That is correct:
60 = 3 x 20.
If you put on a fresh battery 4 volts, delivering 20amps you can get 80 watts
but on a regulated mod, if you set the mod to 80 watts, once the battery drops below 4 volts, it would have to deliver more than 20 amps to deliver the 80 watts.
When it's down to 3 volts, it would have to deliver 80/3 = 27 amps
Okay, so I guess regulated mods such as the ipv 3 fix this by using two batteries. Seems like people are really pushing the safety of batteries in those types of devices. I really appreciate all your responses, I've learned a lot about batteries and ohms law over this. Now to figure out mech mods Lol.