Can it have something to do with a small resistance change when the battery is warm while it is being charged vs a room temperature already charged battery?
I think one of the biggest challenges when one is doing research and comparisons between vaping vs smoking is that a cigarette is pretty much a cigarette, but to what do you compare it? an ego aio with a 0.6ohm coil or a smok tfv 8?
It s is kind of pointless if volume for volume vaping is 100x...
Good advice would be to visit your nearest vape shop. Make sure you tell them you don't want to get involved in the hobby.;)
Just a few pointers.
1) It can take some time to find a flavor or two that you like
2) If you still have cravings for cigarettes don't be scared to buy liquid with more...
Before I forget at the bottom of the part of the top section of the coil there is a small metal ring make sure it is fully screwed down. Sounds much more complicated than it is ;)