Ultrafire Fast Charger for 18650 batteries. Perfect charger for rechargeable lithium cells, automatically charges them to the level required, will no over-charge cells, will not charge over-discharged cells. - International worldwide power input 100 - 240V - Automatically adjusts power input - US-style flat pin plug - Premium quality and extremely durable - Microprocessor-controlled auto-cut-off charging - Low battery temperature rise - Will not charge over-discharged batteries AW 18650 Battery - Capacity: 2600mAh - Rechargeable for 600-800 times - Peak Voltage: 4.2V - Nominal/Working Voltage: 3.7V - Temperature: -40C~60C