Shop removable 18650 and 21700 lithium-ion batteries for compatible devices. This collection is for individual external battery cells, not battery-powered kits, mods or chargers.
Choose the cell specified by your device manufacturer. Check the 18650 or 21700 format, terminal style, protection requirement and continuous-discharge rating before ordering. Use a compatible charger and keep spare cells in an insulating case; never carry a loose cell with keys or coins.
18650 or 21700?
These are different battery sizes and are not interchangeable unless your device instructions explicitly allow both. Compare each product’s exact specifications with your device manual before use.