Thunderbolt cable plugged via USB on iMac charges iPad Air but not new MacBook Pro

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Thunderbolt cable plugged via USB on iMac charges iPad Air but not new MacBook Pro

Does the new 2021 MacBook Pro not allow charging via a USB-Thunderbolt cable plugged into an iMac? It works with iPad Air (when iMac is on or off) so no problem with the cable.

I'm not concerned with speed, which I know will be slower, just having it work (for overnight charging convenience). Is it a permissioning thing to allow the computers to be connected? iTunes does not recognize the MacBook as being connected either.

MacBook Air 13″, macOS 11.2

Posted on Mar 29, 2021 7:55 AM

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Answer 1

Top-ranking reply

Scott Watson4 Author

Level 1

97 points

Mar 29, 2021 3:16 PM in response to Scott Watson4

Ok I'm answering my own question. After trying a Thunderbolt to Thunderbolt cable (instead of USB to Thunderbolt) the MacBook charges from the iMac. I guess USB is not strong enough to carry the power a MacBook needs.

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Answer 2

Rudegar

Level 10

180,282 points

Mar 29, 2021 8:18 AM in response to Scott Watson4

different devices require a different amount of current before they to into charging mode, an iphone requires less current than and ipad, so ipads only charge very very slowly on the old 5watt iphones ac chargers, it's likely that the imac can't provide enough current for the macbook pro to charge but enough for the ipad to charge.

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Answer 3

Mar 29, 2021 8:20 AM in response to Rudegar

That makes sense, thank you. I wonder if using the thunderbolt connection on the iMac would be any different (ie if I bought a thunderbolt to thunderbolt cable)?

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Thunderbolt cable plugged via USB on iMac charges iPad Air but not new MacBook Pro

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