Thanks for the replies. I wouldn't know if it's going to get hot or not, as i haven't even charged them yet. I just noticed that the space is so tight in my SRT for the 3S(yet my 5S hardcase fits perfectly ) that they would have no room for expansion. I just wanted to make sure the packs wouldn't be any bigger during use or charge, as there is no room to accommodate growth and I didn't want to create that pressure within the packs.