I recently purchased the smok g320. The store I bought it from its reputable and I just haven't had time to drop in. However, why would one of the three batteries that power this suddenly drain extremely quickly as I've changed no settings? It's not the cell itself. It is whichever battery is in slot A. Can't make heads or tails of this especially since I'm completely in the dark with all the technical jargon. Perhaps, someone with more knowledge could explain in as simple terms as possible?