Why do EV and e-bike batteries keep catching on fire?

An overheating e-bike on board a TTC subway car led to a fire at the Sheppard-Yonge Station on Sunday. A shipload of lithium-ion batteries caught fire in Alaska burned for days. The proliferation of electric bikes and vehicles has meant an expansion in the use of lithium-ion batteries — and an increasing number of battery fires.

In the case of the e-bike fire aboard Toronto transit, fire crews were able to extinguish what Toronto fire chief Matthew Pegg called an “aggressive fire,” with one person suffering non-life threatening injuries. “The failure of this lithium-ion battery pack occurred very rapidly, with the battery pack igniting into a significant and aggressive fire within seconds of the presence of visible gases being omitted from the battery,” said Pegg. Pegg’s comments come as lithium-ion battery-related fires have risen dramatically in the last year.

In 2022, there were 29 lithium-ion battery fires in Toronto. That number nearly doubled in 2023, with the fire on Dec. 31 bringing the total to 55.

There have also been many reports in the United States of fires stemming from the batteries of e-bikes and e-scooters. In June 2023, four people were killed when fire erupted at an e-bike shop in New York City. In just New York and Los Angeles, there have been at least 669 lithium-ion battery fires since 2019, CBS News reported .

The main risk, said Michael Pecht, a mechanical engineer at the University of Maryland, is that there can be a fire or explosion. This can be a particular risk if the fire starts in a residential building, especially at night. “I would be concerned about having an e-bike in an apartment,” said Pecht.

Often, consumers get blamed, either for using the wrong charger or that the battery was abused. It is true that improper charging can cause batteries to overheat and start fires. But the bulk of the problem seems to be in manufacturing.

“But think about it,” said Pecht. “here have been fires and explosions and recalls as a result, with Chevrolet Bolt, Hyundai’s Ioniq, and almost every other e-car. And those batteries were made by some of the leading battery companies with good chargers and (battery management systems).

” “The problem is that billions of batteries are being made each year by each of these companies and quality issues can affect performance,” Pecht continued. If there’s a defect in a battery, they can result in internal short circuits and what’s called “thermal runaway,” which is one of the “primary risks” of lithium-ion batteries, according to the UL Research Institute, an independent safety organization. “It is a phenomenon in which the lithium-ion cell enters an uncontrollable, self-heating state,” it says in a post.

This can overheat the cell, bringing battery temperatures to dangerous and hazardous levels that can destroy the battery and, sometimes, cause fires. And so, defects within the batteries can spark the fires. “The companies who make the e-bikes are often smaller battery companies and many have quite poor quality control and are thus at a much higher risk of having defects that can result in thermal runaway,” said Pecht.

When fires are sparked from a lithium-ion battery, there is more to worry about than just the intense heat generated by the flames. Experts have pointed out that toxic gases can also be emitted when a lithium-ion battery experiences thermal runaway. “While the fire itself and the heat it generates may be a serious threat in many situations, the risks associated with gas and smoke emissions from malfunctioning lithium-ion batteries may in some circumstances be a larger threat,” reads the introduction of a paper in science journal Scientific Reports .

This not only adds another layer to the danger bystanders may face when in the vicinity of a lithium-ion battery fire, but also poses a toxicity hazard to firefighters trying to quell the blaze. Though Pecht has said that even the batteries produced by established manufacturers come with risks, most incidents are caused by cheap, poorly made batteries. “Buy from a reputable company and if possible know that the battery comes from a reputable battery manufacturer,” said Pecht.

“Store the ebike in a place that would not spread a fire if one occurred (and) be careful about mom and pop shops in China especially. ” Our website is the place for the latest breaking news, exclusive scoops, longreads and provocative commentary. Please bookmark nationalpost.

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