STEVAL-ISQ008V1: Battery Fuel Gauge via MCU

This user manual describes the functions of a single cell Li-Ion battery fuel gauge technology using an MCU within the STM32 (ARM Cortex™-M3 core) family. The fuel gauge demonstration board is used to show the capability of an STM32 microcontroller to be used for battery fuel capacity monitoring.

The fuel gauge implementation is based on the STM32 microcontroller; the MCU is used for monitoring the capacity of a single cell Li-Ion battery. An on-chip 12-bit ADC from the STM32 family is used for battery capacity calculation.

The fuel gauge technology is a smart system which monitors battery capacity, predicts remaining capacity, and displays its status. The basic ideology used for battery capacity measurements is Coulomb counting, in which the current flowing through the battery is continuously monitored and integrated to calculate the capacity.

Current measurement is done when the battery is both discharging and charging. Therefore both the IN and OUT current are taken into account to calculate the remaining capacity of the battery. Battery capacity is measured in mAh.