Several unfortunate accidents involving e-scooter fires have occurred and continue to happen. This has made people wonder what causes an electric scooter to catch fire.
Electric scooters can catch fire at times. However, the occurrence of such incidents isn’t as common as it was several years ago. The main reasons why an e-scooter can ignite are using faulty, low-quality batteries and improperly charging, maintaining, and storing the scooter.
Why are some electric scooters catching fire?
Electric scooter batteries are the main cause of fires.
Most electric scooters are powered by lithium-ion batteries. They have numerous benefits – a high energy density, high efficiency, and a lightweight, compact design. Also, they have a fast charge rate, can be recharged many times, and last longer than their counterparts.
However, although this popular battery type offers many benefits, it also poses a fire hazard, as it contains a combustible electrolyte and lithium compound. If a lithium-ion battery is improperly manufactured or managed, it can catch fire and burst into flames, causing considerable damage to property and even casualties.
Lithium-ion batteries basics
Now, before I begin explaining in detail why lithium-ion battery failure is the most common cause of electric scooter fires and how a fire can be prevented or stopped, let’s see what a Li-ion battery is made of and how it works.
What are lithium-ion batteries made of?
Lithium-ion batteries contain a positive and negative electrode – a cathode and an anode. They also comprise a separator and an electrolyte.
The cathode is made of lithium oxide, with lithium cobalt oxide being the most commonly used material. On the other hand, the anode is made of graphite. The content of both electrodes is separated by a permeable separator that holds a lithium-based salt electrolyte.
How do lithium-ion batteries work?
Put simply, a lithium-ion battery works by transferring electrons and lithium ions between the electrodes through the electrolyte and an outer circuit.
During charging, lithium ions flow from the positive to the negative electrode via the electrolyte. The electrons produced during this transfer also flow from the positive to the negative electrode, but they do so through an outer circuit, which in this case, is the circuit of the electric scooter. When there’s no longer a movement of lithium ions and electrons, this means the battery is fully charged.
On the other hand, when the battery is discharging, these electrochemical processes are reversed.
This transfer of electrons and ions is what produces an electrical current that’s used to fire up the electric scooter. Once the lithium-ions have successfully reached the positive electrode, the battery is considered fully discharged.
Needless to say, any interference in the operating conditions or change in the electrochemical reactions in the battery could cause bad, or even fatal, incidents.
What causes a lithium-ion battery to catch fire?
Let’s see now why lithium-ion batteries are susceptible to fires.
Construction and design defects
Unfortunately, there are unconscientious electric scooter manufacturers that create poor designs and use cheap, low-quality materials when making their batteries. Also, it’s very likely that the batteries aren’t open to quality control inspections as well.
Not following certain standards when manufacturing a lithium-ion battery can lead to serious issues, such as a short circuit and thermal runaway, which can cause the battery to catch fire.
For instance, if the separator holding the electrolyte gets damaged during the manufacturing phase, this can make the lithium ions and electrons flow freely from the positive to the negative electrode and vice versa. This often causes a short circuit, which creates gas pressure and heat.
If the amount of gas and heat is higher than the amount of gas and heat the battery is able to dissipate, this leads to thermal runaway – one of the primary causes of lithium-ion battery fires.
Internal short circuit
In a lithium-ion battery, a short circuit occurs when the cathode and anode are interconnected electronically, which results in the delivery of a significant amount of energy and uncontrolled current.
When a short circuit is prolonged, this leads to self-discharge and an increase in the internal temperature of the battery. If the temperature exceeds a certain level, the electrolyte can begin decomposing, and thus cause thermal runaway posing serious safety hazards.
Short circuits are usually caused by:
- poor battery design
- poor cell quality
The battery’s content and design
A lithium-ion battery is more prone to catching fire compared to other battery types due to the following reasons:
- Its lithium salt-based electrolyte is highly combustible.
- During charging and discharging, the materials in the cathode expand and contract, which puts stress on the battery. Consequently, it can release oxygen, which is also highly combustible.
- It has a relatively small storage capacity and it stores a considerable amount of energy.
Most lithium-ion battery failures are produced by construction defects, flawed design, improper storage and operation, thermal runaway as well as mechanical and electrical abuse.
During discharging, lithium ions move from the negative towards the positive electrode. If the battery is over-discharged, the negative electrode (anode) will begin dissolving in the electrolyte. Once dissipated into the electrolyte, the copper particles increase the risk of a short circuit, which can trigger a fire.
Moreover, a short circuit can also trigger chemical processes that create combustible gases, such as oxygen and hydrogen.
For a lithium-ion battery to operate properly, its safe and optimal charge levels need to be maintained. Overcharging the battery or charging it at a fast rate can cause it to exceed its charging limit, and thus reduce its performance or make it useless altogether.
Moreover, one study has shown that overcharging a Li-ion battery leads to thermal runaway too. And once the battery’s internal heat gets out of control, this inevitably leads to a fire.
However, any e-scooter rider should know that most scooters coming from reputable suppliers are usually equipped with a Battery Management System (BMS). The function of the BMS is to prevent you from overcharging or depleting your scooter battery.
Batteries rarely get physical damage in electric scooters since they’re typically encased in hard-wearing plastic or metal boxes.
However, frequent shocks and hits can damage a battery by puncturing or breaking it. Once the battery gets damaged mechanically, this can cause a short circuit, which, in turn, can result in gas and heat accumulation. And as you may already know, these changes lead to a thermal runaway.
Every rider should know that a mechanically damaged battery can instantly cause a fire or give rise to a defect that can cause the scooter to catch fire later.
Other factors that can damage lithium-ion batteries include:
- very high temperatures (e.g., above 55°C/130°F)
- charging in zero-degree temperatures (32°F)
- using ultra-fast chargers that are not suitable for Li-ion batteries
The chances of an electric scooter that has a waterproof battery and casing catching fire are quite small. Unfortunately, not all e-scooters are waterproof, which increases their risk of turning into a fireball.
In such scooters, moisture and water may enter the area where the wires come in, and thus over time cause the metal connections between the battery’s cells to rust. Once they do, this can lead to a short circuit and cause a fire.
Exposure to high temperatures
Electric scooters using lithium-ion batteries should be operated in temperatures ranging from 14 F° – 113 F° (-10°C to 45°C).
When the outside temperature is higher than the internal one of a Li-ion battery, its cells begin to heat.
When the battery gets heated to a certain level, this leads to a reaction between the electrolyte and the positive electrode. This reaction causes more heat to be produced, which, in turn, increases pressure in the cells. Consequently, the cells respond to that pressure by discharging content that may ignite a fire.
In addition to triggering a thermal runaway, a battery’s increased temperature may also result in the creation of combustible gases, which cause the battery to burst into flames.
What is thermal runaway?
The chain reaction phenomenon known as thermal runaway occurs when the lithium-ion battery gets into a self-heating state. This leads to a sharp increase in the temperature and pressure and an uncontrollable release of energy in the cell.
As a result of this, the chemicals in the battery begin to dissolve. Also, smoke and toxic and combustible chemicals and gases are emitted, which, in turn, leads to even more heat. Needless to say, this causes the temperature to rise fast, and eventually, the lithium-ion battery can ignite a fire.
You can find out more information about thermal runaway in the study here.
What causes thermal runaway?
There are several causes of thermal runaway. However, one study shows that one of the most common causes of this phenomenon is a li-ion battery’s internal short circuit.
Other common causes of thermal runaway include:
- mechanical damage
- improper use of the battery
- external short circuit
- very low-temperature environments
Thermal runaway prevention
Decreasing battery loading is an essential prerequisite for warding off thermal runaway events. Battery loading includes improper discharging and charging as well as frequent hits and shocks.
Thermal runaway can be prevented in the following ways:
Using battery management systems (BMS)
Most modern electric scooters are equipped with electronic battery management systems. The BMS prevents the battery from overcharging or fully discharging. It also detects a rapid increase in temperature and causes a cutoff to prevent the battery from overheating.
Using a sturdy battery pack casing material
Most Li-ion battery packs are enclosed in sturdy plastic or metal casings. Such casings help protect battery packs from overheating during discharging and charging.
Ensuring heat dissipation
The most common methods electric scooter manufacturers use to ensure heat is released from battery packs include:
- using a fan
- using air cooling
- wrapping the battery pack in a liquid cooling jacket
How common are electric scooter battery fires?
Let’s get one thing straight: the risk of a lower-power commuter electric scooter or one produced by a reputable manufacturer turning into flames is low.
The incidence of electric scooter fires may have been higher 10 or 15 years ago. However, it’s been decreasing in recent years thanks to the many safety features of modern batteries that power scooters. Also, manufacturers have started applying better methods of building scooter batteries.
However, the truth is that any device that uses electricity is a potential fire hazard, especially when safety measures aren’t taken to minimize this hazard.
So, needless to say, government and the industry should bring in tougher regulations for manufacturers of electric scooters. They should also set strict standards according to which batteries will be designed and tested. Until this happens, no one can guarantee that an electric scooter won’t ever catch fire and turn into a fireball when it’s being ridden, charged, or simply parked in the driveway.
How can you tell whether an electric scooter battery is damaged?
Being able to tell if your scooter battery is damaged can protect you from many unwanted occurrences. So, here are several red flags you should look out for.
When a battery gives off a foul odor, this is a telltale sign that pressurized gasses are being released and the battery is defective.
If you notice that your scooter battery often releases excess heat, this is a warning sign that it’s going bad.
You’ll know a battery is corroded if it has water drops on the shrink wrap surrounding the battery or if the cable connections are rusted. However, unless you’re skilled at disassembling an electric scooter, the best option is to take your scooter to a workshop or a mechanic.
Swelling and/or bruising
When a battery looks bulged or bent or has even the slightest bruise or dent, this is an indication that’s defective and should no longer be used.
Electrolyte leakage can lead to serious defects in the electric scooter’s body and electrical system. It’s a grave issue that must not be ignored.
If your scooter battery makes unusual popping or clicking sounds, this is a sign it’s going bad or it’s already dead.
If any of these signs are present in your battery, stop using it and get it replaced!
Should you be worried?
You’ve probably heard a few stories or seen several videos on the internet of electric scooters catching fire and causing damage to property or putting someone’s life in danger. However, there are millions of electric scooter owners that have never complained about their scooter batteries.
So, to make sure you get yourself an electric scooter that’s unlikely to ignite and put your life in danger, here are a few things you should consider before buying one:
- Always purchase from retailers you know or reputable brands
- Avoid buying an e-scooter that costs way less than other models
- Make sure that the e-scooter you’re planning to buy was designed and manufactured following correct procedures as well as strict standards and regulations
- Perform regular checkups as part of your scooter maintenance routine, specifically on the battery
How can you prevent an electric scooter fire?
In what follows, I’ve provided several useful tips on how to minimize the risk of an e-scooter battery fire in different situations, such as when:
Buying an electric scooter
- Buy e-scooters as well as batteries and chargers from sellers you already know or reputable manufacturers to make sure you get high-quality products. Also, check if they were manufactured following British or European standards.
- Check if the electric scooter you want to buy has been recalled.
- Register your scooter so that the manufacturer could reach out to you more easily and provide you with any safety information or let you know they’re going to recall the product if they decide to do so.
- If you buy separate electric scooter accessories, make sure they’re compatible.
Riding your electric scooter
- Make sure you use your battery within the temperature range recommended by the manufacturer.
- Avoid overloading your scooter battery by adding any extra accessories to the device to prevent it from overheating and igniting. Your scooter should use as much power as the battery is designed to offer.
- Unless your e-scooter is IP rated, do not ride it on rainy days. When a Li-ion battery is exposed to water, this can corrode the cells. This, in turn, can cause a fire. It may also be a good idea to additionally waterproof your scooter for a bit more protection.
- If your e-scooter gets wet, place it in a dry place to allow the water to evaporate before riding it.
Charging your electric scooter
- Adhere to the charging times provided in the manufacturer’s instruction manual, especially when you fully charge your e-scooter.
- Only use the charger that’s been approved for your scooter by the manufacturer. If you notice the charger is damaged, replace it with one from the same manufacturer or a reputable seller. Your scooter battery needs to be charged according to its specific charging voltage. Moreover, using the wrong or damaged charger may cause overcharging.
- Place your charger on a non-combustible surface.
- Make sure the battery pack and charger aren’t covered during charging. If you cover them, this can cause overheating and eventually a fire.
- Avoid overcharging your battery as this can cause it to heat up and ignite fast.
- Charge your battery at the temperature range of 4°C – 43°C (39°F-110°F). Charging at temperatures higher or lower than this range may cause electrochemical reactions in the battery and cause it to catch fire or explode.
- Most modern electric scooter batteries come with a Battery Management System to prevent overcharging, overheating, and fire. However, as soon as your battery has been charged, unplug your charger from the wall.
- Unplug your charger, too, if you spot that the battery releases a foul smell, smoke, or extreme heat during charging.
- Install a smoke detector or heat alarm in the area where you usually charge your scooter.
- Avoid riding your scooter right after you’ve charged it. Give the battery 5-10 minutes to cool down and then you can go for a ride.
- Don’t charge the battery immediately after using it either. Give it an hour to cool down before charging it.
- Avoid charging your e-scooter while you’re sleeping or not at home.
- Use un-coiled extension leads.
- Make sure you never charge or store your e-scooter near flammable objects or materials, such as vinyl wood, fabric, and paper.
Take a look at my guide on how to charge your electric scooter for all the detailed steps.
Storing your electric scooter
- Make sure you never keep your e-scooter in extremely cold or hot places. It’s recommended that you store it at a temperature of 59 °F / 15 ° C. Also, don’t leave it in your kitchen or out in the sun for an extended period of time since high temperatures can cause a thermal runaway.
- Don’t keep (or charge) your e-scooter in communal areas or emergency exit routes, as in case it catches fire, this will make it harder for you and anyone else to escape.
- Store your charger and battery in a dry, ventilated, and clean place.
- If your battery is removable, store it in a fireproof bag.
- Store your e-scooter and li-ion battery according to the manufacturer’s instructions, if you know you’re not going to ride your two-wheeler for a prolonged period of time.
Maintaining your electric scooter
- Test and replace the electrical system, including the battery, regularly. And whatever accessory needs to be changed, ensure you replace it with one from either the manufacturer or a reputable retailer. In this way, you’ll ensure the accessory meets proper safety standards.
- Avoid putting too much tension and pressure on your electric scooter. Doing so can damage its components and battery, and thus cause a fire.
- If you spot visible leakage or the battery looks worn out, discolored, or bulged, stop using it right away and replace it.
- Make sure you never install batteries that have been damaged or dropped in your scooter. Even if one battery cell is worn out, this can result in a short circuit, which, in turn, can cause a fire.
- Don’t keep your scooter battery completely full or empty. It’s recommended you keep it at 20-80 percent.
How do you extinguish an electric scooter battery fire?
First things first, if you suspect your e-scooter is defective and it’s going to ignite, you should make sure you and anyone else stay away from it. If your ride catches fire, it may release smoke and toxic fumes or explode, so it’s best you don’t stay anywhere close to it.
Now, if your scooter explodes and the fire spirals out of control, the best thing to do is to call emergency services to put the fire out and stay out rather than trying to extinguish the fire on your own.
On the other hand, if the fire isn’t big and looks controllable, try to smother it by using a regular ABC fire extinguisher. Class BC and DC fire extinguishers can be helpful as well.
In case you don’t have a fire extinguisher nearby, it’s best to submerge the battery in water. The water will cut off the fire’s oxygen supply and reduce the temperature of the lithium salts.
Although the risk of an electric scooter igniting or exploding has been minimized in recent years, it still exists. However, this doesn’t mean you should refrain from buying that amazing, modern vehicle you’ve been thinking about.
Buying an e-scooter from a reputable seller, storing it properly, and charging your battery correctly are some of the steps you can take to reduce the risk of your scooter catching fire.
Also, make sure you maintain both your scooter and your battery by closely following the manufacturer’s instructions.