Samsung S9 overheating and draining battery

[Ezechiel20]

My Samsung S9 is overheating and draining the battery fastly. Even when I am not using the phone and all connexion disconnected. 

[pmartel]

Have you recently changed your SIM card? I already got this issue.
If not, I would completely reset the phone.

[Ezechiel20]

I haven't changed the SIM card since I have it. Do mean you remove the SIM and reinsert it?

[pmartel]

No, it not what I mean. I got this problem when I changed my SIM because I changed of service provider.
You could try to make a factory reset. But first, make a backup of everything that is on your phone because it will be wiped out.

[RedDogRabbit]

I'm not sure why changing Carriers / SIM would have any effect on the way a device is running, with the only explanation I can think of, is if you're using Cellular Data, but the signal is very weak.. That MIGHT cause the device to run a BIT warmer.. but not much. 

[RedDogRabbit]

If you're talking about the Samsung Galaxy S9 (SM-G960W), it was released in 2018. It is 6 years old, and if it's still got the original battery, then I would expect it to behave like that.

Replace the battery, or replace the device with a new one. 

[Helenna]

Hi, we recommend you to visit the nearest Samsung authorized service center and get the device examined by the service technician.

They will check the device and assist you accordingly. Here is the link to know the nearest Samsung authorized service center.

https://www.samsung.com/ca/support/service-center/

[JSL12]

I have the EXACT same issue with battery drain that started the day you posted this.  My Samsung Galaxy S9 won't stay running for more than 2 hours.  Apps vary causing drain but it is usually One UI Home and Google Play Services but it does vary.  May carrier is Verizon and my other cell I use is a Pixel and also on Verizon with no issues.

[RedDogRabbit]

If you still have the original battery, it's SIX YEARS OLD! Of course it's not holding a charge! 

This is Samsung Members Canada BTW. 

[JSL12]

Pretty sure it isn't the battery as all diagnostics pass.  I believe it is an app issue but can't track it down.  Find it VERY interesting the OP had the same problem starting the same day I did.