The Samsung 30Q is a stalwart for those looking for the most capacity you can squeeze out of an 18650, without too large of a compromise in output. These cells are rated for 20A continuous discharge at around 3.7V, but above that you shouldn't push these any further as they're only technically a 15A battery. So, basically, don't use these for mech mods, unless you'd like a wispy cloud that lasts all day.

Great for applications below 70W for better battery life !

Specs:

Nominal Capacity: 3000mAh
Nominal Voltage: 3.6V
Maximum Voltage: 4.2V
Discharge Current: 15A Maximum Continuous
Approximate Dimensions: 18.33mm x 64.85mm