luthj
Engineer In Residence
Don't need to solder anything; can buy a battery kit for 18650: https://vruzend.com/product/vruzend_basic_kit/
Primarily attracted to 18650 of the cost. You can buy a bunch for pretty cheaply.
I am a bit confused. Don't most 18650s come without terminal studs? If so, how do you attach the studs without spot welding?