I've run the Kick 2 and Crown 2.0 in a HCigar Brass Nemisis Clone with the following cells:
I use the stock connection pins, and do NOT use the 7mm fuse ring.
With some batteries the button sticks out further than others...but this causes no problems with firing or using the locking ring.
Efest 18650 2250mah Hybrid, Black Jacket, Flat top. No issues, works just fine.
Panasonic High Drain NCR18650PF Hybrid 2900mAh, Green Jacket, Flat Top. No issues, works just fine.
Efest 18650 IMR 2000mah, Red Jacket, Flat Top. No issues, works just fine.
AW 18490 IMR 1100, Red Jacket, Button Top. No issues, works just fine.
Efest 18500 1100 V2, Red Jacket, Button Top. No issues, works just fine.
Efest 18500 1100, Red Jacket, Flat Top. No issues, works just fine.
NHaler 18500 IMR 1100 "Kick Battery", Purple Jacket, Flat Top. No issues, works just fine.
Efest 18350 IMR 800, Red Jacket, Flat Top. No issues, works fine.