Help with DC power: power banks fail but adapter works?!!

[elebot]

hi,
I am trying to power a 5v USB thermal printer via a power bank (Xiaomi to be specific). Funnily
I tried two power banks and some AC-DC adapters but they did not work.
However, i have one particular adapter that works and so does as Lead Acid battery.
All adapters/banks show 5v although I probably have not tested under load.

The current drawn varies and has a max of 1.5a which all power sources support.

i would really like to run off the power bank since it makes it portable.Is there something to the technology used? can some tweaks make these banks power the printer?

TIA,

 

[shrtrnd]

I'd take a look at the AC/DC adapters that aren't working. The barrel jacks (if that's what they use) to supply power come in different barrel/pin diameter sizes. It's possible that the power connectors for those
adapters are a different size, and therefore not making proper connections.

 

[elebot]

Sorry for the delayed response - i did not realize there was a reply.
I'm using the same custom cable but will double check again. Is there any monitoring in the power banks which prevents variable loads from working correctly?