Nitecore UMS4 - personal opinion


Newly Enlightened
Jun 22, 2017
I just bought a Nitecore UMS4 charger, and having tested it - i.e. used it as a battery charger - I have some thoughts on it. Figured I'd share them. Sadly, it becomes mostly a rant.

I will not get into the technical details and specifics and statistics for this charger. Someone else has already done that far better than I ever could here:

I bought my UMS4 as a charger for use with protected 21700 button-top cells, and size-wise, it works perfectly. I was a bit concerned, because a friend of mine has the Nitecore i4, which states on the box it supports 21700...but it had no chance for protected button-tops. My Fenix ARE-C2 doesn't say anything about 21700, but still takes unprotected flat-tops without issues. But it also can't take protected cells.

But the UMS4 takes 4x Coast ZX955 (78mm long) side-by-side at the same time, no problem. The springs extend far enough that it could take even longer cells.
It also has an easy to read LCD screen that automatically dims after a short period of time, but immediately brightens up again if a cell is removed, added, or any of the buttons are pushed.

However, this is where the positives end, at least for me.

Because the charger has a micro-USB port. Not USB-C like I expected and thought it had from the images I saw. Also, no power adapter is included, only the charger itself and a 50 cm micro-USB to USB-A adapter cable. Pure luck that the extra charger that I had purchased earlier for my phone (15 W EP-TA200, 5 V / 2 A) was USB-A, so I could at least test the charger when it arrived.

Specifications on the product page says:
Input DC 5V/2A 12V/1.5A
18W (MAX)

I have no idea how much current the included cable supports, I find no official specifications on this anywhere, and a certified high-end micro-USB charging cable seems non-existant. To my knowledge, the USB 2.0 standard (which the micro-USB is based on) is minimum 500 mA (standard says maximum 500 mA, but that's for PC devices). Personally, I don't mind the very slow charging speed as a result, actually I prefer it - but should I ever need to just get some charge in 4 cells at the same time quickly...I can't, because of the micro-USB limitations.

Meanwhile, USB-C has supported 65 W and above for a long time already, so I just don't get the reasoning from Nitecore for this. And I see other brands also use the micro-USB port - what is wrong with the C7 power connector, and let the charger handle the rest!?

The build quality of the UMS4 feels really cheap and plasticky. The charger is very light, not even close to the Fenix ARE-C2.
Further feeling of the cheapness is the springs underneath both buttons audibly flexes and doesn't sound properly secured at all when pushing the buttons. Also, when pushing the buttons, the LCD screen distorts in the corner.

But all in all...I think I will buy another UMS4. Fenix doesn't seem to have any 4-port 21700 chargers, relevant XTAR's are unavailable to me, and other chargers doesn't seem to accept protected 21700 cells.