I did a little test using an ipv2 and a Sony battery from a laptop power pack (please for the love of god don't copy me, I knew what I was doing could end badly but I have a wee bit of experience with electrics and explosive devices) I popped a very low amp battery into my ipv2 think the spec was a max of just over 4a continuous,
Popped my plume veil on top set with a dual coil set up to run one ohm 2ohm per coil and bumped the watts up to 50 (the wattage will keep going up but the volts will only go so high depending on build with my ipv)
Hit the power button and............
Watched the fully charged battery hit rock bottom as the power sagged, then.........
Got a check batt message on the ipv screen, no Big Bang no smoke, no heat,
But......
Not every mod is equal, don't test your luck as one day it will run out