Screenshot from the Fire Safety Research multi camera video
16 Dec 2022

UL´s Fire Safety Research Institute makes full scale test over-charging an e-scooter in a residential living room


UL’s Fire Safety Research Institute (FSRI) has initiated a research project in partnership with the Fire Department of the City of New York (FDNY) to study thermal runaways in lithium-ion batteries especially for e-bikes and e-scooters when intentionally over charged inside a residential living space. 

In the multi camera video released on the Fire Safety Research Institute´s homepage, the e-scooter has been intentionally overcharged almost two hours, inside the living room of a four bedroom family bungalow.


Screen shot from the video


At 1 hour and 38 seconds, the thermal camera starts showing signs of the battery heating up. Only 60 seconds later,  smoke and gases can be seen being released from the e-scooter.  Only ten seconds (!) later, an explosive fire development was recorded and the entire living room is lit by the radiant heat within less than three seconds. 


Screenshot of the multi camera video


E-bike, e-scooter and other e-mobility devices have become common modes of transportation. These devices are often powered by lithium-ion batteries due to their favorable combination of low weight and high energy density. If these batteries fail, they have the potential to catch fire and cause explosions.

To better understand these failures, UL’s Fire Safety Research Institute (FSRI) has initiated a research project in partnership with the Fire Department of the City of New York (FDNY). This project studies and seeks to answer the following questions through conducting experiments in both laboratory and residential test structure settings using carefully designed and placed instrumentation:


  • How does a common e-scooter battery fail when exposed to different thermal runaway initiation methods (i.e. overcharge, external heating)?
  • Are there differences in battery failure behavior for thermal runaway initiated by external heating versus overcharge?
  • What fire dynamics result from an e-scooter that is overcharged into thermal runaway?
  • Are there differences between an e-scooter fire in a bedroom with the door closed and an e-scooter fire in a living room open to the remainder of the home?
  • If occupants are in the home, what thermal and gas concentration exposure will they experience?
  • Are there considerations for the public or fire service because of these experiments?


Read the full article here


FDNY is experiencing a concerning trend in electric mobility (e-bike, e-scooter, etc.) device fires. In 2021 alone, NYC responded to 104 fires that were initiated by lithium-ion batteries, resulting in 79 injuries and 4 deaths. Some of these fires have shown damage from pressure as seen in video on this page. Through their response to these incidents, FDNY has gained valuable insight and knowledge. This information was shared when they held a first of its kind symposium titled “Lithium-Ion Batteries: Challenges for the Fire Service” in partnership with the FDNY Foundation, FSRI and NFPA. This symposium was held September 6-7, 2022, with over 300 attendees with the intent to learn more about the hazards of lithium-ion batteries and share knowledge about operating with this evolving hazard.