A battery fire during routine testing at Archer Aviation's San Jose, California facility triggered an evacuation and left three people injured, the company and local authorities said.

Archer said the incident involved 30 Molicel batteries and attributed it to "employee error." The company said the small fire occurred in its "77 Rio Battery lab" and was quickly extinguished, with all employees safely evacuated.

The three people injured have since been released, and all evacuation orders were lifted. Archer said its Midnight electric air taxi aircraft was not involved in the fire.

The affected batteries were transported to a remediation station and submerged in a suppression tank, with a fire watch team standing guard. Molicel describes thermal runaway as a dangerous chain reaction in lithium batteries that can cause them to overheat, fail, catch fire, or explode.

Source: New York Post