18650 RS25 Hercules Fumytech has a capacity of 2500 mAh and 20A in discharge rating for the use of being used with regulated mods and mechanical mods. The RS25 has Lithium-Ion chemical for minimal auto discharge  

The Fumytech batteries have undergone extensive testing are reputed for their reliability, with useful information is indicated on the protective sheath of the battery, maximum power, limited value of the coil, etc…

Specifications:

WARNING:
Use are your own risk, Misusing or mishandling lithium-uon batteries can pose a serious risk of personal injury or property damage. YDL and Evolution Vaping cannot be held liable for any damage caused to persons or property as a result of incorrect usage and handling.

DO NOT: Carry loose batteries in a bag/pocket
DO NOT: puncture/damage the metal cylinder
DO NOT: Remove outer wraps
DO NOT: Discharge/Charge past those recommended by manufacturer
DO NOT: Leave on charge unattended
DO NOT: Discard in fire

ALWAYS: Check that no wraps are ripped/teared
ALWAYS: Store batteries in a battery case when not in use
ALWAYS: Check that the batteries are not dented/punctured
ALWAYS: Check that the batteries are suitable for intended purpose
ALWAYS: Dispose of in dedicated batteries disposal bins