yeah i was told the same when i was starting to vape that using wall plugs overloads the battery it can cause it to become unstable we've all seen these horror stories my mate actually charged his through a wall plug and it basically melted
With everything else going on in this thread, I forgot to reply to this... do you know what the wall plug was, and what the charger was? - I have also had a cheap non-CE charger melt on me - when doing research into unbranded ecigs from dodgy chinese suppliers.