Get LG HD2C 25amp, 2100mAH 18650s at imrbatteries.com for $5.50 U.S. Dollars each. These apparently are more powerful and longer lasting than Sony VTC4s, the batteries we all USED to care about, however there's another good option I'd personally suggest over the LG HDC2. Most will tell you the HDC2 batteries are the best for average or casual cloud chasers and can pump handle a lot of wattage. I suggest LG HD4 batteries that are 25amp rated and also 2100mAH and $5.50 a pop. The HD4s were just released to the market two days ago, and since LG rates HD2Cs as 20amp continious and HD4s at 25amp continious, I bet the newer model is going to be either a bit more powerful at different points of it's charge cycle but doubt there any worse performers. Check around for the HD4 benchmark test results around the internet and decide. HB4s I save for my TFV8 Cloud Beast Subohm Tank at nearly 145W vaping a .15ohm Clapton Coil Core. HB6s are rated as pushing less power much sooner in the cycle than HB4s and the initial extreme powerhouse HB6 cell can be, the fact is overall HB4s are all reg. box mod users need for very serious coils and wattages. 1500mAH, however, 30amp continious without a doubt. I love mine still.