There are currently apps in the app-store (so it does not require jailbreak) that tell you :
Exact percentage value of battery level you have on your iPhone. I have tried Apple's official Code Sample, although it tells you when your iPhone is charging and discharging but it gives me values in 5% steps. How do these apps get exact values of battery percentage?
Applications like Battery Health show
- Current Maximum Capacity vs Manufacturer's Capacity
- Current Discharge Rate
- Lifetime Battery Cycle Count
The same application also gives information about the Charging Rate in Watts when the phone is charging (check images) and current Charger's Power Rating.
How do these applications get so much detail about battery health when [UIDevice] provides so little information about it and almost no information on battery health and performance.