Turning off Power Delivery on USB-C/TB3 ports possible?

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Turning off Power Delivery on USB-C/TB3 ports possible?

I use my 2018 Macbook Pro 'docked' a lot of the time. I typically have three devices connected to it that provide pass-through charging.

LG 27" 4k monitor connected via USB-C
G-Technology G-RAID 16TB array, connected via USB-C
G-Technology G-DRIVE 4TB Time Machine, connected USB-C

I'm doing video editing and working with Lightroom/Photoshop all day. All of these just love delivering power to my laptop but I also know that lion batteries don't really like being connected and charging all the time, even if it's a piddly amount provided by each of these. On Windows machines, the end user is offered options concerning switching the Type-C’s output, choosing whether to receive power or send power. Fearing for yet another laptop battery repair in two years time, I feel like this is an oversight on Apple's part. (Or, I simply haven't found out HOW to switch PD off yet..) and something that I want to set up to disable the delivery of constant power to my laptop.

MacBook Pro with Touch Bar

Posted on Jul 20, 2020 12:59 PM

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Answer 1

Top-ranking reply

darklordenron Author

Level 1

13 points

Jul 22, 2020 8:32 PM in response to Kappy

Well, you seemed to be indicating that leaving it plugged in all the time wasn’t harmful to the battery when it actually is. Hence, updated the thread to reflect what was discussed so it may be helpful to others should they stumble upon the post in the future. Fine, judging by your snarky response perhaps it is better to consult Apple directly. I just thought you might be interested to know that leaving it plugged in isn’t really a healthy option. Just trying to be helpful, jeez.

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Answer 2

Kappy

Level 10

361,849 points

Jul 20, 2020 1:21 PM in response to darklordenron

I also know that lion batteries don't really like being connected and charging all the time, even if it's a piddly amount provided by each of these.

This is untrue. Apple uses Li-Poly batteries, not L-Ion. The batteries can be connected to the charger forever but that will reduce a battery's life expectancy. To avoid that, you should allow the battery to fully discharge (not below 5% remaining charge) at least once every 2 to 3 months. I you do this, then the battery should last its normal life expectancy.

The battery's life expectancy is 1,000 full charge cycles. If you fully depleted and recharged the battery once per month, then the battery should last about 80 years. Of course, that's not likely but it may last for 5 years before replacement is needed. If you don't let it discharge and recharge, however, then the battery will last only a couple of years.

About Batteries in Modern Apple Laptops

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Answer 3

Jul 22, 2020 7:15 PM in response to Grant Bennet-Alder

Update:

I received a phone call from Business Support in regards to this issue and apparently, after consulting the powers that be, they state that the battery in the MBP (and Air and every other device that doesn't use a mains cord for power such as the iMac) does NOT like being kept charged for extended periods of time. Draining it once every few months doesn't actually 'reset' the battery or anything like that. Batteries in general like being charged up, then discharged and the MBP's are no exception to that long-standing practice. It shouldn't matter how quickly or hard they drain, ultimately simply cycling them is the important part.

So long story short coming from Apple themselves, if you leave your machine plugged in to power of any kind all the time, the battery health WILL suffer. Luckily I was suffering from the butterfly keyboard issues and due to that replacement the battery will also be replaced alongside it. But man, my MBP has 344 cycles on it and is at around 80% battery health according to their in-store diagnosis. Either it's just a faulty battery or keeping it plugged in to things that provide power truly does affect it in a negative way. It would've been a $200 charge for just keeping external drives and monitors plugged into it. I may well be going for an iPad Pro and an iMac in the very near future rather than docking up a laptop.

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Answer 4

Jul 20, 2020 2:30 PM in response to darklordenron

Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, the charged state may even decline during stressful work.

When used only on battery, your computer has no extra cushion of power, and will perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which will be somewhat slower) when no AC sources are at hand. There are three micro-controllers cooperating on battery and charging issues, and your Mac will NEVER over-charge.

A charge cycle is ever-so-slightly destructive to batter longevity. When operating as designed (and not using Battery Health Management) battery charge level is allowed to decline to about 92 percent level before initiating a recharge cycle to top up to about 99 percent.

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Catalina software 10.15.5 for MacBook Pro with T2 chip (2016 models and later) includes a new feature called Battery Health Management. Based on your usage patterns, this widens the hysteresis to initiate a charge cycle at a lower level, and stop before 99 percent.

About battery health management in Mac notebooks - Apple Support

https://support.apple.com/en-us/HT211094

This relaxes the set points around re-charging (based on your usage patterns) and can improve long term battery lifetimes. When active, recharging may stop short of 100 percent charged.

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Readers have also reported that the FIRST source of power supplied to your computer will be the source used, and any arriving later will be ignored. Since, under rules of USB Power Supply Protocol, Voltages and Currents above the nominal 5 Volts at 0.5 Amps must be negotiated before they will be supplied, it is completely believable that this may be true.

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Answer 5

Kappy

Level 10

361,849 points

Jul 22, 2020 8:07 PM in response to darklordenron

How is that any different than what was posted by myself and Grant? If you want Apple's seal of approval, then always ask them, not us.

FYI: These are user-only forums. This is not Apple Support. if you need to contact Apple Support, then contact product and tech support: Contacting Apple for support and service including international calling numbers.

These forums only provide help with Apple products. Thank you for your understanding and support.

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Answer 6

Jul 20, 2020 2:11 PM in response to Kappy

Very interesting indeed. I admit I haven’t been paying much mind to the recent advances in battery tech over the last 5 years so you may well be correct. I’m in the process of getting information from Apple themselves through the business team on that. Comforting, nonetheless to hear you say that however! (They seem to think it’s just a faulty battery as well tbh..)

In any case, perhaps this is how the tech is intended to work and if so, I got worked up for nothing and need to accept and embrace it, haha. Appreciate the reply and I’ll update as well as more details become available.

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Answer 7

Jul 23, 2020 8:53 AM in response to darklordenron

darklordenron wrote:

Well, you seemed to be indicating that leaving it plugged in all the time wasn’t harmful to the battery when it actually is.

That is NOT what is written in Apple articles.

Apple articles suggest you should leave it plugged in all the time.

Older articles (now retired) suggested you give it a little exercise once a month or so. Newer article suggest you enable "Battery Health Management" and based on your observed usage patterns, it will take care of itself.

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Turning off Power Delivery on USB-C/TB3 ports possible?

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