Review: UltraFire C20 / Crelant 7G3CS clone

UltraFire C20 / Crelant 7G3CS clone

Reviewer's Overall Rating: ★★★★★

Summary:

Battery: 1x 18650 unprotected/protected, 2x CR123A
Switch: Forward clicky + micro switch for mode selection
Driver: Proprietary switching buck driver, 3.0V - 6.0V
Modes: High, Low, Stand by + dimming, fast 10Hz strobe, SOS
LED Type: XM-L 1C (Cold White) unable to comfirm or deny U3 bin at the moment
Lens: Coated glass lens
(single violet coating on both sides it seems, or 2 coatings blue and red?)
Reflector: SMO - smooth
Tailstands: Yes, perfectly
Body: Aluminum, looks similar to D4/Xiaozhi finish
Price: $31.20, use a coupon "C20", gives $2 discount to $29.20
Valid from 2013-03-18 to 2013-03-28
From: LightsCastle.com
Shipping: 6 days from HK to EU! 2013-03-07 sent, 2013-03-13 received,
trackable via HongKong post

Dimensions:

Battery: 19.1*72.25mm
Power Switch: 18mm, 19.25mm max
Mode Switch: Unknown microswitch on a small PCB
Tail cap: 14*7mm, 14*8mm max
Driver: 19*8mm, there is around 16*5mm inner space for components, then it gets smaller in diameter again (to probably 14mm) and that is a space for cables with depth of 4.4mm. There seems to be enough space on battery side as well if the spring assembly is changed. Retaining ring has 17.0mm inside diameter and is 2mm thick with outside diameter of 19.9mm
LED MCPCB: 12.8mm, 15.2mm max
Lens: 23*1.6mm,
Reflector: 23.0*19.1mm
Pill: LED mounted directly to head, no screw in pill.
Thickness of aluminum below LED MCPCB is only 1mm.
O-rings: 20*1.5mm - body to head, 20*1.5mm - head to head extension,
18.5*1.5mm - switch assembly, 23*1.5mm - lens
Body: 134.9*25.0*22.1mm

Pros:

  • Well designed mode operation
  • Not pure PVM, though some slight flickering can be sometimes seen on camera (very hard), sounds like 12-16kHz noise to me, I do not think it switches completely ON/OFF just has a frequency at some output level. It's normal with switching buck drivers with a coil.
  • Dimming
  • 10Hz strobe and SOS are hidden behind a fast double click at any time
  • Forward clicky switch turns on high every time
  • Unless powered off it remembers 2 custom light outputs
  • Light weight
  • Great flawless finish
  • Smooth square threads
  • Stainless steel bezel on head and tail
  • Chromed steel pocket clip
  • Bigger than average reflector, 23mm that is also deep 19mm, nice beam and throw for the light size
  • Coated glass lens
  • Smooth reflector = less light loss
  • Works with 2x CR123A as well = can buy primaries if need be
  • Does protect lithium battery over discharge (around 2.8V) and does warn you in advance (around 3.0V)
  • Slimer body than averegy
  • Comes fully featured with anything you might want and not get with other lights (coated glass, clip, stainless details, mode switch, dimming, operation on primaries, holster)
  • Clip easily removable without tools, but stay on strong
  • Well designed (Crelant) and built (UltraFire)
  • Does not overheat on high
  • Unprotected battery safe (tested)

Cons:

  • Longer than average
  • Knurkling could be more pronounced
  • No options on LED tint and a rather smaller MCPCB
  • Questionable waterproofness of mode switch - will have to test later
  • Holster is quite narrow but tall enough
  • Constant brightness only on high in the range of 4.2-6.0V
  • You might not like that it starts always on high, depends on your needs and preferences
  • This driver type does take some type to start, you will probably not notice unless trying to do fast strobe with it, tapping the power switch. It may be around 100ms
  • Power switch depth is a bit bigger and you do have to press a lot inside due to the stainless steel bezel
  • Disassembling the mode switch might be a bit of a pain, it should unscrew from the outside if you can get a grip on the stainless steel ring

Features / Value: ★★★★★

Comes in a bubblewrap envelope plus extra packaged in LightsCastle box with bubble wrap and hiding already in the holster. It has black O-rings and a black silicone boot, will tailstand by default. Driver is a custom switching buck driver with a wide voltage range of operation from 3.0V up to 6.0V (tested, maybe higher but not officially on UF C20). It features 2 switches, main forward clicky power switch in the tail cap and a mode microswitch on the head. Power switch always turns on high and mode switch will switch between High/Low/Standby(Off) in that order, at any time you can do a fast double click and it will turn into fast 10Hz strobe, another fast double click changes to SOS, with a single click you return to Standby. When on High or Low you can hold the mode switch and it will start dimming/ramping (after about 2-3s) the output down/up/down/up/... as long as you hold, when it reaches maximum it flashes 3 times, no signal on minimum. CPF - selfbuilt: UI video description. Minimum output is very low, it is possible to look into the light, I wouldn't say it would wake up somebody when turning that on in the night, you can't see the beam during a cloudy day indoors on minimum. You can reprogram via dimming both High and Low mode to any output you like and it will remember that as long as you do not switch off the main power via power switch. When you use the power switch it always starts on High with both High and Low mode set to their default brightness. You can use the mode switch to turn off the light into standby as I call it and it will rememer your settings of High and Low mode. Yes you can make both modes the same, basically any output from ~1 lumen to maximum (500 lumens). Only body to head is screwed (tail is part of the body) and it has 2 places for O-rings, only one is used and the more inner one might get caught in the threads a little if used. All O-rings are already installed, no spares. Head extension, lens, power switch has an O-ring. It also comes with a holster that is a bit tight/narrow to insert the light, it's stretchy though and will hold very well when inserted. Emitter is an XM-L 1C cold white on a small 12.8mm aluminum MCPCB.

It is a good value for the money, already comes with many extras other cheaper lights do not have and you would have to pay for if wanted when modding.

Rivals:
Crelant 7G3CS, $45
SUNWAYMAN C20C, $70

Given price and features it competes very well with other flashlights of similar design. Main reason for this being it's a copy of Crelant 7G3CS. Either like it and save some $ or buy the original and probably completely same light for $45. Compared to other lights like the D4/Xiaozhi it has many features already that would bring the price of D4/Xiaozhi above $30, clip, coated glass, holster, dimming/ramping, leaving out the nearly impossible modes to have stainless steel bezels and mode switch.

Package and overall:











Design / Build Quality: ★★★★★

Manufacturing is very good to me, all edges are clean, nothing sharp, even compared to Crelant pictures from CPF the holes on tailcap stainless steel bezel are rounded, cleaned, unlike on the Crealant. I have not noticed any problems with quality apart from one spot where the paint got scratched probably and that the wires could have heat resistant insulation. Do you get these on Crelant? I do not know. Design is good (Crelant) and so is manufacturing (UltraFire) of the parts. Assembly is good and nothing to complain about. O-rings everywhere to ensure waterproofness, my only concern is the design of the mode switch, whether it is waterproof (submersible) or only rainproof. There is plenty of plastic inserts, emitter MCPCB is centered by one as well and reflector sits nicely on the plastic. Nothing wobbles or moves. Body is aluminum with only one little nick near the mode switch, the finish is a nice matte black but cannot comment on it's durability or how hard anodized it is, Crelant 7G3CS is HAIII, maybe UltraFire copied that as well but does not say as they also do not say it has a coated glass lens! The body is slim and has checkered texture, it could be more pronounced though. Flashlight tailstands and headstands perfectly. Nothing is glued and the only part I opted to not disassembly was the mode switch. MCPCB has thermal compound below it, not glued.

Driver is a switching buck converter type. It operates on a wide range of voltage from 3.0V to 6.0V, maybe even higher but UltraFire puts the cap on 6.0V in specifications. I couldn't identify the integrated circuit so as to avoid frying it I stopped testing at 6.0V as well. There is a frequency in the output but it is very high (12-16kHz) and in my homble opinion is not a PVM as it does not seem to switch fully on and off but it is more like a noise in output, an output ripple. CPF review of Crelant 7G3CS also noted that.

Battery compartment is big enough for unprotected 18650s, but also for 18650 with a button top and a protection board like a 69.6mm Sanyo UR18650FM. A battery of dimensions up to 19.1*72.25mm should fit without any modifications needed. There are gold plated springs on both battery contacts. Unprotected battery may rattle a little to the sides when the light is shaken but an electrical tape around the battery should solve it nicely if it bothers you.

Weight is 70g, same as D4/Xiaozhi, to my surprise even the heads feel the same weight with all the internals. D4 body is more thick and provides better grip. The dimensions do not change the weight as you might think. C20 longer body is slimmer and the head weights the same since D4 has a heavier brass pill.

Upon arrival there was no dust on the emitter or the reflector. Finally a light that came in clean.

Pictures of a flashlight murder, I mean, disassembly:




























Zoom in/click it:

Battery Life: ★★★★★

As expected, nothing unusual, it eats battery power like any other flashlight. All measurements were done on the tail cap, therefore they are not the amperages through the emitter! These are very likely higher. I may measure these later when modding it with XM-L2 T6 3C. Maximum output is rated at 2.4A (UltraFire, Crelant is at 2.0A). Measured with a DMM (10A range) with thick leads and a freshly charged Sanyo UR18650FM, but mostly the table will be with my CC/CV adjustable buck driver able to supply from around 1V to 10V at up to 4A, giving me the option to test all the way up and down the range.

UltraFire C20 - current draw
Vcc [V] 3.50V 3.60V 4.20V 5.00V 6.00V
Max [A] 1.00 1.18 1.92 1.85 1.55
High [A] 1.00 1.18 1.92 1.68 1.45
Low [A] 0.10 0.10 0.17 0.25 0.34
Min [A] 0.00 0.00 0.01 0.01 0.01
Sby [A] 0.00 0.00 0.00 0.00 0.00

UltraFire C20 - power draw
Vcc [V] 3.50V 3.60V 4.20V 5.00V 6.00V
Max [W] 3.50 4.25 8.06 9.25 9.30
High [W] 3.50 4.25 8.06 8.40 8.70
Low [W] 0.35 0.36 0.71 1.25 2.04
Min [W] 0.00 0.00 0.04 0.05 0.06
Sby [W] 0.00 0.00 0.00 0.00 0.00

UltraFire C20 - estimated LED current
85% 3.15V 3.15V 3.20V 3.25V 3.25V
Vcc [V] 3.50V 3.60V 4.20V 5.00V 6.00V
Max [A] 0.94 1.15 2.14 2.42 2.43
High [A] 0.94 1.15 2.14 2.20 2.28
Low [A] 0.09 0.10 0.19 0.33 0.53
Min [A] 0.00 0.00 0.01 0.01 0.02
Sby [A] 0.00 0.00 0.00 0.00 0.00





Update:

LED current (XM-L2 T6 3C):

Modded driver, LED current (XM-L2 T6 3C):


Bear in mind these are aproximate, only a few measurements it still took quite some time to do and write it all down. Yes the driver could be better for a single lion cell but probably will have the same output curve as a Nanjg 105C or other AMC7135 drivers. The advantage is it's a switching type and can handle 6.0V.

Freshly charged Sanyo UR18650FM protected 4.13V (open circuit) has been drawn on high/max 1.7A, low 0.15A, min 0.00-0.01A. Some other numbers, open circuit voltage, batteries either Sanyo UR18650FM protected or Samsung INR18650-20R unprotected (yes the 2000mAh unprotected power beast able to give 20A): 3.9V high 1.38A, 3.8V high 1.26A. It can safely run on an unprotected battery and it will shut down around 2.85V, lowest measured shutdown was 2.7V. It does warn you around 2.9-3.0V with 10 slow flashes that you should change the battery. I've let it run down on high, tailstanding, it gets warm but you can always grab it and it won't burn you and your hands will cool it down. Battery was raising 2.95-3.00V afterwards when I got to it. You don't have to worry much about it overheating really as the output power is reasonable, just on the limit for this body size. UltraFire says it is a 2.4A maximum, which is probably true at the voltages above 4.2V. 4.2V gives the highest current draw from the power source, it goes down from there to both sides. With higher voltage the light output seems constant from around 4.2V all the way to 6.0V. You can also see that in the power being drawn that it is flat. The graphs should have the highest point at 4.2V so the lines are not precise and I couldn't get it to plot correctly with trendlines either, would probably have to make much more measurements. More real current draw with 18650s is probably 2A for the UltraFire C20. It probably draws a little current in the standby mode but it does not show on my DMM in 10A range, would need one with a wide precise measuring range to measure 2A and at the same time be able to measure units of mA or uA. There is one trick possible when powering it with an adjustable powersource instead of a battery. As you maybe noticed there is a max setting added to the high one. Max means I've used the dimming/ramping function and after it blinked on me I've let the mode switch go. That one would expect would be the maximum = high setting. It is like that on the lower voltages but not on the higher ones as you can see. Now here comes the trick, set the power to 6.0V and cycle it to maximum it will draw 1.55A from the power source, now lower the voltage of the power source to 3.9V and it will draw 2.62A. Yes the driver could be better, much better, have a stable output between 3.0-6.0V on all modes. But with that we are probably talking about a light that costs $100+? I have no idea what the integrated circuit is as it has no label. Somebody could guess? Or knows from their Crelant light? Also anybody knows what the sensing resistors are to change the output?

Light Output: ★★★★☆

Can't measure output but will provide pictures. On high it nicely illimunates the whole room when pointed to the ceiling. The drawback to me is the cold white emitter. Have been walking and running with it outside in complete darkness and it has a decent throw to me, usually used some medium output. It can reasonably illuminate trees and buildings up to 100m. Beam seems very nice to me, it is slightly tighter than the D4/Xiaozhi with a clean focused hotspot. It has a lot of output for indoor use but works well outdoors as well. I'm taking one star down for the cold tint, otherwise there is nothing bad with the output, it is better than the D4/Xiaozhi apart from the tint which is a personal preference.

Beamshots showing a comparison with D4/Xiaozhi;
D4 - Samsung INR18650-20R unprotected: High 2.11A, Medium 1.04A, Low 0.11A,
UF C20 - Sanyo UR18650FM protected: estimated LED current, High 1.76A, Low 0.16A:

Precise LED current may vary, temperature freezing -5°C or so.
I would still say that C20 had a little less current on high than D4.








The trick:



Outputs at 6.00V:



Minimum output:





Adjustable switching DC/DC buck converter:



Summary: ★★★★★

There could be more to write about the light, but I hope pictures will say more than words. One thing to note is be careful when pulling the plastic around the spring from the battery side as it was really stuck on mine and I managed to elongate the spring. That meant to take the whole thing down completely because after desoldering the spring it would not get soldered back so I took the driver out in the end etc and did it properly. It could be smaller in design as proved by Sunwayman that made a side switch light that is shorter than the D4/Xiaozhi. Does the side switch make any light longer? No. It really does not, it is on the side of the MCPCB and driver cables. What makes the light longer then? The deeper reflector, the stainless steel screw in bezels on both ends, the driver spring assembly. The advatange of the length is that the lens seems quite deep and protected. It comes with a chrome clip (not stainless steel, it is very magnetic, I've checked all the shiny parts with a magnet, only the clip is much more magnetic and seems chromed), stainless steel bezels and switch part, square threads on body tube, side switch, dimming/ramping, forward clicky power swith that starts always on high, hidden strobe and SOS modes, battery undervoltage protection for a single lithium cell. Design is nice and despite it being a clone light the manufacutring and assembly is flawless on my sample. The head is flat on one side but it does not help it from rolling, what does stop it to roll is the switch or clip. You can take the clip on and off in a second and stays on well. It is small enough and easy to carry in a pocket but it is slightly longer than other single 18650 lights. Tested it outdoors in freezing temperatures, no problems. If the mode switch is water tight it should withstand going underwater. Some of the flaws I see on it is the LED tint, thickness of material under the MCPCB, small MCPCB, wires that are not heat resistant and the driver not being made to have constant brightness with a single lion cell on all modes. PWM noise is not an issue and it's only coming from the coil I think, it's quite hard to hear it with the light to my ear. Overall it is a good flashlight for a reasonable price for what it has, hardly it will be possible to find a similar light for this price.

Flashlight was kindly suplied by LightsCastle.com for a review via BLF thread: Asking BLF members to Write reviews for us, probably selected/requested by other memebers, I've made no specific request.

There is a special coupon code "C20" that you can use on LightsCastle.com after adding UltraFire C20 to your shopping cart, it will give you $2 discount on the flashlight from 2013-03-18 to 2013-03-28, bringing the price down to $29.20.

As far as I've been able to search for this light and similar flashlights LC is the cheapest even without the discount. Only other place that has it is dx.com for $34.60, that's more than $5 plus. Original Crelant 7G3CS is around $45 (150%) and Sunwayman C20C at a whopping $70 (233%).

I think this is a must get if you like the features of the light especially the driver and modes. Yes it is modable but you should reprogram the Nanjg 105C for a mode switch if you use Nanjg 105C, other thing that you might want to get moded is the MCPCB and there lies the limit of 15mm diameter. There is not much else to change or add except that LED type and or tint. I can live without GITD.


Recommended mods:

  • Don't fiddle with it or you might have to replace the wires :p
  • Change the MCPCB for a custom copper one with bigger diameter and modify the plastic centering ring to sit on top of the MCPCB
  • Change LED for your preferred type and tint
  • Put a grease on the threads, I used a teflon grease
  • When changing the silicone boot you will have to cut out almost the whole inner nub out

Modding

Silicone sealed mode switch to protect from water and to secure the cables:


Driver mod, removed R1/R2 and replaced them with a piece of copper wire:

It’s a good thick piece of copper wire
It was meant to be turned around but when soldering it started to turn itself into the final position as you see it, rolled it around on the pads and let it be. Heated the wire from above with a soldering iron, solder paste on the pads. It heated the pads from the copper wire. You can see a dot on top of the copper wire from the soldering iron.

The green and yellow wires are power input and microswitch connection to my “test rig”.

Graph with a R0 (= copper wire, short circuit R1/R2) LED current above in battery life section.

LED changed to XM-L2 T6 3C with the original MCPCB.

Drilled holes into the LED centering ring and enlarged them to fit the thicker cables on MCPCB.

Important! Isolate the wires properly, I've put a kapton tape over them above the centering ring. Tried to isolate the reflector with kapton tape but it was shorting out the LED. Driver survived this even after resistor mod both on my test rig set to 3.5V (4A max), and 3.8ish V UR18650FM with a battery protection. It was audible that the coil is under heavier load and is stressed.

The driver should not get warm or hot even at 3A to the LED, that is now that the cooking R1 and R2 are removed. They are basically one resistor as they are in parallel so they can handle the heat. They are designed to 0.25W (0.125W each) and are stressed at 2.4A to 0.216W, that means they get very hot.

Kapton tape isolation and centering ring mod:

Submerged after sealing the mode switch:

Let it tailstand on high afterwards, it got hot but not burning hot. There was some humidity condensed on the inside of the lens, no other traces of water anywhere.

Looks interesting. Thanks for the review.

Thanks for the review, looking forward to more pics and beamshots.
Question: does applying and removing the clip damage the finish?
I have on light with this kind of clip and it scratches the ano whenever the clip is turned or removed.

Very nice! I've been wanting to do a review of this light. No wonder Crystal didn't send me this one, she already sent this one out to you. Are you able to measure output in Lux and lumens? The interface sounds great and far better than the horrible interface on my Crelant 7g2cs. Looking forward to the rest of the pics. 8)

Great review! Looks like a solid light!

The only difference in the interface between the 7G2CS and the 7G3CS is that the 7G3CS starts to ramp up and down faster, and has two modes which can be memorized while the light is turned on via the tailcap switch.

The downside is you can't turn it off instantly anymore via secondary switch.

I'm quite happy with mine for $45, although in terms of machining, and fit, IMO it is inferior to the older 7G2CS, and the V9CS.

Yes that is correct, I’ll post add that later, it is from Crystal’s LightsCastle thread where you could sing up for a review. No chance to pick what to review. I liked the offered light so I said yes and got it :slight_smile:
No I am not able to measure Lux or Lumens but I’ve made comparison beamshots with my D4/Xiaozhi that is XM-L T6 3C at 2.1A (Nanjg 105C).

My humble guess would be 500 lumens OTF. It really should not be a big difference with the reflector and lens, they do help but I would guess not as much as a potential U3 bin.
I may try later to compare the reflectors I have if need be.

I’ve spent just couple days taking the darn thing apart and documenting it, then using it and taking beamshots.
Now writing it down in the HTML to insert it here and work around the HTML modifications this place does to my code.

I’ll answer questions later when it’s all done. Feel free to ask.

I might have to sell my modded UF T20 and T50 to buy this to mod with the NANJG 105C.

Thanks for review, after reading it I am glad that I ordered C20, If DX does not ship my order in couple of days I am ordering from LC

Thanks for the review Jack (and looking forward to more). This light caught my eye on LightsCastle and I too requested a review sample (no wonder I never got a response on it). I like the looks of it and the two switches, but I'd have to hear more about the modes and mode memory (I'm confused how it works).

-Garry

The 7G2CS is also brighter by a bit. I would stick a couple 16340s in there in a heartbeat. You can bet 99% for sure it had the exact same driver as the Crelant.
Not suggesting anyone else do it until confirmed though…

Yeah I tried to get one to review and compare also :wink:

I did not ask for anything specific, only listed types (bike, 18650, 26650, AAA) of lights I would interested with bike lights being the first. And got this and definitely liked it :slight_smile:

I’ll try to read it and somehow organize it, mainly I begin to dislike the review template as it is not very fitting for a review of all the parts and functions. Might change it for future reviews. But everything should be covered in the horde of text needed.

Soon I’ll get to pictures, I may post the whole text and then add pictures.

Thanks for the detailed review and discount code! I’ll be ordering this instead of the T50, glad I waited, this has a much better UI.

The 7G2CS is rated at 650 lumens, the 7G3CS at 500, and the 7G2 is noticeably brighter IMO. The 7G2 also throws a whole lot better due to the larger reflection.

IMO 7G3 is the perfect host for an XP-G2 instead of the U3.

The 7G2 has no problem with two 16340/18350 batteries. I'll test the 7g3 tonight. If it fries... well I'll test out crelant service I guess :o

do you know which one is brighter and floodier?

The Crelant takes 2x16340 for sure. All the 18650 Crelants like 2x 4.2V batteries to get max brightness and regulation.

With the 7g3cs I get 541 lumens with 1 18650 and 664 lumens with 2 16340.
The 7g2cs I got 556 lumens with 1 18650 and 811 with 2 16340.

Pictures uploaded, beamshots after I sleep, it’s past 2am!

I don’t know UF T50 but I can say that D4/Xiaozhi has wider beam by a very little and a slightly less bright hotspot. Crelant 7G2CS and UF T50 seem as bigger lights. Think of this one as a longer D4/Xiaozhi with narrower body tube.

A mode with XP-G2 sounds nice if XP-G2 can handle the currents of supplied by the driver. The reflector was designed with XM-L in mind as far as I’ve read somewhere. Probably the CPF review of 7G3CS.

Feel free to make any comparisons with other flashlights, I don’t know what other similar lights with a mode switch there are.

Wanted to finish this much earlier but then it would miss pictures, beamshots, plus my experience from using it. So it took some time, a week.

Got the code to share today when Crystal asked about the review since I wanted to have it done earlier. So I had to post at least something today!

All pictures are clickable to zoom in if needed, they are automatically resizing with a limit to max-width of 100% so if a page is smaller they will adjust to it but if it’s bigger they won’t upsize :slight_smile:
Should fit all of the small screens, like mine 0:)

I think the double R180 resistors (R1 and R2 in parallel = 90mohm) might be the sense resistors or something. It does have to have some I believe. Might allow for changing the output power DIY. Input welcome, I will have to to study more about the switching buck driver when needed.

Awesome pictures! The attention to detail is amazing. I love the exploded view with all the pieces lined up. Even has graphs too!
Excellent review JackCY!

Damn you Jack... I just ordered one. Not sure why... guess I want to compare the original to the copy :p

@Tecmo - You're right, it works great with 2x16340 or 18350 batteries. Just like every 18650 light I have tried so far, will not fit the protected Keeppower 18350 batteries.

Not bad. I say it’s a sexy, black light. Since it doesn’t overheat when put into high, I can use it without worries. >)