With the proliferation of lithium-ion batteries, stories about battery fires have become regular occurrences. But the question is: do these batteries pose a real safety concern, or are these incidents a minute percentage of the batteries installed?
I was in the latter camp until recently, and I’m still not convinced it’s an issue. However, there is no denying the number of fires is escalating.
The Massachusetts Department of Fire Services has created a checklist to track lithium-ion fires. Deployed by 38 cities and towns, the checklist has identified 50 fires in the past six months. That’s over double the annual average identified by the national fire data reporting system.
The fires have occurred in a range of devices including scooters, e-bikes, and hoverboards (9), laptops (8), and cell phones and tablets (8). Power tools were responsible for six fires. Of the 50 fires, 56% of the devices were not charging at the time of the fire.
New York City has also had a spate of fires. The city reported over 200 incidents that have injured 100 people and killed 14.
As you would expect, the problem isn’t isolated to the United States. Data from insurer Zurich showed that the number of fires in the UK increased almost 150% from 2021 to 2022. And the London Fire Brigade has said that lithium-ion battery fires now pose the fastest growing fire risk in London which in 2023, has had on average an incident once every two days.
Many of the fires with smaller consumer devices stem from low quality batteries. It’s like anything else – you get what you pay for. When you buy a lower cost device there is a risk that the level of quality control is insufficient.
The larger question is whether lithium-ion poses a problem with large-scale commercial battery energy storage systems (BESS). We’re still at the early stages of deploying these systems, but according to a recent report there have been 141 BESS incidents to date worldwide. The majority of these were fires, and 60 of them involved residential units. Another report indicated that through 2021, fires may have impacted about 4% of the total installed BESS capacity in the U.S.
What causes the fires? Thermal runaway. Wikipedia describes thermal runaway as a process that is accelerated by increased temperature that releases energy that increases the temperature even further.
The challenge is that when thermal runaway occurs, the fires are very difficult to extinguish. Fires can escalate quickly, reach temperatures of 1000 to 2000 C, and release toxic gases.
It’s too early to tell whether this is a burgeoning problem. It appears many of the fires occur in smaller, low-quality devices. And developers of commercial battery storage systems are now integrating safeguards to prevent thermal runaway. Nonetheless, it’s an issue that warrants continued monitoring.
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