Watch out! Your FP-Sensor doesn't like it.
The battery of the iPhone 5S has an electric charge of 1510 mAh (1.51 Coulomb) and works on 3.8 volts. So the electrical energy stored in the battery is
1.51 A x 3,600 sec x 3.8 V = 20,656.8 J
that means approximately 21 kJ (kilo Joule).
One Joule in everyday life approximately represents the energy required to lift a small apple (with a mass of 100g) vertically through one meter or the kinetic energy released when that same apple falls one meter to the ground.
So your fully charged iPhone approximately offers the energy released when 21,000 apples fall one meter to the ground.
If you don't like s falling to the ground take chocolate bars.
Hey, for your kids …
The 7 has a 1,960 mAh battery.
How many apples?