What is the fuel-gauge IC

We may all be familiar with the battery charge indicator on our device. The little blinking light or bar meter indicator that let’s us know when we need to recharge our battery. But did you know that the calculation of the remaining battery capacity (power) is performed within the battery and that calculation is transmitted to the device from within the battery to the device through the connector. The calculation of remaining battery capacity is performed by the fuel-gauge integrated circuit.

More Info:
The fuel-gauge stores cell characteristics and application parameters used in the calculations within the on-chip EEPROM. The available capacity registers report a conservative estimate of the amount of charge that can be removed given the current temperature, discharge rate, stored charge and application parameters. Capacity estimation is then reported in mAh remaining and percentage of full charge.