Nitecore UM4 Intelligent Charger is a multi-functional charger which is capable of 3000mAh max output. It has four slots for charging four batteries at the same time. Single slot max output up to 1500mAh. Just like UM2 charge, UM4 also incorporates an optimized IMR battery charging program, which is able to monitor the entire charging process. It also could automatically detects power level of batteries and selects the appropriate voltage and charging mode.