BQ26500

(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to Absolute Maximum Rated conditions for extended periods may affect device reliability

The bq26500, the first in the bqJUNIOR family of advanced  gas gauge device for handhald applications, is a highly accurate standalone single-cell Li-Ion and Li-Pol battery capacity monitoring and reporting device targeted at space limited portable applications. The BQ26500 monitors a voltage drop across a small current sense resistor connected in series with the battery to determine charge and discharge activity of the battery. Compensations for battery temperature, self-discharge, and rate of discharge are applied o the charge counter to provide available capacity across a wide range of operating conditions. Battery capacity of BQ26500 is automatically recalibrated, or learned, in the course of a discharge cycle from full to empty. Internal registers include available capacity, cell temperature and voltage,  state-of-charge, and status and control registers.

The bq26500 can operate directly from single-cell Li-Ion and Li-Pol batteries and communicates to the system over a simple one-wire bi-directional serial interface. The 5-kbits/s HDQ bus interface reduces communication overhead in the external microcontroller.