Why is my battery meter unreliable below 60%
Sometimes my battery meter stays long at a particular percentage, and then quickly drains 2% or 3%. So I'll be on 50% for about five minutes, and then quickly drain to 49%, 48% in a minute, and then stay at 47% for a longer time. The battery seems fine but the meter is unreliable.
2 
What did you try to do already? Reset? Anything changed on the phone?
Oros さんによる
I've done a Factory reset, but it's still the same
enasowah さんによる
Factory reset as in restore on iTunes?
If yes, check battery health using either app battery life on app store, 3Utools (Windows desktop application) or Coconutbattery (Mac OS X).
If you see near or under 65% consider replacing the battery.
Battery % fluctuating going like that is usually a bad battery too.
Ben さんによる
No I didn't restore form iTunes
The battery capacity is 93%. 7% wear level.
enasowah さんによる