Those conditions were blamed for an explosion at a General Motors battery testing lab last April that caused $5 million in damage and sent one person to the hospital. GM said flammable gas had vented from an experimental lithium ion battery that heated up during extreme testing.
"Lithium ion is very controversial in the safety engineering space," said Brian Barnett, vice president for battery technology at Tiax, a technology firm in Lexington, Mass. He spoke last month at a conference on battery safety in Las Vegas, where more than three-quarters of the presentations focused on lithium ion batteries.
The cause of the fires in the two Dreamliners has still not been determined and neither Boeing nor the Japanese company that made the batteries, GS Yuasa, have publicly commented on likely factors. Boeing subjected the batteries on the plane to thousands of hours of testing and installed numerous safety systems specific to the batteries.
"We have high confidence in the safety of the 787 and stand squarely behind its integrity as the newest addition to our product family," Boeing Chief Executive Jim McNerny said Friday.
For The Record
Los Angeles Times Monday, January 21, 2013 Home Edition Main News Part A Page 4 Local Desk 2 inches; 63 words Type of Material: Correction
Dreamliner batteries: An article in the Jan. 19 Section A on lithium ion battery safety and the grounding of Boeing 787s said the battery in a Chevrolet Volt automobile burst into flames seemingly spontaneously. The battery ignited after a crash test damaged the vehicle's cooling system and the test car was left parked with the battery fully charged, eventually causing it to overheat.
For The Record
Los Angeles Times Saturday, January 26, 2013 Home Edition Main News Part A Page 4 Local Desk 1 inches; 62 words Type of Material: Correction
Dreamliner batteries: An article in the Jan. 19 Section A about lithium-ion battery safety and the grounding of Boeing 787s said that Toyota Motor Corp. had decided against using the technology. Although the automaker has abandoned plans to use lithium-ion batteries in its standard Prius hybrids, it does use them in the Prius plug-in hybrid as well as the all-electric RAV4 EV.
Barnett and others emphasize that it's not uncommon to see problems in relatively new technologies. But they add that most lithium ion fires are caused by an external problem, such as a bad circuit or a software glitch that leads to overcharging. Another common problem in consumer electronics is the use of low-cost wiring and other components that can overheat and spark or catch fire next to the battery itself.
Eskra, the battery fire investigator, said he's seen fires started by Chinese-made toys that use lithium ion batteries hooked up to chargers designed for nickel cadmium or nickel metal hydride batteries. Manufacturing errors, including allowing tiny metal particles to contaminate cells, can cause dangerous shorts, although they are exceedingly rare.
"Somebody tried to cut corners somewhere," he said, noting that most lithium ion fires are caused by a tiny part that malfunctioned somewhere along the line and are easily resolved. "It's a $2 fix, but it takes half a million dollars in research to figure out what it is."
Sometimes the problem is more persistent. In 2006, Sony announced a global recall of more than 10 million lithium ion laptop batteries used in a variety of laptop computers after more than a dozen fires, and two years later issued a second recall.
Still, considering the vast proliferation of lithium ion batteries and the relative paucity of serious problems, there seems to be safety in numbers.
"All batteries are energy storage devices and if they're not manufactured or managed correctly, there is a risk," said George Kerchner, executive director of trade group the Rechargeable Battery Assn. "But lithium ion is a ubiquitous technology and it wouldn't be out there if it weren't safe."