Do wireless chargers only work well when plugged into the wall?

[JnEricsonx]

Silly question but, how well would they work if they were connected to a portable battery/power bank, etc.

 

[ManiacJoe]

Previous thread:
https://forums.androidcentral.com/g.../961357-question-about-wireless-chargers.html

 

[Dooki]

Wireless charges are not efficient. If you have a battery pack just use a cable.

 

[hallux]

The smarta$$ in me reads only the title and says "well, how else do you expect it to work?"