How to calibrate the battery on my Nokia Lumia 635??

[Windows Central Question]

This is my problem ...

Many days ago, i bought this phone on at&t (Go phone device) and i found a little prbblem whit my battery. The battery is uncalibrated.

And this my horrible history: I charge my phone every day from 15-20% to 100 % and many days ago I saw I had an unusual problem ... was that when I was in 100 derrepente down to 97 % and stayed at there for more than 20 after 97 % down to 93 % faster and over again lasted about 20 minutes time again, that always happens in all percentages ( 36 %, 25 % , 85 %, 65 %) and when in 2% not willing to 1% and again shuts.
please help me!

 

[Skamath]

If you mean that the % stayed at 97 while you were using the phone for 20% it is common for apps to update at a set interval. eg If you have the insider app the % on the live tile will stay till it is time to cycle and check for the battery level but if you tap on the tile and get into the app itself it will show you the real time % and when you exit back to the live tile again it will show the updated % as you initiated the app.
I dont think batteries these days have such issues.