I have been looking for a possibility to fly quads using 18650 cells.
To test if they can tolerate high current draw, I bought two Samsung 2500mah INR18650-25R (Original).
These batteries are rated for 20A discharge at 25C
Charged them to 4.2V and connected them in series.
First tested using my 2 inch micro. AUW become 198gm. It runs on 1104 7000kv motors and 2 inch 4 blade props.
Got 3min 40sec flight time.
I have virtual current meter setup in betaflight. Which is close to accurate. It showed 17A in the beginning with 80 percent throttle, and eventually increased current draw to 24A and throttle to 90 percent. Then I started losing power. In the end used around 1000mah. Which is 40 percent of the total capacity.
It was 6V on my OSD, when I was to land.
Batteries landed with 43C temperature.

Charged batteries back to full and this time trying with 5 inch quad with 2205 2300kv motors and 5030 2 blade props. AUW 400gm.
Got 11min flight time.
Unfortunately there is no virtual current meter. So no amp draw recorded. 
It was 6.4v on my OSD, when I was to land.
Batteries landed with 43C temperature.
Used 1663mah which is close to 70 percent of capacity. In the beginning with 70 percent throttle, and eventually got increased to 90%.