By Meghan Friedmann July 5, 2020
GUILFORD — The Guilford Fire Department is warning people to be careful with portable chargers containing lithium-ion batteries after one caught fire and exploded Wednesday afternoon, according to a release on the department’s website.
The charger was sitting on a semi-non-combustible surface and no one was injured, said Deputy Fire Marshal Jim Considine.
Considine advised people to keep those chargers away from combustible items such as sofas and beds.
They should not be left unattended while plugged in, and users should follow the manufacturer’s instructions regarding charging times, he said.
But the charger that caught fire this week had not been plugged in for two to three hours before the incident occurred, Considine said, adding that the circumstances surprised fire officials.
Its owner informed fire officials that prior to that, she had charged it for about two hours, according to Considine.
The device, which is used to charge phones or other electronics when no power outlet is available, had self-contained lithium-ion batteries and was a common model that can be easily purchased in retail stores, Considine said.
He declined to name the product brand and said there has not been a recall.
Over the years, there have been other, periodic reports of explosions involving lithium-ion batteries.
The U.S. Fire Administration said lithium-ion batteries were the cause of nearly 200 fires between 2009 and 2017, according to a report from the Atlantic, which describes a 2016 incident in Buffalo, N.Y., in which a man got chemical burns after his laptop battery exploded.
Lithium-ion batteries occasionally can catch fire when overheated or punctured, according to the report, which describes the concerns raised about poorly-made batteries available on the market.
“While lithium batteries are normally safe, they may cause injury if they have design defects, are made of low-quality materials, are assembled incorrectly, are used or recharged improperly, or are damaged,” a 2019 safety bulletin from the Occupational Safety and Health Administration said.
Explosions like the one in Guilford usually result from what’s called a “thermal runaway,” which occurs when the battery cell heats up and starts a chemical chain reaction within the battery itself, Considine said.
That reaction may produce gaseous vapors that can ignite, he continued.
The deputy fire marshal listed four main conditions that lead to thermal runaways: internal short circuits, external short circuits, excessive currents when charging and discharging, and overcharging.
“It’s a definite known problem,” Considine said, adding that the battery in the Guilford charger was the same kind that has been found in exploding vape pens.
But as far as Considine was aware, Wednesday’s fire also was the only time an exploding battery was reported in Guilford over the last 15 to 20 years, he said.