I guess part of my problem is even when I take the fill cap off the metal ce2s (which I prefer) I can never get it on right. I have tried a hundred ways. So I vape it as long as I can standto and then trash em. Don't get me wrong I think even 3 days to a week is well worth the $$ I am paying as it is saving me tons of cash in cigs but I am always looking for another way to be a cheap ... vaper. AAHHHH never mind I am acutally to happy to even care as long as they last a week I am in heaven. But thanks for the advice in advance from our fellow vapers