That's what I had expected and the only reason I've recommended the 40 over the 30. I've also heard that it reads temp much lower than others. 400 to 450 is where I vape TC in my mods. Probably comparable to the 40 at 500+, I don't know. There are some derogatory comments being made about it's battery life.....reason I asked.In wattage regulating mode, I notice slightly better battery life than feom my istick 30... due most likely to the 2600 mah battery. In TC mode, it depends on the temp cutoff you select. At lowish 400-450 degrees, it's actually pretty decent. Beyond that, it's less battery efficient than wattage mode.