The LUC V2 Charger is a smart charger and has a two-bay lithium ion battery charger with adjustable outputs. What makes this charger special is the USB output that allows the charger to perform as a power bank to charge other usb devices. The LUC V2 charger is compatible with most cylindrical Lithium batteries ranging in size from 10440 to 26650 it also features digital display with charging indicators for each channel.Once you battery is fully charged, the LUC V2 automatically stops to prevent the battery from overcharging. The charger also detects your battery power status and selects the appropriate voltage and charge mode prior to charging. These safety features protect your battery from damaging and protects your charger from possibly ruining.