I've flown in and out of SFO plenty of times in the past 6 months (canadian) and i've gone through security with upto 4 18650s, 90ml of juice and a tube mech mod without any issues at all.
Just be sure to keep your juice in the same plastic bag as your other liquids (lotion, shampoo, etc) and you should be fine.
PS: my tube mech mod is the pipe bomb made in fresno (legit looks like a pipe bomb too lol) and i haven't had any issues crossing security check with it in my carry on backpack.