Uneven Battery Drain, Even After Cell Swap

Discussion in 'Xiaomi Redmi Note 4G/LTE' started by tesla-poland, Mar 28, 2018.

  1. tesla-poland

    Aug 13, 2016
    2
    0
    11
    Male
    Hello,
    I own my device for few years now. Around MIUI 7 update a certain issue emerged: the battery percentage has become unreliable.
    The thing is, that when my phone is at 60% or less displayed energy and it turns off, when turned back on it's usually on 15% of power - the rest of which vanishes very, very quickly and the device goes black. In practice, this means that I can't reboot my device (on purpose, or worse – by accident) without a power supply.
    If I do reboot when around 50%, the phone starts and displays ~15%, and connect a charger immediately – after 2 minutes battery level goes back to 50%.
    Moreover, if I don't reboot and use it normally – drain pace is constant throughout.
    I thought this may be due to battery degradation, so I swapped it for a new one. To my surprise, the problem persisted. Still – a reboot makes it underestimate how much energy is left.
    Does anybody have this problem? Can anyone reveal the cause?

    BTW: I swapped the original 3200mAh battery for a 3900mAh one, and the MIUI Security still displays 3200. Is there a way to make it reset properly?