Resolved Why doesn't iOS count the battery percentage right?

[axari]

Sorry for my poor English.

I have an iPhone 6s, which is on iOS 13.3, I replace the battery before 6 months and its health at 97% capacity. I mostly charge my phone to 85% or 90%, after recharge my phone I reboot it and battery is standing at 95% or 97% if I recharge it to 90%, and if I charge it to 85% then its on at 92% or something after reboot...

If I use cellular data, battery drains like hell, like I watch YouTube from 4G it drains 35% to 40% in half an hour, after watching a half hour video I reboot it then iOS give to me 20% more battery life. And if i don't reboot my phone, the % is stuck...

 

[BugeyeSTI]

Sounds like a battery issue. Maybe the battery you purchased is lacking in quality.. You may consider replacing it again as the fluctuations you've been experiencing isn't normal.

 

[axari]

Sounds like a battery issue. Maybe the battery you purchased is lacking in quality.. You may consider replacing it again as the fluctuations you've been experiencing isn't normal.

Well, I don't think so, my sister's new iPhone 8 have the same issue.

 

[BugeyeSTI]

Did you have your battery replaced by apple or a 3rd party? What you are describing isn't normal battery behavior. It has nothing to do about iOS reporting the percentage right. If you did have it replaced by Apple take it back to be diagnosed. You and your sister can try to restore the phone using iTunes to see if it's a software issue. Apple will have you do that first anyway so you'd be saving time

 

[digitalexplr]

Why do you reboot your phone after recharging it?

 

[axari]

Did you have your battery replaced by apple or a 3rd party? What you are describing isn't normal battery behavior. It has nothing to do about iOS reporting the percentage right. If you did have it replaced by Apple take it back to be diagnosed. You and your sister can try to restore the phone using iTunes to see if it's a software issue. Apple will have you do that first anyway so you'd be saving time

I replaced my battery from apple authorized dealer, and i was restore my iphone from DFU mode and sister’s iphone too, but issue isn’t solve.
[automerge]1576783415[/automerge]

Why do you reboot your phone after recharging it?

for checking my battery behavior.

 

[fireboy60013]

That’s a defective battery sounds like

 

[Bandaman]

I’ve had that glitch happen as well where after rebooting the battery percentage is completely different, but I haven’t seen that in quite a while. Could be a faulty battery.

 

[axari]

Thank you everyone for you replay, i search my issue on google and found one very helpful article about battery calibration, and now my battery works great...

link: https://www.appledystopia.com/how-to/calibrate-iphone-battery/