18650 diameter 18.4 mm height 65 mm stable 35A current charge and discharge times in 1000 the battery capacity of 2600 mAh standard voltage 3.7 V full charge voltage 4.2 V Note it operates when the voltage is reduced, voltage can not be lower than 2.7 volts, otherwise the battery would be damaged.
18650 rechargeable Li-ion battery 
Durable and long lifespan Capacity: 3800mah Voltage: 3.7V

• 18650 protected rechargeable li-ion lithium battery.
• Suitable for laser pointer, flashlight torch and other electronics products.
• Safe and environmental friendly.
• Rechargeable Times: Up to 500 times.
• Model: 18650.
• Battery Type: Lithium-ion
• J Battery
• Rechargeable
• For Camera, Flashlight, standalone fan etc
• Battery Capacity:  18650  3800 mAh 3.7V