A versatile charging solution for those of us with multiple battery types.
I upgraded my old two-slot dual-charger with the newer Nitecore UM4 Intelligent 4-slot battery USB smart charger last week and it's a fantastic upgrade. The device measures the recharge capacity and "age" of a battery and it handles so many of the various types of rechargeable batteries that power flashlights today that I'm surprised I didn't buy one sooner. These are great value and perform their job perfectly well, regardless of the battery brand. I fitted a Fenex, Acebeam, Olight and a Manker battery side-by-side without any issues, with a constant feedback visible on their charging progress on the LCD window. It also correctly identified my oldest and least reliable battery as "poor" whilst the three that were well-maintained or new were correctly rated as "good". It handled my old AA Ni-Cad batteries with the same amount of ease. The unit is deceptively lightweight and comes with a USB cable for immediate use at home or in the car. Two buttons allow the user to quickly select a battery in any of the 4 slots and then cycle through its charging properties. A four-bar display above each battery shows when it's ready. It's almost essential for those of us with multiple brands and types of batteries and it has the reliable Nitecore name that I so often rely on.
