Wow, I am so happy I got this passthrough. So I've been using a large battery since last night and the smaller manual and auto that came with the kit I ordered. Yes, I have been a complete hog since this came yesterday, so no comment on that, ok? 
They can all be on usbs and a wall charger at the same time and I still have the passthrough to use. (I don't want to let the charge go all the way out of the batteries before I charge them again, I believe this is the correct way to take care of the batteries, right, rather than letting them get too low before charging.
I love this thing, it is so great not to have a battery to worry about and I do the most vaping while at the computer anyway.
If you knew the battery and especially the obtaining of a charger issues I've been having with my mods, you'd see why I am so amazed at all this, as simple as it is...
They can all be on usbs and a wall charger at the same time and I still have the passthrough to use. (I don't want to let the charge go all the way out of the batteries before I charge them again, I believe this is the correct way to take care of the batteries, right, rather than letting them get too low before charging.
I love this thing, it is so great not to have a battery to worry about and I do the most vaping while at the computer anyway.
If you knew the battery and especially the obtaining of a charger issues I've been having with my mods, you'd see why I am so amazed at all this, as simple as it is...