Same with me. iPhone SE suddenly got less than half the battery life as stone as I got the beta back in May. I already had my settings optimized with background app refresh of on most my apps etc. after a month I realized it was my WiFi. If I turned it off, it was back to what I expected. Filled bug reports and waited, but even after the public release, same problem. Tried restoring my device in case it was some thing buggy from upgrading or the betas, but no Improvement. Finally decided it must be the model of phone itself so I boy the bullet and upgraded to the iPhone 11Pro. Guess what? Still the same issue! If I turn WiFi off I get 2 full days, but worth WiFi on, only one. The graph in the battery setting shows a steady slope down at more than twice the angle with out any usage by me if WiFi is on. Without WiFi, it looks almost flat over 24 hours if I don’t use the phone, while with WiFi ON, its a steady drain from 100 - 0 over 24 hours. This is UNACCEPTABLE, Apple!!!!! iOS 12 was a perfect update, how can 13 be this bad still after months and countless updates??!?!?? FIX IT