Amphenol Advanced Sensors, a company comprising industry-leading sensor brands, including Thermometrics, Inc., Telaire, and NovaSensor, is offering its Coolant Leak Detection Sensor for use in Electric/Hybrid Electric Vehicles (EV/HEV) to detect the presence of water and coolant in the vehicle's battery pack enclosure.
Assembly of water leak detection sensor in EV battery packs
Capable of detecting even small amounts of water/coolant, the Battery Management System (BMS) then alerts the operator to take proper countermeasures to reduce the risk of pack failure and possible electrocution hazards.
Recent widespread implementation of large format battery-powered industrial equipment, stationary power, and road vehicles has presented some unique engineering challenges in onboard diagnostics (OBD) and fault detection for long-term, low maintenance battery systems. One of the most significant challenges is to ensure the safety and reliability of these power management systems is the presence of water.
While substantial design measures are taken to prevent water intrusion into the battery enclosure, there are still instances where this can occur. In stationary power systems, exposure to rain and standing water from flooding is not only a short-term concern, but also contributes to corrosion or leakage of the enclosure, exposing the battery system to water. In mobile applications, the pack shell can be damaged from debris penetrating the shell and from the long-term effects of corrosion. Seams and joints in the enclosure can also open because of twisting or vibration.
Additionally, many large format battery pack enclosures utilize cold plate cooling systems, which can develop leaks over long duration use. Temperature and barometric pressure variations within the air space of an enclosure may also allow condensation to form.
Amphenol Advanced Sensors employed its Thermometrics, Inc. brand to design the Coolant Leak Detection Sensor as a cost-effective solution to address the safety and reliability concerns associated with the presence of water/coolant in battery packs.
The sensor operates on standard 5V power and can detect as little as 2.8mm of standing water in the bottom of the battery pack enclosure. For diagnostics, the sensor includes a 510kΩ resistor in parallel with two plated contacts for open/short circuit detection. Its small footprint allows for various mounting positions, along with custom length wire leads and connector options.
The Coolant Leak Detection Sensor is validated against aggressive automotive standards and includes 2D barcode for full traceability requirements.