Creating a huge 12v battery pack from many 3.7 cells

do the maths based on marketing numbers to see discharge rate.
At 2A you are going to need high quality batteries to sustain that discharge rate.
I’d still be contemplating a LiFePO4 battery pack as they have high discharge capability, and for the weight will give you more runtime than most other chemistries

Well, that’s why, given that I have over 100 of those 3.7v 2200mah li-ion batteries, I wanted to know if it was feasible to make a monster battery pack out of them. Sounds like it is more trouble than it is worth, even just as a goofy project.