Magsafe vs. TB4 Charging on new MacBook Pros

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Magsafe vs. TB4 Charging on new MacBook Pros

I want to know what charging method takes precedence when you have more than one source of charging connected to a MacBook Pro. For instance, you can charge the new MacBook Pros via the MagSafe port or their Thunderbolt 4 ports.

As detailed below, I will have at least two charging sources connected to my MacBook Pro:

I have a new 16" MacBook Pro (MBP) M1 Max that came with the MagSafe cable and the 140W USB-C power adapter/charging brick. As detailed below, I'll have at least two charging sources connected to my MBP:

My MBP will almost always be connected to an LG 5K UltraFine monitor that was made for use with MacBooks and an OWC ThunderBolt 3 hub. Both the hub and the monitor charge any MBP they are connected to, whether you want them to or not. The version of the LG monitor I have charges at 94W, and the dock charges at 85W.

I always had both the LG monitor and the dock connected to my 2017 MBP, so I guess that must not have been an issue. I guess the MBP somehow sorts this out.

Anyway, I'd really like the LG monitor and the Hub to not charge my MBP, but I don't think I can make that happen. There are no settings on the monitor or the dock to turn off the charge they provide to the MBP.

Does anyone know whether plugging in the MagSafe cable and power adapter would bypass charging from both the dock and the LG monitor?

I called Apple today and spoke with a senior rep, but he was no help. As is so often the case with tech support people, he kept repeatedly answering questions I wasn't asking while not answering the questions I was asking. He seemed to be saying that you shouldn't connect multiple charging sources, but that is hard to avoid when accessory manufacturers want to include charging capability as a benefit to attack buyers. I have to figure the MBP sorts out how much charge it accepts and from which source (just as an iPhone controls how many watts it takes in). I'd love to find out for certain that connecting the MagSafe charger bypasses any charging provided via the TB4 ports.

Posted on Oct 28, 2021 7:48 PM

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Answer 1

Oct 28, 2021 7:52 PM in response to JDLee

If you connect more than one power source, your Mac charges only from the adapter providing the most power.

from:

Charge your 14-inch or 16-inch MacBook Pro - Apple Support

.

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Answer 2

JDLee Author

Level 1

40 points

Oct 28, 2021 10:45 PM in response to Grant Bennet-Alder

Hi Grant -

Wow! Thanks! I spent over an hour on the phone and at least another hour searching for an answer to that question. The call with the tech support guy was particularly frustrating, and even more so now that I know there is an answer. I don't know how I didn't see that.

So, based on that, it seems clear that if I keep my MacBook Pro plugged in with the MagSafe and the 140W Apple Power Adapter that came with it, only that will be charging.

If you're wondering, the reason this has become important to me is this: I found a "MagSafe-style) right-angle USB-C adapter online that has 24 pins and actually completes a ThunderBolt 3 (and maybe even ThunderBolt 4) connection. It has two parts: a USB-C/Thunderbolt 3 style tip that you leave in the USB-C/ThunderBolt port and a piece that interfaces with it that has a female USB-C/Thunderbolt 3 port that you plug a USB-C or Thunderbolt 3 (or perhaps 4) cable into.

I can use this with my LG 5K UltraFine monitor and it does two things: First, if I move the monitor around on its arm, it prevents pressure from damaging the Thunderbolt 3 port on the back of the monitor. Second, I can have a second Thunderbolt cable with the same piece on it. I connect that cable to my other Mac, and I can switch back and forth between the Macs easily without plugging and unplugging the Thunderbolt 3 cables all the time. However, I read one review in which a user said that these tips can get hot and perhaps damage equipment if they are providing a charge in addition to data transfer. Now I can make sure they aren't providing a charge. Thanks!

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Magsafe vs. TB4 Charging on new MacBook Pros

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