iPhone reading different battery percentages

[Alexrat1996]

I'm having a big issue with my iPhone 6s Plus I been charging it with the Alpatronix bx150 battery case once to reach 95% charging it started to beep my phone.
That causes my phone to read different battery percentages lets says it at 95% when I reboot with the lighting cord connected it reads 90% that's not normal I did a restore already same issue.
what can I do at my end?

 

[crispApple]

Maybe this helps?

https://forums.macrumors.com/thread...ing-battery-percentage.1950894/#post-22473129

 

[Alexrat1996]

Maybe this helps?

https://forums.macrumors.com/thread...ing-battery-percentage.1950894/#post-22473129

I did not change my time at all and I did a restore via iTunes same issue

 

[zoneee]

On my iphone 5s the battery is not read correctly, sometimes it says 11%, then it goes down to 1, if i plug it it goes back to 11%.
some other times it will tell me i have 20% and shut down after a few minutes.

this happened only lately, i wonder if this is a software issue.

 

[Newtons Apple]

I'm having a big issue with my iPhone 6s Plus I been charging it with the Alpatronix bx150 battery case once to reach 95% charging it started to beep my phone.
That causes my phone to read different battery percentages lets says it at 95% when I reboot with the lighting cord connected it reads 90% that's not normal I did a restore already same issue.
what can I do at my end?

I would just use the supplied charger to charge the phone.

 

[Alexrat1996]

Apple Store told me to get a mophie case