I have the same charger and it buzzes too.I try to make sure to keep it unplugged when not in use.Sometimes it buzzes and sometimes it does not.If it bothers you,replace it.12-15 bucks is a small price to pay for piece of mind.
I want to start making my own liquid.I am hesitant to buy the wal-mart vg and tractor supply pg.I have heard it may cause an aftertaste.Any suggestions?