I've been experiencing lately major battery loss after the update for Android 10.
My battery was replaced after the update, with an original one of course, and just for a couple of days I managed to enjoy the battery life (it lasted even for a day and half). Then, I started to notice that my phone lasts for one day (maybe less).
As a side note, at this moment I haven't installed as many apps as I had before the battery change and don't use more apps on a daily basis.
I have already restricted some apps that run in the background, checked the brightness on Auto and try to clear app history whenever I don't use my phone for a long time during the day. It feels frustrating and to be honest, what is the point in having so many customization options (live wallpapers, themes, AOD, Edge screen lighting, etc) if I need to turn them off?! They seem useless.
I hope the battery usage issue is being handled so that we may enjoy the features of this OS.