Lithium ion battery fires became the fourth-most-lethal type of fire in New York City last year, with 216 fires injuring 147 New Yorkers and killing six, according to the New York City Fire Department.

The problem isn’t going anywhere in 2023. Over the weekend, NYC had its first fatal fire of 2023: a charging e-bike battery exploded in a Queens home, killing one person and injuring 10. That's why Sam Lamontaro, director of engineering at Aufgang Architects, hatched a new bike room design he said can help building owners mitigate fire risk.

Fires caused by e-bike batteries and chargers come with greater risk than other types of building fires: They reach higher temperatures, release toxic white smoke and can reignite after being extinguished.

Lawmakers have been trying to figure out how to regulate the second-use batteries and chargers that have caused fires since October. But the prevalence of e-bikes in the city, and in particular food delivery workers’ dependence on vehicles for their livelihoods, has stopped lawmakers from issuing bans.

Some residential building owners and condo board and co-op buildings are considering bans, Bisnow previously reported, and Fordham University banned e-bikes and scooters in December.

That’s where Lamontaro thought Aufgang could make a difference. If bike storage rooms were built with containing fire in mind, maybe fire wouldn’t spread through a building as fast and the FDNY would have more time to respond, he said.

“I wrote an internal memo to the architects at the firm,” Lamontaro said in an interview last week. “It talks about the design of the room from an architectural standpoint — to have a room completely encapsulated with concrete, what type of density we wanted for sprinklers in this room, the increase in [electrical] outlets that we would require for these bike rooms so there's no use of extension cords.”

The firm embraced the idea, and Aufgang this month launched advertising of its bike storage rooms to both new builds and apartments that could benefit from retrofits. They feature thick, cinderblock walls and a fire alert system that has infrared sensors, smoke and heat detectors.

If the pipes connected to sprinklers in a building’s bike storage area can accommodate a higher volume of water, Aufgang places sprinklers on a 10-foot-by-10-foot layout capable of unleashing 1.1 liters of water per minute.

“You're not looking to extinguish the batteries, because the batteries themselves, if they do burst, they don't need oxygen. They create their own oxygen,” Lamontaro said. “So what you hope to do is to contain it, keep it from spreading and causing any type of chain reactions. So you want to decrease the heat with the sprinklers and decrease any flame spread.”

Aufgang’s design — the thickness of the cinderblock, the sprinkler density — is based on standards set by the National Fire Protection Association. But while NYC building codes draw on NFPA standards, those standards haven’t yet formed for battery storage areas, Lamontaro said. At present, that means that Aufgang’s design hasn’t yet faced the test of a real fire caused by lithium-ion batteries.

Adam Barowy, a research engineer at Underwriters Laboratories Inc.’s Fire Safety Research Institute, has spent the last few months conducting experiments to better understand how lithium-ion battery fires work, and what types of solutions could eventually make them safer to live with.

In November, the FSRI published a demonstration of its findings thus far: After batteries overheat, they release gas that ignites suddenly and creates a pressure build-up capable of blowing out the windows on a single-family home.

While apartment blocks tend to be more robustly constructed, scientists still lack well-rounded research on things like the best ways to tackle fires caused by lithium ion batteries, Barowy said in an interview.

“There really is no data right now on how sprinklers can reduce the impact of an e-bike fire,” Barowy said.

However, building codes often lag behind current threats because they require robust testing before approving proposed solutions, Barowy said, meaning that New York City is unlikely to see building codes updated for e-bike fire safety until next year at the earliest. And while some developers will be pushing ahead with creative solutions that place their buildings ahead of code, he said, there won’t be a one-size-fits-all solution for the risk.

“There's a certain desire to solve the problem conclusively and quickly,” Barowy said. "But if you look at really how most fire hazards end up being resolved, you'll see what we always call 'layers of protection.'"

Contained bike storage in one single area of a building would help, he said, plus a thorough detection system and public education on safe storage and charging.

“None of these things can really work on their own, but all of them start really meaningfully tackling some amount of the challenge.”