Why don't my CE2 cartomizers work on my 5V device?

[Mr Pickle]

I just bought some 2.8ohm CE2 ceramic cartos, and they only work at 3.7V. Correct me if I'm wrong but I thought 2.6 - 2.8ohm were rated for at least 5V.

Has anyone had this problem, or have an explanation? Is there a solution?

 

[washvap]

That's odd, they should work. Have you measured them yet? Also, what device are you using them on?