Hello, i bought an iPhone 11 back in November of last year and have been using this phone since then. However my battery health is dropping really fast as it is currently 86% after 5 months. I use my phone for average 8 hours a days and use fast charginh. My friend gas gad his iphone 11 pro for about a year and a half and his health is 84% and his average is 7 hours. Is there a fault in my phone or am i doing something wrong?