I. Introduction
The battery SOC can be estimated through two distinct approaches: The first method, termed Coulomb counting, assumes knowledge of the initial state of charge and perfect knowledge of battery capacity to compute the remaining state of charge after accounting for the amount of Coulombs transferred from/into the battery. This approach has the following sources of error:
Uncertainty in the knowledge of initial SOC;
Uncertainty in the knowledge of battery capacity;
Errors in measured Coulombs as a result of errors in the measured current and errors in time differences due to timing oscillator inaccuracies/drifts.