Far too many conflicting opinions about MacBook Pro battery

[DD88]

I was looking for the best ways to charge my Macbook Pro in order to preserve the battery life for as long as possible but there so many varying opinions on here and YouTube and Reddit users are exactly the same.
Here is what I’ve read and discovered so far from other users, these are not my opinions but what I’ve seen people post and talk about :

1. Don’t let your MacBook charge above 80% but don’t let it drop below 20%
2. Charge it up constantly and leave it charging, the battery has a memory and will actually last longer when you unplug it
3. Dont leave it plugged in as this drains the battery even more, reduces battery life by 75% and makes the battery swell up ( even though a reddit user left his plugged in for a year and it worked fine )
4. In clamshell mode when charging constantly my MacBook Pro exploded after 2 weeks and the battery was bloated pushing my trackpad up and cracking my screen
5. only ever charge to 50%, 50% battery drains slower than 100% battery and lasts twice as long
6. Kepp it on charge for a few weeks but always discharge it and take the charger out for a few days or so and repeat process ( or the battery bloats ).
7. Battery memory means that even if your charger is plugged in your machine constantly it “learns” and tells the cpu that it’s not even charging anymore and preserves battery life in that way, even though it is charging as it’s attached to the mains.

These are only a few of the quotes I’ve seen, so what’s the best way to keep battery life good ?

 

[spiderman0616]

The best way is whatever you feel comfortable doing. These batteries are not the delicate flowers that people make them out to be. I have a 16" MBP from work that I leave plugged in all the time with battery optimization turned on in macOS. The built in charging feature keeps it at about 80% all the time and only goes up to 100% when I've been using the machine off charger on a trip or something.

The 14" also has optimized charging turned on but is almost never used docked or plugged in. I usually only plug it in when the built OS notification comes up saying my battery is low and needs a charge.

Both laptops seem in good working condition.

 

[f54da]

Li-ion batteries are li-ion batteries. Nothing too special about mac batteries in terms of composition, so same principles apply

You want to maximize battery life? Use the laptop in a freezer, always plugged-in, with max SoC locked to 20%. Clearly that's not very fun, so I recommend you just remember that lower cycle-average SoC is better than higher cycle average SoC, and lower depth of discharge is better than deeper ones. You can use this information as you see fit.

Worst case if you cycle 0-100 each day, it's going to last about 3 years until it gets to 80% health. That's really not too bad.

 

[Nathan King]

I was looking for the best ways to charge my Macbook Pro in order to preserve the battery life for as long as possible but there so many varying opinions on here and YouTube and Reddit users are exactly the same.
Here is what I’ve read and discovered so far from other users, these are not my opinions but what I’ve seen people post and talk about :

1. Don’t let your MacBook charge above 80% but don’t let it drop below 20%
2. Charge it up constantly and leave it charging, the battery has a memory and will actually last longer when you unplug it
3. Dont leave it plugged in as this drains the battery even more, reduces battery life by 75% and makes the battery swell up ( even though a reddit user left his plugged in for a year and it worked fine )
4. In clamshell mode when charging constantly my MacBook Pro exploded after 2 weeks and the battery was bloated pushing my trackpad up and cracking my screen
5. only ever charge to 50%, 50% battery drains slower than 100% battery and lasts twice as long
6. Kepp it on charge for a few weeks but always discharge it and take the charger out for a few days or so and repeat process ( or the battery bloats ).
7. Battery memory means that even if your charger is plugged in your machine constantly it “learns” and tells the cpu that it’s not even charging anymore and preserves battery life in that way, even though it is charging as it’s attached to the mains.

These are only a few of the quotes I’ve seen, so what’s the best way to keep battery life good ?

1. This is generally accurate; however, doing this consistently will likely not make a large difference in battery life.
2. False. Lithium batteries do not have memory. This sometimes happened with nickel-cadmium batteries, and usually only if the battery was charged/discharged within 5% of the same point repeatedly.
3. Leaving the laptop plugged in all the time isn't ideal, but it likely won't decrease battery life significantly. The operating system will eventually realize that the laptop is constantly plugged in and will lower the maximum charge.
4. I doubt the battery expansion was directly related to leaving the laptop plugged in.
5. Technically speaking, the battery is under the least stress around 50%, but the battery does not drain faster at charge levels above 50%. Trying to keep the battery level around 50% isn't worth the hassle as it probably won't significantly increase the lifespan of your battery anyway.
6. Try to cycle the battery once per month. One cycle is from 100% to 0%; however, it does not have to be fully drained on the same charge. For example, if I let my battery drain from 100% to 50%, charge it back to 100%, and discharge to 50% again, that's one cycle.
7. This is not battery memory. There is a MacOS feature that will recognize that you are not using your battery and eventually limit the charge to a level below 100%.

Generally speaking, I wouldn't think too much about it. Try not to discharge below 20% regularly and use the machine unplugged from the wall every once in awhile. That's it. All batteries have a finite number of cycles, and babying your battery won't make much of a difference.

 

[f54da]

From what I've seen in most analyses, suggests that optimal storage SoC (assuming SoC is actually maintained rather than allowed to discharge) is as low as possible without hitting the critical vMin. Keep in mind we care about voltage not SoC here, and consumer electronics already set user-facing SoC so that 0% doesn't actually mean complete discharge. I've never been able to find evidence to support not going lower than 50%, and in fact most graphs show the exact opposite, lower cycle-average SoC is better (in fact the benefits of lower SoC are strong enough to offset even a deeper DoD).

Only thing I don't like going below 10% SoC because resistance increases there, so not a good idea to do heavy workloads under that regime on battery. No idea how higher resistance impacts aging though..

I am not a material engineer, but I'm guessing that even though 50% is balanced between anode/cathode, the side-reactions that are responsible for calendar aging are much more sensitive to one over the other.

Also battery expansion is absolutely related to keeping laptop plugged in at a high SoC, for same reasons as above.

It's up to you how you want to play the game of short-term battery capacity vs long-term battery life though. Only you know your usage pattern, and I've told you enough so you can plan it yourself. Like I said, in ideal world you will use the laptop only in refrigerator, locked to 20% SoC, plugged in all the time. You can loosen those conditions as your needs permit.

 

[Fatus_Asticus]

You have to keep in mind that people have a wide variety of use scenarios and on top of that they have an even larger number of worries or lack there of. Some people think nothing of grinding their batteries running then down to zero and others will baby it with 5 cycles in 2 years never exceeding 50%. So obviously where you fall in that wide array is up to your personal preferences.

The physics is pretty clear though. You don't want it sitting at 100% all the time constantly getting charged. The more cycles you have, the more likely it will impact your total battery life. You can let the Mac handle that or you can use a third party program like Al Dente and set the percentage to whatever you want.

I personally use Al Dente because it gives me finer control over what I'm doing and I don't have to worry about the Mac thinking I'm going to be on wall power but I won't be or vice versa. Its dead simple and I don't have to worry about it.

 

[TinyMito]

Stop with the battery anxiety, use your laptop for work and entertainment. There is enough other important things to worry about in life.

 

[barkomatic]

Yeah, you're going to find a ton of conflicting and rather tedious advice about battery health. People will advise strange charging patterns, apps that supposedly preserve battery health (but don't) etc.

I think it's best to simply follow the advice that Apple gives--and not random self appointed experts.

 

[motrek]

1. This is generally accurate; however, doing this consistently will likely not make a large difference in battery life.
2. False. Lithium batteries do not have memory. This sometimes happened with nickel-cadmium batteries, and usually only if the battery was charged/discharged within 5% of the same point repeatedly.
3. Leaving the laptop plugged in all the time isn't ideal, but it likely won't decrease battery life significantly. The operating system will eventually realize that the laptop is constantly plugged in and will lower the maximum charge.
4. I doubt the battery expansion was directly related to leaving the laptop plugged in.
5. Technically speaking, the battery is under the least stress around 50%, but the battery does not drain faster at charge levels above 50%. Trying to keep the battery level around 50% isn't worth the hassle as it probably won't significantly increase the lifespan of your battery anyway.
6. Try to cycle the battery once per month. One cycle is from 100% to 0%; however, it does not have to be fully drained on the same charge. For example, if I let my battery drain from 100% to 50%, charge it back to 100%, and discharge to 50% again, that's one cycle.
7. This is not battery memory. There is a MacOS feature that will recognize that you are not using your battery and eventually limit the charge to a level below 100%.

Generally speaking, I wouldn't think too much about it. Try not to discharge below 20% regularly and use the machine unplugged from the wall every once in awhile. That's it. All batteries have a finite number of cycles, and babying your battery won't make much of a difference.

Good post. I have not seen it recommended to charge cycle every month. I have seen recommendations to do a full cycle (100% to 0%) every 6 or 12 months. I don't know if that's to extend the battery longevity somehow, or to just recalibrate the battery.

I use my new MacBook as a desktop almost exclusively (plugged in all the time). I've owned this computer for 1-2 weeks, and this morning I woke up to find that it had discharged the battery to 80% and is showing a message saying "Charging on hold (Rarely used on battery)". So, great. That's one less thing to worry about. Thanks, Apple!

This deserves reiteration: if you have the option to plug your laptop in while using it, do so. If your laptop is plugged in, it's using wall power, and thus not putting wear on the battery.

Too many people think that using a laptop when plugged in is somehow simultaneously charging and discharging the battery, which is not physically possible.

 

[motrek]

...
The physics is pretty clear though. You don't want it sitting at 100% all the time constantly getting charged. ...

Constantly charging a battery is called trickle charging and will quickly ruin a lithium-ion battery.

No laptop that was made after the early 2000s does this.

If you leave a MacBook plugged in, it will charge up to 100% and then stop charging. The battery will slowly self-discharge by a few percent (usually takes 2-3 weeks), at which point the laptop will charge itself back up to 100% (usually takes less than an hour).

The only concern with leaving a MacBook plugged in all the time isn't that it's constantly charging (it's basically never charging), but that it's not super-terrific to keep a lithium ion battery essentially stored at 100% charge.

 

[autofree]

I had a Macbook Pro 2013. Kept it plugged in most of the time. By the time I sold it just last month, it had 251 cycles. The health was at 85%. I used it like normal and didn't think much into it. Plugged it in whenever I was home. 85% retained capacity seems good for a 9 year old battery.

It still ran like a beast. I finally upgraded to the MBP 16 after getting good discount.

 

[dhuang]

I realized that trying to maintain 100% battery health is a futile effort and ultimately left to chance.

My new 13" M1 MBP went from 102% to 80% (2 -> 66 cycles) in a year.
I was using Al Dente with a 80% limit and super OCD about battery maintenance.
It had a 'Check Battery' condition before I traded it in.

My refurb 14" M1 Pro MBP is currently at 99% from 100% (14 -> 30 cycles) in 3 months.
I just have 'Optimized battery charging' on, that's it.

 

[motrek]

I realized that trying to maintain 100% battery health is a futile effort and ultimately left to chance.

My new 13" M1 MBP went from 102% to 80% (2 -> 66 cycles) in a year.
I was using Al Dente with a 80% limit and super OCD about battery maintenance.
It had a 'Check Battery' condition before I traded it in.

My refurb 14" M1 Pro MBP is currently at 99% from 100% (14 -> 30 cycles) in 3 months.
I just have 'Optimized battery charging' on, that's it.

I suspect that a lot of battery longevity has to do with battery "trauma," e.g., deep discharges and high temperatures.

It's pretty easy to e.g. leave a laptop in direct sunlight by accident (e.g., put it on a table in the morning and by afternoon the sun has moved such that it's hitting the laptop directly). That can't be good for the battery at all.

Also I think people don't understand just how hard it is on a battery to run it down to below 10%. Some people even try to do this on purpose because they don't understand how charge cycles are counted.

 

[jav6454]

Yeah, you're going to find a ton of conflicting and rather tedious advice about battery health. People will advise strange charging patterns, apps that supposedly preserve battery health (but don't) etc.

I think it's best to simply follow the advice that Apple gives--and not random self appointed experts.

Agreed. This is the best advice. Also, don't overthink your battery.

 

[1madman1]

Some of my previous notebooks, specifically Sony and IBM/Lenovo, let me manually specify a maximum charge value. In the case of the Sony the value was retained at the BIOS level and once set it absolutely never charged past the defined value until you changed it. Really wish Apple let you do that...

 

[jav6454]

Some of my previous notebooks, specifically Sony and IBM/Lenovo, let me manually specify a maximum charge value. In the case of the Sony the value was retained at the BIOS level and once set it absolutely never charged past the defined value until you changed it. Really wish Apple let you do that...

It is done automatically for you. If you have your Mac connected to power, then Optimized Battery Charging will learn this and allow your battery to drain and drop to 80%. Once this is reached, your Mac will keep the battery at said level.

 

[Isamilis]

I was looking for the best ways to charge my Macbook Pro in order to preserve the battery life for as long as possible but there so many varying opinions on here and YouTube and Reddit users are exactly the same.
Here is what I’ve read and discovered so far from other users, these are not my opinions but what I’ve seen people post and talk about :

1. Don’t let your MacBook charge above 80% but don’t let it drop below 20%
2. Charge it up constantly and leave it charging, the battery has a memory and will actually last longer when you unplug it
3. Dont leave it plugged in as this drains the battery even more, reduces battery life by 75% and makes the battery swell up ( even though a reddit user left his plugged in for a year and it worked fine )
4. In clamshell mode when charging constantly my MacBook Pro exploded after 2 weeks and the battery was bloated pushing my trackpad up and cracking my screen
5. only ever charge to 50%, 50% battery drains slower than 100% battery and lasts twice as long
6. Kepp it on charge for a few weeks but always discharge it and take the charger out for a few days or so and repeat process ( or the battery bloats ).
7. Battery memory means that even if your charger is plugged in your machine constantly it “learns” and tells the cpu that it’s not even charging anymore and preserves battery life in that way, even though it is charging as it’s attached to the mains.

These are only a few of the quotes I’ve seen, so what’s the best way to keep battery life good ?

It’s quite simple actually, but it needs habitual changes. Main two principles are:
- use it between 45% - 75%. Yeah I know this is short range, but this is the ideal one. You can “break” it to 20% - 80% when needed. For sure, overnight charging should be avoided
- avoid heat in any form (ie, in car, outdoors, or long cpu intensive process)

Other than that, there is small manufacturing variation. It’s like lottery where the “defect” may appear anytime. This is why same type of device may have different battery health even though they’re treated mostly the same.

For Mac, you can use charge limiter tools which stop charging at certain %.

You can check this reference for details.

 

[motrek]

It’s quite simple actually, but it needs habitual changes. Main two principles are:
- use it between 45% - 75%. Yeah I know this is short range, but this is the ideal one. You can “break” it to 20% - 80% when needed. For sure, overnight charging should be avoided
- avoid heat in any form (ie, in car, outdoors, or long cpu intensive process)

Other than that, there is small manufacturing variation. It’s like lottery where the “defect” may appear anytime. This is why same type of device may have different battery health even though they’re treated mostly the same.

For Mac, you can use charge limiter tools which stop charging at certain %.

You can check this reference for details.

- If possible, you should plug a laptop in when you're using it. I'm not sure how this agrees with your idea that a laptop should only be used when it's between 45% and 75% charged.

- Why in the world would you avoid charging a laptop overnight?

- Intensive CPU use will not heat up the battery. The CPU and the battery are on different sides of the laptop and the heat from the CPU is exhausted in the opposite direction of the battery.

- Most of the testing, information, etc. at "Battery University" is from 15-20+ years ago and is out of date.

 

[MajorFubar]

I'm with @jav6454.
Unless you believe Apple have a conspiracy to purposefully charge their laptops' batteries in a way that is bad for their longevity, I think you should let the tools already built in to the system manage the charging.
I tend to take zero interest in the so-called battery health, and instead I use the amazingly reliable and valid metric of 'how long does the machine stay switched on'.
First-hand example:
As well as my M1 MBA I have a 2012 A1278 13" MBP which I bought from the refurb store, so it was nearly new.
I couldn't tell you what its battery health is, and I bet its cycle-count reads like a long-distance trucker's odometer.
But I can still get about 4 hours' use out of its original battery just browsing the web and doing basic things.
Used daily for nearly ten years. Plugged it in every night to charge.
YMMV.

 

[1madman1]

It is done automatically for you. If you have your Mac connected to power, then Optimized Battery Charging will learn this and allow your battery to drain and drop to 80%. Once this is reached, your Mac will keep the battery at said level.

Not on my Macbooks it doesnt.... likely a newer OS only feature if it does. It's not possible for me to upgrade past Mojave.

I remember configuring my IBM T42p for this back in ~2005, Sony SZ780 in 2008.

 

[Isamilis]

- If possible, you should plug a laptop in when you're using it. I'm not sure how this agrees with your idea that a laptop should only be used when it's between 45% and 75% charged => you may need check the link provided

- Why in the world would you avoid charging a laptop overnight? => because it will stress the battery by having 100% charge for long period.

- Intensive CPU use will not heat up the battery. The CPU and the battery are on different sides of the laptop and the heat from the CPU is exhausted in the opposite direction of the battery => my experience, high cpu will also affect battery health due to its heat, especially if it runs for long time. I usually put the MacBook on the floor or add fan close to it.

- Most of the testing, information, etc. at "Battery University" is from 15-20+ years ago and is out of date => the document was updated in 2021. Happy to read if you have more recent articles on battery maintenance.

Just comment on the above. Again, it’s up to the owner to concern or not concern with the battery. I am not expert, I just follow what the articles suggested. Just saying, my iPad M1 bought in Jan this year, still has 105% battery health. My 2014 MBP is also at 81% health last year (before I gave it to my daughter).

 

[spiderman0616]

I left my 16" Pro in Sleep mode all night last night while plugged in with Optimized Charging turned on, as I usually do most weeknights. When I clicked my mouse to wake up the laptop this morning, it was still at this level:

Do not listen to anyone saying you can't leave these things plugged in at all times. You totally can if your processor and OS are new enough.

 

[DJLC]

I use my 14" MBP plugged in about 99% of the time. I bought in February, and I'm currently at 98% battery health.

At no point have I seen charging automatically limit itself to 80%. If I leave macOS to its own devices with optimized charging enabled, it sits at 100% all the time.

I use AlDente and keep it between 50% and 80%. I'll set it to top up to 100% if I know I'm gonna be mobile. The AlDente app also isn't super reliable all the time, but I feel a little better about my battery getting some variation with it vs. relying on macOS.

All this said: I really don't care that much. The battery will wear out eventually. And I'll either swap a new one in myself or upgrade to a new MacBook at that point. Whatever. Not that big of a deal IMO. I'm doing what I can to prolong its life, but I'm not losing any sleep over it either.

Also will add: I've seen many MacBooks over the years with swollen batteries that shattered the trackpad and ruined the whole device. But I've also never seen that symptom in a MacBook that's less than five years old. Not saying that's never happened, but I'd think it's a rare exception rather than a rule.

 

[spiderman0616]

I use my 14" MBP plugged in about 99% of the time. I bought in February, and I'm currently at 98% battery health.

At no point have I seen charging automatically limit itself to 80%. If I leave macOS to its own devices with optimized charging enabled, it sits at 100% all the time.

I use AlDente and keep it between 50% and 80%. I'll set it to top up to 100% if I know I'm gonna be mobile. The AlDente app also isn't super reliable all the time, but I feel a little better about my battery getting some variation with it vs. relying on macOS.

All this said: I really don't care that much. The battery will wear out eventually. And I'll either swap a new one in myself or upgrade to a new MacBook at that point. Whatever. Not that big of a deal IMO. I'm doing what I can to prolong its life, but I'm not losing any sleep over it either.

Also will add: I've seen many MacBooks over the years with swollen batteries that shattered the trackpad and ruined the whole device. But I've also never seen that symptom in a MacBook that's less than five years old. Not saying that's never happened, but I'd think it's a rare exception rather than a rule.

For me, if I take it off the charger, it will sit back at 100% for a week or two and then will go back down to 80 and stay there. I know some people have had it where it never happens, but I have not seen that issue so far.

 

[motrek]

For me, if I take it off the charger, it will sit back at 100% for a week or two and then will go back down to 80 and stay there. I know some people have had it where it never happens, but I have not seen that issue so far.

I was happy the other day when my new MBP limited itself to 80% charge, and the immediately unhappy later in the day when I took it off the charger for ~10 minutes and now it has gone back to charging to 100%.

IMO the software should understand that if you only use the laptop on battery power for a few minutes once in a while, it still only needs to charge to 80%.

I'll investigate programs that limit charging later today. I tried AlDente last week but was annoyed that it has an always-present icon in the menu bar.

To be clear, charging to 100% isn't murdering anybody's battery. It's simply not optimal. There are many things that are much worse for a battery.