Replying to the suggestion below: What I did was I went to Settings, Battery and toggled OFF Battery Percentage. Then I scrolled down and selected Battery Health, and toggled OFF Optimized Battery Charging. Then I did a hard restart of the phone, went back into the Battery settings again and turned Optimized Battery Charging back ON and Battery Percentage back ON. My battery percentage indicator immediately went from 1% to 79% after that. I was at 49% battery life (iPhone SE, iOS14.2) before trying this, and when it was completed less than 2 minutes later it had dropped to 41%. But not giving up, will try again and see if the method works after full charge. As Apple has suggested a complete wipe as one solution, can anyone report if that solved the iOS14 battery drain issue?