Help Awful battery life on S6 Edge

[Erkan12345]

So I've had my S6 Edge for about 18 months now, and whilst the battery life hasn't ever been what most people would call good, it's become completely unbearable on my device now. On a regular weekdays when I'm away from 8 AM to around 3 PM it works since I don't use the phone more than about 15 minutes on both commutes combined, but even then the phone goes from somewhere around 80% to about 30%. When I for example go out for a whole day, I always end up coming home with a dead phone, even tho I almost never use the phone for more than 1 to 2 hrs actively.
A couple days ago I decided to look a little deeper into my battery problem, and found out that in standby my phone uses between 5 and 6 per cent of battery per hour (WiFi/Mobile Data on, I always turn the one that I'm not using off, Bluetooth on since I own a gear, Location on high accuracy). Even in safe mode the phone still used about 3.5% of battery per hour in standby.
With a little mix of gaming, YT, IG, Snapchat, browsing the web etc. I can sometimes get around 2 hrs maybe 3 hrs SOT (brightness on 50%), but that will only work if I'm within 5 feet of a charging cable since it uses so much in standby.


Does anybody know any apps that monitor which apps use power when the screen is off? None of those I've tried (Accubattery, the built in one, Gram Battery monitor) have been able to do it or have any general tips that could save me battery?
Should I change the battery? According to Accubattery it has lost about 25% of it's capacity (around 2000 mAh instead of the original 2600 mAh)
Thank you for your help.

 

[svim]

Looking over your thorough observations, it does appear to be a matter where the battery could be failing. Did you buy this phone new or was it pre-owned? If new, there's a good chance the phone was just sitting on a shelf so it's a matter where the battery wasn't charged for almost a couple of years. Smartphone batteries need to be charged up at least partially every few months or so, or they age prematurely. If pre-owned, there's no way to determine if the previous owner charged the battery regularly or abused it by running it completely down on a frequent basis (another way to shorten a battery's overall life). But this is just supposition (as I'm admittedly becoming more and more biased against phones that don't have user-replaceable batteries), it could very well be a matter of just some background process heavily tapping the battery.

If you do opt to change the battery yourself, just be prepared it's not going to be simple project. You do need to have all the proper tools or you can seriously damage your phone:
https://www.ifixit.com/Guide/Samsung+Galaxy+S6+Battery+Replacement/44648