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[kramnala58]

Regarding air travel, the unit that Homie linked is only 8000mAh, which is allowed in carry on luggage as long as there are no exposed terminals.
But here is an interesting PITA fact. If you fly in or out of China with any battery like this, and the power is not marked on the unit, it will be confiscated.

When we flew through Shanghai, they were fairly strict. I believe 10,000mAh is the max. I also believe you can only have one. I have a 'brick' type that looks similar to the one Homie linked to, but I also have one that serves as a case for my iPhone 6+ that isn't easily recognized at a charger. They didn't recognize it, so I was okay. Nonetheless, they still pulled us aside with our checked bags because I have a bluetooth keyboard for my iPad in it. The xray machine picked up the internal battery in it, so they questioned be about it and were leaning toward making me leave it behind.