Battery Health Management is a new feature in macOS Catalina 10.15.5 that may improve your Mac’s battery life. It’s similar to the Optimized Charging feature on iOS 13 and iPadOS 13 devices, albeit, specific to MacBooks.
Battery Health Management adjusts the max battery capacity of your Mac’s battery using software and only lets it charge up to that limit. This feature comes in handy especially for devices that have a lithium-ion battery, which is almost every device today, including Macs.
Lithium-ion batteries degrade over time and use. However, they are only greatly affected if they are frequently topped up since while filling up your battery to the brim the chances of power overflow increase. Features like Battery Health Management stops extra power from coming in and learning from your usage, stop taking in charge, or in other words top off the limit on how much you can fill up the battery.
Here’s Apple’s explanation of the feature:
Based on the measurements that it collects, battery health management may reduce your battery’s maximum charge when in this mode. This happens as needed to ensure that your battery charges to a level that’s optimized for your usage — reducing wear on the battery, and slowing its chemical aging.
For example, when you first get your Mac, the battery capacity may be complete 100 percent. However, with use and the Battery management feature working on deciphering your behavior, your battery capacity may be reduced to 90 percent, for instance. But it will let you use that 90 percent entirely, thereby helping the battery from dying out soon in the long run.
However, if you keep your Mac plugged to a power source at all times, the Battery Management feature may hold off the capacity at an even lower limit, which will eventually lower the hours you get when your Mac’s not on charge.