I am completely satisfied with Xtar sv2 Rocket 
I have the UMS4, not a bad charger but especially for NiMH mediocre.
+ Good selection of charging current
+ Cool temperature of NiMHs which getting correct terminated.
— Slot-Sharing: Insert batteries in shared slots or use all slots the current get halved. Not really a 4-slot-charger
- bad termination of NiMHs which don´t reach > 1,5V at charging. Timer switches off after 20(!) hours, I´m sure the cells get melted before
- 1A Standard current also for AAA
- NO way to copy slot-settings to other slots, every slot have to be configured
- no other features
- sensible Micro USB
- Display show to less values, even it only shows 1 slot it changes 3x for all values
The Vapcell S4 Plus is not perfect, but the Nitecore UMS4 is IMHO far away from the Vapcell.
This is too much for them.
You can change it manually but most of my otherchargers use 400-500mA default current, dunno why Nitecore decide to change with 1A default. So the Nitecore is nor for an user which want an easy charger
I need a charger for 26650s and D batteries that is idiot proof (for an alcoholic friend) , are any of these Nitecores right for him?
They charge Ds and 26650s, but are they simple to use?
I got an S4 + V2 a week or so ago. Overall I like it, though there are some things I would change in the UI. In particular it would be nice if the voltage reading functioned after the cell is fully charged. It just freezes on termination, so it is impossible to read the resting voltage of the cells. I saw a thread here where they are discussing changes for the V3. I will be interested to see what they do. I do like all of the information available on the screen for each cell while charging… if you don’t mind having to step through each slot. BTW, I have not tried charging 4 cells at 3 amps each. I probably never will as none of my cells require it, and lower current charging is easier on the cells. Probably adding cycle life.
My “daily driver” is still the MC3000. It is used on average 3 hours every day! I have about a dozen charging routines setup on my phone for different cells and chemistries (yes it connects via bluetooth). The app gives very precise control for about evy parameter that controls charging. It is just a couple of presses to get the one I want for any one or all of the slots. It also shows info for all the slots without any button pushes. Is it, an “old” design? Well maybe, but cell chemistry has not changed, so it does what it is supposed to do, and does it well. Mine is 9 years(+) old and still working. We will see if the S4 makes it that long…
But for more casual use, and if it lasts, the S4+ V2 is a good choice for a first charger. OH, and BTW, I was happy to find that it fits my USB (on cell) rechargeable 21700 cells. The only charger I have that does.
I have a Nitecore UMS2 modified to accept 26800 cells. My main charger is a Vapcell S4 Plus.
The Nitecore (which I purchased on Nitecore’s website) came with only a USB-Mini to USB-A cable. Using the wall adapter that came with my phone resulted in charging speeds of 1 amp per slot simultaneously or 2 amps for a single slot in use. After purchasing a power adapter with Qualcomm Quickcharge certification it now charges cells at the advertised speeds. The Nitecore has only two buttons and I find the interface functional but somewhat inconvenient.
The Vapcell comes with a barrel-plug power supply capable of powering the device to the charging speeds it is rated for. I find the user interface less cumbersome on the Vapcell—the added button must have given them more freedom to design a better UI.
Thank you for the tip! Looking forward to it.
I primarily use the ISDT C4 Evo for single/dual cell charging. It has limited support for very large batteries, as well as short batteries in less common sizes, but the control and display are excellent.
My secondary charger which covers more cell types is the EBL Touch Charger. The Interface is not as nice as the C4 Evo, but it is a pretty competent multi channel charger and has a good power supply that feeds nearly 5a at 12v to the charging dock— So it can definitely do more simultaneous fast charging if you need that (For 3 and 4 cell lights)
I also keep an old Nitecore D4 around which I primarily toss in my bag. It’s less configurable, has limited power output, but it gets the job done when I’m mobile.
Yes, they are simple to use.
They're about as idiot proof as a Li-Ion or universal charger can be.
In other words, your friend still has to treat Li-Ion cells with respect because they can be much more dangerous otherwise. 
Overall the Nitecores are simply to use, also because of very limited features
In one thing I´m not sure, the default charge current for some cells. For AAA it´s to high, I also have 1200mAh 18650 and the Nitecore will charge this size by default with 1A
. I see chargers output betweem 500, 750, 1000, 2000 and 3000 milliamps. Is there an issue at 3 amps vs. 2 amps vs. one amp vs. half an amp?
I plan to use two Convoy H1 headlamps attached to a wall 42” opposite a painting, each ramped to 20-30lm, both 519a, one at 3000K, the other at 4500K, for 4-5 hours per night, so will recharge once per week, more or less. Can’t order until after Chinese New Year break.
My other lamp is Convoy M3c 70.3 with 26800 where I use the onboard charging feature. I am about to order Convoy S11 GT FC-40, 26650, for the car, and S21D w. 219b using 21700 cell for dog walking. I don’t have any rechargeable batteries other than those high capacity LiOn.
Does one output cause the batteries to last longer vs. others?
I think that a charger with a single fixed output should be avoided. Cells with different capacity and chemistry really need different charge rates. Get something with adjustable charge rates!
Typically LiIon cells are specked at 0.5C in amps. So a 3000 mAh cell might be charged at 1.5 amps (1500 mA). Some cells can be charged with much higher current for fast charging as long as temperatures are controlled. But you need to check the data sheets for the cell in question, as they vary quite a bit. Higher charge rates do impact the number of charge/discharge cycles that a cell can achieve. Meaning you get fewer cycles at higher charge rates.
So it becomes a trade off, faster charging means fewer cycles. I tend to use 250 to 500 mAh for small cells (14500/16340). Note though, the 500mAh minimum you mention for some chargers can be on the high side for many of the smaller cells! I use 1 amp for 18650, and 1 to 1.5 amps for 21700 and 26650. 2 amps for the 10 amp hour NiMH “D” cells. But this is a generalization. You need to know the cells you are charging. For me, low and slow is better. Within reason of course.
I know you said that you don’t (yet) have some of the cells that I mentioned, but it make sense to get a charger that gives you the flexibility to charge them in the future. This flashlight hobby tends to become an addiction. You may just have some in the future.
As only an infrequent user, I need to delve deeper into Li-ion battery tech….good to know this stuff!
Thanks :+1:
I totally agree
I have many different cells and a charger without adjustable current is a NoGo, it´s something I had over 30 years ago, but there were only one capacity, NiCd AA with 500mAh
Also looking for a new 4 bay charger. My OPUS stopped detecting cells in charger. Need something AAA and 16340 friendly. Have Xtar VC2SL but it it gets the AA and AAA cells to hot for my liking. USB C input would be nice but not a deal breaker.
Look above in the thread. It seems like the S4 V2 gets lots of love. I got one recently. Overall I like it. Two things, when the cell finishes, the volt meter freezes at that point. Meaning you can’t cme back and see the resting voltage. Also, the capacity test is strange. You can set the charge current, but the charger sets the discharge current . Not sure what it uses to make the decision, but so far it hasn’t matched what I wanted. So, if you can live with those quirks, and don’t mind having to push a button to view the status of the individual cells, it is overall a good one.
I’m still loving the MiBoxer C4-12 and would buy another in a heartbeat if they still made them. If you can hold off a little while Dennis mentioned that the new Vapcell S4 V3 will be released soon (not sure if that will be after the new year’s holiday or later in spring). Sounds like it should be improved in several ways and it’s already a pretty solid charger overall. If I had to buy another right now it might be the S4. I still prefer the Maha for NiMH.
Nitecore UMS4 has been my regular charger. Now I have a newer one, Vapcell S4+. Both are working fine.
I have some chargers with USB-C like the Xtar VC4SL and ISDT C4 EVO, also the Nitecore UM2 and Skyrc NC1500 with µUSB. I can only recommend if you don´t need that really, go for a charger with a own Power Supply, because it work while the USB-chargers have sometimes or often problems with some Power Supplies; maybe except the NC1500.
I would still recommend the Vapcell S4+, it´s an awesome charger for it´s price. It also supports 250mA charging for low capacity cells.