The metropolis with the most electric bikes faces, on average, 3 fires a day caused by their batteries

Touted as much cheaper alternatives to electric cars, new electric bikes can also catch fire, even more often and with at least as serious consequences.

Unlike an electric car, you can take an electric bike into your apartment and repair and maintain it yourself, at minimal cost and without the hassle of all sorts of strict regulations. To some extent this isn’t necessarily a problem, as the hardware supplied by the manufacturer, from the drivetrain to the batteries, is well tested and generally very safe. The problems only arise when, motivated by a desire to save even more money, commuters and small dealers who put a lot of mileage on these vehicles decide to avoid the high charges for replacing worn-out batteries by buying reconditioned or ‘compatible’ batteries from less than reliable sources such as Aliexpress. In the absence of a better understanding of the risks involved, the search for the cheapest possible repairs is extended to other very important accessories such as the power adapter.

And to make the recipe for disaster complete, most electric bike owners solve the problem of charging from the comfort of their own home by hooking up the AC adapter to the vehicle parked right next to the front door of the apartment, possibly before bed. Left overnight to charge, the battery can always provide unpleasant “surprises”. And if the AC adapter is not compatible with the battery (too high voltage), or if the battery has been improperly ‘repaired’ (e.g. by shunting a defective cell group), then the risk of accidents increases exponentially.

With no noxious or smelly gasoline, electric bikes can easily be mistaken for alternatives based solely on manual pedaling, their owners not realizing that ranges that can reach several dozen kilometers involve a lot of potential energy stored in the batteries. Released suddenly and uncontrollably, such as by spontaneous combustion of the electrolyte stored in the dozens of Li-Ion cells, all this energy can turn an electric bike into an unquenchable torch, emitting toxic gases and flames so great that evacuating the battery or the bike outside the home becomes virtually impossible.

Attempting to address the problem, landlords of housing developments offered for rent in New York City have tried to ban bicycles from being brought into the apartment, or even the perimeter of the building. But the measure was abandoned after the initiative sparked a minor revolt among the many tenants who depend on this method of transport for their commute or even their daily income. Alternatively, authorities are now trying to ban the sale of used or reconditioned batteries throughout New York State. At the same time, best practice rules for electric bike owners are being strongly promoted, for example discouraging overnight or unattended charging of batteries. Another plan is to set up dedicated hubs for charging electric bikes, moving the danger to a carefully supervised and controlled space. The problem is that most people who depend on these vehicles use them throughout the day and have little incentive to wait 6-8 hours for a battery charge before heading home.