S21 battery is draining so fast

[-eMeM-]

Mobile data: off, Wifi: off, BT: off,  NFC: off, 5G: off during sleep at night situation:

*2 nights ago, the battery was 33% I wake up and was 0%, the phone was off

**last night battery was 42% I wake up and was less than 10% 

I never have any problem with Samsung phones, and this is really bad. Now I'm scared I will oversleep and late on a job if my phone will be dead when the alarm should be ringing.  And only one solution is to leave all night phone on charger!!!!  

[V1per87]

I had the same issues with my note 20 ultra 5g, was very annoying nothing can be done until they release a major update for the battery life.

[Magpiemale]

maybe your security virus is scanning i know i set mine to scan while i am sleeping and i set an auto restart a few hours after ... i always leave mine on slow charge.. samsung say the phone will charge quickly but if you use this method as a go to it could/will make the battery less efficient.. maybe someone else can chime in but thats what the small print says on their phones.. handy to have but on an 8 hour sleep fast charge isn't necessary
check your battety on the app to see where the drain is ?

[WHATaTOPPER]

you should look into your battery settings it will give you some indication to what is draining your battery

[WHATaTOPPER]

when I said battery setting sorry I meant device care

[Pugs1957]

Can you post a screenshot of your battery stats so we can see what is draining the phone?

[-eMeM-]

@V1per87 I hope so they will do something as soon as possible  

@Magpiemale, where I can check settings for this security virus when should scanning or not 😕 and I know the overnight charging is killing the battery and I never before left all night phone on the charger doesn't matter slow or fast. 

@WHATaTOPPER  and @Pugs1957  give me a sec to check and I will post battery status, just I'm not sure how I can check what is going on during the night 😕 I never checked my battery status because I was always happy with battery and never have any issue, till now 😞 

[-eMeM-]

So, I use this phone like every one before it. I understand if I'm on the phone all day of course battery will be drained, but during the night what can cause that, I really don't know what I need to look at and change and that will have an influence on battery. 

And thank you guys for help and advice! 

[Hel393]

using the s21 I put all the apps I hardly use into a deep sleep and those I use daily into sleep mode hopefully this might help you

[Joeeye]

Truth be told I've found slow charging far less efficient than Samsungs 25W charge on my Samsung phones (Note 10+ 5G, S20 Ultra and S21 Ultra). If I charge my phones with the 45W charger to 100%, they don't have as long run time as if I charge with the 25W. If I slow charge its even worse.