Problems with iphone 6s
hello guys, i have a problem with my iphone 6s, the battery of my phone no longer lasts as it used to, before I had another battery because after the update of ios 13 it no longer had the performance as it used to, I changed the battery because I thought it was the problem, but it was not so, maybe it's the fault of the update or the phone, I don't know, please help me. thank you.
iPhone 6s, iOS 13