18650 battery not working in Fenix TK12

[z_dumbo]

Hi



I just got my wonderfull new Fenix TK12,

I also bought 2 Ultrafire 18650 3000mAh batteries + WF 139 charger



when I put 1 18650 battery in the TK12 it doesn't work (no light),

but it works perfectly with the other,



the 2 batteries were 100% charged before use



any idea?



thanks