As of macOS 10.15.5 Catalina, your Mac notebook analyzes your daily charging routine and activates charging only when the operating system predicts the computer will be connected to a charger for an extended period of time. They’re calling this Optimized Battery Charging and it boils down to ensuring your Mac is still fully charged when unplugged.
Depending on your device usage patterns, the useful Optimized Battery Charging feature may decide to temporarily suspend charging above the eighty percent threshold, which helps increase battery lifespan and limit battery aging. Should that happen, the operating system will decide to resume charging at the right time, so that the battery gets to hundred percent just before you unplug. For instance, if you use your MacBook around the same time each morning, macOS may resume charging before you start using the notebook in the morning.
Because Optimized Battery Charging is on by default, rookies might be wondering why their battery doesn’t seem to be charging. In those cases, the Battery icon in the macOS status bar may read “Not Charging” even though the computer is connected to power.
According to Apple, if your Mac has temporarily suspended charging, the battery may need to drain to 90 percent or lower before the algorithm resumes charging. You can immediately resume charging by turning off battery health management in your Energy Saver preferences.
Thankfully, macOS Big Sur lets you force an immediate full recharge of the battery when charging is pending without having to turn off the Optimized Battery Charging feature. As explained by the French blog MacGeneration.fr, you can do this by clicking the Battery icon in the macOS status bar and selecting the option labeled with the text “Complete recharge now”.
You may not see this option if your Mac is not connected to power or the Optimized Battery Charging feature has been trned off. By the way, clicking the Battery menu bar item also reveals the estimated amount of time that it will take to fully charge the battery. Apple notes in another support document that batteries in Mac notebooks may not charge up to 100 percent. “It’s normal for a battery with over 95 percent charge not to charge anymore,” it explains.