Meet Ben, your go-to scooter aficionado and in-house wordsmith at Rider Guide. With a genuine passion for two-wheelers (6 years of riding), he’s not just penning reviews but sharing firsthand experiences in an articulate narrative. You can catch him ripping through rocky trails on his Suzuki Vstrom 1000 or doing 45 miles an hour on his Dualtron Victor when he’s not busy at his writing desk, offering you the most unique and informed perspective on every scooter that rides the streets.
Basically, everyone is familiar with what batteries are. Batteries are essential to our daily lives, powering everything from cell phones, to electric vehicles, to electric scooters. While they are incredibly convenient and reliable, batteries can also be dangerous if not used properly. You just need to search for battery-fail videos online to see how scary that situation can be. Battery fires are a very real hazard and can cause serious damage to property and even loss of life.
Lithium-based batteries are a top choice for many devices, including electric scooters, for good reason. They pack substantial energy in a small space, making them compact yet powerful. This makes them ideal for use in a number of portable devices like electric scooters as they occupy minimum space, add minimum weight, and still deliver high power outputs, which is key in these devices. Apart from that, they are also environmentally friendlier than most other battery types and can be recharged multiple.
However, the very properties that make lithium batteries efficient also introduce potential risks. The lithium used is a very reactive alkaline metal that is highly combustible. And while lithium-ion batteries do not contain free lithium metal, they still do contain lithium-ion and other flammable electrolytes that may pose a risk.
It is also important to remember that any time you store large amounts of energy in a confined space, there is potential for release in an uncontrolled or violent manner. This can lead to the generation of heat, smoke, or even a fire, which is why it's so important to carefully manage the life cycle of batteries and pay special attention to safety and fire/explosion issues.
Although incidents of lithium battery fires are infrequent, their potential severity demands our attention. To keep ourselves safe, it's crucial to understand how these batteries function, recognize what can instigate a fire, and be equipped with knowledge on prevention and timely intervention.
Evidence of Lithium Battery Related Fires
In 2018, the U.S. Consumer Product Safety Commission released a report detailing more than 4,232,808 incidents of product recalling due to the fire or overheating risk involved with lithium-powered products over a five-year period. This included 483 types of products, ranging from electric scooters to laptop computers, with 500,000 hoverboards and a few electric scooters being recalled between 2012 and 2017.
There have also been several high-profile incidents involving battery fires, such as the 2019 MacBook Pro recall by Apple Inc. Over 432,000 MacBook Pro laptops were recalled in this recall due to the risk of battery fires. In 2017, Samsung recalled its Galaxy Note 7 smartphone (2.5 million devices globally) due to numerous reports of battery fires.
While the number of incidents is relatively small compared to the millions of lithium-powered products in use, it's still important to be aware of the potential risks and exercise caution when using any battery-powered product. Fortunately, the number of recalls and incidents has also been dropping in recent years as manufacturers adopt better ways of designing and building these batteries.
What Type of Batteries Do Most Electric Scooters Have?
The obvious difference between the two batteries is the material and technology used. The lithium battery is more expensive, more efficient, and has a higher energy density than lead-acid batteries– (250-670 Wh/L vs. 80-90 Wh/L ). This means you can get more power out of a lithium battery than a lead-acid one, making it a better choice. Apart from this, lithium batteries shine over their lead counterparts by:
- Having a lower charging time
- Lower self-discharge rate of around 1.5-2% per month against 4-6% of lead-acid batteries
- Much longer lifespan than lead-acid batteries
- Lead-acid batteries also require more maintenance than lithium-ion batteries. They must be regularly cycled (discharged and recharged) to maintain their battery life.
- They are smaller and weigh less. This is a huge benefit for electric scooters, as dimensions and weight should be kept to a minimum.
However, there are some downsides to using li-ion batteries in scooters. One is that they’re extremely sensitive to temperature and are inherently flammable. This means that lithium-ion batteries tend to degrade much faster when exposed to temperature extremes – either hot or cold. Exposure to temperatures outside the operating condition can lead the lithium battery to fail and may also become fire safety hazards.
To fully grasp how these fires occur, you need to first understand how batteries work.
How do Lithium-ion Batteries Work
- An Anode (Negative Electrode): Typically made of graphite.
- A Cathode (Positive Electrode): Made from a metal oxide, such as lithium cobalt oxide (LiCoO2) or lithium iron phosphate (LiFePO4).
- A micro-permeable separator- A thin insulating piece, often made of a porous polymer, that prevents the anode and cathode from touching directly and only allows the flow of lithium ions through it (i.e., it doesn’t conduct electrons).
- An electrolyte, which is a lithium-based salt that carries the lithium ions from the anode to the cathode and vice versa through the separator.
Charging Phase: When you connect the battery to a charger, an external voltage is applied. This voltage is greater than the battery's voltage, creating a potential difference. This difference pushes lithium ions from the cathode, where they are embedded in the lithium metal oxide structure, through the electrolyte and towards the anode. At the same time, electrons are freed from the cathode and move through the external circuit towards the anode. However, these electrons cannot pass through the separator, so they take the longer path around it(outer circuit). Upon reaching the anode, the electrons reunite with the lithium ions, forming lithiated carbon. The battery is considered fully charged when there's no more significant movement of ions.
Discharging Phase: When the battery is connected to a device (like a scooter), the built-up energy or chemical potential difference in the battery causes the lithium ions at the anode to move back through the electrolyte towards the cathode. Simultaneously, electrons are liberated from the anode, traveling through the electric scooter's external circuit, providing it with power. These electrons then rejoin the ions at the cathode. The battery is deemed discharged once the maximum amount of ions have transitioned back to the cathode.
The operation of lithium-ion batteries relies on these carefully controlled electrochemical reactions. A stable environment is pivotal for their optimal function. Any deviations in these conditions could disrupt the reactions, potentially leading to mishaps.
With this understanding of battery function, we can explore potential risks, such as fires.
What Causes an Electric Scooter Battery to Catch Fire?
If a battery's integrity is compromised, particularly the crucial barrier of the electrolyte separator, it can lead to dangerous scenarios. A damaged separator can allow unintended contact between the cathode and anode, resulting in a short circuit. This rapid, uncontrolled movement of electrons and ions can produce excessive heat or even a spark. Should this heat not be efficiently dissipated or if it surpasses the battery's thermal limits, a fire can ensue.
Complicating matters, the very chemicals that power these batteries can exacerbate a fire. The electrolyte, which contains volatile organic solvents mixed with lithium salts, is inherently flammable. Moreover, because the cathode is constructed from a lithium oxide compound, there's a potential for oxygen release when subjected to certain conditions—providing yet another fuel source for the flames.
In essence, many battery fires stem from a combination of structural vulnerabilities and suboptimal usage or handling. Notable causes include:
- Electrical short circuits
- Manufacturer defects and design flaws
- Abnormal or improper usage of the battery
- Rapid discharge
- Use of low-quality components in the battery
- Mechanical damage
- Charger issues, among others
What is Thermal Runaway?
A thermal runaway can happen when there is a sort of failure in the battery, such as a short circuit or thermal failure. Once the battery goes into a thermal runaway, the internal temperatures rise within a fraction of a second, and the stored energy is released uncontrollably. The heat causes the chemicals in the battery to break down, which releases more heat. This increases the temperature, and eventually, the battery can catch fire/self-ignite. Thermal runaway can also result in the ejection of toxic gasses, smoke, and other particulates in a violent manner.
How Do I Know if an Electric Scooter Battery is Damaged?
- Excess Heat: It's normal for lithium batteries to generate heat when operating or charging. But if your scooter battery feels extremely hot oftenly, then there is a high chance it’s defective.
- Odor: If you notice a foul smell ( a faint burning smell) coming from your battery, it's a good indication that the battery is going bad. The odor is caused by the release of pressurized gasses, which is a byproduct of unintended chemical reactions that takes place inside the battery.
- Visible leakage: Visible leakage from a battery is a serious problem that should be addressed immediately. If left untreated, the leaked electrolytes can cause extensive damage to both the electrical system and the body of the scooter. In addition, the leaked contents are highly corrosive and can eat through metal, paint, and plastics.
- Swelling: Another sign is bulging. If the battery is visibly swollen, it's also likely damaged and should be replaced.
- Noise: If the battery produces strange hissing and popping sounds during operation, it might be a tell-tale sign that it’s failing
How do you Prevent Electric Scooter Battery Fire?
Observing Proper Charging Practices
- First, always follow the manufacturer's instructions found in the user manual when using or charging batteries. This will help ensure that you use the battery safely and correctly.
- Only use the charger that came with your device. Some aftermarket chargers can be unsafe and may not meet the proper safety standards. Each battery has a specific charging voltage that needs to be adhered to.
- Always use rechargeable lithium batteries from reputable manufacturers and retailers. Counterfeit or knock-off batteries may look identical to authentic batteries, but they often don't meet the same safety standards. For example, they may have lower-quality materials that can lead to overheating and fire.
- Charging should be conducted at a temperature between 40°F- 110 °F (4°C- 43°C ); charging at a lower or higher temperature than this can trigger some unwanted chemical reactions in the battery cells leading to a fire or explosion.
- Never overcharge your rechargeable batteries; only recharge them for the amount of time specified by the manufacturer. When batteries are overcharged, they can heat up and catch fire easily. So be sure to unplug batteries once they are fully charged. Thankfully most electric scooter batteries have a Battery Management System in place to prevent lithium battery fires.
- Never leave your electric scooter unattended while it is charging. Many battery fires occur when people leave their devices plugged in and unattended for extended periods of time. If you must leave the house or go to sleep while your batteries are charging, be sure to unplug them first.
- Watch where you charge your electric scooter. It should be away from flammable surfaces that can easily catch fire in case the battery malfunctions. This includes things like paper, fabric, and vinyl wood. If possible, try charging the battery in a fire-safe charging bag.
- During charging operations, it is normal for a healthy battery to be slightly warm. However, if you notice the battery becoming excessively hot, releasing smoke, or emitting a smell, immediately disconnect it from the power source. These signs could indicate that the battery is overheating and could potentially catch fire.
When in Use
- Do not overload the battery. When a battery is overloaded, it can overheat and catch fire. Before adding any aftermarket additions to your scooter, it is important to check the manufacturer's instructions to ensure that the device does not require more power than the battery can safely provide.
- Avoid exposing the battery to water and other liquids as they may cause corrosion or damage to the delicate internal components of the cells, which can eventually trigger a lithium battery fire. Avoid riding your scooter in wet conditions if it is not IP rated.
- Avoid operating a battery that has obvious signs of damage. Replace the battery immediately.
- Only use the battery within the manufacturer's recommended operating temperature.
- Avoid storing your scooter in areas that have relatively high temperatures and high humidity. Always store the scooter batteries in a cool, dry place away from direct sunlight. The recommended storage temperature is about 59° F (15° C), and the ideal range is between 32°F(0°C) to 86°F ( 30°C). High temperatures are likely to increase the battery's self-discharge rate and the possibility of a failure, which can lead to a fire. Never store the scooter battery at a temperature greater than 60 °C as it may trigger a thermal runaway to occur.
- Store your scooter battery in a dedicated space away from any hazardous and flammable materials.
Maintenance and Disposal Practices
- Make sure you regularly inspect your electric scooter's batteries for any signs of damage. If you notice anything unusual, such as swelling, leakage, or discoloration, discontinue use immediately and replace the battery.
- Be sure to recycle your lithium-based batteries properly. Many communities have special collection facilities for recycling these batteries. Alternatively, you can contact your device manufacturer to see if they offer a take-back program as they do for some electric cars.
- Never dispose of lithium-ion batteries in a fire.
How do you Stop an Electric Scooter Battery Fire?
Prioritize Safety: If you suspect your battery might ignite, distance yourself and others immediately. The potential for explosions or harmful fumes is real. Also, remove any flammable objects in proximity to prevent the fire from spreading. If the situation looks dire, don't be a hero; ensure everyone's safety and let trained professionals tackle the fire.
Using Fire Extinguishers: For a small fire, use a standard ABC or BC dry chemical fire extinguisher, commonly available at hardware stores. Remember, lithium-ion battery fires are classified as Class B due to the flammable electrolyte they contain. Despite the name, lithium-ion batteries don’t contain metallic lithium, so they aren’t Class D fires. Using a Class D extinguisher won't help.
Water as an Extinguisher?: Using water to put off lithium-ion battery fires is a highly controversial topic with many schools of thought. Lithium is a very reactive metal and reacts violently with water. However, contrary to what people think, lithium-ion batteries contain really small traces of elemental lithium, which cannot trigger a major violent reaction, especially when dealing with small fires.
For small fires flooding the battery with water has proven to be an effective method. However, just to be on the safe side, it's advisable to use the designated fire extinguisher for these kinds of fires.
Major battery fires are often extinguished by water. The water cools the temperature of the lithium salts to sub ignition ranges (below 500°C ), preventing them from igniting again. The lithium salts are self-oxidizing and cannot be starved of oxygen, so some traditional methods of extinguishing fires would not work.
How Common are Scooter Battery Fires?
The seemingly many videos on the internet are isolated cases that get blown out of proportion through the resharing network, making the situation look more grave than it is.
A good example is the Galaxy Note 7 fire that had everyone thinking the phones were exploding at the speed of unpopped popcorn on hot oil.
For scooters, the statistics are even lower as most come equipped with battery management systems. Therefore, while they do occur, lithium battery fires are not as common and maybe just 1 for every 10 million.