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viorelgn

macrumors 6502
Original poster
Sep 16, 2013
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Romania
I have a MBP 2017 13 inches. Will this damage the battery? Or should I be unplugging it and using it not connected when it reaches 100 percent.
 
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I think it doesn't damage the battery.
I have the same MBP and I think I've read somewhere that there's a part (in the battery? in the charger?) that stops the electricity when it reaches 100%
 
I believe that doing this would not cause any damage from over charging, as it will stop charging once it reaches capacity.

But, keeping your battery @ 100% charge all the time can cause to deteriorate faster.

If you are using your laptop as a desktop that is plugged in 100% of the time, I would recommend occasionally letting the battery discharge then plug it back in.

I use an old MBP as a desktop, which stayed plugged in for months at a time, but the battery was already shot, so I am unsure about the impact of it.

Another example may not be a good one due to technology changes and advancements in lithium-ion batteries, but in 2003, I let my parents use my 2001 iBook G3 while I was in Afghanistan, and it stayed plugged in all the time due to my parents not having wifi, and the laptop being plugged into a cable modem using ethernet.

When I got back, I unplugged the power and a few minutes later the laptop just shut off. It basically fried the battery from being plugged in for almost a year.
 
I believe that doing this would not cause any damage from over charging, as it will stop charging once it reaches capacity.

But, keeping your battery @ 100% charge all the time can cause to deteriorate faster.

If you are using your laptop as a desktop that is plugged in 100% of the time, I would recommend occasionally letting the battery discharge then plug it back in.

I use an old MBP as a desktop, which stayed plugged in for months at a time, but the battery was already shot, so I am unsure about the impact of it.

Another example may not be a good one due to technology changes and advancements in lithium-ion batteries, but in 2003, I let my parents use my 2001 iBook G3 while I was in Afghanistan, and it stayed plugged in all the time due to my parents not having wifi, and the laptop being plugged into a cable modem using ethernet.

When I got back, I unplugged the power and a few minutes later the laptop just shut off. It basically fried the battery from being plugged in for almost a year.
Once a week a use it my MBP on battery till 20% then charging.
 
From what I hear, discharging the laptop down most of the way, as others have suggested, is likely the best option for maximizing your battery life. However, it's never been made clear to me just how much of an effect this has, especially compared to the random variance from one battery to the next. Keeping your laptop plugged in all the time isn't going to wreck havoc on your battery, so I'd do whatever is most convenient for your use case.
 
I only remove it from charging when I go to meetings or I'm at home at the sofa basically...
 
I use mine as a desktop with a Satechi USB-C dongle hooked up to an external display. I’m always worried about leaving it plugged in too long. My parents killed an old Macbook that way(leaving it plugged in forever). I take it I should not be that worried. Is it a good strategy to let it run off battery to 30-40% twice a week? And keep it plugged in the rest of the time.
 
I used FruitJuice for years, download from Apps Store. Very good. It gave advices when to plug / unplug the power to optimize battery life (I have no relations with the developer)
 
I used FruitJuice for years, download from Apps Store. Very good. It gave advices when to plug / unplug the power to optimize battery life (I have no relations with the developer)
Its a good app ? i installed now.
 
Maybe 5-6 years ago, there was an article on some chemistry website that calculated and tested the optimum charge cycle to maximum the runtime of lithium-ion batteries could get down to 80% (I think) from maximum capacity.

I think the highest hour count was charging to 70% of capacity and draining to 30%. This degraded the batteries’ capacity the slowest.

IIRC, the heat generated from charging from a dead battery up to 70% caused increased degradation, and charging the last 30% caused extra heat and more wear. Charging from 0% to 100% caused the most wear.

The optimum long term storage of batteries was (I think) 40%-60%. Storing a fully charged battery caused it to wear more quickly, same with a fully depleted battery.

Obviously, charging habits like this is probably inconvenient for most people in real life situations, and unrealistic, but give good guidance on how to charge and store batteries for our devices.

Later, I will try to find and link the article I am referring to.


eeping your laptop plugged in all the time isn't going to wreck havoc on your battery,
I think it depends on how long it is plugged it, leaving it plugged in for almost a year wrecked havoc on my two year old laptop’s battery.

But, occasionally cycling it would keep it in good shape.

My parents killed an old Macbook that way(leaving it plugged in forever)
Same thing happened to me by my parents.

I take it I should not be that worried.
I think if it is occasionally unplugged to let the battery drain and recharge, you will be fine. The twice a week, weekly, and monthly intervals people are suggesting are just that, suggestions. Do what is convenient for you.
 
this might be a stupid question but if you use your laptop as a desktop with a closed lid, how do you turn it on and off?
Does the display keep working even if the lid is shutdown?
 
this might be a stupid question but if you use your laptop as a desktop with a closed lid, how do you turn it on and off?
Check out this from Apple Support:

Clamshell mode: Use your Mac notebook computer in closed-display mode with an external display

Basically, to go in clamshell mode your laptop needs to be connected to a power source other than the battery, you need a keyboard and mouse connected to the Mac laptop, and an external display connected.

If the computer is shutdown, that you need to press the power button to turn it on. To turn it on if it is on standby, then just move your mouse or press your keyboard. To shut it down, you can do so from the Apple symbol on the desktop, then click on shutdown.

Just a note, some Apple keyboards and Apple monitors have power buttons on them, so you can use that to startup if you had one of these.

Does the display keep working even if the lid is shutdown?
The laptop display will turn off during clamshell mode.`
 
Check out this from Apple Support:

Clamshell mode: Use your Mac notebook computer in closed-display mode with an external display

Basically, to go in clamshell mode your laptop needs to be connected to a power source other than the battery, you need a keyboard and mouse connected to the Mac laptop, and an external display connected.

If the computer is shutdown, that you need to press the power button to turn it on. To turn it on if it is on standby, then just move your mouse or press your keyboard. To shut it down, you can do so from the Apple symbol on the desktop, then click on shutdown.

Just a note, some Apple keyboards and Apple monitors have power buttons on them, so you can use that to startup if you had one of these.


The laptop display will turn off during clamshell mode.`

Yep, the MacBook is really good with clamshell mode. Just don't shut off the computer, and you can log out and put it to sleep when you leave, and a mouse jiggle or keyboard press (external) - will turn it back on. Must be plugged into power like you said.

I've found having my laptop opened is far more beneficial to my usage style because I can easily provide my finger for fingerprints instead of typing in a password. Also having laptop lid up gives me another screen and dissipates heat better. So I rarely use clamshell mode.

Laptop's display shuts off in clamshell mode, and if connected to power, will send video to an external display.
 
I drain mine once a month, seems to be fine. I sold my last laptop after 2 years. It was still in perfect condition somewhere between 98-100% health if not mistaken, only like 30 drains total.
 
I would be willing to guess apple has thought about this.

I use battery primarily, and plug it in at night to get a full charge for my day.

Kind of like my iPhone.

But to each his own.
 
I would be willing to guess apple has thought about this.
I tried to search for something on Apple's webpage about this, and I can only find quotes from now broken links to Apple.com.

This was a quote from the now broken link:

https://www.apple.com/batteries/notebooks.html said:
For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing.

This same quote is used on many different websites, so it is probably legit.

I noticed that Apple also removed anything on their site related to calibrating the battery/pmu.

If you follow the link: https://www.apple.com/batteries/notebooks.html It forwards to a new updated site that doesn't mention leaving the laptop plugged in without occasionally cycling. It also doesn't mention calibrating the battery.

Maybe things have changed, but I would still follow the old advice from Apple and discharge it every once in a while, like monthly.
 
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I tried to search for something on Apple's webpage about this, and I can only find quotes from now broken links to Apple.com.

This was a quote from the now broken link:



This same quote is used on many different websites, so it is probably legit.

I noticed that Apple also removed anything on their site related to calibrating the battery/pmu.

If you follow the link: https://www.apple.com/batteries/notebooks.html It forwards to a new updated site that doesn't mention leaving the laptop plugged in without occasionally cycling. It also doesn't mention calibrating the battery.

Maybe things have changed, but I would still follow the old advice from Apple and discharge it every once in a while, like monthly.

Yeah you can find those old Apple pages on the web archives http://archive.org/web/ -- I'm too lazy to look for it, but I've had to use it when I reference those old pages where Apple actually recommended a full discharge once a month. People can't believe it today lol.

I find it can be helpful in re-callibrating the % reader on my Watch, Phone. Haven't had to do it on my MBP/MBA ever -- but yes, it is healthy to give it a discharge once or twice a month (I wouldn't go down to 0%, but below 50% definitely).
 
I tried to search for something on Apple's webpage about this, and I can only find quotes from now broken links to Apple.com.

This was a quote from the now broken link:



This same quote is used on many different websites, so it is probably legit.

I noticed that Apple also removed anything on their site related to calibrating the battery/pmu.

If you follow the link: https://www.apple.com/batteries/notebooks.html It forwards to a new updated site that doesn't mention leaving the laptop plugged in without occasionally cycling. It also doesn't mention calibrating the battery.

Maybe things have changed, but I would still follow the old advice from Apple and discharge it every once in a while, like monthly.

Wow thats interesting!!! Ya I mean I just use both. Can get a battery replacement in the future if i need it
 
I recently picked up a MacBook Pro 2018. I use it, then plug it in when the battery gets low. Sometimes my iPhone goes off completely, then I charge it over night. Some people say it’s good for the battery, some people say it’s bad, I never know who to believe lol

Is it the same principle for the MacBook Pro, let it go to 0% and then recharge, occasionally?
 
I recently picked up a MacBook Pro 2018. I use it, then plug it in when the battery gets low. Sometimes my iPhone goes off completely, then I charge it over night. Some people say it’s good for the battery, some people say it’s bad, I never know who to believe lol

Is it the same principle for the MacBook Pro, let it go to 0% and then recharge, occasionally?

Lithium Ion / Lithium Polymer batteries do not like to go below 20% if it can be helped.

Check out: https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

It's a lot to read but --- basically: 1. Avoid heat. 2. Don't let charge drop too low. 3. Don't leave at 100% for long periods of time (1 month+).
 
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