Hello,
I'm pretty new to vaping and have had an Alien 220w Mod with a tfv8 baby beast and LG DBHG 21865 Batteries (Brown).
I wanted a bigger tank and found the tfv12 but I am not sure if I need to buy different batteries.
The LG HG2 Brownies at lowest charge are capable enough to reach 100watts to 110watts max safely in the Alien 220W given the Alien takes batteries down into the 2.8 to 2.9v charge level per battery. It is a nice mod but a bit overspeced as it can not do 220W consistently even with 30amp CDR batteries (LG HB6 1500mah 30amp CDR) it caps out at about 160 to 170watts max, though you can take batteries higher if you swap out batteries in the 1/4 to 1/3 charge level left instead of draining them down fully before recharge. Adding a tank that is way over powered, and needing a lot of power, averaging minimum of about 100watts or more just to function right, it will kill your HG2 battery charge quickly, so, a good battery that is a balance between power and runtime you'd probably be better served with Sony VTC5A (2500mah 25amp CDR) batteries to handle 100 to 130watts comfortably. That or you might look at the TFV8 Full Sized Cloud Beast, the bigger brother to the Baby Beast.