There are three types of VV-VWs.
Nearly all VV-VWs take common batteries. A few hundred charges and you replace them and start over. What wears out are the 510/eGo threads, the buttons (the fire button in particular), the electrical contacts (from erosion) and whatever chip runs the show. If you can get replacement parts for everything... your mod can last forever. With a few exceptions - good luck with that last part.
No matter what you get, after the initial fun of playing with the buttons, try to settle on a few settings... and stop playing with the buttons. ;-)
Wear and tear on fire buttons is, unavoidable... but many mods have seriously HD buttons just for this reason.
Don't over-tighten your atty. Reusable attys like a Protank and many of the RBAs may have SS threads and can accelerate wear of the mod threads, and may even damage the positive contact mounting as well.
Disposable attys... like cartos, with or without carto tanks, have soft aluminum threads and will strip out far easier if you do happen to get overly aggressive.
Occasionally cleaning your batteries and the mod electrical contacts will extend their lives dramatically. Lots of interweb info on cleaning electrical contacts.
The chip itself is generally not something you can extend the life of (other than using high quality batteries in good condition) with the exception of the obvious, like avoiding extreme temperatures, water and dirt.
If you're a DIY'er with soldering skills and electrical knowledge... you might get a VV-VW to last a life time. You also may end up replacing every part in it 3 times over during that lifetime.
There are a few VV-VWs that are self-contained. The Innokin iTaste models 3.0 "stick" form mod and the MVP 1 and 2 "box" mods. The batteries are sealed in the units - 800mAh and 2600mAh respectively. Depending on use, you can probably get 1-3 years out of these. I've heard reports of folks who have figured out how to replace the battery in MVPs... so who knows.
Now... on to the latest trend. At least, that's how I see it. The mechanical mod... no PCB, no wire - no nothing. Just a battery holder and a HD button to complete the circuit. With some of them, you can buy replacement wear parts like springs, buttons and atty threaded connections.
So how does this figure in, you ask? Easy... the "Kick". Originally designed and developed by Evolv, the Kick converts nearly any mod that uses 18XXX batteries into a VW device.
As with all good things, the Chinese were fairly quick to clone it, and $12 Smok and $18 Sigelei Kick or "Stomp" clones are plentiful. Evolv now has the Kick 2 with upgraded features - and there is a similar device with several unique features, including only 1/2 the thickness of the Kick, called the "Crown" as well.
Buy any mechanical mod that suits your fancy, toss a 18000 battery and a Kick in it, and you have a sophisticated VW mod, that, unlike most, you may be able to replace all the wear parts on. A Sigelei 19 for example... you can get different atty heads and replacement/upgrade button assemblies. That only leaves the tubes in the middle, and they might last forever with modest care.
Yes, the Kick, Kick clone may take a dump, but at the prices they sell at... who cares. Even if all you do is get a mech mod and put a resetting safety fuse in it... if all you use are 2.0Ω attys... you're probably still in good shape.
With any un-chipped device that won't warn you about the battery condition, you will have to take responsibility of that yourself. If you have a multimeter, it's maybe a minute out of your day to look at the condition of a few dozen batteries.
It would be irresponsible of me not to warn you... unregulated mech mods can be dangerous. In the hands of a dummy, even a Kick'd mech mod can be dangerous... but then, so can a VV-VW.
That's it.
