My battery health is going down fast!
Seems like since iOS15 it's been dropping faster.
For months I was at 100%.
At 92% now.
My original iPhone X from release date works fine but shows SERVICE BATTERY.
I'm thinking this battery health indicator is a sham.
I'm typing this on my M1 MBP bought in March 2021 with 100% battery health and age of 10.4 years!
Someone messed up and put 11 instead of 21 in the field for year built.
But if it works all day, not bulging or smoking/sparking then I guess it's fine.