The Texas Instruments bq27505-J4 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 micro-controller firmware development. The bq27505-J4 resides on the system’s main board and manages an embedded battery (nonremovable) or a removable battery pack.

The bq27505-J4 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), temperature (°C) and state of health(%).

Battery fuel gauging with the bq27505-J4 requires only PACK+ (P+), PACK– (P–), and Thermistor (T) connections to a removable battery pack or embedded battery circuit.