If you need a reliable vape battery for your mod, the upgraded Samsung 18650 - 25R is what you're looking for. Although the specs are largely the same, the 25R5 packs a better life cycle than the phased out 25R2, with a 2500 mAh nominal capacity, 3.6 v nominal voltage, and a max continuous discharging current of 20A. The 25R5 can last for more than 250 charge cycles, longer than almost any other battery on the market.

Warning: Rechargeable batteries can be dangerous if not treated correctly.

ALWAYS store batteries safely in an insulated case
NEVER put batteries loose in pockets or bags
DO NOT overcharge or over-discharge batteries
USE recommended chargers
DO NOT use in devices that may short circuit
REPLACE your batteries periodically
NEVER use batteries that are damaged in any way