Lithium-Ion Battery Fires: What You Need to Know

Chances are, your house is full of devices powered by lithium-ion batteries. These rechargeable batteries are found in everything from children’s toys and cell phones to power tools, e-bikes and electric vehicles. Rechargeable batteries are a good idea for electronics using a lot of power over a short amount of time; they are more environmentally friendly and cost-effective than single-use batteries. But if these batteries overheat, are exposed to saltwater or are damaged, there is a risk of fire and explosion.

You’ve likely seen recent news stories explaining the dangers of lithium-ion batteries. After hurricanes like Helene and Milton in 2024, saltwater from the storm surge came in contact with lithium-ion batteries in electric vehicles and other battery-powered items like golf carts and scooters, causing numerous house fires. If you’ve taken a flight in recent years, you’ve likely heard the requirement of keeping spare lithium-ion batteries in your carry-on baggage. These scenarios have made people more aware of lithium-ion batteries, but the real risk isn’t always understood.

Why are lithium-ion batteries popular?

Devices that use lithium-ion batteries can be smaller than those with traditional batteries. Because lithium is the lightest of the metal compounds, more energy can be stored in a smaller space, leading to smaller devices. When you are talking about handheld devices like cell phones, a smaller and lighter product is the goal.

Consumers like lithium-ion batteries because they can be recharged, eliminating the need to buy new batteries. Additionally, lithium-ion batteries do not have a memory effect, which is common with other types of rechargeable batteries. Batteries with a memory effect lose capacity and available voltage when the battery is recharged before it has been fully discharged. Lithium-ion batteries aren’t negatively impacted like nickel-cadmium and nickel-metal hydride batteries with regard to the memory effect.

Are lithium-ion batteries a fire risk?

If stored, used and charged properly, lithium-ion batteries are typically safe. Follow these steps to use lithium-ion batteries safely:

• Store batteries in a cool, dry place and away from flammable material and possible flooding. Keep them out of the sun and avoid extreme cold.
• Follow the manufacturer’s storage recommendations.
• Use the charger provided with the device. Some chargers are set up to cycle on and off during the charging period to keep the device’s temperature down. Using a different charger can cause batteries to overcharge, which is a safety issue.
• Unplug the device when charging is complete to decrease the risk of overcharging.
• Do not charge devices on your bed or under a pillow. Ensure there is enough airflow to the charging device to maintain a cool temperature.

It’s also important to note that these types of batteries have a limited lifetime. It is typical for rechargeable batteries to last two to three years or up to 500 discharge/charge cycles. Some signs of age include the battery discharging more quickly than is typical, getting hot or swelling, or losing the charge when not in use. If you notice any of these signs, stop using the battery and seek an approved replacement. Do not attempt to replace a lithium-ion battery yourself before consulting the manufacturer.

What causes lithium-ion battery fires?

When a battery generates more heat than it can release, its temperature rises quickly in a process called "thermal runaway." This can cause the battery to catch fire and even explode. Counterfeit batteries have an increased risk because they are of lower quality than batteries produced by certified manufacturers.

Things that can increase the risk of thermal runaway and lithium-ion fires are:

• Continuing to leave a battery plugged in after fully charged
• Physical damage to the battery or its exterior compartment
• Charging the battery too quickly (typically with a charger that did not come with the electronic device)
• Exposing the battery to extremely hot or cold situations
• Exposing the battery to saltwater by storing it in a basement or garage that may flood
• Using uncertified batteries

The increased use of electric scooters, e-bikes and other powered mobility devices in cities across the U.S. has led to more deadly fires resulting from these devices. People living in multi-unit buildings often have to store and charge their electric scooters and e-bikes inside their apartments, increasing the risk of fires breaking out.

In New York City, the Charge Safe, Ride Safe pilot program was rolled out to address the issue of fires caused by lithium-ion batteries. Many food delivery workers use scooters and e-bikes for their jobs, and it was important for the city to find a way to keep them and their neighbors safe. Many of the fires were caused by these batteries when the device wasn’t being charged. The pilot program sought to address issues with people using e-bikes and scooters with unsafe, uncertified lithium-ion batteries by launching a municipal trade-in program. The program also addressed the issue of charging these vehicles inside apartments and workplaces by increasing the availability of fireproof charging cabinets on public sidewalks.

Another area of concern is the storage of tools and lawn equipment powered by lithium-ion batteries. These tools are often stored in sheds, basements or garages, where they may be exposed to extreme temperatures and flooding.

Traveling with lithium-ion batteries

From laptops, phones and digital cameras to devices as small as electric toothbrushes, you likely have a device powered by a lithium-ion battery whenever you travel. The FAA allows these devices to be placed in checked baggage as long as the battery is properly installed and the device is powered off. However, according to the FAA, uninstalled or spare lithium-ion batteries (including power banks) must be carried on the airplane. Why is this?

These spare batteries create a fire risk when placed in checked baggage because they have exposed terminals, which can create a circuit when they come in contact with other batteries or metal such as keys or coins. When a fire happens in the cargo hold of a plane, it is an extremely dangerous situation because it can grow before anyone becomes aware of it. Fires that start in the cabin are also dangerous, but they are usually caught early, and flight attendants are trained to put them out using fire containment bags and other methods.

Early signs of a lithium battery failure

It is important to regularly inspect your devices that use lithium-ion batteries. This will help you to notice when a device is malfunctioning. Fires can start from these batteries even when they are not charging due to the energy they contain.

Some reports of lithium-ion battery fires have noted the device making a hissing, popping or crackling sound. Sometimes, the batteries will discolor or melt. People have also noted a foul odor associated with battery failure (as chemicals are emitted when a battery fails). If you see or smell smoke, it is likely that a fire has already started.

How do you put out a lithium-ion battery fire?

The best advice when encountering a fire from a lithium-ion battery is to leave the area and call 9-1-1. These types of fires burn very hot, can spread quickly, and can even cause explosions.

Because these fires are caused by flammable liquids inside the battery, water or foam extinguishers will not always put them out. The type of fire extinguisher you need depends on what the battery contains. If the fire is small, a fire blanket can be used to smother it.

Because of the risk of secondary ignition, it is still important to call the fire department to come out, even if you believe you’ve extinguished the battery fire. Heat can be emitted from these batteries even when no visible fire is present. Often, a fire will occur in one of the battery’s cells and then travel to a second cell where an explosion can occur. The fire department can remove the battery from your property and dispose of it.

How to properly replace and dispose of lithium-ion batteries

Your lithium-ion battery is starting to show signs that it isn’t working properly—now what? It is important to consult your device’s user manual when you encounter this issue. Some lithium-ion batteries can be replaced, and some cannot. Some devices may require a professional installation. If you are able to replace the battery on your own, use only certified battery replacements approved for that specific device.

If you have a lithium-ion battery that you need to dispose of, do not place it in your household trash or recycling. Batteries can get crushed or overheat, causing fires during transport or at the landfill or recycling center.

Removable rechargeable batteries can be found in items such as power tools and cordless vacuums. These can be brought to battery recycling centers for disposal. If you need to mail a battery to dispose of it, ensure the battery is packed correctly (in a sealed plastic bag with all terminals covered by electrical tape and placed in a rigid box with sufficient packing material). The box must have a label indicating it contains a lithium-ion battery.

Many devices have batteries that cannot be removed. Those devices should be taken to certified electronics recyclers. Additionally, some businesses—like Staples and Best Buy—offer electronics take-back or household hazardous waste programs that will take these types of devices for disposal.

If you have large lithium-ion batteries in an electric vehicle or as part of your solar energy backup system, consult with the manufacturer before removing or replacing the batteries, as special precautions might need to be taken.