New MacBook user requests help with Clamshell Mode.

[telepati]

Hello,

I purchased Base MacBook M3 Pro. I have a Dell U2720Q monitor and I want to use it with Clamshell mode.

Furthermore, I connected it with the original USB-C cable included in the Dell Monitor's box, and it recognized the monitor immediately.

However, there are a few things that bother me. In a few videos I watched on YouTube, the AC cable is usually connected. Is this necessary? Because it is currently working smoothly without the AC cable connected.

Isn't having the AC cable constantly plugged in bad for the health of the battery?

If it works without an AC cable, why is it needed?

Another issue is Display options. This is my first time using a computer with an external monitor. I am ignorant about this subject. There are three display options. Which one should I use, Main Display (I suppose this the MacBook Screen), External Display (Dell) and Mirror Display(?). Of course, I should choose External Display. However, when I selected the Mirror Display feature, it seemed to me that the screen responses were much faster. Of course, this could be an illusion. Does the Mirror Display option consume more battery? Also, when this feature is selected, the MacBook screen seems to stay on, I'm not sure.

I'm looking for assistance from those who use Clamshell Mode. Thanks for everyone.

 

[iStorm]

However, there are a few things that bother me. In a few videos I watched on YouTube, the AC cable is usually connected. Is this necessary? Because it is currently working smoothly without the AC cable connected.

Isn't having the AC cable constantly plugged in bad for the health of the battery?

If it works without an AC cable, why is it needed?

It doesn't really matter. It looks like this monitor supplies 90W of power to your Mac through USB-C PD, which should be enough to run this Mac and keep the battery charged. If you plug in the AC cable, then the Mac will just draw power from that instead of through USB-C.

Reasons for plugging in the AC would be if the Mac is consuming more than 90W of power. You'll notice this if the battery starts draining when it can't keep up. This is probably more common for monitors that only supply 60W of power, using a heavy workload, or when the Mac is supplying power to other connected devices.

Another issue is Display options. This is my first time using a computer with an external monitor. I am ignorant about this subject. There are three display options. Which one should I use, Main Display (I suppose this the MacBook Screen), External Display (Dell) and Mirror Display(?). Of course, I should choose External Display. However, when I selected the Mirror Display feature, it seemed to me that the screen responses were much faster. Of course, this could be an illusion. Does the Mirror Display option consume more battery? Also, when this feature is selected, the MacBook screen seems to stay on, I'm not sure.

I'm not sure I'm following. If the Mac is in clamshell mode, you should only be seeing the the Dell display. Main, External, or Mirror shouldn't even be an option. These are only options when the MBP is open and using both displays at once.

 

[telepati]

@iStorm Most likely, I made the Clamshell connection incorrectly and that's why I see the Display options. I guess I'll have to play around a bit. Thank you also for your detailed explanation about the battery, it was very helpful.

 

[SunMac]

You might want to try a DisplayPort to USB-C cable and having a direct power connection to the Mac. See if that works. The direct Thunderbolt 3 connection might not be working correctly with the Mac.

About the concern with always being plugged in. I use a third party app called Al Dente to keep my MacBook battery level at 75% since It's in clamshell mode most of the time. I had worries about that issue as well.

My battery health drained to about 90% in less than a year with my M1 Pro while not even using clamshell mode and I had Apple replace the battery. Since then I have been using Al Dente to protect my battery and MacOS reports my battery health is still 100% after about 5 months of using it.

Oh and yes for clamshell mode to work the Mac has to be plugged into a power source.

 

[telepati]

About the concern with always being plugged in. I use a third party app called Al Dente to keep my MacBook battery level at 75% since It's in clamshell mode most of the time. I had worries about that issue as well.

My battery health drained to about 90% in less than a year with my M1 Pro while not even using clamshell mode and I had Apple replace the battery. Since then I have been using Al Dente to protect my battery and MacOS reports my battery health is still 100% after about 5 months of using it.

I was not aware of this application. Can you share the settings you use in the application?

 

[SunMac]

I was not aware of this application. Can you share the settings you use in the application?

There are not many settings to mess around with in the free version. Just set the battery limit to 75%. The Pro version has a lot more features to keep your battery at optimal health. The app is actually really well made and the website has all the info about each feature and more in depth info on battery health in general. You should check it out.