A
AC Question
Most power banks comes with li-ion or polymer cells with a rated voltage of 3.7V.
The standard input voltage of smart devices is 5V so power banks need an output of 5V to charge smart devices.
If I want to figure out how many times a 5000mAh rated power bank(lets assume that power bank really have that capacity) can charge my xiaomi mi4 (3080 mAh ) what calculation do I need to make?
For example do I use the following calculation or i need to do something differently?
5000mAh*3.7V=18.5Wh
18.5Wh/5V=3.7Ah=3700mAh
3700*0.9=3330mAh
3330*0.9=2997mAh
so 2997mAh/3080mAh=0.97 time
in first time 0.9 means 10% loss from boost converter in the power bank and second 0.9 means 10% loss from smartphone circuitry.
The standard input voltage of smart devices is 5V so power banks need an output of 5V to charge smart devices.
If I want to figure out how many times a 5000mAh rated power bank(lets assume that power bank really have that capacity) can charge my xiaomi mi4 (3080 mAh ) what calculation do I need to make?
For example do I use the following calculation or i need to do something differently?
5000mAh*3.7V=18.5Wh
18.5Wh/5V=3.7Ah=3700mAh
3700*0.9=3330mAh
3330*0.9=2997mAh
so 2997mAh/3080mAh=0.97 time
in first time 0.9 means 10% loss from boost converter in the power bank and second 0.9 means 10% loss from smartphone circuitry.