New York City struggles with a problem: fire. In particular, escooter and ebike lithium-ion batteries catch fire and sometimes explode. And there is no sign that it will end any time soon.
Earlier this year I wrote an introductory article on the burn rate in lithium-ion batteries. Today I want to look at New York as a cautionary tale in the fight against battery fires as e-bikes (and, to a lesser extent, e-scooters) become mainstream.
I will be following a third article tomorrow, exploring possible technological solutions to prevent battery fires.
What Causes Battery Fires?
In the case of e-bikes and e-scooter fires, there are numerous causes. First, when we talk about a lithium-ion battery for e-bikes or e-scooters, we are talking about a number of connected batteries that are stored in a plastic case. There is an enormous amount of energy in this small space.
Each of the batteries is prone to overheating which can be caused by;
- bad design
- mounting errors
- electrical short circuit
- using the wrong charger
- A damaged battery management system (BMS) causes overheating and insufficient cooling
- damage to the case.
Once a battery overheats, it can lead to a thermal reaction in a battery. This is known as a thermal runway. The reaction produces enough heat to ignite or explode adjacent battery cells as well.
These fires happen incredibly quickly and due to the self-perpetuating process of thermal runaway fires, lithium batteries are also difficult to extinguish. They can leak toxic chemicals dangerous for people and pets.
Large batteries such as those used in electric vehicles can re-ignite hours or even days after the event, even after being extinguished. Fortunately, this is much less common with e-bikes and e-scooters.
The problem in New York
To date this year, 130 reported fires involving lithium-ion batteries in electric bicycles and scooters have been reported in New York. Five people died. By comparison, there were only 65 fires on e-bikes and e-scooters around this time last year.
It is worth emphasizing that these fires represent only a small percentage of all fires in New York. It is also very likely that the growth of e-bikes and e-scooters living in the city is responsible for the increase.
But the fires are still a cause for concern, causing property damage, injuries and less often death. The ferocity of burning a lithium-ion battery means calling out multiple trucks, diverting attention from other emergency services.
Furthermore, the fires point to a bigger problem facing the city.
New York has more than 65,000 delivery drivers, many of whom use e-bikes. Gig economy workers are pushing their ebike to its limits beyond the daily commute, outsourcing all the risk to the riders.
Ebikes are ridden for hours on a doll and in extreme weather conditions such as heat, rain, hurricanesand snow, all of which can corrode a battery case, increasing the potential for battery damage.
For many riders, the only place they recharge is at home in their cheap apartment. The problem worsens when delivery drivers share apartments, store their e-bikes indoors and all charge their batteries overnight. And on a long shift, a rider may need more than one battery.
Earlier this year, journalist Wilfred Chan . wrote visited an ebike shop in New York equipped with powerboards that charge multiple batteries for delivery drivers. The staff offered her a charging point for $50 a month.
Amazingly, there have been no fires so far.
Is cost efficiency to blame?
With the exception of some rental arrangements I’ll share with you tomorrow, most riders have to pay for their own bikes, batteries, and chargers, making them cheap or second-hand. e-bikesand batteries attractive.
Reputable brands undergo extensive performance and safety testing to comply with UL Solutions UL 2849, the standard for electrical systems for eBikes. However, black market or cheap purchases may not include a certified battery management system that stops charging when a battery is full or overheats.
According to David TenHouten, VP, vehicle technology at micromobility company Birdthere is also a question of how far an operator pushes the boundaries within the safe cell parameters.
Salespeople can push things to the limit, or you can be a little conservative. Basically, if you’re more aggressive, you can get more performance out of the cells and push them further and get a little more range, but you get into the risk limits at the edges.
The problem increases with age, as “these batteries don’t get any younger. They actually just age a lot very quickly.”
Charlie Welch, CEO of Zapbattstresses that the problem is that manufacturers set specifications for their cells that you have to follow quite strictly.
Often, everyone drives e-bikes and e-scooters as if they stole them. It puts the cell in a worst case scenario every day, like someone jumps on it, guns on full blast, then later puts it in a warehouse, fully charged, and leaves it there all night. Which from a cell perspective is where it doesn’t want to be.
Unfortunately, cheap e-bikes and repurposed bikes and chargers aren’t the only culprits.
In 2015, Pedego recalled: every model they’ve ever sold due to battery fire potential.
Specialized Bicycle Components Recalls Electric Mountain Bike Batteries several times due to fire hazard.
Santa Cruz Bicycles issued a recall message for Heckler 9 electric bicycles sold between January and March 2022.
I spoke to Jim “Jimmy Mac” McIlvain, and author, editor and bike expert who follows ebike fires. He notes that:
“Established companies such as Specialized, Santa Cruz and Pedego stand behind their products. But the number of e-bike companies selling to US consumers has been far exceeded 181 brands! Brands you’ve probably never heard of.
If one of those brands ignites a catastrophic house or forest fire, they simply disappear, without recourse for the consumer or municipality.”
To date, there is no evidence that fire departments track the brand of ebike batteries or charges that catch fire.
According to McIlvain, neither he nor his wife would charge their e-bikes in their home, noting, “And if a battery were dropped or damaged, we’d never use it again.”
So what is New York City doing about the problem?
Downtown residents take advantage of the convenience of gig economy drivers. Still, the city has made no effort to provide infrastructure such as charging stations and secure storage areas.
Instead, much talk fails to get to the root of the problem and recognize that micromobility as a movement is growing rapidly without any sign of abating.
The New York Housing Authority recently announced a proposed change government housing regulations prohibit residents and their guests from storing or charging e-bikes or e-bike batteries in apartments or common areas. This has the potential for illegal underground storage schemes (yes, with batteries all charging overnight) – this is making my head spin.
The Metropolitan Transport Authority (MTC) of New York is consider a ban on e-bikes and e-scooters. This is despite the fact that there to date no related fires in the transport network.
Interestingly, New York City Councilman Gale Brewer suggests: legislation second use or refurbished batteries.
This won’t do much to stop the fires caused by new store-bought e-bikes. She also suggests that delivery posters and delivery apps should make riders aware of potential battery risks. She also sees a need for fireproof storage units with charging ports (not sure who’s going to pay for that).
Brewer’s most interesting idea is to call Congress to call a hearing to push for federal legislation to hold battery manufacturers accountable.
McIlvain believes that it is inevitable that the government will have to intervene, noting that “the toaster in my kitchen, the nightlight in the hallway and all the power tools in the garage must meet a federally recognized safety standard, so why should I don’t e-bike?”
What is clear is that micromobility is rapidly gaining traction, and this is a complex problem that requires a complex solution that involves manufacturers, drivers, delivery services and city officials.