Help my battery is on 26% after just 3 hours screen on time all day

[ForeheadBoss]

I recently purchased the Galaxy S20 refurbished in 'Pristine' condition from music magpie, everything is working great apart from the battery life. Over the whole day I have had roughly 3 hours of screen time and there is only 25% battery left , bearing in mind the phone is set to 60Hz, on FHD+ and a relatively low brightness .Samsung diagnostics says the battery is in good condition. In addition, lots of battery usage is going unacounted for in battery usage (Images attached ). Accu Battery says battery discharging is 20% an hour.  I have a 14 (bearing in mind I've had it a week already) day money back guarantee so should I return it and get another one in the hope that the battery is better? Or is this a more widespread software related issue? 

[leicesterMan]

That's mine, I charge it , once a day at night

[leicesterMan]

Samsung s20 ultra 5g, on wqhd+screen

[AshtabS9Ultra]

The s20 was never great on battery life, for a used phone that isn't too bad on the s20 you got to bear in mind the battery could have been heavy used, they only stay fresh for 18 months then the life slowly but surely get worse. My brand new s20 back in the day wouldn't even get the battery that you are stating .

[BandOfBrothers]

Hey @ForeheadBoss 

For some reason I'm not seeing your attached images 😒

Can you run a full day and then in your device care under battery screen shot that using the scroll capture to include your apps that are showing using battery and post the results back in your thread.

When you recieved the phone may I ask did you factory reset it which is is good idea to clear out any redundant data and files etc , even though I'd expect the seller to do this too, but it's a good starting point.

The battery effectiveness will reduce with time due to the amount of time's the phone is charged and discharged.

Also did you set the phone up as New when setting it up or use a Samsung Cloud Back up or via Smartswitch ?

I've known some people experiencing issues when setting up from a back up as this can transfer redundant files or problem apps into the phone that can cause issues in rare instances.

Here are some generic troubleshooting tips you could consider to try before sending the phone back within the Cooling Off Period you've mentioned.

• Clear your phone's System Cache Files by turning your phone Off and then from a set series of button presses go into the phone's System Files and clear the cache. No information is lost this way. You may need to insert your headphones or hook upto a computer with your data cable to get to this menu on the phone. https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ 
• In Settings, Apps, Choose the App, Storage clear it's Cache.
• Put the phone in Safe Mode which disables your downloaded app's but let's your stock app's keep working. If the issues stop then this highlights a downloaded app as the possible issue. Come out of Safe Mode and start deleting your most recent downloaded app's one at a time until it stops. https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ 
• Factory Reset after backing up but when resetting the phone back up choose to set it up as a new device and then see what happens.
• Consider moving resource hungry apps to Sleep or Deep Sleep mode.
• A Samsung Experience Store or Samsung Service Centre can check the phone.

I wish you all the best with this. 

[ForeheadBoss]

Not quite a full day . Lots of battery use is unacounted for, is that normal ?

[BandOfBrothers]

Thank you @ForeheadBoss 

I think from what I see your signal connection isn't the strongest which can deplete the battery as the phone works harder to maintain connection.

Also I see you use Google Chrome is a known battery resource.

My preference is Samsung Internet which I've found to better optimised. That's my personal thoughts on this.

Battery monitors like the one your using are a good tool but beware as this is constantly monitoring your phone it itself uses quite a bit of battery.

Take a look at each % readout next to each app.

[ForeheadBoss]

Ok thanks just wondering if the percentages should add up to the amount of battery used or is it normal for some battery usage not to be counted?

[BandOfBrothers]

The % your seeing is what the apps and some services are using.

There are background activities etc that uses resources that you won't see usage for.