The battery packed inside your electronics gadgets — such as iPhones and MacBooks — is a perishable item. Over the course of repeated charge-discharge cycles, it loses its mojo due to electrochemical degradation. When that happens, the battery gradually loses its ability to retain electrical charge.
As a result, your devices tend to last fewer hours, even though MacBooks have a better record at it than Windows machines. As the battery loses its ability to provide enough juice for a sustained period of time, certain performance optimizations (read: slower performance) kick into action. Soon, you are left with no other option than getting a battery replacement.
Now, there is no magical pill to avoid battery degradation. What we can do, however, is somehow slow down the electrochemical degradation so that the battery lasts longer. Apple lets iPhone users do that by letting them limit the charging to the 80% level. Unfortunately, no such solution exists for MacBooks.
What’s the solution?
The Mac developer and open-source communities have created a handful of battery management tools over the years. But as Apple shifted from Intel to in-house silicon, many of those projects vanished, while the remaining few are pretty expensive.
One such tool that I recently came across— and which gets the job done — was Actually Mentor. This free and open-source application has one core objective, which is to limit your MacBook’s battery to the 80% level. Though it only works on Apple silicon, it has been forked with expanded silicon support and more features, too.
The app is as simple as it gets. It lives within the menu bar and only offers a small drop-down window as its user interface. Installation is fairly straightforward, and all you need to do is give admin access in order to get it running.
As far as functionality goes, all of it revolves around the 80% charge limit. If the battery is above that level, the app can manually discharge it to reach the target, even if the charging cable is plugged in.
While charging, as soon as the battery reaches an 80% level, further top-up is paused. And as soon as the tank drops below that baseline, charging is resumed. In a nutshell, your MacBook will never go past a certain level.
Thankfully, the app’s functionality is active even if you close it, or the system reboots. If you seek more controls, I’d recommend an Actually Mentor fork named Battery Optimizer for Mac.
This one works with Intel and Apple silicon Macs, replaces the macOS battery icon with a hardware-based charging level indicator, allows periodic calibration, temporarily allows a full charge, creates a log, and shows status reports, as well.
Why do I need one?
There are two questions you might ask before installing an app like Actually Mentor. First, does maintaining an 80% charge baseline even matter? Second, what about Optimized Charging that Apple already offers? Well, let’s start with the first dilemma.
Research suggests that lithium ion batteries — the kind you will find inside laptops — undergo stress when subjected to high temperatures. Likewise, if a battery pack is constantly kept at a high voltage potential, the ionic composition is stressed.
Ideally, a lithium ion cell should not remain at the voltage ceiling prescribed for common electronics gadgets for an extended period. For lithium-based batteries, a reduction in peak charge voltage can help prolong their life by hundreds of cycles.
Then there’s the question of capacity loss, which depends on the depth of power discharge. Tests suggest that discharge beginning around the 85% level offers the best battery longevity, though the lower limit might vary.
“A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid,” says a detailed technical analysis. “To make this feature user-friendly, a device should feature a Long Life mode that keeps the battery at 4.05V/cell and offers a SoC of about 80 percent.”
This is where tools like Actually Mentor and Al Dente come into the picture. Now, let’s address the question about Optimized Charging, which is baked at the system level within macOS.
Well, it doesn’t technically limit the charging level to the 80% mark, but only slows down further top-up, a term commonly known as trickle charging. “Your Mac delays charging past 80% when it predicts that you’ll be plugged in for an extended period of time, and aims to fully charge the battery before you unplug,” explains Apple.
What’s the best way forward?
The folks behind Al Dente suggest that a charge limit between 50-80% should keep your MacBook’s battery in optimum shape for the long run. Actually Mentor, on the other hand, takes a more straightforward approach and locks the upper limit to 80% for charging without addressing the lower limit for discharging.
As a user, I would prefer the latter approach, as it keeps things simple. Moreover, you can choose to enable or disable this limit without going through any technical hoops. If you are someone who intends to get the most out of their Mac’s battery life, Actually Mentor is the cleanest utility for your Apple laptop.
Of course, it goes without saying that you should stick with the official charging brick, or prefer only those third-party options that meet Apple’s voltage and current criteria to juice up a MacBook’s battery. Poor quality chargers often lead to overheating and suffer from unregulated voltage fluctuations, which can quickly turn into a fire hazard, as well.
In a nutshell, don’t stray too far from Apple’s hardware bundle. And where there are software gaps, fill them with functional utilities such as Actually Mentor. It’s just a sweet bonus that this is an open-source project that is constantly evolving from the feedback of an average user like me, and you.