I have a SD845 S9+ (delivered today).. Battery seems to be very good. Don't have enough info on standby drain but don't see heavy drain. I did the following.
1) Setup from scratch.
2) After updating to the latest firmware I reset the phone
3) Disabled a few apps & Bixby, using BX Actions to remap bixby button
4) No AOD, no iris or facial scanning just the fingerprint sensor
5) Charged the phone after turning it on, setup the phone while plugged in.
I'm at 1hr 48 min usage 84% battery remaining. I used the phone for browsing and some apps here n there, set them up, not heavy usage. I know I'm happy that I am on the good side of battery (I OCD on battery usage
) and seeing stats like this would make someone who has bad battery go crazy, I'm posting this so that one could try these and see if the battery gets better.