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nolem

macrumors member
Original poster
Jan 9, 2004
58
3
Got it with my new M2 Air. Does anyone else notice that it'll limit charging to the MacBook to 27 watts when another cable is plugged into the 2nd port but not connected to any device? Unplug the 2nd unused cable and it goes to 35 watts. Meaning I need to crawl under my desk and ensure the 2nd outlet is empty if I want to charge at the full 35 watts...

Trying the same scenario with my Anker Powerport III Nano Pro Duo 40W it's actually worse, MacBook charging cuts to 20 watts from 40 as soon as a second cable is plugged into it without a device on the other end.

Any brands out there that make chargers smart enough to avoid this? Or are these things meant to be pieces of art in a wall outlet easily accessible to plug and unplug cables from often.
 
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Got it with my new M2 Air. Does anyone else notice that it'll limit charging to the MacBook to 27 watts when another cable is plugged into the 2nd port but not connected to any device? Unplug the 2nd unused cable and it goes to 35 watts. Meaning I need to crawl under my desk and ensure the 2nd outlet is empty if I want to charge at the full 35 watts...

Trying the same scenario with my Anker Powerport III Nano Pro Duo 40W it's actually worse, MacBook charging cuts to 20 watts from 40 as soon as a second cable is plugged into it without a device on the other end.

Any brands out there that make chargers smart enough to avoid this? Or are these things meant to be pieces of art in a wall outlet easily accessible to plug and unplug cables from often.
That's how it's designed to work: https://support.apple.com/en-us/HT213263

  • If you connect a Mac notebook and an iPhone or iPad, each device receives up to 17.5W.
  • If you connect an iPhone and an iPad, each device receives up to 17.5W.
  • If you connect a Mac notebook or iPhone and an Apple Watch or AirPods, the Mac notebook or iPhone receives up to 27.5W and the Apple Watch or AirPods receive up to 7.5W.
If either device needs more power, unplug the other device and its charging cable from your power adapter.
 
Just odd to me that if it has the "smarts" to drop to 27 watts instead of splitting to 17.5 when one of the 2 cables is not connected to any device, why can't it send the full 35 to the one that is in use.

35 minus 7.5 is 27.5 so it defaults there at the minimum with 2 cables connected as designed. First-world problems I know.
 
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I agree with you this is dumb. It should only split power when a device is actually connected. I’m glad you shared this. I ordered a INVZI 65W power brick. It’s smaller and has 3 ports. With actual smart power management (it only splits power when devices are connected) and it only costs $40.
 
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I agree with you this is dumb. It should only split power when a device is actually connected. I’m glad you shared this. I ordered a INVZI 65W power brick. It’s smaller and has 3 ports. With actual smart power management (it only splits power when devices are connected) and it only costs $40.
That one looks nice, I'll be looking for smart power management fetaures next time I need a power brick. If you don't mind reply back when you have it in person if it doesn't pan out. Read through the product description and was not convinced!
 
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