I've had my iPhone 4S for 3 years and it now runs iOS 7.1
Battery was performing badly so I decided to replace it.
- I bought a spare battery online by duracell direct (average quality good!)
- Replaced battery by myself (easy!)
- First 2 running cycles are OK
Now, the iPhone shuts off at 30 % (sometimes at 20%). I can even reboot it and use sometines below 10 %, but experience is awful. Tried to do 2-3 calibrations but no luck.
I checked real battery status with iBackupbot, seems ok.
Here follows a log frm iBackupBot:
Info da iBackupBot il 30/12/2014 Battery CycleCount: 5 DesignCapacity: 1430 FullChargeCapacity: 1393 Status: Success BatteryCurrentCapacity: 67 BatteryIsCharging: true ExternalChargeCapable: true ExternalConnected: true FullyCharged: false GasGaugeCapability: true