There are two different types of passthrough.
Type one (True Passthrough): No battery, requires you to plug a USB cable into either a computer to wall adapter. Example: GotVapes AMiGo VV Mini eGo Pass Through 3.0-4.8 - Stainless [gv-AMIGO-minipassthrough-STNLS] - $17.95 : GotVapes.com, E-cigarette Supplies - Atomizers Cartomizers Mods Juice and more
Type two (Passthrough Charger): Has a built in battery. Instead of charging through the 510 connector, there is a mini or micro USB port somewhere on it so you can charge and vape at the same time. This type still only uses the battery to power it, not the power source. So if you have a completely dead battery, you may have to let it charge for a few min between each vape. Example: Genuine Joyetech eGo PassThrough 1000mah 3.3v - BLACK [gotvapes-joyetech-ego-PT-black] - $23.95 : GotVapes.com, E-cigarette Supplies - Atomizers Cartomizers Mods Juice and more
Type two is what I have.
Type one (True Passthrough): No battery, requires you to plug a USB cable into either a computer to wall adapter. Example: GotVapes AMiGo VV Mini eGo Pass Through 3.0-4.8 - Stainless [gv-AMIGO-minipassthrough-STNLS] - $17.95 : GotVapes.com, E-cigarette Supplies - Atomizers Cartomizers Mods Juice and more
Type two (Passthrough Charger): Has a built in battery. Instead of charging through the 510 connector, there is a mini or micro USB port somewhere on it so you can charge and vape at the same time. This type still only uses the battery to power it, not the power source. So if you have a completely dead battery, you may have to let it charge for a few min between each vape. Example: Genuine Joyetech eGo PassThrough 1000mah 3.3v - BLACK [gotvapes-joyetech-ego-PT-black] - $23.95 : GotVapes.com, E-cigarette Supplies - Atomizers Cartomizers Mods Juice and more
Type two is what I have.