On the smokestik subforum there is a thread discussing refilling the cartomizers. I pulled the hard cap off and used a syringe, I think the automatic battery was the reason someone recommended against refilling them via condom. The only issue I found was that they are a tad bit deceptive, when they are slush on top they are overfilled, I found this out with a mouthfull of juice. Took off the carto, lightly blew out excess, made sure battery end was dry and all was right with the world. I usually would not recommend auto or low mah batteries, but these are well made and definitely have there uses.