Regarding battery
I changed my iphone battery but the battery health shows 86% only
i changed 2 battery but it show the same issue
and same battery i check with other iphone 7 then it shows 100% in other phone
iPhone 7, 14
If you changed the battery yourself you did not get an Apple battery, so all bets about battery performance are off. As only iPhone batteries can actually measure capacity, most likely the 86% is the value that was saved from the genuine battery. No battery capacity numbers are meaningful with counterfeit batteries.