Nitecore NITECORE UMS4 Intelligent USB Four Slot Superb Battery Charger and LumenTac Battery Organizer

This is my second Nitecore charger, the first being the I2. Nitecore products have always been reliable for my battery charging and the digital displays are as informative as they need to be without being overly complex. The UMS4 is a great unit. Having USB C as an input makes it easy to take this charger where I need to without increasing the amount of cables and adapters I already have. The information readouts on the screen help keep tabs on charging progress, total time charging, and when it's time to retire a rechargeable battery that's been in my rotation for too long. So far I've successfully charged AA, 18350, and 18650 batteries with no issue. Similar to a 4-slot toaster, you don't always use the full capacity, but it's very nice to have when you do need it. If you frequently go through batteries, the investment in this charger and a pack of Amazon Basics rechargeables will quickly pay for itself.

Works great. I love the status screen that tells you all you need to know about battery health and how charged the batteries are

Great charger that shows voltage, current, resistance and time of charging. I know of no chargers that sense between Li-ion and LiFePO4 batteries, so when charging LiFePO4 (lithium-iron phosphate) batteries, the battery type must be set manually to LiFePO4 or it will overcharge them. LiFePO4 should be charged to 3.7 volts maximum. I cannot understand the negative reviews as this is the best charger I have. I use a 45 watt PD charger with it and it charges four 21700 cells in very reasonable time for Li-ion batteries. A PD charger will give the best results. Note that it charges by monitoring current (CC) at the beginning and charges by monitoring voltage (CV) near the end of the charge cycle. This protects Li-ion and LiFePO4 batteries and charges them to 4.2 volts for Li-ion, or 3.7 volts for LiFePO4 batteries safely.

I wanted the fanciest 18650 battery charger I could get. Grok said this was the best one, in terms of performance, that I could buy. So I bought it. It’s got lots of features I probably don’t need and I don’t understand. Thankfully it’s got an auto setting by default. I also got the Qualcomm 18w qc3 ac adapter to pair with it to enable fast charging. Wow, this thing charges my batteries faster than I can run through a set in my vape mod. Leaps and bounds faster than my previous one. Big fan. Very happy. Highly recommendo. 10/10. No complaints.

Best charger of this style out there. I use it on a 5 port 60w Anker power brick. If I use it with a good microusb cable and the quickcharge 3 port I can get 2a on every slot and it's not supposed to do that. I instead always use a magnetic disconnect microusb to USB cable so I don't wear out the port or cable and it's been great. Still get 2A on one or 1A on all 4. If you use it on a weaker power supply it will charge slower. It only works very fast with my big Anker, my small 20w one can't kick it up to full speed. I'm assuming any old charger will run at slower speeds. I'd recommend getting a nice anker 5 port (I have the one with the quickcharge 3 slot up top) This charges everything I have. 21700's fit, nimh charges good, if not too fast(have to manually turn it down for AA and AAA) nimh D batteries fit with no modifications, but only 2 at a time. Can't recommend it enough, my only gripe is the screen never dims. But that's not worth deducting anything. Debating getting a second. 2022 update: the display on mine died. The first time(December 2021) I was able to bring it back by heating it up with a hair dryer. The second time(June 2022) it wasn't coming back. Still worked though. I ended up going with the faster Nitecore charger, the display on it looks better, but I still miss this one. Still 5 stars