Sunwayman is a top brand in high-end flashlights. Most well-known for their infinitely variable magnetic control rings, Sunwayman is now releasing lights featuring a "Smart Switch" on the side, either supplementing or replacing the industry-standard rear switch. On the C20C, Sunwayman has utilized the possibilities of an electronic switch to remove the need for a rear switch, and instead control all aspects of the light by the side switch. This significantly reduces the length of the light, allowing Sunwayman to create one of the few 18650 sized lights that is truly compact enough for every-day pocket carry. But don't be fooled by the size, this light is very powerful, and has surprisingly good throw.
Thanks to Sunwayman for providing the C20C for review.
Iíll be reviewing the C20C in two sections: first, Iíll discuss the light objectively (the facts about the light itself), then Iíll discuss the light subjectively (my impressions about the light's performance when used for specific applications). This is a compact, high powered light designed for a good throw/flood combo, so I'll be reviewing it as such. If you have any other specific applications you'd like the light tested for, let me know and I'll see what I can do.
Below is a video "quick review" you can watch in just a few minutes, if you're not up for reading the full review right now:
This video is available in 720p HD, but defaults to a lower quality. To select the playback quality click the settings button (looks like a gear) after you've started the video.
The C20C comes in Sunwaymans's standard (for small lights) red/black package with the cutout plastic displaying the light, and the stats printed to the side. Included in the package are the light and accessories, manual, warranty card, and add for other lights.
The C20C uses a single 18650 lithium ion rechargeable battery, two CR123 lithium primaries, or two 16340 li-ions. As you can see, the C20C is not much larger than the battery it uses.
This light has matte black (not grey, as some other SWM's) HAIII finish over aluminum, to help protect from scratches and chips.
Here's a quick size comparison of the C20C to some of Sunwayman's other small lights. From left to right: an 18650 battery, V11R, C20C, V20C, T20CS.
Now, let's take a closer look at the C20C, starting from the front and working back.
The C20C uses a Cree XM-L, U2 binned emitter. The U2 is currently the most efficient high-brightness emitter available. The LED is centered in a small, smooth reflector. Because the reflector is not textured, there are a few beam artifacts when close up, but it actually looks pretty good when the distance gets to about a foot. Due to the floody XM-L and small reflector, this would appear to be a pretty floody light, but it actually is surprisingly well focused. See the performance section for more details.
A stainless steel bezel ring protects the head and lens from getting dented on impact. The C20C has cooling fins both near the bezel, and a little further back next to the switch.
The rear of the head has four faces, one with an electronic switch, two sets of cooling fins to either side of the switch, and a low battery indicator LED opposite the switch.
When the battery gets low, the LED lights up solid red, then as it get's lower, the low battery indicator (LBI for short) starts flashing.
The body is round, covered with diamond knurling except for two sections. One section has the Sunwayman logo, the other has the model number and name.
The clip of the C20C is a removable clip-on, and has two small "ears" on the ends to make it easier to take the clip on/off without scratching the finish.
The tail of the C20C is plain and flat, with a section cut out to add a lanyard hole while still allowing the light to do a stable tail stand.
Now, let's take the light apart!
Without the use of tools, the C20C comes apart into two pieces: the head/body and the tail cap. The threads are small, square, and anodized, and feel very smooth. Because of their small size, it takes several turn to take the tail on/off. Because they are square an anodized, they should hold up well long term. The anodizing also allows the light to be mechanically locked out by slightly loosening the tail. When the tail is loose, the light will not be able to be activated accidentally, because the anodizing will prevent an electrical connection. This is helpful for keeping the light off while storing/transporting it for short periods. The C20C also has an electronic lockout feature, you can see the User Interface section for more info.
Inside both the tail and the body, a spring makes electrical contact with the battery(ies). This ensures a good connection with cells of various lengths, and also helps prevent damage to the cells in the case of an impact.
UPDATE: I've found that the bezel of the C20C is easily removable by using the palm of you hand, which isn't too exciting in itself, but the way the head is assembled opens a useful possibility:
The reflector can be removed, and the lens and bezel can be replaced securely. The reflector is not necessary to keep the lens in place, so when it's removed the C20C effectively becomes a "mule", or a light with just the bare emitter. As a mule, the C20C projects a very even circle of light with no discernible hotspot. This can be useful for time when you'd like a dedicated flood light.
The C20C comes with a clip-on clip, the standard Sunwayman lobster-claw lanyard, a velcro-flap holster, and two spare o-rings.
The C20C uses a single electronic side switch to access 4 brightness modes (Turbo > High > Medium > Low), 2 flashy modes (Strobe > SOS), and an electronic lockout.
When the light is off, a quick click will turn the light on to the last used brightness mode (or Turbo if you have removed the battery). From any brightness mode, holding down on the switch for about a second will advance you to the next mode in the Turbo > High > Medium > Low cycle, and the light will continue to cycle each second as you hold the switch, stopping when you release. Another quick click will turn the light off.
When the light is off, holding down on the switch for about a second will activate the momentary on function (at Turbo brightness), and the light will turn off as soon as the switch is released.
When the light is either on or off, two quick clicks will activate the Strobe mode. From Strobe, two quick clicks again will switch you to SOS mode, and vice versa. When in Strobe or SOS, holding down on the switch will activate Turbo brightness (continue to hold to cycle to lower brightnesses), or a quick click will turn the light off.
When the light has been off for more than 7 seconds, a quick click followed by a hold will activate the electronic lockout. While in electronic lockout, the light will not turn on. To leave electronic lockout, do another quick click followed by a hold. The light can also be mechanically locked out by slightly loosening the tail cap (see the Construction section of the review for more info).
You can click on any of these shots to see them full size.
Light in Hand
White Wall (Low, Medium, High, Turbo, with then without reflector)
ISO 100, f/3.3, 1/20"
BeamSlice (With Reflector, Without Reflector)
MugShot (With Reflector, Without Reflector)
Indoor Shots (Low, Medium, High, Turbo)
ISO 100, f/3.3, 1"
Outdoor Shots (Control, Low, Medium, High, Turbo)
ISO 100, f/3.3, 2.5"
Submersion: I submersed the C20C in about a foot of water for an hour, turning it on and off and switching modes (using both switches) during that time, and the light shows no sign of water entering or damaging the light. I do suggest removing the clip and drying it off to prevent rust.
Heat: The C20C gets hot very quickly when on Turbo mode, but it has a built-in timer to step down to High after about 5 minutes. You can choose to override this manually by cycling back to Turbo if you choose, but I recommend you only do so when confident that you are adequately cooling the light.
PWM: The C20C doe use pulse width modulation, at least to some extent, but I cannot see it at all in normal use, or even looking at a fan or running water. I can detect very fast PWM on Low mode by setting my camera to it's shortest exposure (1/4000"). I cannot detect PWM on any other mode, but most lights the use PWM at all, use it on all but the highest mode.
Drop: I dropped the C20C from a height of about 1 meter onto various surfaces including grass, packed dirt, carpet, and wood. The light shows no cosmetic damage and still functions normally.
Reverse Polarity Protection: The C20C has electronic reverse polarity protection. This means that if you insert the battery backwards, it will not damage the light (it just won't work until you put the battery in correctly). Because the protection is electronic (not mechanical), the C20C can still accept flat-top cells.
Over-Discharge Protection: The C20C also features a low battery indicator (LBI) that will alert you when your battery needs recharged. You can see more about the performance of the LBI further down.
All light that we see as white is actually made up of several different colors put together. The relative intensities of the different colors in the mix are what determine the tint of the white we see. For example, cool white LED's have a lot of blue, and warm white LED's have more red or yellow. This measurement was done on a home made spectrometer. The plot below the picture is corrected for the spectral sensitivity of the human eye. Note: the peak in the 900nm region doesn't really exist, it's a piece of the second-order spectrum that's showing up here because of the high intensity of the light source.
Output and Runtime
ANSI FL-1 runtime ratings are the time it takes for a light to fall to 10% of it's original output (counting from 30 seconds after turning the light on). *The C20C automatically steps down from Turbo mode to High mode on a 5 minute timer to prevent overheating. If you desire, you can turn it back to Turbo manually after the auto-stepdown.
The vertical axis of the graphs below represents a relative brightness measurement using a home made light box. The horizontal axis is time in hours:minutes:seconds. Runtimes are stated in hours:minutes:seconds. These graphs may be truncated to show detail.
------ 1x18650 ------
------ 2x16340 ------
Note: I would normally run these tests with 2x16340 AW cells, but one of my AW 16340's is missing, so these were ran with lower quality Ultrafire cells.
ANSI FL-1 standard for stating a light's throwing distance is the distance at which the peak beam intensity (usually at the center of the beam) is 0.25 lux. I calculate throwing distance and candela (lux at 1 meter) by measuring peak beam intensity at five different distances and using the formula lux*distance^2=constant.
Peak Beam Intensity: 4968cd
Throw Distance: 141m
Low Battery Indicator
The C20C features a low battery indicator (LBI for short) that alerts the user when the voltage of the battery drops to a certain point. When the battery gets to about 3.5V, the LBI turns on solid red. When the battery gets to about 2.8V, the LBI starts flashing.
Here's a quick video showing a few seconds of the low battery indicator blinking:
This feature is mainly for when using a single 18650 lithium ion battery. For safety, I always recommend using a protected li-ion cells, but this feature is helpful for letting you know when to change the battery before the protection circuit kicks in. So, when using an 18650 you should change your battery and re-charge the depleted cell when the light first comes on, if possible. If you're still using the cell when the LBI starts flashing, it's definitely time to re-charge. Li-ion cells can usually handle going that low a few times, but it's best not push your luck by letting it happen often.
As a side note, when the LBI detects the voltage of the battery to be 3.5V, it will actually be the voltage under load. While a battery is being used, the voltage appears to be a bit lower than if the battery has no load. This is called "voltage sag", and the sag is greater when the load is greater. So, when the LBI detects 3.5V, it will turn on. If you were to take the battery out and measure the voltage right away, you would measure 3.5V, but if you wait a little while for the battery to recover, then measure again, you'll see the voltage rise back up to the resting voltage. When using Turbo or High mode, the LBI could activate significantly prematurely, because of the heavy load on the battery. When using Low mode, the true resting voltage of the battery will likely be very close to the LBI voltage threshold when it activates, because of the very small load. So what this means is, if the LBI activates while you are using one of the higher brightness modes, you can often switch to a lower brightness and the LBI will turn back off for a time.
When using 2xCR123 batteries, the LBI isn't too much of an issue, because lithium primaries can be fully depleted and then thrown away.
When using 2x16340 lithium ion batteries, the LBI will not activate in time to warn you to change the batteries. By the time the combined voltage of the two cells reaches 3.5V, the individual cells will be about 1.75V each, which is well below the safe voltage to discharge a li-ion. If you are using protected cells, the protection circuit should activate well before this time. If you are using unprotected cells, you'll most likely have to throw them away if you see the LBI turn on.
Quick break down:
+Surprisingly good throw
+Can accept primaries or rechargeables
+Great regulation on any power source
+An 18650 compact enough to pocket
+Low battery warning at good thresholds
+Clip is better than the V10R clip
+Solid tail stand, even with lanyard attached
-Clip is still a clip-on
-Low could be lower
-No magnetic control ring
Sunwayman's made another winner here with the C20C. As I mentioned in the intro, there are few 18650-powered lights that can truly fit comfortable and unobtrusively in a pant pocket, and this is one of them. I currently EDC a high-CRI V11R, but I'm looking to replace it with something 18650 powered. This just might be the thing.
Really, it was tough to come up with negatives for the C20C. What can I say.. it's not made of titanium? No tritium slots? No magnetic control ring? Honestly, my desire is for Sunwayman to make a light just like this, but with two changes: a sub-lumen low, and a magnetic control ring (if it doesn't add more than a few mm in length). I realize this would most likely cut out the LBI, but I'm OK with that.
On the other hand, it's pretty easy to list things I like about this light. At the top of the list, the ability of this light to throw from such a small package was a pleasant surprise. The reflector is small, but it much be just perfectly shaped to aim the light in the way it does. I also appreciate the good regulation on all power sources, SWM is definitely getting better at that.
Sunwayman has also set themselves apart by making their lights incredibly more stylish than the majority of the competition, and the C20C is no exception. This is one of those lights that is just appealing to use. Also, I'm not sure if they purposefully designed the light to be able to operate without the reflector (but still with the lens secure), but I'm really loving that option. If they did it on purpose, I salute them for attention to detail. If not, I salute them for luck.
I think that Sunwayman has also done a good job improving the LBI, causing the light to come on at a slightly higher voltage. I remember the LBI on the T20CS came on a little too late for some people's liking, and now a warning at 3.5V should make most of us happy, especially considering that 3.6 or 3.7 V is considered the ideal for storage. In this case, you know that if the light is not on, it should be OK to store your cell for time, but when the light comes on you know you'll want to charge it.
Overall, the C20C is a great compact 18650 light. Some people are wondering if it's meant to compete with Zebralight's SC600, and if that was SWM's intention, I think they pulled it off pretty well, and for a significantly lower price! If you need a super-low Low mode, you'll have to look elsewhere, but for most tasks 5 lumens shouldn't be too shabby . I don't hesitate to recommend this light if these are the things you're looking for.
Long Term Impressions
I'll fill this part in after carrying the light for a while. If nothing get's added here, either I find nothing else worth noting about the light, or I end up not using it often.