You should not have a problem. I traveled to Germany this year and had a Riva, extra battery, extra atty, small bottle (3ml) of liquid, and my charger in my carry on. I also had more liquid in my checked bag. You can see more stores of how much you should not worry about ecigs on planes here.....
Travel and E-Cig
With a 15ml bottle you should still be fine as long as you place it in a bag with your bathroom stuff. Toothpaste, shampoo, ect.
Hope this helps. Also don't be afraid of bring extra
batteries. They are not dangerous and do not show up on xray as anything strange. They see thousands of Lith-Ion Batteries a day. Phones, Computers, games and everything else uses these batteries.