The way MacBook batteries charge is about to change. Apple has released a new developer preview of macOS Catalina 10.15.5, and as these releases often do, it contains a new feature: Battery Health Management.
The new feature, which will only be available on Mac notebooks with Thunderbolt 3 ports , enables a new default approach to charging and discharging MacBook batteries. According to Apple, the feature is meant to reduce the rate of chemical aging of the MacBook’s battery, thereby extending its long-term lifespan—but without compromising on day-to-day battery life.
The feature works by analyzing the temperature of the battery over time, as well as the charging pattern the laptop has experienced—in other words, does the laptop frequently get drained most of the way and then recharged fully, or is it mostly kept full and plugged in? In the latter case, Battery Health Management is more likely to stop a bit short of full capacity in order to extend the battery’s long-term lifespan. (All charging data is kept private on the MacBook unless the Mac has been opted in to share anonymous analytics data with Apple.)
Charging a modern laptop battery to 100% and leaving it there for extended periods of time—especially at warm temperatures—can dramatically reduce the battery’s usable life. This is hardly limited to laptops: I own an electric car, and the manufacturer makes it very clear that it should be routinely charged to only 80 percent to extend its battery lifespan.
Essentially, Apple has decided it needs to adjust the default MacBook battery-charging behavior to be less aggressive at fully charging batteries in certain circumstances in order to extend battery life. Rather than just silently roll that feature into macOS and wait for users to discover it—it’s been down that path before, with the iPhone—it’s making the change clear. But make no mistake: by setting this as the default, Apple is sending a strong message that this is how MacBook batteries should charge.
Despite all of that, you can turn the new behavior off by unchecking the Battery Health Management box in the Energy Saver section of the System Preferences app. The life of your laptop’s battery is in your hands. You could also uncheck that box if you’re about to embark on an extended trip where you need to be sure your battery is charged to 100%. (Remember extended trips? Me neither.)
Though this feature is available now as a pre-release for developers, it will be coming to those who have opted into the macOS public-beta track soon. And of course, when the 10.15.5 cycle is complete, it’ll be released to everyone running Catalina.
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