Bitcoins with several laptops with no electricity cost. Is it profitable?
Well instead of several laptops, and setting so many PC's that are not designed for this kind of work, and be set on fire after a day working. Why not consider taking some 
 Acalon or Antminer R4, or something that is worth it. 
 However using electricity is never a good idea, it is not cost efficient to mine on electricity. 
 You can buy a bike instead :) and produce it yourself. Just a joke, there are different cheaper ways to make it work.