Battery drain after the last security update (September update) on S21

[Michael2103]

Is anyone experiencing the same issue as the title suggested? It's been more than three weeks now and my battery is getting worse after the last security patch/update pushed in September. 

I am fed with Samsung phones.

The battery used to last about 18hours on battery saving mode and 12 on optimised. Now I can't make it through 8hours both on optimised and battery saving mode.

[xSteveuk]

Hi,
Since your last system update
Have you tried deleting
The cache
This can helpful deleting temp
Files that are no longer needed

https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/

[Michael2103]

Thank you for that. I sure have. Cleared the cache and had to delete most of my apps just to make sure.

[xSteveuk]

On settings Display
Have you got Adaptive brightness turned on as that can drain battery try Turning it off

[Michael2103]

Okay, thank you for that. I have now

[Niknak31]

I'm having the same issues and have done all of the above. Can't even get through a day at work without the battery going completely, really weird as I don't use it that much.

[Michael2103]

In idle mode the max I can squeeze out of it is 6 hours and that happens after I've turned off location and auto sync. It's getting ridiculous now with these so-called security updates

[Niknak31]

I got rid of my s20 FE for the s21 and the battery life on that was amazing, wish I hadn't swapped now.

[Michael2103]

That phone for me was a beast. I am hoping the s22 will be a much better phone, else I am switching to an iPhone 13 Pro Max

[debs13]

Hi.
I did a security update 21st October on my S21 plus and my battery life is depleting alot quicker than before update.
I have again cleared cache and all the other options suggested and nothing solves the issue.
It's so frustrating.