Your cell phone battery states that it has a capacity of 1200mAh. That means it can provide constant current supply of 1200mA for 1 hour (or 3600 sec), if fully charged.
a) What is the total amount of charge in Coulombus unleashed by the battery if it is fully discharged?
b) Your battery provides a constant voltage of 3.7V. What is the energy in Joules stored in the battery?