What did you plug it into? You cannot run most PTs off a PC's USB nor off a battery charger's USB to AC. Go buy a 2amp USB to AC. I use Rosewill RUC6181 4port 2amp USB to AC from NewEgg.com and either use 4 battery cables on it OR use a passthrough, Don't use a PT on it together with
batteries charging or every time you drag it will pull down the amps available to the battery charging cables and it could damage your batteries or they may not charge correctly.
OR
If the PT has an inline real Ego battery (not a hollow imitation) then you may need to wait for it to charge some for the PT to work. Those are basically a battery that is kept charged and you are
vaping off the battery. This type may e able to be powered by a PC's USB or other full 5v 500ma USB to AC.