The Texas Instruments BQ27520-G4 system-side Li-ion battery fuel gauge is a microcontroller peripheral that provides fuel gauging for single-cell Li-ion battery packs. The device requires little system microcontroller firmware development. The fuel gauge resides on the main board of the system and manages an embedded battery (non-removable) or a removable battery pack. The fuel gauge uses the patented Impedance Track™ algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), run-time to empty (minimum), battery voltage (mV), temperature (°C), and state of health (%). Battery fuel gauging requires only PACK+ (P+), PACK– (P–), and optional Thermistor (T) connections to a removable battery pack or embedded battery circuit. The device uses a 15-ball NanoFree™ (DSBGA) package in the nominal dimensions of 2610 × 1956 µm with 0.5-mm lead pitch. It is ideal for space-constrained applications.