SO, I do know the answer to this question, and it may stir a debate, and if it does, I apologize.
Temperature Control is currently not possible or available on any
vaping device... the devices on the market are actually "Temperature Limiting".
The Theory of temperature limiting is that the device will not exceed the stated temperature. Temperature control would mean it will get to and maintain that temperature with a minimum amount of variation.
That being said, Temperature Limiting (which most people erroneously call Temp Control) can be done with a single battery, if that is what you actually want to do.