DETROIT (Bloomberg) -- General Motors Co. is developing post-collision procedures for discharging the battery in its Chevrolet Volt plug-in hybrid following a fire that occurred after regulators crash-tested the car in May.
GM did not publicize its process for depleting power from the Volt's lithium ion battery or handling the Volt after a crash, said Jim Federico, GM's chief engineer for electric cars, on a Chevrolet website.
Depleting power from the battery will prevent a fire.
Nissan Motor Co. has protocols for handling the battery in its Leaf electric car after a collision. Both cars went on sale in December 2010.
GM now has a process in place to draw down power in the battery so it won't catch on fire after a collision. GM is working with the National Highway Traffic Safety Administration to develop standard processes for handling the Volt's battery after a crash and will make them public when completed, Rob Peterson, a GM spokesman, said.
"I can't conceive that they didn't have a standard operating procedure in place for handling a wrecked vehicle before the car went on sale," said Clarence Ditlow, executive director of the Center for Auto Safety in Washington. "NHTSA and GM should have established protocols in place before it went on sale."
NHTSA crash-tested a Volt on May 12. During the side-impact collision test, the battery was punctured and caught on fire three weeks later. GM believes that a coolant leak helped carry an electrical charge to something flammable inside the battery, Peterson said.
In a blog post on ChevroletVoltAge.com that ran Nov. 15, Federico said the Volt is safe. He wrote that NHTSA has given the car its top five-star crash rating. He also said that the car caught on fire because GM hadn't finished a procedure to draw down power in the battery.
"The fire occurred because the battery wasn't completely discharged after the test," Federico wrote in the post. "GM developed its battery depowering process for the Volt after NHTSA's test."
GM had a process to discharge Volt batteries. The automaker didn't distribute it to tow truck drivers, body shops, salvage yards and others who may handle the car after emergency crews stabilize the scene of an accident.
The company was sending engineers out to check any Volt that got in an accident and, if needed, discharge the battery, Peterson said.
"We had a process internally but I don't believe it was shared with anyone," Peterson said in a phone interview. "The incident with NHTSA raised awareness that we had to develop a procedure and alert all stakeholders."
Before the Volt and Leaf went on sale, GM and Nissan had been working to train emergency response workers through the National Fire Protection Association, a national fire prevention and firefighters group based in Quincy, Mass.
Workers are trained to disconnect the 12-volt battery from either car, which will shut down the separate high-voltage battery, said Jason Emory, a trainer with the association and also a lieutenant with the Waterbury, Conn., Fire Department.
Emory said the Volt also has a mechanism to disconnect the 16-kilowatt-hour battery from the car. GM helped train rescue workers to use it before the car went on sale, he said.
Nissan has taught firefighters and rescue teams how to approach the Leaf and make sure the battery is disconnected, said Bob Yakushi, director of product safety for Nissan North America.
After emergency workers stabilize the scene, Nissan recommends a Leaf be towed to one of its dealers where the battery will be handled by technicians, Yakushi said. Nissan has not encountered any fires with the Leaf since it went on sale in the U.S., Yakushi said.
There have been several accidents reported and "quite a few Leafs were destroyed" during Japan's earthquake and tsunami in March while none caught fire, he said.
Nissan has a steel case around its battery to protect the battery from puncture, Yakushi said. Peterson said the Volt does not have such a second protective casing around the battery.
GM placed the battery at the center of the car, which is the safest location, he said. NHTSA asked automakers, including GM, Nissan Motor Co. and Ford Motor Co., that sell or have plans to sell vehicles with lithium-ion batteries about the batteries' fire risk, four people familiar with the inquiry said.
LG Chem Ltd., South Korea's biggest chemical maker, supplies Volt batteries.
NHTSA wants information from automakers that sell or plan to sell electric cars and hybrids, which also include Toyota Motor Corp. and BMW AG, for information on handling them after an accident.
The information will be used for a three-year $8.8 million electric-vehicle safety study it announced in June, an agency official said.