E-mobility Battery Fires Burn Fast. Philadelphians Need to Act Faster.

In the early morning hours of June 19, an e-bike battery in a South Philadelphia home suddenly burst into flames. Though the residents had working smoke alarms on every level of the home, their first alert was not from the alarm, but the fire itself. Flames spread so rapidly and intensely that the fire outran the alert of the smoke alarm, waking one of the residents. Tragically, two lives were lost.

For the Philadelphia Fire Department, our response time is under four minutes. But an e-bike battery fire can spread even faster. Testing from UL Research Institutes’ Fire Safety team has shown that flames emitting from one of these batteries can engulf a room in under 30 seconds. These fires are not only fast; they can be fiercer and more difficult to extinguish, demanding more firefighters, equipment, and water than a typical residential fire.

Sadly, the South Philadelphia tragedy is not an isolated incident. E-bikes and e-scooters have grown in popularity for everything from delivery work to sightseeing. With that growth, lithium-ion battery fires from these (and other devices) have been on the rise in cities across the U.S. and around the world. In Philadelphia, we respond to an average of nearly one lithium-ion battery event per week. The Toronto fire chief recently said the city’s lithium-ion battery fire calls have increased by 250% in the past four years.

Given their frequency and unpredictability, fire departments increasingly must expect that any fire they are called to might involve lithium-ion batteries. That creates more challenges for firefighters and raises the stakes for anyone inside a home when one of these fires starts.

All rechargeable, lithium-ion batteries can go into thermal runaway, which can lead to fire or even explosion. While these batteries power everything from your phone and laptop to your lawn tools and vacuum, e-bikes and e-scooters present an outsized risk because of the amount of power their batteries hold and the conditions they endure. Yet 53% of e-bike owners do not even know that their device is powered by a lithium-ion battery — and not knowing about the power source means not understanding its risks.

So what can be done to get ahead of these fires?

Riders can help protect themselves by choosing devices that are certified to safety standards, including UL 2849, UL 2271, UL 2272. In order to conform to these standards, e-mobility devices and batteries must undergo rigorous testing to ensure they can withstand demanding conditions without presenting a risk of thermal runaway. E-mobility device owners should also only use manufacturer-provided or manufacturer-approved chargers, regularly check batteries for swelling or damage, avoid overcharging and charging unattended, and, most importantly, never store an e-bike or e-scooter where it could block an exit in a fire.

We urge all individuals to exercise care and caution when shopping for and using e-bikes, but we understand that individual actions can only go so far. Currently, city council is exploring policies that have proven effective at reducing deaths from e-mobility fires in other locales. Many state and local governments, like Oregon, California, Illinois, Colorado, Georgia, and Florida, have all passed laws requiring conformance to safety standards for any e-mobility device sold, rented, or leased in these jurisdictions. In 2023, New York City recorded a high of 268 battery fires that resulted in 18 deaths, but after enacting a law requiring any e-mobility device sold, leased, or distributed in NYC meet three ULSE standards, the number of annual deaths fell to one in 2025, according to FDNY.

We believe bringing similar e-mobility policies to our city can make a difference. We are grateful for city council’s attention to this issue. UL Standards & Engagement is proud to work in partnership with the Philadelphia Fire Department, and together we stand ready to provide city council with any data and information they may need.

New technology sometimes brings new risks, but progress happens when we work together to advance technology beyond those risks. We can have safer e-mobility in Philadelphia, and we can all play a role in helping make it happen.

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Kevin M. Donahue is Fire Battalion Chief at the Philadelphia Fire Department. As a fire and emergency services officer with over 14 years of dedicated service in a large metropolitan fire department, Donahue brings a wealth of experience and a deep commitment to public safety. His career has spanned diverse roles and responsibilities, including firefighting, emergency medical response, fire prevention and education, equipment research and development and project development.