You can’t calibrate a iPhones battery by doing this as it’s already calibrated by the OS and the phone manages all that so don’t worry about it

is there anything else I can do about (other than change battery) maximum capacity cuz it's 85%.

Although its a second handed, I want it to last long

What model is it? At that level I spent $70 for a new battery in my 12.

iphone 12

Not only is it a myth, it's complete bullshit.

Just replace it when reaches that 80% mark or when you feel like needing a new battery

yeah i’ll do that