After half a year's use, it is normal that the health surplus is between 85% and 99%, generally around 95%. If it is 100% or less than 80%, it is not normal.
It stands to reason that the charging times of a battery from brand-new to exhausted life are limited. From 100% to 80%, during this period, the battery can complete about 1000 full charge cycles, which means that the maximum capacity of the battery will be reduced by 1% every 50 full charge cycles. From this point of view, a loss of 3% for two months is normal and acceptable.
related data
In the "Battery Health" function, users can intuitively see the maximum battery capacity of the current iPhone. As we all know, the maximum battery capacity of the new iPhone must be 100%.
However, due to the characteristics of lithium battery, the maximum capacity of the battery will gradually lose after the user keeps charging and discharging. Apple officially advises users to quickly replace new batteries after the maximum capacity is lower than 80%.