If a lithium-ion battery catches fire, get everyone out of the area immediately, call 911, and if the fire is small enough to manage safely, use water to cool the battery continuously. Lithium-ion battery fires are uniquely dangerous because they produce extremely toxic smoke and can reignite after the flames appear to be out. Knowing what to do in the first seconds matters.
Get Away From the Smoke First
The smoke from a burning lithium-ion battery is far more dangerous than typical fire smoke. Burning batteries release hydrogen fluoride, a gas that causes severe damage to the lungs, skin, and eyes on contact. A single burning battery can produce between 20 and 200 milligrams of hydrogen fluoride per watt-hour of capacity, and concentrations become immediately dangerous to life at just 30 parts per million. For context, a laptop battery or e-bike battery pack holds enough energy to push a small room past that threshold quickly.
Hydrogen fluoride doesn’t just irritate your airways. It penetrates skin and disrupts calcium and magnesium levels in your blood, which can cause dangerous heart rhythm changes. Even brief skin exposure over a small area can cause systemic toxicity. The batteries also release carbon monoxide and carbon dioxide in quantities that displace oxygen. If a battery fire starts indoors, your first priority is getting yourself and others out, not fighting the fire. Open windows on your way out if you can do so without delay.
How to Extinguish a Small Battery Fire
Water is the most effective suppressant for lithium-ion battery fires. This surprises many people because the longstanding advice for lithium metal fires (a different battery chemistry found in some non-rechargeable batteries) is to never use water. But lithium-ion batteries are not the same as lithium metal batteries, and water works well on them for one critical reason: cooling.
A lithium-ion battery fire is driven by a chain reaction called thermal runaway, where heat from one failing cell triggers the next cell to fail. The only way to truly stop this process is to cool the battery below the temperature that sustains it. Lab experiments comparing water, dry chemical extinguishers, carbon dioxide, and foam consistently show that water outperforms all of them. Dry chemical and Class D powders can smother the open flames quickly, but the fire reignites within 50 seconds once the suppressant is used up because the battery is still hot enough to keep reacting internally.
Water mist applied for five minutes extinguished battery fires with no reignition in controlled tests. The key difference is sustained cooling. A quick blast from an extinguisher won’t cut it. If you’re using water, keep applying it steadily. A standard ABC dry chemical extinguisher will also knock down the flames and buy you time, but expect possible reignition. If you have both available, use the ABC extinguisher to control the flames, then follow with continuous water to cool the battery.
One Important Exception
If the device contains a lithium metal battery (common in some non-rechargeable batteries, older medical devices, and certain military equipment), do not use water. Lithium metal reacts violently with water. These fires require a Class D fire extinguisher with copper powder. Most consumer electronics, phones, laptops, e-bikes, and electric vehicles use lithium-ion, not lithium metal. If you’re unsure, the safest choice is to evacuate and let firefighters handle it.
Step-by-Step Response
- Evacuate the immediate area. Move at least 20 feet away outdoors, or leave the room and close the door if indoors. Do not inhale the smoke under any circumstances.
- Call 911. Even if the fire seems small, battery fires can escalate unpredictably and reignite after appearing to be out. Firefighters need to know it’s a battery fire so they bring appropriate equipment.
- If the fire is small and you can stay upwind, apply water continuously from a safe distance. A garden hose is ideal. A bucket of water can help but won’t provide the sustained cooling needed to prevent reignition.
- If you only have an ABC extinguisher, use it to suppress the flames, then continue monitoring. The fire may reignite. Do not assume it’s out.
- Do not try to move the burning device unless it’s on a surface that will spread the fire (like a bed or couch) and you can safely push or kick it onto a non-flammable surface like concrete or tile.
- If the fire involves an electric vehicle or large battery pack, do not attempt to fight it yourself. EV battery fires can take thousands of gallons of water and hours to fully extinguish.
Warning Signs Before a Fire Starts
Most lithium-ion battery fires give warning signs minutes or even hours before flames appear. Recognizing these signals gives you time to move the device somewhere safe, like a concrete patio or a metal container away from flammable materials, before things escalate.
New York State’s Division of Homeland Security identifies five key warning signs. The device feels extremely hot to the touch, well beyond the warmth that’s normal during charging. The battery or device case is visibly swelling or bulging, which means gases are building up inside. You hear hissing, cracking, or popping sounds from the battery. There’s a strong, unusual chemical odor. Or the device is actively smoking, which means a fire may have already started internally.
If you notice any of these, unplug the device immediately if it’s charging, move it away from anything flammable, and get it outside if you can do so safely. Do not put a swelling battery in a trash can, a drawer, or a car trunk. Place it on a non-flammable surface with space around it and keep your distance.
After the Fire Is Out
A battery that has caught fire or gone through thermal runaway can reignite hours or even days later. Do not bring the device back inside. Leave it outdoors on a non-flammable surface and monitor it periodically. If it was a small device like a phone or laptop, placing it in a metal bucket filled with water for 24 hours can help ensure it’s fully cooled and discharged.
Do not throw a fire-damaged battery in regular trash or recycling. Damaged lithium-ion batteries are classified separately by the Department of Transportation because they pose a higher fire risk during transport. Contact the device or battery manufacturer for specific disposal instructions. Many retailers that sell batteries, including home improvement stores and electronics chains, accept damaged batteries, though some require you to package them in specific ways. Your local hazardous waste collection program is another option.
If you were exposed to the smoke, pay attention to symptoms over the next several hours. Coughing, throat irritation, chest tightness, or difficulty breathing after exposure to battery fire smoke warrants medical attention. Skin that contacted the smoke or residue and develops pain, redness, or whitish discoloration should be evaluated promptly, as hydrogen fluoride burns can worsen over time even after the exposure ends.
Preventing Battery Fires
Most lithium-ion battery fires trace back to a handful of causes: using a charger that wasn’t designed for the device, charging on soft surfaces like beds or couches that trap heat, continuing to use a battery that’s visibly damaged or swollen, or buying cheap replacement batteries from unverified sellers that lack proper safety circuits.
Charge devices on hard, flat surfaces with good airflow. Don’t leave devices charging overnight on your bed. Replace batteries through the original manufacturer or a reputable third-party supplier. And if a battery shows any of the warning signs listed above, stop using it immediately. A $30 replacement battery is a small price compared to what a battery fire can do to a home.