L1N3B3CK said:

I advise you to install "gsam battery labs", and in the settings of this app enable "show more statistics" (this require a PC with adb minimal package installed, USB debugging on on the phone and a USB cable).

It can tell you which app uses what % of the battery and for what reasons (downloading, GPS usage, etc), even for system apps, and most importantly even when the screen is off or the phone is dozing.

This as been my go to app since using android phones, in combination with accubattery (which doesn't show system packages or anything usefull while screen off).

As for my ZF4, when the screens are off it is using 0.5% per hour during night time (deep sleep) and 0.9% during the day (light sleep)

Click to expand...

I did that last night and I found out something strange.

It turns out that the Android System app keeps running in the background due to a wakelock called ImsService which after a little bit of digging appears to be related to VOLTE or network connection as far as I understand. So I switched to 4G and guess what? The battery drain is just gone (keep in mind that I'm still connected to WIFI).

So I went to system apps and cleared the cache for this app, and I'm not sure if it's the real culprit or something else I did.
As a workaround, I created a Bixby routine to switch to 4G whenever I connect to WIFI, and at this point, I think there is something with my home WIFI because the drain is the most noticeable when I'm connected to home WIFI.

Any thoughts on this?

zaidshb said:

I did that last night and I found out something strange.

It turns out that the Android System app keeps running in the background due to a wakelock called ImsService which after a little bit of digging appears to be related to VOLTE or network connection as far as I understand. So I switched to 4G and guess what? The battery drain is just gone (keep in mind that I'm still connected to WIFI).

So I went to system apps and cleared the cache for this app, and I'm not sure if it's the real culprit or something else I did.
As a workaround, I created a Bixby routine to switch to 4G whenever I connect to WIFI, and at this point, I think there is something with my home WIFI because the drain is the most noticeable when I'm connected to home WIFI.

Any thoughts on this?

Click to expand...

Do you have poor cellular connectivity from your home ?

I use to turn off 5g whenever I'm on wifi, it doesn't really matter for me singe the antennas are close from my house.

Anyway keep digging into gsam, you'll probably find more info. Maybe in the "pic button" on the bottom left, then in the third tab on top which should be about cellular reception

L1N3B3CK said:

Do you have poor cellular connectivity from your home ?

I use to turn off 5g whenever I'm on wifi, it doesn't really matter for me singe the antennas are close from my house.

Anyway keep digging into gsam, you'll probably find more info. Maybe in the "pic button" on the bottom left, then in the third tab on top which should be about cellular reception

The signal is excellent and never had an issue with my S21U even though both WIFI and data were always on. I'll keep digging.