Don't let this little guy's low price fool you, this charger is absolutely awesome! Unlike conventional battery chargers that require an AC outlet, Nitecore's UM1 charges via USB. That means that you can recharge your batteries with your computer, your phone charger, your
Rexford Tools SMART Charger, virtually any powered USB port!
Nitecore's UM10 is not only compact, it has a winder integrated into the unit so you can keep the USB cable out of the way when not in use!
Nitecore's design team also integrated a secondary USB port so you can charge your smartphone, or other device while you charge your battery. The intelligent micro controller allows you to select a priority device, and if there is not enough power for both, it will charge the priority device first.
the UM10 Operation Manual