I have a Lavatube from the very first batch (pre-order and all), not Volcano and why should it be as it's the same?, and it still works. I have a Young June Lavatube and it still works. I have a ss Tesla that stopped making contact. And I have a Vamo 5 that I use daily and is still going strong. I think if you treat them, I won't even say well but normally, they'll last for very long (save for the Tesla, I don't know why), probably as long as a Provari and much less expensive. I know I'm not very fashionable as none of these are box mods, lol.
Now, if you buy a box mod with built-in batteries, it will last as long as the batteries last, sorry to say. You can always try to fix that, of course.