I heard some complains about ego pass through, less vapour!
Some manufacturer's add-in batteries for ego usb pass through, including Joye.....was it due to this problem or what??

Means, you need to charge the usb pass through also....what the hack??
My idea of using pass through is to save battery life, but now have to care about the usb pass through battery also, i'm not sure about you all....i don't see the purpose of using it anymore.
unless the user thinks the cost of usb pass through battery is cheaper than ego battery....