18650s are the most common types of batteries in vaping. They are readily available, reliable, and widely tested, and most mods come with compatibility 18,650. While the newer batteries, such as 20700 and 21700, have raised the stakes, we rarely see them in the double or three vape battery mods for their larger size.
Manufacturers still rely on the 18650 because they combine a smaller size with a tried and tested performance. You can also purchase 18650 rechargeable battery online.
18650 ratings and specifications
Continuously Discharge Rate (CDR)
This is the rating used by leading electronics manufacturers and the rating that we can use to compare the battery discharge. When assessed accurately, it indicates that the battery current can be safely disposed of at a sustainable level without damage or reduce capacity.
Rewraps and China produced battery will often overestimate CDR, or use other rankings, not that. One good example is the maximum flow rating (or the maximum current discharge), that may even be the sole rating on packs.
Calculated in mAh (milliampere-hours), the battery capacity indicates the running time. One mAh is equal to the charge transferred by a steady current of milliampere drain for one hour. While this rating is sometimes exaggerated in wrapping the battery, this does not happen as often as it does with the discharge assessment.
It would be more than ratings from leading manufacturers, you will see a pattern: there is always a trade-off between CDR and capacity. There is (still) no CDR 18,650 with more than 30 amps.