Hello everyone
I’m out of luck: the charger nitecore ums4 is powered by a single micro usb port located here :
the charger QC 2.0 is not sold with 
I have to buy it
the site nitecore says : DC 5V/2A 12V/1.5A / 18W (MAX)
do you think this charger qc 2.0 is 100% compatible? :
I also found this one but it is 36W is not good? :
would you know if there are cheap QC 2.0 chargers again better than those 2? 
thank you in advance for your help
Both will work fine.
However, something like this:https://fr.aliexpress.com/store/product/Aukey-Wall-charger-Qualcomn-Quick-Charge-3-0-Tech-2-USB-ports-EU-US-Plug-Wall/1830134_32655938483.html
Would be even better for the future, since it supports QC 3.0(more efficient protocol, can also use it for your smartphone) and USB-C.
Anyway, all choices are from great brands, so I would not worry.
I thank you for your super fast response BlueSwordM 
I think i’ll take the one from your link, but QC 3.0 will not charge the batteries too quickly or disrupt the nitecore charger?
No, nothing.
QC 3.0 is backwards compatible with QC 2.0, and backwards with regular USB 2A charging.
So no problem there
I thank you for this explanation.
but another question worries me:
the usb cable connector aukey of your link is a micro USB type C. While the USB connector of the cable nitecore ums4 is a micro USB type A i think. pic :
then will the nitecore charger support or accept a C-type connector?
No, the USB-C connector is just a bonus inside of the package for other things like your phone/future USB-C lights.
Since the micro-USB is included, it should not be a problem.
in fact i did not understand the connection i apologize.
I will use the cable given by nitecore, i plug the micro usb side on the nitecore charger and the other side usb i plug it into your aukey charger and it works?
Yes, absolutely
I am super reassured thank you for your help soon
you can plug it into a computer usb port as well
cool thanks for this info it can be useful
on my pc i have ports usb 3.0 but at maximum they can go out only 5V?
with the nitecore charger ums4, if i want to charge my 4 battery 18650 together at 1 amp, the 5V will not be enough?
A QC charger is a QC charger, I have not seen any that did not work as expected:
https://lygte-info.dk/info/ChargerIndex%20UK.html
The UMS4 do not need a QC charger to work, it only makes it slight faster in some situations. My review will be published in a couple of weeks.
I saw your link and yes indeed they all work very well. except those with the death head in safety 
thanks for this info . So to pay less i should have to take a non-QC charger?
if yes, i will have bought one, but as on my charger nitecore it was written: DC 5V/2A 12V/1.5A / 18W
looking for a usb charger of 18W i found only QC …
With a non-QC charger the maximum charge power is reduced a bit, but that do not prevent the charger from working.
ha ok but what i mean is that i did not manage/succeed (sorry for my poor english) to find a non-QC charger respecting these specifications: DC 5V/2A 12V/1.5A / 18W
A non-QC charger would only have 5V 2.4A and there are a lot of them.
https://lygte-info.dk/info/ChargerIndex%20UK.html
ah yes like my charger usb galaxy s4 . Thank you for these explanations, good evening
Just use the QC 3.0/2.0 charger so you can charge multiple 18650/21700s at 1A.
Charging large cells can be quite the hassle at 500mA, so 1A is quite good.
thank you BlueSwordM for this info that interests me
Yeah I dont know how many watts a PC output has, but if you want to do 4 at 1 amp it might not work so maybe you would need the reccomended/max wattage Nitecore manual says, but you can probably do 1 or 2 batteries at 1/2 amp from PC, but I’m no expert