Galaxy S9 Plus battery draining at night when not in use

[vindeeslal]

For the past 2 nights I've noticed that the battery on my s9+ has drained completely overnight.

The battery is well over 80% when I check it before going to bed - no apps are left open and the battery usage shows that Google Play Services is using about 4-8% in the background, as well as a few others in the background but nothing significant (0.1 - 2%).

The battery usage chart shows the battery depleting by at least 50% each hour from just before 01:00 AM. I hadn't used my phone since 11:00 PM on both nights.

Can't understand what's happening. No new apps have been downloaded to my knowledge. I have nothing actively showing on the screen (e.g. clock, active wallpaper). The phone is not in use.

As mentioned, it's only started on 13 May, before that there's been no issue - indeed the battery usage over night has been very minimal as expected. During the day I charge my phone to 100% and it will drop to no less than 75% with light usage.

Any ideas?

Thanks.

[Rob99]

Run a virus scan

[vindeeslal]

Hi Rob

I did, no threats were found. Thanks.

[APARMAR]

I wouldn't be surprised if I were you due to the fact that the S9 Plus is almost 3.5 years old. And of course the battery will be significantly worse than when it was released in March 2018. If you are still looking for better battery life, try getting a new battery installed. But I wouldn't recommend this unless you get Samsung to install a new battery as the phone wouldn't be waterproof anymore if someone other than Samsung did the replacement. Hope this clears things up for you!

[antikythera]

Check and make sure you haven't got boinc installed for world community grid or similar. That shouldn't run without a mains adaptor attached normally though. @Rob99 is also right to suspect an app that delivered a payload. Your phone could well be mining cryptocurrency for an unscrupulous app developer or supplier if you have sideloaded anything.

[vindeeslal]

Thanks for your reply. I don't think it's the battery as I'm getting decent life during the day when not being used too heavily. As mentioned, the drain was happening overnight whe not in use and starting at the same time. I could see in the usage stats that Google Play Services was using upto 40%. I don't have any apps set to auto update, and have now gone through disabling alot of their other auto features too. As a test I turned of wifi one night and noticed just a 3% drain overnight. Left wifi on last night and battery drain was just around 4%, so seems good for now. Will keep an eye on it next few nights.

[APARMAR]

Oh ok, good to hear. Let me know if anything changes