The Texas Instruments bq27500/01 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 bq27500/01 resides on the system main board, and manages an embedded battery (non-removable) or a removable battery pack.

The bq27500/01 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 (min.), battery voltage (mV), and temperature (°C).

Battery fuel gauging with the bq27500 requires only PACK+ (P+), PACK– (P–), and Thermistor (T) connections to a removable battery pack or embedded battery. The bq27501 works with identification resistors in battery packs to gauge batteries of different fundamental chemistries and/or significantly different rated capacities.