Hah, can't really tell. First one lasted 3 days, than it was replaced and with hard smoking they last maybe 2 hours with relatively good smoke production.
The replaced battery plus the other one were replaced after another week...
One of them was still giving good smoke but had bad switch which wont go on and the other failed to produce decent smoke...
Now the 2 new batts are about a week old but I got the Screwdriver and put the whole thing in the locker

I would say 3-4 hours if I don't puff much ... otherwise 2-3 hours. I wont vote couse Im not sure about my perception about time
