Lithium Battery 3.7V 18650

A rechargeable 18650 lithium cell - 18 x 65 mm, 3.7V nominal, 4.2V fully charged - the standard cylinder behind torches, power banks and portable builds. Pair it with a TP4056 board or a proper Li-ion charger; never charge it from a plain bench supply and do not run it below about 3V. One honest word on capacity: the mAh printed on budget 18650s is a marketing figure, not a measured one, so plan your runtime on rather less than the label promises.

Key features

• Standard 18650 size, 18 x 65 mm
• 3.7V nominal, 4.2V on full charge
• Button-top terminal
• Charge with a TP4056 board or a Li-ion charger
• Do not discharge below about 3V
• Printed capacity on budget cells is optimistic