I have a 24-inch, M1, 2021 iMac, and am considering buying a MagSafe charger for my iPhone. I am thinking of just plugging it in to one of the iMac thunderbolt ports, rather than having to splash out more money for the recommended 30 watt power adapter.
I can't seem to find out how many watts the TB ports support. Would this work, or would it defeat the purpose of fast charging?
iMac 24″, macOS 15.5
The USB-C Power Delivery standard allows two devices to negotiate delivery of large amounts of power in either direction. The original standard allowed for delivery of up to 100W of power (5A @ 20V). The latest one permits delivery of up to 240W of power (5A @ 48V).
That does not mean that a computer port is required to negotiate the delivery of any power.
I believe that
All 24" M1 iMacs have two USB-C (Thunderbolt 3) ports, and some of them have two USB-C (USB 3 only) ports. As Apple has not said that iMacs are willing to negotiate dellvery of 30W to any accessory, my assumption is that you will not be able to fast-charge your iPhone off your iMac. Charge, yes; fast-charge, no.
Respectfully, Apple appears to disagree with you.
“To wirelessly fast charge, you need an iPhone 16 or later with a MagSafe Charger and one of these adapters:
Which is why I want to know if the TB ports would be an alternative to the “30W or greater, USB-C power adapter.”
Hi,
It is safe to connect your iPhone to your iMac since you can backup your iPhone data on iMac via USB-C connection, though it doesn't mean charging speed is faster with your iPhone via iMac USB-C port.
Ok, well that's good to know. Thanks.
None of these posts have actually answered my initial question though. Can someone tell me how many watts the thunderbolt ports support? Enough for MagSafe charger to deliver fast charging to my phone? Or would I be better to buy a 30 watt adapter?
The Mac's TB power output is irrelevant. No MagSafe adapter can "fast charge" an iPhone. Read Fast charge your iPhone - Apple Support.
Agreeing with kaz-k, there is no harm in plugging your phone into an iMac. But I would not recommend using MagSafe, because it greatly decreases battery health.
Really?!
If that’s the case, I will flag that idea.
Thanks for the info!
To be clear there is absolutely nothing wrong with using a MagSafe charger for your iPhone. There are absolutely positively no detrimental effects. Zero.
Thank you! I appreciate the clarification, and that answers my question.
Thunderbolt ports - how many watts?
