I previously have tested the Folomov EDC C4 flashlight and thought it was solid. Folomov also makes chargers and here is their largest, fastest charging model, the Folomov A4, that’s capable of a combined 8A across the slots with a max per slot of 3A.
Full Image Gallery: https://imgur.com/a/ooUgsp4
YouTube Version of this Review:
Build Quality Build quality seems pretty solid no major complaints. It’s injection molded ABS plastic. It’s sturdy and seams fit together nicely. On the back is the 12V input connector. It’s a little loose in the connection and with the included power supply doesn’t fit quite as far in as I would like. On the bottom there are what look to be vent holes but they are purely cosmetic as they are not cut through to allow air flow nor is there a fan. 
I did have one issue with one of the spring loaded slots with the spring coming disconnected. I was able to easily disassemble and reattach it. The spring slots are a little rough when you pull them back, not as smooth as my Xtar VC4 or Nitecore chargers. That said they work well on a wide variety of cells, anything I tried including a 20700.
The display is inverse of many LCD panels. It’s background is black and the display characters are white. It’s easy to read and decent sized. I like that each cell gets it’s own dedicated spot on the display and you get the voltage all the time.
One thing I wish it did have was little rubber feet. I like to charge on a piece of granite tile and all my other chargers have rubber feet that keeps them from sliding around the table when inserting cells, the Folomov A4 doesn’t so you need to hold onto it with one hand while installing a cell with the other.
Display & UI
When you plug in the charger if there isn’t a cell in the slot you get a “null” message. Upon putting in a cell it will default to 250ma charging which is slow. You just have to press the button once and it goes to 500ma, press again for 1000ma, again for 2000ma, and again for 3000mah if available. The UI here is a little slow, you can’t double click to jump up in rates faster you have to press and wait. It’s not that big of deal for me but something to know about. Each bay is independent as well.
Instead of working from a bank of 8A and the charger deducting amounts as you insert cells, this charger let’s you set each bay as high as you want and takes power from other cells. For example say I charge Bay 1 at 3A, Bay 2 at 3A, it would let me insert a cell into Bay 3 and set it to 3A but since that’s over 8A total it would reduce Bay 1 to 2A without letting you know.
The charger will then analyze the cell and during this analysis phase the capacity in percentage you get may not be true. This is why I prefer voltage to look at. The same holds true for when it’s full. It will sit for quite a while at 98-99% at 4.2V on a lithium ion battery before ticking over to 100%. Not entirely sure why this is. It includes overvoltage protection too, a nice bit of safety. The charger also has 0V activation which I did not test.
How does it handle different sized cells
The A4 handles a wide variety of sizes of cells with ease. I tried everything from normal NiHM AAA, AA cells, to 16340, flat top 18350, and all the different types of 18650’s that I have including protected, unprotected, flat tops and button tops. I also tried a button top protected 26650 without an issue. Spacing on the A4 is large between bays so it can accept 4× 26650 at once which is fantastic as many 4 bay chargers can only accept two at a time.
The AC/DC adapter is a separate piece, it looks like a laptop style power supply. It’s fairly large and has long cables. It’s rated for 110-240V input power. Since this does look like a laptop power supply and it is not branded as Folomov, my advice would be to label the charger so you don’t get it mixed up with something else you may have.
Conclusion
This is a fairly simple charger but is fast for both Li-Ion and Nimh batteries. I would rate it as a good charger but not the best charger. It’s UI is a bit slow when changing charging rates. It seems to hit a wall at 98% with the last 2 percent taking longer than it feels like it should. It has a large external power supply but lots of cord length. The connector into the charger is looser then I would like. However these slight negatives are outweighed by the nice white text, black background LCD Screen, and total of 8A charge capacity, with a maximum of 3A per slot upto 8A total. I like how it can charge a wide selection of sizes of batteries and chemistries it can take. This is a safe charger that does the job well. I can recommend it as a good value fast charger.
Pick it up on Amazon (Referral) if you are interested.