Prototype System Ejects Experimental EV Batteries During Fires

An experimental system demonstrated in China can throw a burning electric vehicle battery pack clear of the car in under a second. The technology is designed to move a dangerous power source away from the vehicle during a fire, but the early-stage setup still faces practical hurdles.

Online videos show the floor of a prototype SUV bursting sideways to launch its battery pack across the ground, sending it stopping 10 to 20 feet away. The prototype relies on a gas generator similar to an airbag inflator. When the vehicle's battery management system detects an impending fire, the generator pushes the pack out of the car.

The hardware grew out of research into side-loading battery swaps used in some electric vehicle stations. While project staff intended the ejection mechanism to remain locked in dense urban areas and crowded spaces, the software to make those location-based distinctions has not been built yet. Observers have also questioned whether ejecting a smoldering pack might create new hazards if it lands near another vehicle.

The test footage was linked online to the China Collision Repair Technology Center and car parts supplier Joyson Electronics. However, Joyson stated it has no partnership with the center, and a brand whose vehicle model resembled the test car also denied involvement.

The testing highlights the ongoing challenge of managing electric vehicle fires. Lithium-ion cells can enter thermal runaway, a state where temperatures climb rapidly past 300 degrees Celsius while venting gas, smoke, and flames. Fire safety researchers note that once thermal runaway begins, current suppression techniques cannot stop it, and batteries can reignite multiple times after firefighters think a fire is out.

Other automakers have explored mechanical solutions for dangerous battery packs. Stellantis has a patent application for a system that drops a burning pack using sliding frames or explosive bolts, while Hyundai and Kia hold a patent requiring drivers to pull a manual lever to drop a pack. Meanwhile, other regions and companies are pursuing different safety approaches, such as mandatory standards preventing fires during thermal runaway or specialized fire hose ports that flood packs with water.

Summary

As electric vehicle fires prove difficult to extinguish with water alone, researchers and automakers are developing mechanical systems to physically separate burning battery packs from vehicles. While experimental ejections and drop systems offer a novel way to manage thermal runaway, the technology remains in early development with unresolved safety and software questions.