Thermal runaway EV battery fires controlled with water cutting tech

According to Swedish tests, the Cold Cut Cobra technology has the ability to effectively manage thermal runaways by using minimal amounts of water.

 

Swedish firm Cold Cut Systems has developed a water jet technology that could help combat the growing threat of thermal runaway fires in electric vehicle (EV) batteries. The Swedish Civil Contingencies Agency (SCCA) recently conducted successful tests on the technology, which is designed to tackle the risk of fires in EVs, a major concern for fire services. Lithium-ion batteries burn intensely, producing "jet flames" and emitting highly toxic gases such as hydrogen cyanide. A small number of EVs burning in an enclosed area, such as an underground car park, could quickly become too hot for crews to access. Additionally, extinguishing an EV fire using traditional means requires a large amount of water - up to 150,000 litres - compared to less than 4,000 litres for internal combustion vehicle fires.

Batteries can spontaneously re-ignite hours or days after appearing to have been extinguished, and current practice involves either allowing the battery to burn itself out in a controlled fire, which some EV manufacturers recommend, or flooding the battery by partially submerging the vehicle for an extended period. The ColdCut Cobra system aims to tackle the fire at its source by using a 300-bar water jet containing abrasive material capable of cutting through a vehicle's floor and titanium battery casing. Firefighters can then directly flood the burning cells, and the SCCA tests suggest that just 750 litres of water are required to extinguish a burning car battery in under 10 minutes.

Originally launched in 1997 to safely cut metal in explosive environments like oil refineries, the ColdCut system has since been adopted by fire fighting teams at paper factories, coal mines and chemical plants. Cold Cut says it has supplied systems to 14 UK fire services for other roles. The ColdCut system has already been adopted by British company Prospeed, for its new 6x6 Rapid Intervention vehicle designed to access underground and multi-storey car parks that traditional fire tenders cannot reach. "The problem of how to handle EV-fires, together with increasing numbers of EVs on the roads, means we have been working with the SCCA to develop a method to handle these types of fires. We are really pleased with the outcome, and are seeing a lot of new interest," said company CEO Johan Ivarsson, speaking to Auto Express. While EV fires are still rare, their incidence is increasing as more EVs hit the roads. Currently, London is the most affected, with the fire service reporting well over 200 electric car fires in the last five years, with a significant jump in 2021.