The popularity of electric bikes and micromobility is on the rise in the U.S. and around the world. More and more people charge their cherished e-bike or e-scooter inside their apartments or garages.
This is a growing safety concern we must take seriously. Are e-bike batteries safe? Both yes and no. Read on to learn more about the risk of battery fires.
Electric bikes undoubtedly have a safer power source than, for instance, very flammable petrol, but lithium-ion batteries used in most e-bikes and electric scooters are only partially safe.
Stories about e-bike batteries that overheat, catch fire, or explode while charging often appear in the news feed, sometimes with fatal consequences. If you search for electric bike battery fires on YouTube, many scary videos pop up.
This article details this increased danger and teaches how to avoid electric bike fires.
Table of Contents
E-bike fire statistics and facts
We have yet to find an overview of all fires caused by e-bikes in the U.S. or elsewhere. This may be because these statistics aren’t collected, or the cause of a fire cannot be rooted to a battery.
We base our facts on news articles, consumer reports, and community forums. Local fire departments, like FDNY, have a few numbers available on their websites.
In 2023, 268 fires in New York City were directly connected to electric bike battery fires, resulting in 18 deaths and 150 injuries.
Looking outside the U.S., China experienced 10,000 e-bike fires and over 200 deaths from 2013 to 2018, according to a recent report.
The London Fire Brigade reported in 2023 that they had to attend to an e-bike fire approximately every two days.
They also said they had to attend 227 fires caused by e-scooters or e-bikes in 2022.
But before we scare you too much, we need to look at how many e-bikes there are without problems.
Statistics can fool you with numbers.
We all know that riding a car is the most dangerous thing you can do to transport yourself, but traveling with an airplane is statistically very safe. Yet, people are more afraid of the latter.
In 2022, over 1.1 million e-bikes were sold in a U.S. bike store, and that number increased in 2023.
So, even with hundreds of fires a year, millions of bikes operate without problems. Have that in mind when you read about fires in the news.
Most fires are caused by cheap micromobility units and not by serious manufacturers.
Anyway, we want you to be safe and not experience the horror of a fire. We will examine the reasons behind fires in e-bike lithium-ion batteries, explain safety measures to prevent them, and identify policies to help mitigate these risks.
Luckily, we have not experienced an electric bike battery fire, not even a smoky one. But we still hear about it in the community on rare occasions. It doesn’t happen often.
We are cautious and follow every single safety strategy we can. So should you.
Why do e-bikes catch fire?
Electric bike batteries can occur due to a variety of reasons. These are the most common:
- Poor battery pack quality from cheap manufacturers is the number one reason. Batteries with manufacturing defects or those made from lower-quality materials are more prone to failures that can lead to fires. This includes issues with the battery management system (BMS), which is supposed to prevent overcharging and manage cell balance. Some cheap e-bikes don’t even have a BMS system, which should be in place for all electric bikes.
- Charging is the period most ebike fires occur. If the battery is left to charge for too long, it can get hot, which can cause lithium-ion cells to become unstable. This could lead to thermal runaway, where one cell overheating can cause adjacent cells to heat and ignite.
- Another reason is damage and wear. Physical damage to the battery, impact or penetration, can disrupt the internal structure, leading to short circuits. Wear and tear over time can also degrade the battery’s protective features, increasing the risk of a short circuit.
- Improper storage and bad handling are dangerous. Storing batteries in environments with extreme temperatures can damage them. Unsafe handling, like dropping the battery, can also lead to issues that may cause a fire.
- The use of non-standard or incompatible chargers is problematic. Chargers not specifically designed for the battery can lead to improper charging rates, resulting in overheating.
Let us look at the battery technology itself. E-bikes use lithium-ion batteries to store their energy, which is also present in electric cars.
The problem starts when the battery is damaged, and a chemical process called thermal runaway starts.
The battery cells are quickly getting way hotter than they should. This results in the batteries being prone to off-gassing, fires, and even explosions.
Batteries can also be prone to overcharging due to the wrong equipment, leading to heating electrical systems.
A spray of sparks, flames, and an explosion can take just a few seconds.
But not all lithium-ion batteries that overheat catch fire immediately. Some generate smoke, which is your queue to unplug and place it somewhere safe to calm down.
What to be done – large-scale
Many cities in the U.S. have looked into ways to avoid this problem. Stores and garages with more than five stored and charged ebikes or scooters require the installation of sprinkler systems and fire-proof doors.
These are expensive upgrades to a building, and many skip them. The last thing we want is a complete ban on transportation methods that use lithium-ion batteries.
Many people depend on e-bikes for commuting or to perform their jobs, like delivery workers. These should be encouraged and supported to buy certified scooters and bikes and not import cheap crappy products.
New York City discussed a complete ban, which we do not want. We encourage everyone to follow mandatory rules so the negative curve can turn.
Other political actions could include banning the sale and import of uncertified brands and batteries. Cheap batteries should never be used on an electric bike. However, this may increase the bike’s price, which may be a problem for many people.
Many larger cities will eventually only accept electric micromobility units certified through safety standards. We applaud that.
On the positive side, many other things are also done, especially in large cities like New York. Spaces for safe charging are available here and there, often converted newsstands.
The main goal is to prevent people from charging inside their homes or offices.
We’ll now look at different methods for avoiding fires and staying safe in a day-to-day scenario.
How to stay safe – small-scale
First, the general public who owns an electric bike or e-scooter must know that batteries may spark a fire. Many people don’t know that. This is the first step to making people more aware and keeping a close eye on maintenance and charging.
If you are in the buying process, you can look for certified ebikes that comply with standards for electric micro-mobility devices. Bikes manufactured by the certification UL 2849 ensure that they are regularly tested and inspected.
Also, check that the battery conforms to UL2271, which certifies the safety of batteries used in light electric vehicles like e-bikes and scooters.
Not all e-bike brands, even if they are ever so popular, are certified with UL 2849.
Unfortunately, it doesn’t mean brands that don’t comply automatically are unsafe.
Safety tips for avoiding e-bike battery fires
If you already have an e-bike, you can take many battery safety precautions and check a few things.
- Read the manual before charging. Follow the manufacturer’s guidelines for charging, storing, and maintaining the battery.
- Look for safety certification. Use batteries certified by UL 2271, which are safe to charge indoors. Also, check that the e-bike itself is UL 2849 certified. You can check this on the battery’s label or a sticker on the bike.
- Avoid charging overnight.
- Buy original spare parts. Don’t buy cheap, off-brand batteries and chargers. Only buy original parts from the same manufacturer as the bike. Many third-party chargers deliver too much power to the battery, which leads to overheating.
- Store the battery in a dry, temperature-controlled climate. Don’t leave it in direct sunlight, for instance.
- Don’t charge many e-bike batteries or other devices from the same outlet. Skip extension cords.
- If you notice the battery or charger getting hot, stop charging at once. This may be a signal that something is wrong.
- Swelling, smoke, or the smell of burned plastic are also bad signs.
- Contact the manufacturer immediately if you experience problems with the battery. Don’t use the battery. You’ll get a new one if the bike is under warranty.
- Don’t try to fix a broken battery or open it. If something is damaged, get it repaired by professionals.
- Unplug the charger when not in use.
- Don’t charge the battery if you don’t plan to use the bike.
- A strap-on temperature sensor on the battery with an alarm can provide extra safety measures if the temperature is too high. Some also use fireproof boxes while charging.
Remember this list when looking for a new e-bike, and check the certification on the equipment you already have.
How to put out a battery fire
If you find yourself in the rare situation of an e-bike battery fire, here are a few things you can do.
If it starts first, it is difficult to put out an ebike battery fire. I would say it’s nearly impossible.
If a fire happens when you ride outside, the obvious thing is to stop, hopefully in a safe location away from buildings and other things that can catch fire. Then, get off your bike and away from it at a safe distance.
If you are home, problems can escalate quickly and turn into a blaze. If you see smoke and the battery is not yet on fire, unplug it immediately. Try to get the battery outdoors, away from the apartment or garage, if possible.
If the battery is on fire, the most important thing is to get out. Save yourself, your family, and everyone else in the house. You can try to throw water on the battery with a garden hose, for instance, but it will not put it out. However, you might save some of the surroundings and keep the battery cooler.
In fact, you need a special fire extinguisher for lithium-ion fires that people don’t have at home. Normal fire extinguishers will not work.
Always call the fire department.
Are e-bike batteries dangerous?
E-bike battery fires are extremely rare. If you have a bike and battery from a serious brand, you will likely never experience any problems.
Most fires happen to cheap, uncertified import batteries.
But we think it is important that you know of the danger. The first step is to follow the guidelines provided by your e-bike manufacturer, and we think you will be fine.
We encourage you to use your e-bike as much as possible and enjoy the ride. Don’t worry, and spend much time thinking of fires. You can rely on e-bikes from serious brands.
Remember to get inspired by the benefits of cycling.
Download the e-bike charging safety guide
COMING: Ensure your safety by downloading our upcoming comprehensive safety guide. Print it out and place it wherever you charge your ebike. It’s a small step that can make a big difference.
