I don't know what devices you plan to put on the mod or what resistance
coils you plan to run, so I'll have to be a bit generic in my response.
I suspect the blue battery is a generic IMR, but I'm not sure. Because it's an unknown battery I would not use it without a fuse. I'll give you a link to one later in my post. Also, once I had known good batteries, I would not use this one anymore.
As degnr8 said, these are Panasonic batteries, not high drain and typically have protection circuits. Their amp limit for continuous discharge is 6.8A, so you're limited to not going below about 0.9 ohm
coils, including some margin for handling shorts. They rate 3400 mAh so should last a long time, but their internal resistance is IMO likely high so you might get a lot of voltage drop in use and not see all the mAh. I'm also not sure how safe they are if the protection circuit fails. I would not use these in a mechanical mod.
If you will be using coils above about 0.6 ohms, I suggest something like the
Panasonic NCR18650PF at 2900 mAh with a 10A continuous discharge rating. I know this is a safer chemistry battery. It's not protected but if you stay above 0.7 ohms you can add a re-settable
Vape Safe Fuse 2 for short protection and I recommend you do this. Shorts can happen even if you're not using RBAs/RDAs.
In case you don't know this, there is a
Ohms Law online calculator here. Plug in numbers for your coil resistance and the battery voltage, use 4.2V as that will be the voltage when it's fully charged, hit calculate and you'll see the current (I) draw in amps. It's important to stay well within the battery amp limit for safety.
Hope this helps
