No, it's not guaranteed that an iPhone battery health will be at 85% after one year; it can vary. According to Apple, it's not unusual for iPhones to retain a battery capacity of 95% or above after one year.
While 85% is possible, it's not a universal or expected outcome. Battery health degradation depends on several factors, including usage patterns, charging habits, and environmental conditions. Apple considers a battery at 80% capacity or higher after one year to be in optimal condition and covers it under their standard 1-year warranty.
Therefore, the battery health after one year could be higher or lower than 85%, depending on individual circumstances.
