It's firing my 1.1 right now. I read 1.0 is the limit... haven't tried. HOWEVER, it will not fire above a certain V either. so before you try it, drop down to like 3.1 v and up gradually from there. I think my 1.1 ohm gives an error at 3.7 or 3.8. Nope... just tried it... 4.2v is where it errors at for a 1.1. At 4.0, the vape gives me a headache. At 4.1... omfg... I vape the 1.1ohms at 3.1-3.4v, higher than that, and it's really harsh.