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I have had a 2015 retina MBP from new. After 120 cycles (1.5yrs) the battery was below 84% (coconut) and it was ‘power babied’. Co-incidentally the screen laminate was peeling so Apple happily replaced under warranty and surprisingly replaced the battery and keyboard at the same time for free. Since then I just used and abused it for almost 5 years carefree and now its done 800 cycles and is about 80% (due for replacement).

Lesson learned. Just use the laptop as it’s meant to be used and not worry too much about it, though obviously not all batteries end up being equal. Either way they are a disposable (sic) item that will need replacing in the medium-long term no matter what.

My M1 Pro is about 20 months old and at 95% it’s only 50 cycles on it, so maybe it’s a reasonable specimen. But the battery goes so much further on these machines that an 80% battery would still easily outlast anything using intel.