The bq26220 is an advanced battery monitoring device designed to accurately measure the charge and discharge currents in rechargeable battery packs. Intended for pack integration, the bq26220 contains all the necessary functions to form the basis of a comprehensive battery capacity management system in portable applications such as cellular phones, PDA’s, or other portable products. The bq26220 works with the host controller in the portable system to implement the battery management system. The host controller is responsible for interpreting the bq26220 data and communicating meaningful battery data to the end-user or power management system. This device provides 64 bytes of general-purpose flash memory, 8 bytes of ID ROM and 32 bytes of flash-backed RAM for data storage. The nonvolatile memory can maintain formatted battery monitor information, identification codes, warranty information, or other critical battery parameters during periods when the battery is temporarily shorted or deeply discharged.