MacBook Pro insists on charging FROM my mobile devices using USB-C

[dweber]

Macbook running 12.6.3 but this has been a problem forever. Did a full reinstall and had the same experience.

Using a USB-C cable, I directly plug in a phone or a battery pack into my Macbook which is 1) fully charged and 2) plugged into the wall.

The MacBook says "hey, a cell phone? I better pull power off of this as fast as I can."

(It sucks to plug in a phone that needs a fast charge because I'm leaving for an appointment in 20 minutes only to discover it has done a *fast discharge* during all that time.)

Sometimes I can turn this off on the other device. Other devices without a UI cannot have this changed and just sit there losing their charge.

How in the world can I stop this on the MacBook side?


MacBook Pro (15-inch, 2018)

 

[chabig]

The MacBook says "hey, a cell phone? I better pull power off of this as fast as I can."

How did you determine this?

 

[dweber]

How did you determine this?

Because the device *rapidly* drains power, and if it has a UI it says the other device is pulling charge.

 

[chabig]

Interesting info. I’ve never heard of that UI. It doesn’t sound like something Apple would do. Can you post a screenshot?

 

[cthompson94]

so you basically want the Mac to be a passthrough?

 

[DeltaMac]

If you know this happens, why not use a different method for charging your device? (ignore the MBPro for charging devices)

Have you tried other cables? Tested different USB-C ports on your MBPRo?

And, this might be a good question to ask at an Apple store (where someone else can "touch and test" your MBPro.

 

[dweber]

so you basically want the Mac to be a passthrough?

I plug things into my computers all the time to charge them. It has worked this way for nearly 20 years. Only with USB-C on a MacBook does it decide to do the exact opposite.

Interesting info. I’ve never heard of that UI. It doesn’t sound like something Apple would do. Can you post a screenshot?

Here is what it looks like on an Android phone. (And, yes, I've attempted to turn over control to "connected device" and it fails.)