General Motors has announced enhancements to the vehicle structure and battery coolant system in the Chevrolet Volt that would further protect the battery from the possibility of an electrical fire occurring days or weeks after a severe crash.
The enhancements come in response to a National Highway Traffic Safety Administration Preliminary Evaluation to examine post-severe crash battery performance.
NHTSA opened a preliminary evaluation on November 25, 2011, 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.
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
“The Volt has always been safe to drive. Now, we will go the extra mile to ensure our customers’ peace of mind in the days and weeks following a severe crash,” says GM senior vice president global product development Mary Barra.
GM will conduct a program to further protect the Volt battery from the possibility of an electrical fire occurring days or weeks after a severe side crash. Modifications 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 conducted four successful crash tests between December 9 and 21 of Volts with the structural enhancement. The enhancement 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,” say Barra. “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.”
The modifications and enhancements will be applied to all Volts, including vehicles sold in Europe. GM also says it will continue its leadership role in helping the Society of Automotive Engineers develop standards that will help tow truck operators, salvage yards and vehicle recyclers in the proper handling of electric vehicle components. GM will help develop educational materials that can be used by these stakeholders in the future.