Excessive battery drain when S8 is idle

[Ground Sloth]

I did a little experiment yesterday. I charged both my S6 and S8 to 100%, and then I didn't use them for the rest of the day. Fifteen hours later, the S6 had 94% battery life remaining while the S8 had only 75% battery life remaining. Both phones are on the same network. The S8 was upgraded to Oreo recently, but this was an issue even when the S8 was running Nougat.

The main culprit by far for the battery drain on the S8 was Android System, which doesn't really tell me much. On the S6, Android System only consumed 1%.

Could this possibly be an issue with Bixby running in the background even though I never set it up? What else could it be?

 

[El Presidente]

Do you have WiFi calling enabled? I've found that has caused excessive battery drain for me on occasion.

 

[Ground Sloth]

Do you have WiFi calling enabled? I've found that has caused excessive battery drain for me on occasion.

Wi-Fi calling is disabled on both phones, as is "Enhanced LTE services", which is required for things like video calling and HD voice.

 

[El Presidente]

Could you try turning it off for a night, see if that makes a difference? It has no impact whatsoever on my wifes S7 (same network as me), but for some reason, it doesn't play nicely with my S8+.

 

[Ground Sloth]

Could you try turning it off for a night, see if that makes a difference? It has no impact whatsoever on my wifes S7 (same network as me), but for some reason, it doesn't play nicely with my S8+.

I think you misread my previous post. Wi-Fi calling is already turned off. I only turn it on if I need it.

 

[El Presidente]

I think you misread my previous post. Wi-Fi calling is already turned off. I only turn it on if I need it.

You're right, I apologise.

Unfortunately, Android System covers a whole host of things including Bixby so it could be any number of things causing the issue.

GSAM Battery might give you a better overview on what the issue is, but you may need something like this to find out what's draining the battery/keeping it awake.

 

[Ground Sloth]

Booting into recovery mode and then wiping the cache partition didn't help, and neither did a factory reset. Android System continues to consume an excessive amount of battery when the phone is idle.

Battery life with Nougat wasn't great, but it's definitely worse now with Oreo.

 

[Deleted User]

I'm having the same issue since the update to Oreo. I started a separate thread and clearing the cache partition was the only advice. Someone else suggested an app might not be playing well with Oreo, but I don't see anything abnormal in the battery activity. My phone gets about 40 to 60 percent worse battery life than before the upgrade. It's a bummer!

 

[Ground Sloth]

Some people who had battery issues after upgrading to Oreo are saying that the battery life of their S8s have improved in recent days. No one really knows why, but it might having something to do with Samsung's Device Maintenance app being recently updated. I'm waiting for confirmation before I update.