[Review] Folomov EDC C4: XP-L, integrated charging, power bank feature

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[Review] Folomov EDC C4: XP-L, integrated charging, power bank feature

Folomov EDC C4

MSRP: $45

Manufacturer page: http://www.folomov.com/en/content/?134.html

Store link: https://www.amazon.com/dp/B0782CQGBV

I was sent this light to review free of charge but, as always, I've tried to be as unbiased as possible.


Folomov is a new brand to me, and the C4 made an okay first impression. The EDC C4 is a 1x18650 flashlight with built-in charging and power bank functionality. The UI isn't great, and the electronics construction is iffy. It's the cheapest good option for a flashlight/power bank.

Album link: https://imgur.com/a/P2NyMaR



The EDC C4's package is a black cardboard box with orange text boxes (Folomov's color scheme). There's a window on the front that shows the light. The specs are all on the back.


The box contains:

  • A Folomov EDC C4
  • A 2600mAh protected 18650 cell
  • A special USB cable
  • Two extra o-rings
  • A lanyard
  • A manual


Manual and Specs

This isn't a section I've ever included before, but I felt that there were a few things about the specs that I should point out. I don't have any way of measuring lumen output, but I know these specs are exaggerated, or they at least abuse the ANSI FL1 standard. 1200 lumens for 2 hours isn't possible with a 3400mAh cell. I really wish I could make a runtime graph for you guys to illustrate how the light actually performs.
Another thing that bugs me is that I got the C4 with a 2600mAh cell, not a 3400mAh cell like the light was tested with, which makes the runtimes even more inaccurate.



The Folomov EDC C4 has fair build quality. The anodizing is even, but it's thin and you can easily see the milling marks on the head and tail. The threads and o-rings come pre-lubed, but the threads are triangular. The spring is gold plated, but there's only one and it's not very stiff. None of this stuff is *bad*, it's just a bit underwhelming for a $45 light, especially when there are plenty of other brands that give you more for less. The C4 is small. It's 99mm long; only 6.5mm longer than a Zebralight SC64. It's also light, at only 50g. Nothing is thread locked, so it's easy to fully disassemble.


The C4 has a plain tailcap with a spring and no button. The spring is held in by a triangular bit that fits into a groove on the inside of tailcap. On the outside there's a small hold for a lanyard, and a ring of square knurling. The end of the tailcap is completely flat, which means the C4 can tailstand very well. It would have added a couple mms, but a magnet in the tail would've worked well.


The body tube is also square knurled, with four flat spots that line up with the button and the charging port on the head. One flat is silkscreened with Folomov's logo, and the other with the model name and a warning to only use 18650 cells in the light. There is a groove for a clip at the tail end of the tube. The body tube is non-reversible due to different thread lengths. The threads are triangular, and the o-rings are pretty skinny. On the rest of my lights, I can feel it when the tailcap starts tightening over the o-ring. I don't feel that resistance at all with this light. The C4's o-rings do keep water out though.


The head of the EDC C4 has a grey rubber switch boot covering an indicating electronic switch on one side, and a grey rubber cover for the micro USB charging port on the opposite side. The cover is pretty secure. I wouldn't worry about it coming open accidentally. There are shallow heat fins that go around that area of the head.

The battery contact is a circular brass(?) button on the driver. I suspect they did that because a spring would have meant more length.

The bezel is female threaded, and unscrews to reveal an o-ring (not pictured) lens, reflector, emitter gasket, and MCPCB. The manual says the glass is "double coated mineral glass", and I'll take their word for it. It's not an especially thick coating though. The reflector is smooth and shallow, and seems small, but that's just because the head has thick walls. The MCPCB is very small for an 18650 light, at only 11mm in diameter. Folomov made this decision so they would have room for the charging port and the button.

They could have raised the MCPCB up a couple of milimeters, but that would have required either a shorter reflector or a longer light. The soldering job was sloppy on mine. When I first took my C4 apart, the positive lead came unsoldered. It didn't help that there was so much slack in the wires. The negative lead wasn't soldered nicely either; it was hanging off of the edge. It's actually soldered on in that photo, just not the end of the wire. Milling marks are just cosmetic, and triangular threads aren't a huge problem, but bad solder joints are a very valid reason for staying away from a flashlight. I didn't try to get the driver out. Hopefully the connections were better in there.


EDIT: I took the head apart (not easy, there was glue) and the solder connections in there were just fine.

Clip and Lanyard

The Folomov EDC C4 ships with a clip pre-installed, and a lanyard that can be threaded through a hole in the tailcap. The clip is pretty standard. It looks similar to the clips that Sofirn and ThorFire use. It's much easier to remove than their clips though. Taking it off and putting it back on didn't scratch the anodizing. It's a good clip. The lanyard is also very standard. Thicker round cord for the loop that goes around your wrist, thin cord for the hole in the tailcap. I don't use lanyards, but if I did I would like using this one.


Battery, Charging, and Power Bank

The C4 can take any 18650 cell: flat top, button top, protected, or unprotected. Folomov ships a 2600mAh protected button top 18650 with the C4. I took the wrapping off to see what kind of cell it was, but I haven't been able to find any info on it. It's definitely not manufactured by one of the big five. The protection circuit is similar to the style that Olight used on their H2R cells. It's all on the positive end.

The C4's button lights up in different ways when the light is on to show the battery status. If the battery is over 50% charged, there's a solid green light. If it's between 10% and 50%, there are slow red flashes. When the battery capacity is less than 10% (around 3.3V), there are fast red flashes.  
The EDC C4 charges via micro USB. A cable is included. It charges cells at 0.7A. That's not especially fast, but it's not too slow either. It's a good enough rate of charge for any 18650 cell. The light flashes red when charging, then shows solid green when it's finished.

The main selling point (?) of the Folomov EDC C4 is its ability to funciton as a power bank. To do this, plug in the included cable to the micro USB port on the light, then plug in a USB cable to the female side of the cable. The C4 charges things at up to 0.7A, and the voltage drops to about 4.6V when charging something that draws that much current. Once the cell in the light drops to 3V, the power bank feature stops working.
The included cable is interesting, so I thought I'd spend a bit talking about its anatomy. It's essentially a splitter, with no circuitry in it whatsoever. If you plug the male USB A plug into a USB power source, whether that's a laptop, power bank, or USB wall wart, it will output to the micro USB plug and the female USB A port. This means that you can plug the cable into something, charge the flashlight via the micro USB cable, and charge another device from the USB A port. How the light knows whether to charge or be charged is a mystery to me, but it works. The end voltage is around 4.15V. It's a bit low, but capacity-wise there's pretty much no difference between that and 4.2V.

The light itself has no LVP, so it's a good thing a protected cell was included. I left it on overnight, and it was at about 2.4V in the morning. It does have reverse polarity protection though.


Modes and UI

The EDC C4 has 4 modes and three blinky modes. Low (10 lm), Middle (75 lm), High (200 lm), and Turbo (1200 lm), Strobe (1200 lm), SOS (1200 lm) and Beacon (75 lm). The mode rotation goes L -> M -> H -> T -> H -> M -> L. There is mode memory.
From off, press and hold to turn the light on in the last used mode, single press to advance modes, double press to go into Strobe, then again to go to SOS, then again to go to Beacon, and single press to go to the last used non-blinky mode, and press and hold to turn the light off. The blinky modes can also be accessed directly from off by double clicking. Once the cell reaches about 3.3V, the light only lets you use low and medium. It might be worth noting that as the voltage decreases, the brightness of all the modes decreases.
I'm not a fan of press to turn on and press to turn off. I mentioned this to Folomov, and I was told that the UI was designed this way to prevent the light from coming on in your pocket. They may have a point with that. The button protrudes, and it can be pressed when the light is pressed against a flat surface. Besides the pressing and holding, I think the mode spacing needs a bit of work as well. The jump from 75 lumens to 200 lumens isn't very big. A sub-lumen mode would also be fantastic.
The manual says the light has overheat protection. I don't have a way of testing that for sure, but it does seem to level out at about 123 degrees F (50 degrees C). Another neat feature, which may have been necessary due to the button in the head, is that the C4 is bump-proof. If you bump the light in such a way that the cell loses contact with the head, it will stay on and stay in the same mode it was in before it was bumped.
The EDC C4 has a locking feature. Triple clicking the button when the light is off will lock the light. Another triple click unlocks it.


Beam and Tint

The EDC C4 uses a cool white (6500K?) Cree XP-L and a smooth, shallow reflector. The beam has a well defined hotspot. The emitter is well centered, and there are no rings or holes in the beam.

vs 4000K 90+ CRI 219C in a Fenix UC30:


Modding Potential

Disclaimer: Do this stuff a your own risk. If you mess up and break something, that's on you. Also, doing any of this will totally void your warranty.

Driver: 21mm
MCPCB: 11mm

The emitter could definitely by swapped, but the driver's probably not replaceable.

Bottom line:


  • Integrated charging
  • Can function as a power bank
  • Comes with battery


  • Iffy solder joints
  • UI and mode spacing aren't great


Thanks for reading my review! If you have any questions about this flashlight, I'd be more than happy to answer them.


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Edited by: Virisenox_ on 05/30/2018 - 16:34