One Chevy Volt burns, another smokes, NHTSA starts probe

Following problems while under close monitoring by the National Highway Traffic Safety Administration (NHTSA), the U.S. Government has started a safety defect investigation of the lithium-ion batteries in General Motors Co.’s Chevrolet Volt.

The probe began after one Chevy Volt battery pack caught fire after a crash test. Another crash-tested battery emitted smoke and sparks, according to the NHTSA report.

General Motors responded in a statement that the Volt “is safe and does not present undue risk as part of normal operation or immediately after a severe crash.”

The latest fires are in addition to a battery fire in a crash-tested Volt six months ago.

NHTSA learned of a possible fire risk involving damaged Volt batteries when a fire erupted in a Volt being stored in a parking lot of a test facility in Burlington, Wis. The fire was severe enough to cause several other vehicles parked nearby to also catch fire.

The car had been subjected to a side-impact crash test more than three weeks earlier, on May 12, during which the battery was punctured and its coolant line ruptured.

Last week’s tests of three battery packs were designed to replicate the May test. In that test, the Volt was subjected to a simulated side-impact collision into a narrow object like a tree or pole followed by a rollover, the agency said.

The first battery tested last week didn’t catch fire. But a battery test on Nov. 17 initially experienced a temporary temperature increase, and on Thursday caught fire while being monitored. Another battery tested on Nov. 18, which was rotated 180 degrees within hours after the test, began to smoke and emit sparks shortly after the rotation.

The tests were conducted by the NHTSA and the Energy and Defense departments at a defense facility near Hampton Roads, Va.

So far, no fires have been reported in Volts involved in roadway crashes, NHTSA said. More than 5,000 Volts have been sold.