Learn more about micromobility battery safety
E-bikes & e-scooters are accelerating in popularity
Personal ownership of micromobility devices is skyrocketing thanks to their versatility and increasing demand for last-mile delivery.
Most micromobility owners store and charge their devices indoors.
The batteries that power them pose significant fire risk
When charged or stored indoors, malfunctioning lithium-ion batteries can cause fast-spreading, destructive, and deadly fires that are difficult to extinguish and complex to remediate. Insurers are taking notice, increasing rates and even canceling policies for properties who don’t address these risks.
Between 2017 and 2022, there were over 25,000 incidents nationwide related to lithium-ion battery fires or overheating.
Why micromobility batteries fail
Batteries can fail due to poor design, manufacturing defects, unsafe charging practices, or battery damage. The more risk factors present, the higher the risk of thermal runaway and dangerous battery fires.
Lithium-ion batteries are ubiquitous in household devices like cell phones, laptops, and electric toothbrushes. But micromobility batteries are 8-15x larger and are uniquely prone to thermal runaway.
Thermal runaway is a rapid, uncontrollable chain reaction that can result in spontaneous combustion.
Indoor micromobility battery fires can become catastrophic in an instant
The speed of thermal runaway can render typical consumer protections like smoke detectors & fire extinguishers useless. Traditional firefighting methods like water & foam can’t easily contend with battery fires.
E-bike battery fires cost NYC an est. $518.6 million from 2019–2023.
Counterintuitively, blanket bans can increase risk
Prohibiting micromobility indoors seems like a straightforward fix. However, given peoples’ dependence on these devices, bans are rarely successful. When implemented poorly, bans can inadvertently increase fire risk by driving users toward covert storage & charging practices.
FAQs
The basics
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Electric micromobility (e-MM) refers to small, lightweight electric vehicles designed for personal transportation. These include electric bicycles (e-bikes), electric scooters (e-scooters), electric skateboards, onewheels, and other similar devices. While most common in urban environments due to their suitability for shorter trips and limited storage requirements, e-MM devices are gaining popularity in various settings including university campuses and suburban areas.
Many e-MM devices are powered by lithium-ion batteries, which offer superior energy storage capabilities. The decreasing cost of these batteries has contributed significantly to the growing accessibility of e-MM devices, with lithium-ion battery prices dropping by approximately 34% over five years and 82% over a decade. However, not all e-MM devices use lithium-ion technology, with some utilizing alternative battery types or power systems.
These vehicles provide an affordable and convenient transportation option that helps reduce traffic congestion and emissions. They're particularly valuable for short to medium-distance trips and can serve as an effective last-mile solution connecting riders to other forms of transportation.
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A lithium-ion battery is type of battery used to charge a wide variety of consumer items from cars and phones to children's toys. The technology has proliferated because it holds a large charge in a relatively small/lightweight compartment, and can be easily recharged.
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They can catch fire a number of ways: on their own due to poor manufacturing or damage; while being attached to the wrong charger or device; or as a result of the spread of fire from another source to the device. It’s important to note that due to the sensitive nature of the technology, even a small flaw that isn’t apparent to the user could cause the device to fail. Similarly, because they contain so much power within the battery, even a small fire that spreads to a lithium-ion battery could cause a much larger, and more dangerous, fire once the battery is involved.
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A lithium-ion battery contains thousands of smaller cells. A failure in even one cell can cause a domino effect to the others. This means that once a device fails, there is no way to prevent a larger failure and therefore a fire.
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They catch fire faster, and create more fire when they fail. These fires look more like explosions than they do traditional home fires, where smoke precedes the fire. The risk significance of this is that they made catch fire and fail before a smoke detector can go off and provide a resident time to escape. Without warning a time to escape, the change of the fire being deadly increases significantly, as does the damage from the fire.
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These are standard organizations that set minimum safety standards for consumer devices.
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No, they are simply a guarantee that a manufacturer has met minimum safety standards. How a battery is stored, charged, used, and maintained can all impact risk.
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It requires submersion in water or specialized fire retardant materials. These devices are so unstable after catching fire that they are known to reignite. Fire fighting and clean up from lithium-ion batteries requires expertise, and additional expense.
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Outside, or in a location that is away from residents, and includes fire proof materials to prevent the spread of a fire.
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Next to a bed, or in the pathway to an exit such as a doorway, hallway or exit. Charging them near debris can also add fuel in the case of a fire.
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While it might seem logical to ban these, we have seen bans be ineffective. This seems to be because demand for these products by consumers is great, and bans have thus far driven the use underground resulting in less safe usage, rather than eliminated their use. Based on this evidence, we believe that both bans and safe usage require planning, education and enforcement to have a real impact on risk reduction.
The risks
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Property managers should be concerned because they create a fire risk, a risk that increases if they are improperly used or managed. Luckily, there are steps you can take to manage that risk.
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Each contains it’s own risk, and minimizing the risks for each is essential to safe usage. Luckily, there are steps you can take for each component of the device and its risk profile.
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All lithium-ion batteries present risks. This is no different than other flammable or combustible materials. Like those materials, how the batteries are purchased, used, stored and maintained can determine how much risk they present to a user or facility. There are a number of ways to reduce and manage the risks they present.
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Any device that does not have UL or EN certification presents significant risks as there is no way to know if it was properly made or maintained. The flaws that make a battery unstable can not be seen or found by consumers, so without certification, one cannot know how risky that device may be. There have been numerous cases of poorly made batteries exploding inside their packaging before they are charged or used.
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Lack of Certification: Certification means a device was properly made to minimum standards. A non-UL or EN certified device can be unstable from the point of manufacturer, meaning it doesn’t even need to be used to fail and catch fire. We have seen non-UL devices catch fire in.
Improper charging
Improper use
Device size
Storage location
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If fire spreads to the device, it will fail and catch on fire. The amount of fire produced by these devices is significant, so extension to a e-MM device can cause a fire to get much larger and more dangerous quickly.
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Maintenance and repairs can make a device more vulnerable to failure and should only be conducted by certified professionals. At home repair kits and other consumer repairs should not be considered.
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New technologies are being explored as we speak. None of them are yet available or proven in consumer devices. Millions of e-MM devices have already been manufactured and sold, and will be in the consumer market for some time, so learning to use, maintain and store these safety is essential for any user or property manager.
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Risk can increase at any stage in a battery life cycle. Risk reduction should happen at every stage of a battery life-cycle.
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Like e-MM, the size of the battery is of particular risk, as is the all weather usage. However, while EVs do have fires and the fire service is still studying this risk, they differ in a couple critical ways. One, they are all extremely well-made from know manufacturers who prize certification and safety. While there are some e-MM devices that are in a comparable category, they are rare compared to the proliferation of cheaply made, uncertified e-MM devices. Lastly, and most importantly, cars are rarely charged inside a home. Many e-MM devices charge inside homes, often next to beds and exits. This makes them far more likely to cause a deadly fire than a device charging outside or in a parking structure.
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All of these items are powered by lithium-ion batteries. They differ in ways that are significant to safety. One, because these devices are smaller so are their batteries. That makes any resulting fire smaller and less risky. Two, they are made by a small number of known manufacturers who put a premium on certification and safety. Not only are they all made with UL certification, but the negative attention of a small number of fires in these devices early in their development caused the manufacturers to increase their safety oversight of these devices. e-MM devices have exploded in popularity, and so has the number of fly-by-night manufacturers who cannot be held accountable for producing unsafe devices. There are goo manufactures of e-MM devices, but they are vastly outnumbered by cheap and uncertified device manufacturers. Lastly, the use of e-MM devices on the streets makes them prone to post-production damage (dents, salt and water exposure, overheating) that can increase their fire risk.
Additional micromobility safety resources
Coming soon!