Metis Engineering’s Battery Safety Sensor is designed to monitor the health of a lithium-ion battery pack and detect cell venting, an early sign of catastrophic battery failure.

The company has now released a beta version that features a new streamlined design, optimized for manufacturing in the high volumes required by automotive OEMs. It says units are already on trial with a number of EV OEMs and battery manufacturers.

The sensor is designed to pick up a range of environmental parameters, including Volatile Organic Compounds (VOCs), Pressure Change, Humidity and Dew Point. An optional Accelerometer can record shock loads. This data can be used to crosscheck with other inputs, such as cell temperatures, to detect cell venting.

The sensor relays the data over a configurable CAN interface to a control unit, such as the vehicle’s ECU, to alert the driver that cell venting has occurred. The sensor can also trigger a process to cut the circuit to the battery pack, allowing it to cool down and hopefully prevent thermal runaway.

Metis explains that standard battery management systems (BMS) are designed to monitor the health of the battery pack, but typically have only one temperature sensor for every few cells. “This system works fine if it happens to be the cell with the temperature sensor that goes bad, but if the cell is a distance away from the sensor in the pack, by the time the sensor registers the change in temperature, if at all, it would very likely be too late.” The Metis Battery Safety Sensor, however, “typically detects venting within seconds.”

“The release of the beta versions of our Production Battery Safety Sensor marks another key milestone as we roll out the technology,” said Metis Engineering Managing Director Joe Holdsworth. “The sensor is already on trial in electric sportscars, buses, aircraft and vans, and the feedback has been universally very positive. My team plan to make one or two minor modifications before we sign off the final spec [which will be] ready for delivery in Q3 this year.”

Source: Metis Engineering