Is it ok to leave my 14 inch Macbook M3 Pro Max plugged in all the time while I use it?

That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device. (It is NOT an iPhone.)

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

That blocky device that plugs into the wall is the POWER ADAPTER. I am not trying to be a jerk about terminology, what these boxes do and how they do it is essential for understanding how they all work together. The LEDs in the MagSafe end are controlled by commands from the computer.

The CHARGER is inside the MacBook Pro, and is completely under program control. Your Mac accepts some power when needs to run, and accepts more power when intends to charge its internal battery. A power source like the Power Adapter can not 'force itself' on your MacBook Pro. Only the algorithms inside your Mac can decide when is a good time to charge the battery.

Since someone mentioned exercising their Mac on battery alone, monthly, Apple no longer recommends that. That function has been incorporated into general battery algorithms.

Do not spend a moment thinking about or fussing with your battery. That is great job -- for a computer.

The classic way to brute-force improve battery longevity was to create a hysteresis -- to postpone staring a charge cycle until the charged state had declined to a lower level, such as 92 percent, and when topping off, stop before 99 percent. 

Catalina software 10.15.5 and later for MacBook Pro with T2 chip (2018 models and later) includes a new feature called Battery Health Management. Now, based on your usage patterns, this widens the hysteresis to initiate a charge cycle at a lower level, and stop well before 99 percent. 

About battery health management in Mac notebooks - Apple Support

About battery health management in Mac laptops - Apple Support

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. Recharging may only begin at a lower level than the previous "normal" threshold of 92 percent or less, typically around 80 percent.

void_ranger9 wrote:

Hello, I gathered my information from Battery University - specifically **-602 & **-603.

There is also a good article from iFixit about battery calibration, however, this article pertains more to brand new replacement batteries.

See here:

https://batteryuniversity.com/article/**-602-how-does-a-battery-fuel-gauge-work

https://batteryuniversity.com/article/**-603-how-to-calibrate-a-smart-battery

Thank you. The newest article there was updated almost a year ago. So, that's something I'd take into consideration.

Calibration is what I was getting at but maybe you guys are right on that too. Maybe it is not necessary at all to pay attention to your battery indicator anymore.

Calibration hasn't been recommended for years. And remember, you were never calibrating the battery. You were calibrating the battery sensor. And they've gotten better.

But because of the natural degradation of batteries over time, I think it may be beneficial to perform a calibration a few times a year. That is assuming at some point you will pull it off of the charger. If you never pull the laptop off of the charger for its entire lifetime then who cares what happens to the battery I guess, right?

Calibrating the battery won't make it last longer. But I do agree that if you never or rarely take it off charge, the accuracy of the gauge is not a big issue.

My personal opinion is that everyone is spending way too much time worrying about their batteries. I think this is especially true with iPhones. Apple started including Battery Health after the throttling debacle (which was a communication issue, not a technological issue). And now people obsess about it. And to no good end. It makes people anxious, and they spend a lot of time trying to "manage" their batteries.

Turn on optimized battery charging. Don't let the device get too hot. Don't bother looking at Battery Health unless you notice a problem or you're near the end of the warranty. Don't spend too much time thinking about it. Unless, of course, you need a new hobby. ;-)

[Edited by Moderator]

I do still believe discharging the battery every once in a while is a healthy thing to do. And maybe Grant Bennet-Alder can weigh in on this as he seems to have a quite a bit of knowledge on this matter. I would be happy to accept his idea that this is no longer needed if he can expand a bit for me.

While I do believe what he said is true, specifically this part:

"That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device."

It is true that computers are more than capable of powering themselves off of a battery, but as he said, they also have no issue only using the power adapter as a power source. In fact, like he said, they probably perform better on the power adapter as they can input more power to the device than what the battery can provide. Look at desktop computers after all.

That is great news!.. for the computer inside your MacBook chassis but (from my own research) it is not great for the battery inside of that chassis. And yes, macOS is designed to discharge your battery to 80% after sitting on the power adapter for a long time but I think a full discharge and recharge once in a blue moon would be a good idea for calibration purposes.

Summary: If you are not worried about the battery being calibrated, leave it plugged in 24/7 if you wish to do so. This will not harm the computer part of your MacBook.

Again, this is just the conclusion I have come to from my own research and experience.

Sonyappleman wrote:

I effectively use it as a desktop, connected to one external monitor. I use the MacBook itself as a second monitor.

No need to disconnect your MacBook, if you don't take it away to work on battery.

System Settings > Battery > Battery Health> Enable

System Settings > Battery > Options > and enable/disable certain options that's valid for your work. Mine is like this,

I practically never unplug the MBP, only when it's absolutely needed. Sometimes for fun, I work the whole day on battery, just to check everything is alright with battery life. My MBP is more than 5 years old, and still has ~90-91% battery health. The newer MacBooks should surely do well. Good that you are using the MacBook's screen, even as the 2nd monitor. 👍

Yes, this is fine.

I would however unplug it at least once a month and drain the battery to between 10%-20% and charge it back to 100%.

void_ranger9 wrote:

I do still believe discharging the battery every once in a while is a healthy thing to do. And maybe Grant Bennet-Alder can weigh in on this as he seems to have a quite a bit of knowledge on this matter. I would be happy to accept his idea that this is no longer needed if he can expand a bit for me.

That was essential with older battery technologies like NiCd and NiMH. But it offers no benefit at all for Lithium Ion, at least for the battery health. What it can help is the accuracy of the state-of-charge indicator, by setting low and high checkpoints for the battery management process to extrapolate from. But with the newest battery management technology even that isn’t necessary, as the monitor is actually in the battery, and can report the chemical state of the battery. That’s why Apple dropped the recommendation to “recalibrate” the battery gauge for older iPhones.

IdrisSeabright wrote:

Why do you believe it's a "healthy thing?" Could you share your research?

Hello, I gathered my information from Battery University - specifically **-602 & **-603.

There is also a good article from iFixit about battery calibration, however, this article pertains more to brand new replacement batteries.

See here:

https://batteryuniversity.com/article/**-602-how-does-a-battery-fuel-gauge-work

https://batteryuniversity.com/article/**-603-how-to-calibrate-a-smart-battery

If we take the Author's question more literally, "is it ok to leave my MacBook plugged in all time time?", It is okay. You guys are correct. Battery health should not be impacted because of the new technologies Apple has implemented.

Calibration is what I was getting at but maybe you guys are right on that too. Maybe it is not necessary at all to pay attention to your battery indicator anymore.

But because of the natural degradation of batteries over time, I think it may be beneficial to perform a calibration a few times a year. That is assuming at some point you will pull it off of the charger. If you never pull the laptop off of the charger for its entire lifetime then who cares what happens to the battery I guess, right?

Thanks for all the information though, this thread has been beneficial for me!

[Edited by Moderator]

Absolutely!

I see way too many questions about batteries on here. Batteries have a "shelf life" and should be treated as such. Do not waste your time stressing or thinking about your battery. It will go bad eventually no matter what you do.

Thanks for your insight

I have a MacBook Air that's on its second battery. I had Apple replace the first one long ago because it was about to go "vintage" which makes obtaining Apple service difficult. They were reluctant to replace it because it was at exactly 80% but it would occasionally dip into the high 70s. It was well beyond warranty so I happily paid the $129 or whatever they charge.

Seven years later that battery is now indicating "service", and I may replace it. Or not, because it still lasts the better part of a day which is good enough for me.

That Mac is now in its fourteenth year, and built well before Apple's far more advanced power management features were implemented. I pay no any particular attention to it; I just use it like the tool it is.

The point is that your Mac's battery will last a long time, and aside from certain common sense actions like not leaving it in a car parked in the South Texas heat for hours on end (don't do that) or neglect using the Mac at all for many many months (don't do that either) there is little you can do to affect its longevity.

If you keep your Macs a long time, well into their "vintage" years, you may want to replace it once. Budget about 50¢ a week for battery depreciation and you'll have more than enough saved to replace it... should you want to, considering it'll be quite old by that time.

Let me add on, it’s good to occasionally charge your Mac to 100 percent to maintain accurate battery state-of-charge estimates. If it’s always at 100%, you may never know if your battery state of charge estimates are accurate.

Refer to this article on maximizing your battery performance: Batteries - Maximizing Performance - Apple

Sonyappleman wrote:

Thanks, I appreciate the advice.

Could you briefly explain reason for draining it? Does it need to have 'charging cycles' for the health of the battery?

Initially, I was thinking I would just unplug it every night, and let it go into sleep mode, not sure if that would be of any significance or not.

There is no need to unplug it at night nor once a month.

void_ranger9 wrote:

I do still believe discharging the battery every once in a while is a healthy thing to do. And maybe Grant Bennet-Alder can weigh in on this as he seems to have a quite a bit of knowledge on this matter. I would be happy to accept his idea that this is no longer needed if he can expand a bit for me.

Apple stopped recommending that for rechargeable batteries years ago. Given Apple's current (over?) emphasis on maintaining battery health, doesn't it seem likely that, if discharging it was necessary, either it would be included in the algorithm or that Apple would recommend it?

Why do you believe it's a "healthy thing?" Could you share your research?

I highly recommend reading Lawrence Finch's User Tip When to charge your iPhone or iPad - Apple Community.

As he wrote,

"While this tip is specifically for iOS devices, the same principles apply to all other Apple devices (watches, AirPods, MacBooks) as well as most other manufacturer’s products that have Lithium chemistry batteries."

Personally I cannot fathom why people continue to obsess about this subject. Does charging an iPhone or iPad cause you the same concern?

Zachyy wrote:

And will go bad especially quick if you leave it in storage for a long period of time. Better to use than to store!

The problem is not storage but rather leaving a battery at 0% for an extended period. Storage, if done correctly, doesn't drain a lithium ion battery especially fast.

Store it half-charged when you store it long term.

If you want to store your device long term, two key factors will affect the overall health of your battery: the environmental temperature and the percentage of charge on the battery when it’s powered down for storage. Therefore, we recommend the following:

• Do not fully charge or fully discharge your device’s battery — charge it to around 50%. If you store a device when its battery is fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge. Conversely, if you store it fully charged for an extended period of time, the battery may lose some capacity, leading to shorter battery life.
• Power down the device to avoid additional battery use.
• Place your device in a cool, moisture-free environment that’s less than 90° F (32° C).
• If you plan to store your device for longer than six months, charge it to 50% every six months.

Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it.

Batteries - Maximizing Performance - Apple