by

Reviewer's Overall Rating: ★★★



Battery: 1 x 18650
Switch: Side switch, electronic
Modes: 11: 4+2 white, 3+2 red (blinky modes are hidden)
LED Type: XM-L2 (CW)
Lens: Glass, AR coated
Tailstands: Yes
Price Payed: Review sample. Retail price $67.31
Date Ordered: October 2013



  • Handy size
  • Fresh design with integrated Anti-roll feature
  • Good build quality
  • Good thermal characteristics - no problems during 2.5h runtime test without any cooling
  • Side clicky (with negligible parasitic drain -> no worries!)
  • UI is pretty nice, allowing also the use of morse code without accidentally changing modes
  • Nice beam with LOP reflector
  • Nice tint for CW (near neutral)
  • Well spaced modes (low modes could be even lower, both on red & white)
  • Hidden blinky modes
  • Secondary red emitter for night vision (or signaling)
  • Blinky modes available also with red emitter
  • Current regulated -> No PWM on any mode
  • Good regulation & runtime
  • Flat bezel
  • Square threads (also anodized -> can be locked out)
  • AR-coated lens
  • Comes in a retail box, suitable for gifting


  • Mode memory doesn't remember the last used mode after using other emitter! After using white emitter, the red emitter always starts on high (and vice versa)
  • Lens in front of the red emitter is red -> not possible to mod with white emitter and use as head lamp
  • Red lens protrudes and is on the opposite side than side clicky  -> "automatically" hits the surface when putting the light down (hasn't scratched yet, but I'm afraid it will)
  • Side clicky protrudes a bit -> may cause the light to turn on in your bag -> remember to lock out!
  • Protected button top NCR18650B barely fits => might have problems with your longest cells
  • Low modes could be lower
  • No clip

Features / Value: ★★★★

The light comes in a retail box which contains the light itself, lanyard, three extra O-rings, warranty card, an ad, and a manual (in English and Chinese). Note also a spelling mistake..

The box says also "independent dual light source", which is not the whole truth, as the emitters can't be turned on simultaneously.


This light has as many as eleven well spaced, current regulated modes. Blinky modes are available, but well hidden.

UI is otherwise very good, but the mode memory issue surprises the user once in a while.. 


Normal operation is very straight-forward:

- Click on (white light, last used mode), click off

- Use of Morse code is possible, as long as the light is on or off more than 0.3s (see blinky modes)

Changing modes:

When the light in on, keep the button pressed to start changing modes (starts from current mode, in order: Turbo -> High -> Med -> Low -> Turbo -> ...), release button to select that mode (this mode is remembered after turning off and on again)

Blinky modes:

- Fast, less than 0.3s, double click (no matter on or off) for strobe

- Another fast double click for SOS

- Click to return to normal mode (remembers in which mode you were before activating the strobe)

Red emitter:

- When the light is off, long press to turn on red emitter

- Click to turn off (*

- Long press while on to change modes (*

While red light is on, fast double click to turn on red strobe (and another for red SOS) (*

(* Same as white light

So far the UI looks very good, but alternating between white and red light causes an unpleasant surprise: Mode memory is reset when changing to other color. Imagine a situation where you use red light on with lowest setting to read map, then turn on the white light to look in the woods, and turn back to red light to continue with the map and get blinded by the bright red light bouncing to your eyes from the map!

The turbo mode has an automatic step-down feature: If the turbo mode is used over 4 minutes, the light steps down to high mode (~200lm less) to prevent overheating. If you want to continue with turbo, you can go back to turbo by long-pressing through lower modes.


Value for money: Ok!


Design / Build Quality: ★★★

Design is very fresh, something different than usual lights. This light is surprisingly small for a 18650 light, but has large enough head for heat dissipation. At the first look, the head seems to be square, but the rounded corners makes it feel good in hand.


On the one side of the head is the red emitter, lying under a red lens. Please note that both the emitter and lens are red, so simply changing the emitter to white doesn't make this light a white headlamp.


..and on the opposite side is the side clicky. The switch is quite small, but very responsive and feels good in use.


The seemingly big head doesn't affect the balance negatively, in fact it's the opposite: This light feels very well balanced in hand and the side switch is exactly in the right position (even if the light is small and I don't have the small hands).

The anodization is very good overall. Nice matte finish makes me think that this really is type III hard anodizing. There are no nicks or dings and the light feels to be great quality overall.


Bezel is flat and emitter well centered. Just like I want 'em! LOP reflector projects a smooth and nice beam.


Lens is glass and clearly AR-coated:


Let's see some details.. 

Tailcap taken away. Here we can see the slightly lubed, anodized, square threads and thick O-ring.


A look to inside of the body tube. Driver is mostly hidden under a (plastic?) ring and the only thing which can be seen is a spring. The head is tightly glued to the body tube. I wasn't able to open that seam even with two heavy duty strap wrenches. Sad


The spring at tailcap is thick and of good quality. Nothing else to see here.


Head opened up from the white emitter side. Emitter sits on a thick platform, secured with two screws, there is some thermal paste and even the leads are well soldered. Good quality can really be seen here! White lead between the black and red goes to red emitter.


The red lens protrudes quite much and as it is located on the opposite side than the side clicky, it's natural to put the light down so that the lens hits the underlying surface. This might cause scratches in long term, but I haven't noticed any so far. Maybe I should develop a habit of putting the light down with the "empty" side facing down..



..or simply put it down on soft surface. Smile


Compared to other well known 18650 lights (from left to right: DQG18650, SWM C21C, Convoy S5, XinTD C8 v3):

Some measurements:

Length: 107mm

Head diameter: 26.9mm

Body diameter: 21.5X23.4mm

Tail diameter: 27.0mm

Lens diameter: 22.8mm

Lens thickness: 1.0mm

Reflector diameter: 20.9mm

Reflector depth: 11.3mm

Weight: 124g with one 18650 cell (= ready to use), 79g without


..and here's some pictures confirming the measurements:







And the bottom line in the quality: Absolutely nothing to complain!


Battery Life: ★★★★

Good! 18650 battery and good mode arrangement will allow long runtimes.

I measured the tailcap current and got results of

White: 2.4A on Turbo, 1.6A on High, 0.4A on Med and 0.07A on low.

Red: 0.6A on High, 0.3A on Med and 0.08A on low.

As this light has electronic switch, it has parasitic drain. However, it was measured as 12uA, which can be considered negligible.

This would give only about 1.3h runtime on Turbo, but the step down helps a lot, enhancing the runtime over 2h on Turbo/High.

Calculated runtimes for other modes are: 2.1h on High, 8.5h on Med, and about 45h on low!

I would like to see yet another low-low mode with around 1lm (or 0.005A) no both white and red, which would give us around 500h runtime.


Light Output: ★★★


Runtime graph: (Panasonic NCR18650B 3400mAh cell)

The first almost four minutes are on turbo, rest of the run on stepped down level (high). This runtime test was done indoors, with ambient temperature of 23°C, without any additional cooling. Maximum temperature during the test was 63°C, at 1h25min. This light seems to be well regulated and handles the heat very well.

This light has kind of a low voltage warning (light blinks and continues with low level), which kicked in at 2h14min. Light did shut down at 2h22min, when the cell voltage was 2.9V.


First hour performance graph for the red emitter: 



The initial light output on Turbo was 780lm and ANSI-readings (OTF, after 30s) were:

- 707lm on Turbo
- 500lm on High
- 153lm on Med
- 27lm on Low


- 113lm on High
- 63lm on Med
- 14lm on low 


Those measurements do match pretty well the advertised values, except on the turbo, where Sunwayman might have taken the initial value(or used some kind of cooling?)


Measured throw was 8.5kcd / 185m


Tint is good (for CW) and beam smooth. Lower modes show some tint shift to greenish side, as usual for current regulated lights.


White wall beamshots (1/200s, f/5, ISO80, WB: Daylight)

White: Turbo, High, Med, Low



Red: High, Med, Low



Red, with increased exposure (1/50s):



Beam angles:



Outdoor beamshots:

Coming soon.


Summary: ★★★★

A small dual-purpose light with refreshing new design. Build quality is typical for Sunwayman lights, very good. Thermal design and driver efficiency are top notch, but the UI (memory issues) leaves a bit to ask for. All in all, very good small flashlight for multiple uses.


Verdict: Recommended!


The End (pun intended):


Thanks for reading & watching. Hope you enjoyed the review!



Edited by: _the_ on 11/10/2013 - 04:55
Last seen: 2 days 12 hours ago
Joined: 02/03/2012 - 15:52
Posts: 740

Very helpful, thank you Smile

djozz's picture
Last seen: 5 days 7 hours ago
Joined: 09/07/2012 - 17:04
Posts: 18291
Location: Amsterdam

Thanks for the nice review, with perfect photographing. It sounds like a very good light, although I do not really like the styling of these new Sunwaymans (sort of retro eighties, my first clock radio looked like this Wink )

Last seen: 9 months 4 weeks ago
Joined: 06/03/2012 - 13:05
Posts: 738
Location: Vietnam

Thanks the. That’s one powerfil review!

_the_'s picture
Last seen: 2 months 3 weeks ago
Joined: 07/08/2011 - 06:22
Posts: 3647
Location: Finland

Banggood representative did read this review, liked it, and provided us with a coupon:

Sunwayman C21C for "Price too low to advertise" with coupon bgf134

Sunwayman is known to have MAP => "Price too low to advertise"

The price is very good, but please don't post it here.



kronological's picture
Last seen: 4 years 9 months ago
Joined: 12/12/2012 - 09:23
Posts: 3042
Location: Texas

Very tempting. You can see Sunwayman’s attention to detail and thoughtful design in your pics. Excellent job, as usual, on the review!

No one, after lighting a lamp, puts it away in a cellar nor under a basket, but on the lampstand, so that those who enter may see the light.

My Reviews: Ma

Last seen: 1 week 4 days ago
Joined: 01/30/2011 - 18:18
Posts: 709
Location: UK

Thanks for the review. SWM have some really good new ideas and designs right now which I like.