iPhone 6 and iOIS 10 - erroneous battery level indication?
Had the same issues with over heating, accelerated battery usage, etc and applied the recommended fixes to good effect. However, my battery will indicate some percentage remaining, then suddenly show 20% or less remaining. Plugging in the charger causes the percentage remaining to immediately change back to the previous (normal) amount. If I then immediately unplug the charger it stays at the previous (normal) percent remaining. What's causing that?