Is this something cool?
I wanted a portable battery but I had no money (student life in Mexico), but I had a couple of damaged tablet batteries and a damaged router case.
A year ago I did not use it, but now it is useful when I occasionally go out to capture some Pokémon.
The downside is that it only has one USB port to discharge and micro-B to charge. And of course I do not go out with the antennas, I take them off, I just put them on for the demonstration, haha.