The bq27545-G1 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 for accurate battery fuel gauging. The bq27545-G1 resides within the battery pack or on the system’s main-board with an embedded battery (non removable). The bq27545-G1 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), and temperature (°C). It also provides detections for internal short or tab disconnection events. The bq27545-G1 also features integrated support for secure battery pack authentication, using the SHA-1/HMAC authentication algorithm. The device comes in a 15-ball Nano-Free™ DSBGA package (2.61 mm × 1.96 mm) that is ideal for space constrained applications.