ShogaNinja is definitely on the right path. I think disposables are junk.
Your father in law's first vaping experience needs to be a good one otherwise he'll just put it down and go back to smoking occasionally vaping maybe just to try it or to seem open minded or grateful but in the end the addiction will prevail.
my 2 friends and I have given our Ego-c's away in less than a month and I believe he will do the same as well. The battery life is short, the tank system is convenient but small and gurgles occasionally, It also doesnt put out enough power to run higher resistance heads.
I think you should either buy 2 ego twists (variable voltage) or a vision spinners (same style but longer battery life) 2 chargers (one for home and one for the car) 2 Kanger Evods and a 5 pack of Evod heads.
The evods are great. they dont gurgle unless you forget to wipe the rubber between refills and they are low maintenance. Plus being bottom coil you wont have to tip it back to get the wick wet. They also shouldnt leak unless you run a citrus flavor (I recommend the gorgeous Kanger protank for this. Evod heads are compatible)
With this set up, it should eliminate:
-functional obsolescence (the spinner or twist can drive a 2.5 ohm head no problem and they last long)
-finnicky leaking or gurgling tanks (kanger evod and protank are very reliable. the Evods fit seamlessly if you buy matching colors
-dead batteries (if you buy him 2 batteries and tanks he can easily switch to the other while they are charging so he doesnt have to grab a cig. Plus with 2 chargers he can charge at home or on the go)
-bulkiness (mod batteries look silly to some analog smokers and cigarettes will always be lighter and more convenient than vaping)
This should almost give him no excuse to go back to analogs.
Now the hard part is finding the right flavor. I recommend some fruits, tobaccos, and bakery flavors to mix it up.
Melon boba, bobas bounty, and cafe napoleon are awesome! I'd run high nic levels like 24 or 28. Let him vape his brains out and get nic sick the first time so he doesn't think its too weak for him.
Within weeks he might decide to drop nic levels and get gung ho about juices and mods and you will have done him and his family a great service getting him off analogs!
Good luck and happy vaping!
Vap0rho