Description: 21700 3.6V 4000mAh flashlight Li-ion battery Product No.: HG1AE7005 Cell model: 21700/4000mAh/3.6V Battery Specification: 1S1P/4000mAh/3.6V Nominal voltage: 3.6V Nominal capacity: 4000mAh Charging voltage: 4.2V Charging current: 2000mA Discharge current: 2000mA Maximum discharge current: 20A Discharge cut-off voltage: 2.75V Internal resistance : ≤ 50m Ω Delivery voltage: 3.5-3.85V Battery weight: 65g Product size: 74* 21.5mm (max) Operating temperature: Charging temperature: 0-45°C; Discharge temperature: -20-60°C Storage temperature environment: 1month - 20-60 ° C; 3months - 20-45 ° C; 12months - 20-25 ° C Relative humidity: 65 ± 20% Battery structure: 1S1P Lithium Battery protection: Short circuit protection,overcharge protection,over discharge protection,over current protection, etc Application field: Outdoor lighting, flashlight Li-ion battery