Battery fuel gauges are not a specific brand but a category of devices used to monitor the state of charge (SoC) and health of batteries. These gauges are produced by various companies worldwide, including Texas Instruments (USA), Maxim Integrated (USA), and STMicroelectronics (Switzerland). They serve industries such as consumer electronics, automotive, and industrial automation, providing critical data for battery management systems (BMS). Key products include integrated circuits (ICs) and software algorithms that accurately measure battery performance, ensuring efficient energy usage and prolonging battery life.