The Normal Fire Department responded to a fire at the Rivian manufacturing plant Saturday morning. It was at least the third fire at the plant in the past seven months.
In Saturday's incident, a battery pack went into thermal runaway — when a battery cell overheats and catches fire — in a battery testing area in the southwest side of the plant. That's where the batteries are built for the Rivian vehicles, and it forced the evacuation of the battery assembly area.
Firefighters moved the battery outside after putting it out and said they continued to cool it with water until it was released to Rivian engineers for investigation and disassembly.
The exact cause of the fire is under investigation, but the battery pack had been in a repair area and was being tested when it ignited, said the fire department. A thermal runaway happens when a battery cell overheats and catches fire. The ignited cell releases more heat to the adjacent cells in a self-sustaining chain reaction.
The fire did not involve a vehicle or production equipment. The only damage was to the battery pack, the carrier, and the test booth equipment, according to firefighters.
The report came in about 10:38 a.m. and firefighters said they had returned the building to Rivian's control by 2 p.m. There were no injuries.
The Normal Fire Department has responded to at least two other fires at the Rivian plant since production began last fall. In February, a vehicle caught fire inside the plant, though the sprinkler system kept it from spreading. In October 2021, a small fire broke out in the automated battery assembly area.
