Re: limit vaping to 20 watts
Different 18650s are rated to different constant current outputs - 10A is on the low end. Plenty are fine at 25A and above, although very few can manage a constant 30A (Sonys VCT range contain some).
However, that's constant draw - such as a cordless power drill, or angle grinder, being given a hot supper for a minute at a time, with five or six of those cells set up to provide 40 or 50A at around 8-12v, depending on the exact configuration.
In a vaping device, you rarely use them for more than a few seconds at a time - at higher wattages, even less.
This means you are into the pulsing range, and most cells can handle double their constant current when being pulsed, without any risk.
So a cell rated for 20A constant can typically handle a 40A pulse without risk. And in a mech mod with a fully charged cell, you're talking ~4v at 40A - ~150w depending on resistance of the coil. You can't do anything but pulse at that power level because your lungs can't maintain the airflow to stop the device from drying out/getting too hot/etc - so you take short, very fast, inhales.
If you have any doubt on this, bear in mind that if you were correct and all cells went pop as soon as they went past their rated max constant current draw, there would be hundreds of thousands of battery fires a year from e-cigs. We've seen hundreds in near a decade worldwide.
Real world evidence trumps internet hypothesis every time, I'm afraid.
Steven R
Biting the hand that feeds IT
