Originally Posted by
garykung
Why do you need 2 power banks when your flight has a potentially working charging port and 1 power bank is good enough for a long-haul one-way?
Because you might have multiple devices, and are going to be travelling by land in a vehicle without a power supply after landing? Or you're carrying them as a present? Or like to have backups? Or....?
Not that this is particularly relevant to OPs question...