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mhaeuser / Battery-Toolkit

Control the platform power state of your Apple Silicon Mac.
BSD 3-Clause "New" or "Revised" License
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Lower limit function based on common misconception #48

Open Azirine opened 1 week ago

Azirine commented 1 week ago

Contrary to popular belief, micro-cycles are beneficial for the performance of Li-ion cells. The paper below found that micro-cycles (<2% DOD) increase lifespan in the range of 31% to 50%.

https://www.sciencedirect.com/science/article/pii/S2352152X2201338X

The lower limit function can inadvertently speed up the degration of numerous MacBook batteries, despite users' best intentions.

mhaeuser commented 1 week ago

I don’t think you can easily conclude this at all. This is about comparing deep-only vs charging behaviours that also include micro-cycles during regular discharge. If you hit the lower limit (default is -5%), either you briefly discharged and then returned to idle, or it is “creep”-discharging (might even be imprecision with the reading). Meanwhile, the concept of hysteresis is present in Apple’s implementation and I copied their limits. Unless you can extract information that clearly applies to this different use-case from the data (I don’t have the time to check it all in detail), I trust Apple’s internal decisions regarding their own batteries over experiments on only a few cells with a clearly different workload.