The device uses an integrating delta-sigma analog-to-digital converter (ADC) for current measurement. The ADC measures charge/discharge flow of the battery by measuring the voltage across a very small external sense resistor. The integrating ADC measures a bipolar signal from a range of –100 mV to 100 mV, with a positive value when V_(SRP) – V_(SRN), indicating charge current and a negative value indicating discharge current. The integration method uses a continuous timer and internal counter, which has a rate of 0.65 nVh.