Stick with coils wrapped between .7 and 1.5-1.8 ohms. IIRC those e fest batts have a 10 amp limit so a .7 ohm should be a leave a good buffer zone. Also since you have a mech I recommend picking up a higher amp battery like a Sony vtc4 just to be on the safe side.
For me, I have a trident clone RDA and I like dual coils, 30ga kanthal wrapped 4/5 times around a 1/16 drill bit. Comes out to 1.4-1.5 ohms for a single coil, and almost always exactly .7 ohms for duals. Then instead of wicking I put a cotton cloud under each coil and liberally soak them.
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