Always reading problems about the Vamo V5 :-(
Ive got one on the way and im worried about it now!! Don't want to have spent on something which isn't going to last me a good while!
v5 Vamos are pretty solid mods.
Like all mods sometimes you get a duff one, but they aren't as common as you might think.
A Good rule of thumb for a vamo is buy the stainless steel one.
Two things happen to the brass/chrome types.
i) the plating wears off quickly and they scuff up very easily
ii) the threads on the top cap don't last as long.
If you prefer a 'weathered' look then i) isn't an issue and you can get around ii) by using an airflow controller or an adapter to screw into the top that you then screw your tanks into. You can also buy replacement top caps from places like Steathvape and there are a few posters here who can help you out replacing it, or giving good instructions on how to do it yourself (check out the modders section)
Also always always ALWAYS set the Vamo to RMS mode.
MEAN mode is bad, it's so bad that it shouldn't be there at all. MEAN mode doesn't deliver what it says it will accurately, it's so far out that frying coils is all too easy.
You can stack 18350 batteries in a vamo. It's not ideal from a safety point of view, though if you prefer the output from stacked batteries:
i) USE IMR BATTERIES - these will be a lot safer if you over stress one
ii) Use PAIRED batteries.
Basically if you stick 2 batteries that do not have the same charge in them then 1 of the two batteries works much harder than the other. This over stresses the battery and can cause a problem. If the overworked battery decides that you are pushing it too hard and it doesn't want to be a battery anymore it will get very hot and might start venting hot gas. If one goes it will set off the other one as well. You really, really don't want to be holding a metal tube with stuff in it that's on fire.
If you charge them in pairs, and use them in pairs then you won't get this problem.
The circuitry in a vamo will happily push out good power up to about 5 volts. Especially if you are using IMR chemistry 'high drain' batteries which are designed to be happier at higher current levels. for most vaping levels and most normal tanks (proTanks aspire tanks, aerotanks, iclears etc etc) 1 battery should give more than good enough output.