The bq2011 Gas Gauge IC is intended for battery-pack installation to maintain an accurate record of available battery charge. The IC monitors a voltage drop across a sense resistor connected in series between the negative battery terminal and ground to determine charge and discharge activity of the battery. The bq2011 is designed for systems such as power tools with very high discharge rates.

Battery self-discharge is estimated based on an internal timer and temperature sensor. Compensations for battery temperature and rate of charge or discharge are applied to the charge, discharge, and selfdischarge calculations to provide available charge information across a wide range of operating conditions. Initial battery capacity is set using the PFC and MODE pins.