Unlike NCR18650PF and NCR18650B cells used in e-bikes, laptops, portable scientific or medical devices, the NCR18650GA and NCR20700B / NCR20700A haven’t built-in a PTC switch. Without this are truly bare-bones cells releasing all power for the drone!
Note: A PTC switch (positive temperature coefficient) adds internal resistance (Ω), thus reducing performance.
Inside cell view. Credit: NASA JPL