If you've got the gray Panasonic CGR18650CH, they're just fine for mechanical mods. The reality is, most people don't need 30+amp batteries because they don't build a coil below1 ohm.......hell....those Pannys are rated for 10A so they're actually suitable for most vapers. It's only when you get into the ..5 ohm and lower builds that you're pushing more than 10A. Here's the math:
Battery on a fresh charge shows 4.2v (you won't get 4.2v under load because there is always going to be a drop under load but, for argument's sake, we'll say you're getting 4.2v). So, to find you current (amps), you divide your voltage by your resistance (ohms). 4.2/0.5 = 8.4A. Plenty safe for those Pannys. If you want to find your wattage, just multiply your amp load by your voltage. So 8.4 x 4.2 = 35.28w.
( You may have already known all that but I think it bears repeating over and over because there's too many people out there cloud chasing without the foggiest friggin clue what they're getting into. I talk about battery safety as often as possible)
I'm runnin the neon green Panny NCR18650Bs
Right now all my builds have been around the 1.6ohm range. Been satisfied with all my builds so far