My phone charges slowly and consume battery fast

@majahadlamini for now, this could be a battery issue. Do replace it and then re-evaluate. Make sure that your settings are in a battery saver mode.

Something like this

1. Settings>Connection>more connections settings> disable nearby device settings.
2. Settings>>Location>improve accuracy >disable

• A. Wifi scanning
  B. Bluetooth scanning .

3. Device care>battery >power mode>select "optimised" and "adaptive power saving".
And then click on "app power management >
And enable these 2 options.

• A. Adaptive battery
  B. Put Unused Apps to Sleep.
  

4. Long press on each app specially 3rd party app(LIKE FACEBOOK, YOUTUBE) and rarely used apps and also ON "GOOGLE APP" as well, then click on>app info> go to these 3 options below on by one

• A. Mobile data> allow background data usage>off
  B. Battery >allow background activity >off
  C. Notification >disable unnecessary notifications like promotional and unnecessary reminder notifications.
  

5. Go to settings> privacy > permission manager > location> and check which app have accessing your location all the time and if you not using that apps much, then deny access or set as " allowed only while in use"
As unnecessary location access by 3rd party app causing battery drain.
6.  Go to settings > Google > on device sharing> check which 3rd party apps present there for e.g. if you use paytm , paytm will  shared data to show recommendation and suggestion which also cause battery drain
7.  Go to settings > account and backup> account > check which app syncing automatically there, and if any app which not necessary to auto sync then click on it and "disable sync"
8. Go to settings >apps>search "weather" >click on settings icon right side > change "auto refresh" settings as per your requirements and disable some unnecessary reminder. ( due to auto refresh it continuously consuming battery)
9. If you use Facebook frequently then disable "auto play video"
And if you are mostly uses mobile, on wifi connection then also disable "auto play videos" in YouTube.
10. Settings>Google >click on 3dot at right top corner>usage and diagnostics >off this option. from here

To change the battery and since iFixit does not yet have a guide for this, use something like this video Replacement batteries are readily available at many online places.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!