WARREN, MI – General Motors announced it is adding enhancements to the vehicle structure and battery coolant system in the Chevrolet Volt to further protect the battery from the possibility of an electrical fire occurring days or weeks after a severe crash.

These measures come in response to a National Highway Traffic Safety Administration preliminary evaluation to examine post-severe crash battery performance. 

NHTSA opened its preliminary evaluation on Nov. 25 following a severe-impact lab test on a battery pack that resulted in an electrical fire six days later. The test was conducted to reproduce a coolant leak that occurred in a full-scale vehicle crash test last May that resulted in an electrical fire three weeks later.  

According to GM, the changes will:
Strengthen an existing portion of the Volt’s vehicle safety structure to further protect the battery pack in a severe side collision
Add a sensor in the reservoir of the battery coolant system to monitor coolant levels
Add a tamper-resistant bracket to the top of the battery coolant reservoir to help prevent potential coolant overfill.

GM said the company conducted four successful crash tests between Dec. 9 and 21 of Volts with the structural enhancement and it performed as intended. There was no intrusion into the battery pack and no coolant leakage in any of the tests.

“These enhancements and modifications will address the concerns raised by the severe crash tests,” Barra said. “There are no changes to the Volt battery pack or cell chemistry as a result of these actions. We have tested the Volt’s battery system for more than 285,000 hours, or 25 years, of operation. We’re as confident as ever that the cell design is among the safest on the market.”

Volt customers will be individually notified when the modifications are available for their vehicles. The enhancements are being incorporated into the Volt manufacturing process as production resumes this month.

“We’re focused on one thing right now: doing what’s right by our customers,” said GM North America President Mark Reuss. “We’ll live up to our commitment to make sure our customers are delighted with their purchase.”  

The Volt is a Top Safety Pick by the Insurance Institute for Highway. Through the first 11 months of 2011, Volt owners accumulated nearly 20 million miles without an incident similar to the results in the NHTSA tests, GM said.