Battery chemistry and power explained https://smartgadgetshow.com/batteries_for_vape_modes_explained.htm "hybrid" chemistry, adds nickel to IMR = INR , and i do find them working better overall. Importantly for vapers, the chemistry is very stable, meaning that you don't need expensive built-in protective circuits. my experience and what works for me currently I number my batteries. see why Click to subscribe! https://www.youtube.com/@SmartGadgetShow All of the 18650, 20700, and 21700 vape batteries get their name from their size dimensions. A 18650 battery has an 18mm diameter and a 65mm length, with a 20700 battery has 20mm diameter and 70mm, and the slightly larger 21700 battery is almost the same size as the 20700, but 21mm in diameter. On the face of it these dimensions are quite similar. The difference in performance, however, is very noticeable.