As others have said times will vary depending on how often you vape, how long you press the button, what your using with it, etc. LR attys will drain it faster and DC will really drain them. If you're using LR or DC with 14500s I'd recommend getting IMR. They can handle much higher current drains. 4 hrs or so with a DC doesn't sound that far off base.
You can check your charger by getting a multimeter and I'd recommend you get one anyway, every vapor should have one and they are cheap, check places like Harbor Freight. With a meter you can check what the voltage is off the charger and troubleshoot from there.
You can check your charger by getting a multimeter and I'd recommend you get one anyway, every vapor should have one and they are cheap, check places like Harbor Freight. With a meter you can check what the voltage is off the charger and troubleshoot from there.