OF- you make it seem like the batteries only last a few minutes. Is that the case with the Cera. I don't mind needing an extra battery but to need two... That seems like an issue with the run time, no?
i thought the battery they came with the cera are panasonic NCR18650PF (mine) and on the thermovape page they recommend you to buy protected ones... but this got mentioned also earlier in this thread...
I use the NCR18650PD as well (in fact I'm testing one right now for another, non vape, project.....). TV also used to sell CGR18650CGs which have lower capacity (2200 not 2900) but run slightly hotter. Both are excellent choices IMO.
I think you need two solid batteries (at least). You need to have a fresh one to swap in to test any concerns with performance....otherwise Murphy will talk you into adding more oil to your EO cart and you'll have a flooded cart to add to your discharged battery problems.
I did a fair bit of testing of run times early on it the Beta test phase, I reported them here somewhere. As I recall you can expect half an hour (or a bit more) run time from the CG, closer to 45 minutes from the PD. I ran my Beta unit half an hour straight at one point, it got mighty hot (I could only hold it by the very bottom, thankfully with the latching switch so I didn't have to press the button as well which would not have been possible). The battery held up fine, much better than my fingers did.
You can do the 'back of the envelope math' for yourself. Cera draws about four Amps so dividing 2.2 Ah by four gives half an hour, dividing the 2.9 Ah for the PD by that same four Amps gives about 3/4 hour.
The key is to stay sharp and swap depleted batteries out before you run them into the mud.
Regards.
OF