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darwichee90

macrumors member
Original poster
Feb 26, 2017
55
27
Hi

I have the new Macbook pro 16 M1 Pro. And also got a monitor with USB C 65W PD. I Can´t turn off the charing function on the monitor, so i was wondering if it´s dangerous for the laptop itself, to charge the laptop using this monitor? Because it has a 140W otherweis?
 

chrfr

macrumors G5
Jul 11, 2009
13,716
7,290
Hi

I have the new Macbook pro 16 M1 Pro. And also got a monitor with USB C 65W PD. I Can´t turn off the charing function on the monitor, so i was wondering if it´s dangerous for the laptop itself, to charge the laptop using this monitor? Because it has a 140W otherweis?
It's not dangerous in the least but the charger may not keep up with the power demand of the computer if it's working hard.
 

darwichee90

macrumors member
Original poster
Feb 26, 2017
55
27
It's not dangerous in the least but the charger may not keep up with the power demand of the computer if it's working hard.

yeah thats what i was affraid off, but how do i bypass this then? Do i use the HDMI instead off the USB C port?
 

JPack

macrumors G5
Mar 27, 2017
13,561
26,212
M1 Pro should not use more than 65W in most scenarios. Depending on the monitor, you may to be able to turn off USB-C charging. But if you plug in your 140W adapter, MacBook will choose the best adapter and draw power from there.
 

0906742

Cancelled
Apr 11, 2018
2,313
613
I have monitor that has 60W PD from USB-C. It does not allow to turn PD off, it automatically detect if computer support it. But how MBP M1 Pro 14” acts in case I have monitor with 60W PD and included 67W Magsafe charger also connected to it at the same time? I would prefer if laptop in those cases would only take power feed from the Magsafe charger and disable PD support from USB-C during that.
 

astorre

Suspended
Nov 4, 2021
157
128
I have monitor that has 60W PD from USB-C. It does not allow to turn PD off, it automatically detect if computer support it. But how MBP M1 Pro 14” acts in case I have monitor with 60W PD and included 67W Magsafe charger also connected to it at the same time? I would prefer if laptop in those cases would only take power feed from the Magsafe charger and disable PD support from USB-C during that.
 

0906742

Cancelled
Apr 11, 2018
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So would it be safe to assume that in case on MBP 14" M1 Pro that comes with 67W Magsafe charger and using that at the same time with the monitor that gives 60W USB-C PD, it would automatically take power only from the Magsafe charger and not "advertise" power input from USB-C to monitor at all?

Is it so precise that even with the monitor which has 65W USB-C PD output, it would still use 67W Magsafe instead it both were connected at the same time?

I'm asking this since I put much more trust to Apple original power supplies than that of from some third party. Also I guess using monitor PD output would just heat up the monitor mainboard/power supply more and possibly causing some negative to monitor where panel gets heat from those parts.
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,262
13,349
Back in the firewire days, it was possible to buy a "data only" firewire cable that DID NOT transmit "bus power" through the cable.

I'm wondering if anyone sells a USBc "data only" cable now? That doesn't transmit bus power?

I tried a few quick searches and found nothing. Does anyone have a source for such an item...?
 

0906742

Cancelled
Apr 11, 2018
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Back in the firewire days, it was possible to buy a "data only" firewire cable that DID NOT transmit "bus power" through the cable.

I'm wondering if anyone sells a USBc "data only" cable now? That doesn't transmit bus power?

I tried a few quick searches and found nothing. Does anyone have a source for such an item...?
I'm afraid such does not exist. You can get USB-C cables that aren't capable of transferring highest wattage charging but like cable to gives you issues rather than keep you from charging over it completely. I think there are special USB-C PD cables for higher than 60W or so charging. Not sure thou.
 

astorre

Suspended
Nov 4, 2021
157
128
So would it be safe to assume that in case on MBP 14" M1 Pro that comes with 67W Magsafe charger and using that at the same time with the monitor that gives 60W USB-C PD, it would automatically take power only from the Magsafe charger and not "advertise" power input from USB-C to monitor at all?

Is it so precise that even with the monitor which has 65W USB-C PD output, it would still use 67W Magsafe instead it both were connected at the same time?

I'm asking this since I put much more trust to Apple original power supplies than that of from some third party. Also I guess using monitor PD output would just heat up the monitor mainboard/power supply more and possibly causing some negative to monitor where panel gets heat from those parts.
well if we can believe what is written there, then sure, highest power input would be selected by mac, even when its higher by 1W

for mac juice is juice, doesnt matter where its coming from, adapter or monitor, you wont get more quality power from original mac charger, for example my 65W anker charger gets way less hot than original 67W apple charger

also I think you're overthinking this, that monitor is built for PD, its not like they accidentally put that function there and once you use it it will melt all components, unless maybe if you're using some cheap fake brand fished from deep China
 
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0906742

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Apr 11, 2018
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for mac juice is juice, doesnt matter where its coming from, adapter or monitor, you wont get more quality power from original mac charger, for example my 65W anker charger gets way less hot than original 67W apple charger

also I think you're overthinking this, that monitor is built for PD, its not like they accidentally put that function there and once you use it it will melt all components, unless maybe if you're using some cheap fake brand fished from deep China
Yeah, I know that but this issue keeps coming up over the forums where you often see claims that third party chargers can harm your device. I know it sound bull and probably is in a way but I realize also that power supplies from say LG are not always that good. For example my LG OLED which PSU keeps all kinds of interesting noises plus those had some other issues they actually had replacement campaign for certain model. Just as an example.

Also, back to power supply, I think if there are issues like simply bad quality or failing parts there can be more or less AC current (ripple) in DC output. This can cause issues in device you are feeding from that power supply. Just saying that I out more trust to Apple original power supply. Also in case of new MacBooks with Magsagfe, it would be shame not to use it at all in this case.
 

spiderman0616

Suspended
Aug 1, 2010
5,670
7,499
I can tell you that I have an UltraFine 4K monitor and I am using it basically as a dock for my 16" MBP. The Thunderbolt port connected to the Mac stays connected at all times--this machine rarely leaves my desk. I don't know what the power draw is for that monitor, but I'm using all of the USB-C ports for peripheral connection, and it's used all day every week day for work. I have it set for optimized battery charging, and it's able to both ramp up to 100% quickly if I need it to, as well as hold a steady 80% when it's docked.

Long story short, I think these cables and power supplies are now smart enough to not damage your computer.
 
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jav6454

macrumors Core
Nov 14, 2007
22,303
6,264
1 Geostationary Tower Plaza
Hi

I have the new Macbook pro 16 M1 Pro. And also got a monitor with USB C 65W PD. I Can´t turn off the charing function on the monitor, so i was wondering if it´s dangerous for the laptop itself, to charge the laptop using this monitor? Because it has a 140W otherweis?
No, USB-C charging is self regulating and will adjust to the Mac's power needs. However, should power demand of the Mac exceed what's supplied, then it'll grab power from the battery, so ensure the battery is at least 50% charged at all times before doing an CPU intensive task.
 

0906742

Cancelled
Apr 11, 2018
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I have it set for optimized battery charging, and it's able to both ramp up to 100% quickly if I need it to, as well as hold a steady 80% when it's docked.
How long it takes until battery optimization starts to work once you leave it plugged all the time?
Also if you occasionally use it on battery and/or select that it charges battery fully to 100% and then return it back to charger, how long it takes until it drops it again to 80% and keeps there?

I'm wondering if sporadic use mess up this and takes weeks to return to optimized state or is it clever enough to return that immediately?

You haven't noticed MacBook display suffering from heat? Like bluish patches appearing on full white image or similar using it clamshell mode?

Long story short, I think these cables and power supplies are now smart enough to not damage your computer.
Yeah, I know device itself takes what it needs for the power supply and regulates itself but I was just wondering how well MacBook handle possible situation where power supply is giving a lot of ripple (DC containing some AC)? That is possible with power supply, especially cheap/badly designed or simply aged power supply where capacitors are failing.
That possible ripple is know to damage parts in many different gear or at least causing them to malfunction.
 

spiderman0616

Suspended
Aug 1, 2010
5,670
7,499
How long it takes until battery optimization starts to work once you leave it plugged all the time?
Also if you occasionally use it on battery and/or select that it charges battery fully to 100% and then return it back to charger, how long it takes until it drops it again to 80% and keeps there?

I'm wondering if sporadic use mess up this and takes weeks to return to optimized state or is it clever enough to return that immediately?

You haven't noticed MacBook display suffering from heat? Like bluish patches appearing on full white image or similar using it clamshell mode?


Yeah, I know device itself takes what it needs for the power supply and regulates itself but I was just wondering how well MacBook handle possible situation where power supply is giving a lot of ripple (DC containing some AC)? That is possible with power supply, especially cheap/badly designed or simply aged power supply where capacitors are failing.
That possible ripple is know to damage parts in many different gear or at least causing them to malfunction.
It takes a few weeks at first, but I think it operates on a rolling average, so when I do use it off the charger, it usually starts maintaining 80% again next time I plug in. I don’t pay a ton of attention honestly—it’s become pretty reliable.
 

0906742

Cancelled
Apr 11, 2018
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It takes a few weeks at first, but I think it operates on a rolling average, so when I do use it off the charger, it usually starts maintaining 80% again next time I plug in. I don’t pay a ton of attention honestly—it’s become pretty reliable.
OK, so once you have gotten it to state where is maintain battery at 80% it will return to that mode fast even if you use it on battery occasionally.
 

jaytv111

macrumors 65816
Oct 25, 2007
1,028
875
I think the Mac laptops just take the first power supply you plug in, then reject power from any subsequent power supply. So you can plug in the Magsafe cable into the MacBook first, then plug in the monitor and it will stay powered by the Magsafe power supply.
 

0906742

Cancelled
Apr 11, 2018
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I think the Mac laptops just take the first power supply you plug in, then reject power from any subsequent power supply. So you can plug in the Magsafe cable into the MacBook first, then plug in the monitor and it will stay powered by the Magsafe power supply.
So it does not just see which is the best source but just use what is plugged in first? Does it stay in the plugging order even if your reboot or turn off the machine or monitor with PD in between without removing the cables?

Anyone here actually using monitor with USB-C PD and have cable directly from monitor USB-C to MacBook AND also have Magsafe charged plugged in? It could be nice if someone with this combination would chime in.
 

jaytv111

macrumors 65816
Oct 25, 2007
1,028
875
So it does not just see which is the best source but just use what is plugged in first? Does it stay in the plugging order even if your reboot or turn off the machine or monitor with PD in between without removing the cables?

Anyone here actually using monitor with USB-C PD and have cable directly from monitor USB-C to MacBook AND also have Magsafe charged plugged in? It could be nice if someone with this combination would chime in.
I tested it out with the Apple adapter (it has HDMI, USB-C and USB-A), I was wrong. You can plug in the Magsafe after plugging in the USB-C and it will use the Magsafe. I think in the USB-C only MacBooks it would stay on the first one.
 

0906742

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Apr 11, 2018
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Does it still increase charge cycles while it is constantly plugged in? I mean does it continuously use a little battery then charge back to 80% and repeat that over and over again, or is it so clever that it "disconnect" battery from use and charging and takes power machine needs from the power supply until you disconnect it? I think that would need to follow what happens to charge cycle count in say couple of weeks continuous use with constantly plugged in without any use on battery. Anyone done that?
 

0906742

Cancelled
Apr 11, 2018
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I tested it out with the Apple adapter (it has HDMI, USB-C and USB-A), I was wrong. You can plug in the Magsafe after plugging in the USB-C and it will use the Magsafe. I think in the USB-C only MacBooks it would stay on the first one.
How many watts your USB-C PD and Magsafe charger provide?
I guess if Magsafe is more powerful that is obvious reason for what happened, but if USB-C is higher then it sounds like clever enough for preferring original power supply over "third" party one.
 

spiderman0616

Suspended
Aug 1, 2010
5,670
7,499
Does it still increase charge cycles while it is constantly plugged in? I mean does it continuously use a little battery then charge back to 80% and repeat that over and over again, or is it so clever that it "disconnect" battery from use and charging and takes power machine needs from the power supply until you disconnect it? I think that would need to follow what happens to charge cycle count in say couple of weeks continuous use with constantly plugged in without any use on battery. Anyone done that?
I really don't pay attention to the charge cycles on it, especially because it's a work machine, but it keeps the battery at a steady percentage pretty consistently. If I shut the laptop completely down and then boot it back up, I think it goes up to 100% again and then back down to 80, but I'm not sure.
 

0906742

Cancelled
Apr 11, 2018
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I really don't pay attention to the charge cycles on it, especially because it's a work machine, but it keeps the battery at a steady percentage pretty consistently.
How many charge cycles your MBP has currently?

If I shut the laptop completely down and then boot it back up, I think it goes up to 100% again and then back down to 80, but I'm not sure.
You mean by this that if you power off it completely and then later on turn on, it has charged it to 100% during that time?
How do you power it on after completely powering off? I mean there is no easy way to do it without opening the lid or pressing laptop trackpad or keyboard=
 

jaytv111

macrumors 65816
Oct 25, 2007
1,028
875
How many watts your USB-C PD and Magsafe charger provide?
I guess if Magsafe is more powerful that is obvious reason for what happened, but if USB-C is higher then it sounds like clever enough for preferring original power supply over "third" party one.
Magsafe was connected to 100 watts (165 watt Satechi power adapter which goes up to 100 watts to one port). The Apple USB-C adapter always limits power to 55 watts (when connected to >= 55 watts). I used the 96 watt Apple to the adapter.

You want me to try a 30 watt Magsafe vs a higher USB-C?
 
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