The bq20851-V1P2 SBS-compliant gas gauge IC for battery pack installation maintains an accurate record of available charge in Li-ion or Li-polymer batteries. The bq20851-V1P2 monitors capacity and other critical parameters of the battery pack and reports the information to the system host controller over a serial communication bus. It is designed to work with the bq29311 analog front-end (AFE) protection IC to maximize functionality and safety and minimize component count and cost in smart battery circuits. Using information from the bq20851-V1P2, the host controller can manage remaining battery power to extend the system run time as much as possible.