I'd use Farnell. They're a huge, reputable, supplier that takes product direct from the manufacturers.

I don't know how easy it is to get them to ship to you, nor how easy it is for individuals to buy from them.

UK: http://uk.farnell.com/search?st=18650

Norway: http://no.farnell.com/search?st=18650

Genuine Panasonic 18650s are decent. Not had any problems so far with ThruNite either.

there is probably a more 'electronics' source available, but these are pretty much the go-to batteries for vaping, so probably any reputable vaping vendor might be a good, if overpriced supply...

Norway? Isn't Nkon next to your door?

Never heard of Nkon. If you mean in the almost literal sense then I think you might be conflating Norway and the Netherlands? But if you just mean that they are next door in terms of being in Europe then yes so it seems. I’ll have a look at them thanks, along with the others people have mentioned.

Yes, I meant that-end-of-EU, sorry for coming off cheeky. Winning the great EU customs roulette with batteries is not worth it if there is an OKish intraEU seller. Plus, a lot of discussions about it's batteries in .ru (!) internets.

Hey, also live in Norway, I've ordered from NKON before, just use https://ru.nkon.nl (we're outside the EU VAT region).