There is this great question: What happens if you plug more than one charger in the new MacBook Pro (2016)?
It doesn't tell me how to find out from which source the MacBook is charging though. Right this moment I have a power bank and a MacBook charger (small, not proper wattage) connected to my MacBook Pro and my battery is at 3%. I'd like to know which one I can unplug.
Is there a way to know which port is giving the power? I'm looking for a precise answer, e.g. from a command line tool. It'd also be good to know with exactly how much Watt it's charging.
I don't want to rely on whatever is indicated on the charger.
Best Answer
The one that has the most power is the one that does the charging
From Apple's support page Connect with Thunderbolt 3 on your new MacBook Pro (that was linked in the question), it states that
You need to check the specs of the power bank and the charger. How many watts to each have. To get this info, use the simple calculation:
If you power bank give you 5V at 2A it's capable of delivering 10W. If your charger is capable of 12V at 5A then it's capable of delivering 60W. The one with the most is charging your Mac.
Most likely, your power bank is nowhere close to an AC adapter - that's the one you should disconnect.