I personally recommend at least 2 of any of the following: LG ICR18650HE2 LG ICR18650HE4 Samsung INR18650-25R R2 (BLUE) Samsung INR18650-25R R5 (GREEN) And at least one of the following: Nitecore D2 Digicharger Nitecore D4 Digicharger Nitecore i2 Intellicharger Nitecore i4 Intellicharger I personally don't recommend any Efest batteries, especially for newbies. Efest has been inconsistent at best. They over rate the batteries that they rewrap and over charge for them. I have seen independent tests that say none of their batteries are close to the rating they claim. Is it true? I don't know. They have been the worst batteries I have ever had myself. I also don't recommend Sony VTC3, or VTC4, as there are too may knock offs out there. If you really trust the vendor, they are great batteries. They are highly counterfeited though. I think one of the more important things is choose the correct vendor. Stay away from most vape sites, and Ebay. Be very cautious on Amazon, as there are good ones and bad ones out there. The safest places to buy them is Flashlight suppliers such as illumn.com, or liionwholesale.com (IMO). Any of these batteries should be able to be bought for around $5.00 to $6.00 each. I would suggest you buy at least 2. This gives you a fresh backup at all times. This is another reason to get a separate charger. You can be vaping on one, and charging the other. I personally carry 4 everywhere I go, and keep 4+ fresh ones at home. Normally 1 will last me nearly all day. I am not a big fan of charging in the mod. I also discourage "pass through" vaping especially with a SubOhm tank.