The latest Apple Silicon MacBooks get incredible all-day battery life under optimal usage conditions. Battery health inevitably declines with age, though, so how do you maintain this performance over the long term? Here are a few things you can do.
The sweet spot for a lithium battery in terms of long-term health is between 80 percent and 40 percent. Charging to 100 percent or letting your battery percentage drop too low is considered bad for the cell. Batteries that are full store a higher voltage, which puts more stress on the cell.
Battery University recommends that “a device should feature a ‘Long Life’ mode that keeps the battery at 4.05V/cell and offers a [state of charge] of about 80 percent” to prolong the life of the battery. Many companies have adopted such charging modes, including Apple.
You’ll find this setting under System Preferences > Battery > Battery. Once your Mac has learned your daily habits, it will wait before charging your device fully so that the cell spends less time at 100 percent. The mode was first introduced in macOS Catalina so if you try updating and your Mac is not compatible with this version of the OS then you’re out of luck.
So if you charge your laptop overnight and leave for work at 8 am every morning, your MacBook will wait to top up the final 20 percent or so. If you happen to leave an hour earlier for some reason, you might find that your battery isn’t fully charged. This works identically on the iPhone and iPad.
It’s not possible to “overcharge” your MacBook battery by leaving it plugged in. If you leave it plugged in all of the time, the battery won’t overheat or damage any other components. The one exception to this is if you start to notice the battery bulging, which is a serious problem that could result in harm (tell Apple immediately if you notice this).
The aforementioned Optimized Charging feature takes some of the sting out of leaving your laptop plugged in, but it’s not infallible. If your laptop never leaves your desk or you have a particularly erratic schedule, macOS may not be able to pin down when to delay charging your battery.
That’s why it’s a good idea not to leave your machine on the charger all of the time. Ideally, you’ll want to run the cell down to 40 percent before charging it back up to around 80 percent for best results. This guarantees the battery won’t be under too much stress from the high voltage required to hit 90 or 100 percent.
Carefully managing your battery is work, and most MacBook owners don’t need to get too in-depth. Simply take your laptop off the charger for a few hours a day if you’re desk-bound and you’ll avoid some of the premature aging caused by high voltage.
Extreme temperatures are bad for your MacBook in general. It’s fairly common knowledge that extreme heat is bad for technology, but research conducted in 2021 by the US Department of Energy’s SLAC National Accelerator Laboratory shines a light on just how bad extreme cold can be.
Researchers found that extreme cold can crack the metals used in lithium battery cells, separating the cathode from other parts of the battery. Storing cathodes at below-freezing temperatures “led batteries to lose up to 5% more of their capacity after 100 charges than batteries stored at warmer temperatures.”
The solution is to ensure your laptop isn’t exposed to extreme temperatures. Don’t leave it in a car overnight in the winter, and if you find yourself in a situation where your MacBook may get particularly cold get an insulated case. MacBooks are not ruggedized laptops and aren’t rated for extreme weather conditions.
If you’re really keen on preserving your MacBook battery for as long as possible, the free app AlDente (and the paid version AlDente Pro) might be of interest. The app allows you to set a charging limit so that your MacBook stops short of the maximum capacity at a percentage of your choosing. By default, this is 80 percent.
The free version only has a charge limiter and discharge mode which enables the MacBook to run on battery even when plugged in. This allows you to discharge your battery to a “healthier” percentage without removing the power connector.
AlDente only works with macOS Big Sur or later and works best on most MacBooks manufactured in 2016 or later. Earlier laptops lose support for certain features but most post-2013 models support the most important charge limiter functionality.
If you go this route your battery will remain healthier for longer, but you will be sacrificing some of its potential capacity. You can always disable AlDente (or instruct it to top your battery up to 100 percent) if you know you’re going to need the additional juice. You also have to disable Apple’s Optimized Charging feature for AlDente to work properly.
Note: The authors of AlDente recommend doing at least one complete charge cycle from 0 percent to 100 percent every two weeks to ensure that your battery remains correctly calibrated. The authors note that if things do get out of whack “doing 4+ full cycles will recalibrate your battery and the capacity will go up again.”
If you’re wondering what sort of condition your battery is in, you can head to System Preferences > Battery > Battery and click on “Battery Health…” to see a simple overview.
For a more detailed look including charge cycle count, click on the Apple logo in the top-left corner of your screen followed by “About This Mac” then click on “System Report” on the “Overview” tab. Scroll down to “Power” and under “Health Information” you should be able to see your battery’s cycle count.
Modern MacBook batteries are rated for around 1000 cycles which equates to around three years of average usage. Older models may only be rated for 300 cycles. Your Mac’s battery health report will let you know when it’s time to consider a replacement.
There’s a good chance your MacBook will outlast its battery. If you don’t find yourself thirsting for more processor power, RAM, or GPU grunt, you might get a few more years out of your laptop simply by replacing the battery.
If you purchase AppleCare+, your MacBook is covered for three years which includes the battery. You can take your Mac to an Apple Store or authorized service provider and have them test the battery (and other hardware), then have it replaced for no fee. It’s worth doing this if your AppleCare+ is due to expire soon since you have little to lose.
If your Mac is out of warranty you can pay for Apple’s battery service. This costs $199 for MacBook Pro and 12-inch MacBook, or $129 for a MacBook Air. If your machine is especially old you may find that battery service is unavailable.
You can always purchase a replacement battery and do the swap yourself. iFixit sells batteries for a wide range of MacBook models and features detailed tutorials for opening up your laptop and swapping the battery for a new one.
The less energy your Mac uses, the fewer cycles you will put on your battery. If you are finding that your MacBook isn’t giving you all-day performance anymore, check out some tips for saving energy and getting more life out of it.
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