Help Battery percentage and battery stats don't match

[frusciante54]

I just got this phone, it's been like only 15 days. General Mobile GM5 Plus (Nougat)

I realized that sometimes battery percentage goes down fast, sometimes really slow (like 1 hour passes and the percentage stays exactly the same)

And I have a question, why don't these stats don't match each other?

When you add all those stats, 3 + 2 + 2 + 1 = 8. And it was at 100% when I unplugged it. So it should have been 92, right? Why is it 82 then?
I'm thinking this might be a callibration issue. But I thought those issues started after a little while. And it hasn't even been a month.
And my phone doesn't have a removable battery.
Is there anything that I can do? Should I try callibrating, or are those percentages something else?
Thank you in advance.

 

[chanchan05]

Those stats to not add up to how much your battery lost. Those stats say how much of the lost battery each app used up. What ever Ekran is, it used up 3% of the missing 17%. So it actually used up 0.51% of your battery.

 

[lvt]

The built-in battery stats is usually useless, you need a third-party apps that can provide more details.

The latest version of Gsam offers some new capabilities that are previously reserved for rooted devices.

While you don't need to root your phone, you still have to use ADB commands to give Gsam some permissions.