A single 20700 battery squonk setup on a lanyard is great for driving. Long run time between refills of the bottle, and multiple squonk bottles of liquid used before it's time to change the battery.
This is a pulse bf mod with a dead rabbit sq single coil
rda. I use one of the little ego/510 extenders from Wharf to give the lanyard something to go around; it's the old school extender for use on automatic
batteries, the hole in the middle of the positive pin works fine for squonk use. The lanyard is a generic cheapie, I switch to a
fasttech stainless steel "ego" ring and a stainless steel split ring at the end of it, for durability.