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M1 MacBook Pro battery charge level with external monitor

I have M1 MacBook Pro (16 inch) fully charged, and connected to the charger and a LG 27' monitor, which has own power adaptor. Strangely, M1 MacBook Pro drains its battery level down from 100% to 80% and holding its level. Why does it drain the battery level? This will require additional charging and appears that it is not good for the laptop.

MacBook Pro (2020 and later)

Posted on Jan 26, 2022 10:47 AM

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Posted on Jan 27, 2022 7:13 AM

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries


From the above: "A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. 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. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4.20V/cell."

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Question marked as Top-ranking reply

Jan 27, 2022 7:13 AM in response to Frozen_Green

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries


From the above: "A laptop battery could be prolonged by lowering the charge voltage when connected to the AC grid. 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. One hour before traveling, the user requests the “Full Capacity” mode to bring the charge to 4.20V/cell."

Jan 26, 2022 11:04 AM in response to Frozen_Green

In fact, it is good for your laptop's battery which is why MacOS does that.


"Based on the measurements that it collects, battery health management may temporarily reduce your battery's maximum charge. 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."


About battery health management in Mac notebooks

M1 MacBook Pro battery charge level with external monitor

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