LOLSorry OM - but you have to admit - he is a pretty smart guy but I promise never to mention it to him again.
CDDZ - you are a man that is for sure. I asked you a question.
Were you not listening to me? Pay attention!
When the vapor is almost nil - is it already too late - did it drain too low?
guess i did miss one part, Those batteries have a built in protection cicuit that cuts them off @2.5v. Wait that wa not your question, I do not vape much at 6V, but as long as you charge the batts when you notice the vapor drop off. A volt meter would be a good investment if you choose to use unprotected batteries.