18650 batteries have a diameter of 18mm and a length of 65.0 mm hence the name 18650. Used in high power flashlights and e-cigarettes and vaporizers. Many new devices are taking advantage of the 18650 battery like power tools, cameras and laser LEDs. With a higher drain than usual lithium batteries the 18650 is perfect for devices demanding a higher current.
Most new 18650 lithium batteries are rechargeable for up to 500 cycles and take an average of 2-3 hours to fully charge. It is recommended to charge your 18650 li-ion batteries every 6-12 months if they are not in use.