Description:

Lithium batteries carry an inherent risk due to the large amount of electrical energy they store. This can lead to fires caused by resistive heating from faulty connections, or more dangerously, from chemical reactions within the cells, such as thermal runaway. Thermal runaway is when a battery's temperature rapidly escalates, triggering a chain reaction that can result in combustion. Given these risks, managing and containing fires in lithium batteries requires specialized equipment and safety protocols to ensure both energy storage and safety.

Control module

Our typical targets are batteries based on LiFePO4 (LFP) cells, which are not known to suffer from thermal runaway problems. However, they are not devoid of fire hazards, especially after being abused like overheating, freezing or deep discharging.

The electronics is a build variant of our "RAFEX" fire extinguisher controller. We removed the power supply, unneeded relay and terminals. Only kept the management port, because that's how we connect this controller to the BMS.

Firepro aerosol extinguisher device

Specifications 'embedded':

  • Drive and monitor one electronically triggered aerosol fire extinguisher unit
  • Bi-color LED for status/warning/alarm indication
  • 10+-Year maintenance-free lifespan
  • 3.3V power from BMS
  • 3.6V LiSOCl2 battery as backup
  • Backup 125°C bi-metal activation switch
  • Automatic test of trigger & igniter circuit
  • Latching NO relay contact to signal alarm state
  • Non-latching open-drain output to signal status change
  • LVTTL RS232 telemetry link
  • Conformally coated bare board 56×50mm
  • Status on battery LCD and via CAN-bus on HTML/JSON backend