The bqJUNIOR series are highly accurate standalone single-cell Li-Ion and Li-Pol battery capacity monitoring and reporting devices targeted at space limited portable applications. The device 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, selfdischarge, and rate of discharge are applied to the charge counter to provide available time-to-empty and time-to-full information across a wide range of operating conditions. Battery capacity is automatically recalibrated, or learned, in the course of a discharge cycle from full to empty. Internal registers include available time-to-empty, cell temperature and voltage, average current, and other status and control registers. The bqJUNIOR 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