ELI5, how do devices that use batteries, like phones, know the percentage of the charge remaining?

Question

ELI5, how do devices that use batteries, like phones, know the percentage of the charge remaining?

In: Technology

Answer 1

The battery pack or the android main board has a “battery fuel gauge” IC which keeps track of the charge state of battery. You cannot achieve that level of precision by only measuring voltage. Basically, it uses fuel gauge. There are several algorithms for Li-Ion chemistry, and the gauge might use one or more of them.