MacBook Air M1 2020. I got it on November 11, 2023. Maximum Capacity was 100%. On January 23, 2024, Maximum Capacity was reduced to 99%. On January 30, 2024, when I upgraded to MacOS Sonoma 14.4, it dropped to 98%. Now, on February 4, 2024, it is down 97%. Cycle count is 51. Why is it falling so fast?
MacBook Air 13″, macOS 14.4
Since macOS has never disclosed the Battery's Maximum Capacity before, people don't really understand how Lithium batteries work & behave. It is perfectly natural for the Lithium battery in Apple devices to have their Maximum Capacity (aka Full Charge Capacity, FCC) fluctuate both up & down. See my write up in this other post here:
Battery Health draining fast - Explanation how Lithium Batteries Behave -- hwtech -- Apple Community
The maximum charge capacity of any battery will decrease over time. The rate of decrease is not linear, and it's not always in the same direction. It might stay at 97% for a long time, or it may decrease to some other number, or it may increase to some other number... etc. It will last for years but the long term trend is down.
The maximum capacity is rapidly decreasing
