How to convert milliamp-hours (mAh) to watt-hours (Wh).
The energy E(Wh) in watt-hours is equal to the electric charge Q(mAh) in milliamp-hours times the voltage V(V) in volts (V) divided by 1000:
E(Wh) = Q(mAh) × V(V) / 1000
So watt-hours is equal to milliamp-hours times volts divided by 1000:
watt-hours = milliamp-hours × volts / 1000
Wh = mAh × V / 1000
Find the energy in watt-hours when the electric charge is 300 milliamp-hours and the voltage is 5 volts.
The energy E is equal to 300 milliamp-hours times 5 volts divided by 1000:
E = 300mAh × 5V / 1000 = 1.5Wh