General Motors has announced enhancements to the vehicle structure and battery coolant system in the Chevrolet Volt and Vauxhall Ampera following post-crash fires .
The changes are designed to offer additional protection for 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 in the US to examine post-severe crash battery performance.
NHTSA opened a Preliminary Evaluation on 25 November 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.
GM will conduct a Customer Satisfaction Programme 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,” said GM. “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 vehicle. The enhancements are being incorporated into the Volt manufacturing process as production resumes this month.
The modifications and enhancements will be applied to all Volts, including vehicles sold in Europe. The European New Car Assessment Programme (EuroNCAP) has awarded the Chevrolet Volt the top five-star safety rating.
GM is keen to stress that during the first 11 months of 2011 Volt owners accumulated nearly 20 million miles without an incident similar to the results in the NHTSA tests.