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jwolf6589

macrumors 601
Original poster
Dec 15, 2010
4,735
1,499
Colorado
I sold my old 2012 MacBook pro to a technician who diagnosed the trackpad problem to a blown off battery. I left that Macbook mostly plugged in all the time do you think this caused the battery problem? I ask because I do not want to REPEAT this problem with my present 2020 Macbook Pro because often things do not break down during the 3-year apple care warranty.
 

supertiffany

macrumors 6502
Apr 4, 2019
394
465
isnt that macbooks when plugged and the battery is fully charged it will use the power directly from the source and the battery wont be charging?
 

supertiffany

macrumors 6502
Apr 4, 2019
394
465
I don't know. I just wonder how the battery blew off.


yeah, most of the users leave the macbooks plugged some even do it to their ipads

it must be a very long time that your macbook was plugged to have that battery blew off, that's the only reason.
 

jwolf6589

macrumors 601
Original poster
Dec 15, 2010
4,735
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Colorado
yeah, most of the users leave the macbooks plugged some even do it to their ipads

it must be a very long time that your macbook was plugged to have that battery blew off, that's the only reason.

No I unplug it every now and then to go to the library, travel with it, or so forth.
 

chrfr

macrumors G5
Jul 11, 2009
13,418
6,888
I sold my old 2012 MacBook pro to a technician who diagnosed the trackpad problem to a blown off battery. I left that Macbook mostly plugged in all the time do you think this caused the battery problem? I ask because I do not want to REPEAT this problem with my present 2020 Macbook Pro because often things do not break down during the 3-year apple care warranty.
Yes, a battery that sits on the charger all the time can certainly swell up. Batteries that do get used also can, but it is better for the battery to periodically let it discharge.
 
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jwolf6589

macrumors 601
Original poster
Dec 15, 2010
4,735
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Colorado
Yes, a battery that sits on the charger all the time can certainly swell up. Batteries that do get used also can, but it is better for the battery to periodically let it discharge.

Hmm.... I let it discharge everyone and then. How often should I do this?
 

jwolf6589

macrumors 601
Original poster
Dec 15, 2010
4,735
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Colorado
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries -- good information on how to prolong the life of your battery!

I am confused. That article is too technical for me.
[automerge]1589815799[/automerge]
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries -- good information on how to prolong the life of your battery!

Should I let the laptop discharge once a month?
 

CheesePuff

macrumors 65816
Sep 3, 2008
1,444
1,544
Southwest Florida, USA
It will run off of the wall power and keep the battery charged, then as it falls to 95% it will charge it back up 100% again.

I have left my 2015 15" MBP plugged in for nearly 3+ years now full time and it has 40 battery cycles and 99% battery capacity.
 
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jwolf6589

macrumors 601
Original poster
Dec 15, 2010
4,735
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Colorado
My 2014 and 2015 have been plugged in for the past six weeks continuously. They are used about 90% plugged in connected to KVMs. I've had no problems with them.

I just called Apple and they told me that since 2015 they have resolved the battery expanding issue that I had with the 2012 model causing the trackpad not to work which makes the machine worthless for travel since I cannot plug a external mouse in while sitting down in a airport seat. They said since I am not doing heavy video editing (I sometimes do light) I should be fine leaving it plugged in most of the time. I am talking a trip to Alaska in early June so the battery should get some use then on the trip in which it will not be plugged in all the time.
 

Dhock_Holiday

macrumors regular
Sep 17, 2019
191
203
I have usually left my laptops plugged in most times, the system will regulate the voltage and make sure the battery isn't overcharged. I would say battery swelling is more of an issue when the battery has some defect or is exposed to extreme temperatures.
 

aZZaneko

macrumors member
Jul 21, 2012
62
91
I've had a swollen battery on both MacBooks I kept plugged in 99% of the time. It took a plastic MacBook about 3 years, while Retina 15 MPB lasted 5-7 years before the trackpad began to act funny due to pressure, I guess.

It's the reason I went with a Mini this time. I just really don't want to worry about the battery I don't even use most of the time.
 

BigMcGuire

Cancelled
Jan 10, 2012
9,832
14,020
Should I let the laptop discharge once a month?

Leaving your laptop plugged in today will not hurt it. 8 years ago, battery technology and charging technology was a bit different. Today there are many different things working together to keep your battery "healthy" while plugged in on Apple's side.

My laptop has spent the vast majority of its 2 year life plugged in. I do try to take it off the charger and run it down to 60-80% once or twice a week (if I remember) to keep the battery "exercised" in a way.

Swollen batteries usually are a result of manufacturer defects. That's why they don't happen to everyone, even those who leave their laptops plugged in all the time.

If you unplug your laptop now and then to go to the library and when you travel, you should be fine. This is what I do.
 

magbarn

macrumors 68030
Oct 25, 2008
2,945
2,234
Lithium batteries do not like to be at 100% all the time. Their happy zone is between 20-80%.

My wife and I have owned MacBooks for the last 15 years and I use mine as they are intended: I use them on battery and then charge when getting low. My wife leaves hers plugged in all the time. The last 3 macbooks she’s had all had battery issues within a few years while mine are still going great. My oldest machine a 2012 Macbook Pro 15 retina, still has 88% after 8 years and 500+ cycles.

My wife’s 2015 MacBook 12 has only 70 or so cycles and is down to 65%. Her last macbook’s battery also crapped out early. There’s a reason why Tesla allows you to purposely limit charge percentage on their cars to extend battery life. I stop mine from charging above 80% as my commute is only 30 miles.

Newer MacBooks may have better battery protection built in, but Apple’s beta MacOS has a new optimized battery charging setting to reduce battery aging that was copied over from iOS...
 

BoneHead001

macrumors 6502a
Nov 13, 2013
526
243
Livonia,MI
Lithium batteries do not like to be at 100% all the time. Their happy zone is between 20-80%.

My wife and I have owned MacBooks for the last 15 years and I use mine as they are intended: I use them on battery and then charge when getting low. My wife leaves hers plugged in all the time. The last 3 macbooks she’s had all had battery issues within a few years while mine are still going great. My oldest machine a 2012 Macbook Pro 15 retina, still has 88% after 8 years and 500+ cycles.

My wife’s 2015 MacBook 12 has only 70 or so cycles and is down to 65%. Her last macbook’s battery also crapped out early. There’s a reason why Tesla allows you to purposely limit charge percentage on their cars to extend battery life. I stop mine from charging above 80% as my commute is only 30 miles.

Newer MacBooks may have better battery protection built in, but Apple’s beta MacOS has a new optimized battery charging setting to reduce battery aging that was copied over from iOS...

You should plug it in as much as possible. Keeping the battery topped off reduces charge cycles and extends the overall life of the battery. Lithium ion batteries do not have a memory like the old nicad batteries. Charging as often as possible is the best way to keep your battery healthy.

It's been known for a long time. It's the same reason that it is recommended you plug in your laptop if you can. Just run the battery down at least once a month and you'll be fine. It's way better to plug in and use a charge cycle every 3 days than to use 1.5 cycles every day.

You can read about all kinds of stuff here:

http://batteryuniversity.com/learn/article/how_to_charge_when_to_charge_table

When draining the battery all the way down and recharging it you are not recalibrating anything on the battery itself. It may help a little for the battery percentage in the software to be slightly more accurate but again the battery has no memory whatsoever. It is not possible to "recalibrate" the battery itself. The more you drain it low the more charge cycles you will incur and the less life you will get out of it.

This applies to all lithium ion powered devices. I always top off my batteries when possible, like driving in the car, and I see excellent life compared to many others because of this habit.

Yes, it’s better to use portable Macs off of the main supply (use the laptop battery). From time to time, (as it helps to keep the battery “healthy”), run the MBP off the mains supply (use battery) until the battery percentage reads around 80% and recharge. Once or twice a month is enough.
 

justashooter

macrumors 6502
Apr 8, 2020
335
194
I sold my old 2012 MacBook pro to a technician who diagnosed the trackpad problem to a blown off battery. I left that Macbook mostly plugged in all the time do you think this caused the battery problem? I ask because I do not want to REPEAT this problem with my present 2020 Macbook Pro because often things do not break down during the 3-year apple care warranty.
I am a big fan of exercising the battery. I also have a 2012 MacBook Pro 13 (bought new in 2012) and it has over 1820 cycles on the battery and charges to 83% of its design capacity. I let it run down to the battery warning at least once a week. Apple has added new software for the battery in the recent Catalina update, so maybe it will save the batteries, but I would still run mine down if I bought a new MBP. I still us Mojave. - Cheers!
 

Fishrrman

macrumors Penryn
Feb 20, 2009
28,147
12,305
NO.
You DO NOT want to leave a MacBook Pro "plugged in ALL the time".
Even Apple acknowledges this now.

My opinion only follows:
"Fishrrman's rules" for keeping your battery in good repair:
Rule #1: Take it OFF power at least every 2nd day, and "run down" the battery to about 35-40%. Then re-connect the charger.
Rule #2: SHUT DOWN the MacBook Pro at night, and remove the charger or unplug it at the wall outlet. Re-connect in the morning.
Rule #2 (modified): If you're going to let the MBP sleep at night, remove the charger or unplug it at the wall outlet. Re-connect in the morning.
 

magbarn

macrumors 68030
Oct 25, 2008
2,945
2,234
NO.
You DO NOT want to leave a MacBook Pro "plugged in ALL the time".
Even Apple acknowledges this now.

My opinion only follows:
"Fishrrman's rules" for keeping your battery in good repair:
Rule #1: Take it OFF power at least every 2nd day, and "run down" the battery to about 35-40%. Then re-connect the charger.
Rule #2: SHUT DOWN the MacBook Pro at night, and remove the charger or unplug it at the wall outlet. Re-connect in the morning.
Rule #2 (modified): If you're going to let the MBP sleep at night, remove the charger or unplug it at the wall outlet. Re-connect in the morning.
Exactly, this isn't junk science. Many EV Car manufacturers already have figured this out. They usually set a 20% head room on the battery as draining it to 0% shortens lifespan. Better ones like Tesla also allow you to put charge limiters so you can the battery going to 100% every night you plug it in which is also harmful. The lithium batteries powering the EVs are just larger versions of what's in your macbook.
 

mcaswell

macrumors 6502
Dec 22, 2013
390
228
Apple is including a "battery health management" feature in macOS 10.15.5, releasing soon, which should eliminate, or at least reduce, the need to really worry about this.
Really looking forward to this, as I leave mine plugged in almost all the time (and it would be a pain to unplug it periodically, as I use a dock with my external drives running through the same cable that supplies power).
 

KPOM

macrumors P6
Oct 23, 2010
17,987
7,777
Really looking forward to this, as I leave mine plugged in almost all the time (and it would be a pain to unplug it periodically, as I use a dock with my external drives running through the same cable that supplies power).
Note that this works differently from similar sounding features on Windows PCs. It doesn’t simply stop charging at 80%. I’ve been using the beta for a about a month now, and it seems to let the MacBook Pro maintain close to a full charge when plugged in.
 
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