I'm being constantly asked this question each and every day, "Which 18650 batteries are best for vaping?" And, even see similar questions being asked on Facebook community too. So here's some information about various batteries that are best for mech mods or regulated mods ..
Forget Sony batteries. Sony stopped making (or selling) their VTC line of batteries. Most of them are fakes that online sellers are selling. And if anyone has an oldie stock left, you may be lucky to get hold of them but that's a bit rare scenario.
The good batteries for sub-ohm vaping (and for your 50w or more wattage mods) are:
LG 18650HG2: 20A continuous discharge / 30A peak discharge. 3000 MAH
LG ICR18650HE2: 20A continuous discharge / 35A peak discharge. 2500 MAH
Samsung INR18650-25R: 22A continuous discharge/35A peak discharge. 2500 MAH
All three of those are 20A continuous and 30 to 35A pulsed. I have used the above batteries and pushed them to their limits. Even shorted them while using on mechs. You can trust these batteries. These batteries are good for any mod you have (or wish to buy). Be it a mech mod or VW mod or TC/TP mod. GOOD SAFE BATTERIES!
eFest purple 18650s are nothing but re-wrapped LG HE2 .. note that eFest doesn't make anything, they just get hold of the LG HE2 bats and rewrap them with their own branded covers. Lame but true. And their new claims about 35A, 3000 MAH batteries are dangerous! Those are max 10A batteries that the advertise as 30 or 35A. That's the reason I have stopped sourcing those batteries. Their previous batteries (2500 MAH) were good and I have sold over 100 such batteries. New batteries are nonsense, so goodbye eFest.
AW IMR by Andrew Wan. I have chased Andrew for months to get 18xxx batteries from him but no luck. The reason, Andrew has signed up with UPS and UPS does not ship IDG (Internationally Dangerous Goods) to India. So I contacted UPS and gave them the suggestion that DHL is shipping IDG to India, then why not you guys ship to India? But their canned reply, "We don't ship to India for now but will pass the suggestion to higher management". UPS Sucks!
Gave Andrew a suggestion to signup with DHL or Fedex .. but his application to signup is in the pending status since forever. So his only option is to ship batteries through UPS. Requested him to send batteries through a third party shipper but he refused. His words, "As soon as the batteries get out of my hands, they get replaced with cheap batteries. Has happened many times and I'm done with hurting my reputation". Fair enough. Andrew, we appreciate you for the good work and just hope that you find a way to ship batteries to India. You have enough buyers here in India.
Well, customers can still go ahead and buy AW batteries from AW authorized resellers mentioned at Candle Light forums and/or CPFMarketplace.com and you can even contact Andrew on either of the two websites mentioned. If you can get hold of original/authentic AW batteries, there's nothing like that. Those batteries are awesome performers! I have owned a couple of AW 18650s and man, the performance speaks out on those batteries.
[size=1.35em]Battery Safety ....[/size]
Don't just buy any cheap batteries that you see online. Don't just trust anyone blindly when it comes to batteries, especially Chinese sellers. Always buy from a trusted source where others have bought and left their reviews. Although FastTech is a trusted place to buy batteries but I'm sometimes skeptic as I see so many noob batteries being listed where they claim 70A continuous rating for 18650s. That's a bunch of bullocks! The three batteries I have mentioned above are good batteries and you can trust those for performance.