How to use MacBook Pro in clamshell mode without charging it?

That's on theory. I have a MBP M1Pro purchased on August 22. I use it mainly at home connected via USB-C to an LG display and occasionally when traveling.

Well, situation to my complete disappointment is that I have 67 charge cycles and an awful 88% of actual battery health!

How this is possible if "there is no bad impact on battery life whatsoever"?

I contacted Apple support and they say that keeping battery fully charged is a source of distress for the batteries as is the full charging cycles. What is the truth? Is it possible that my batteries are somewhat defective?

Thank you,

Alessandro

Your MacBook Pro  uses ‘smart charging’ to charge in the optimum way, and only when necessary. Plugged in is Not necessarily actively charging. There is substantial hardware and software cooperating on battery and charging issues. Simply asserting a charging voltage against one of the interface(s) will NOT successfully charge your MacBook Pro.

Closed display mode requires that you provide power. There is no bad impact on battery life whatsoever.

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which could be somewhat slower) when no AC sources are at hand. Your Mac will NEVER over-charge. 

There is a built-in utility called caffeinate that will temporarily stop your Mac from going to sleep.

The App Store has amphetamine.

I found Fermata to be useful to stop sleep as well.

Several other options out there.

Capstan62 wrote:

That's on theory. I have a MBP M1Pro purchased on August 22. I use it mainly at home connected via USB-C to an LG display and occasionally when traveling.

Well, situation to my complete disappointment is that I have 67 charge cycles and an awful 88% of actual battery health!

How this is possible if "there is no bad impact on battery life whatsoever"?

I contacted Apple support and they say that keeping battery fully charged is a source of distress for the batteries as is the full charging cycles. What is the truth? Is it possible that my batteries are somewhat defective?

Thank you,

Alessandro

Leaving the Mac plugged in will not damage the computer or the battery.

Yes, I agree. Also yes, Apple support's stance is reasonable. Referring to a more common issue, even companies like Tesla are facing challenges in developing batteries for electric vehicles, battery life. Batteries are still become a significant bottleneck for technologies that heavily rely on power storage, especially in terms of efficiency. Bad news, this problem doesn’t seem likely to be resolved in the near future. So hearing some such not-responsible 'advertisement' saying that it wont ruin battery life seems remain an open question.

One thing I'm quite sure about "plugging all the time": is when you are doing such a task that will put your Macbook in a task that cause a temperature rise. You will still degrade your battery life fast (remember, it's only a laptop, not a pc), but it's still much better compared to when you are not plugging it while doing intensive work.

Well, just sharing. I might be wrong though

Capstan62--

<<. connected via USB-C to an LG display >>

Exactly How much power is that LG display supplying during ordinary use?

A MacBook Pro may need in excess of 80 Watts to both run and maintain its battery level. Some peripherals supply substantially less, but still tout their power-delivery ability.

Providing less most of the time WILL consume some battery over time. When doing stressful work, if not enough power is coming in, your Mac will freely "borrow" power from the battery. This use does not generate any error messages.

Standard USB-C cable is capable of CARRYING only 60 Watts.

Are you using a premium, 100 Watts, or super-premium 240 Watts USB-C cable?

Cables that "shipped in the box" are notorious for being 'lowest bidder' cables. Unless clearly marked to the contrary, they are unlikely to be premium cables.

more information MAY be available from

 menu > about this Mac > (system report) > Power

I don't have a reference system available right now so I can't tell you whether this will report actual power or power capability.

Most of the overall thickness of a USB cable comes from the thickness of the insulation.

The difference in power-carrying of the conductors can not be detected by measuring the overall diameter of the cable. The difference between wire sizes used is extremely small.

USB power delivery cables are electronically tagged to indicate how much power they can carry.

_______

if you have complaints of battery issues possibly related to power delivery rates, you owe it to yourself to obtain a 100 Watt or 240 Watt certified USB-C cable and see if your results are any different.

but how can you explain the display-macbook on the apple store run out of their battery life so quickly?

Hi Grant.

my LG 27UP850-W is capable of delivering 96W over the USB-C, so this is not the case.

thanks

Alessandro.

I am using the USB-C cable shipped with the monitor. It is at least 1.5x thicker than the (80W) Apple cable, so I am super confident LG did it right.

Ale