New Hydrogen Sensor Solution for Detecting Thermal Runaway in Battery Management Systems

Posifa Technologies released a new sensor solution for detecting thermal runaway in battery management systems (BMS). Built on the company’s MEMS hydrogen sensor technology, the new PGS4100 hydrogen sensors accurately detect hydrogen concentration in the air by measuring the change in thermal conductivity of the gas mixture within BMS compartments. This technology enables faster reaction times for triggering battery failure alarms in electric vehicles (EVs), ensuring compliance with safety standards.

The PGS4100 series is designed with a relative humidity sensor and a barometric pressure sensor. This strategic incorporation enables the sensor to counterbalance thermal conductivity changes influenced by humidity in air and elevation changes, enhancing the accuracy of hydrogen concentration measurement. This level of precision enables the PGS4100 to meet industry standards for flammable gas detection.

Built around Posifa’s second-generation thermal conductivity die and packaged in an SMD form factor, the PGS4100 operates using a pulsed waveform. This design approach ensures the sensor’s heater temperature aligns closely with the ambient temperature, thereby ensuring intrinsic safety.

The PGS4100 series supports analog voltage and I2C digital outputs, with future models slated to support MODBUS/UART and CAN bus. Encased in an IP6K9 compliant enclosure and equipped with a wire harness terminated with an automotive-grade connector, the PGS4100 series exemplifies durability.

Key features of the PGS4100 series include compensation for humidity and pressure, ensuring accurate functioning in harsh environments. Notably, the sensor remains non-reactive to “poisons” or contaminants, guaranteeing long-term stability and reliable performance.

“Because of the extremely small size of the sensor element and its straightforward principle of operation, Posifa’s hydrogen sensing technology can be offered in many different form factors and adapted to a very wide range of OEM requirements,” said Peng Tu, president and CEO of Posifa Technologies. “We have the manufacturing expertise and resources to deliver hydrogen sensing solutions at various levels of modular integration. Our technology can thus, for example, be integrated into any type of battery pack irrespective of ventilation technology, communication protocol, and so forth.”

Further information about the PGS4100 series hydrogen sensors is available at