Putting out a lithium fire depends entirely on whether you’re dealing with a lithium-ion battery (the rechargeable kind in phones, laptops, and EVs) or a lithium metal battery (single-use, found in some medical devices and military equipment). For lithium-ion fires, water is your best tool. For lithium metal fires, water is extremely dangerous. Getting this distinction right is the most important thing you can do.
Lithium-Ion vs. Lithium Metal: Why It Matters
Lithium-ion batteries power most consumer electronics: phones, laptops, tablets, e-bikes, and electric cars. They contain very little actual lithium metal. When they catch fire, the burning material is mostly the flammable electrolyte solution inside the cells, not metallic lithium itself. That means water works well to cool them down and suppress flames.
Lithium metal batteries are single-use, non-rechargeable cells containing pure lithium metal, which reacts violently with water. These are less common in everyday life but show up in certain medical devices, military equipment, and some consumer electronics like watches and calculators. If a lithium metal battery catches fire, you need a Class D fire extinguisher containing copper powder. Do not use water, ABC extinguishers, or any other standard firefighting agent on a lithium metal fire.
If you’re unsure which type you have, check the battery label. Rechargeable batteries are almost always lithium-ion. If a device uses disposable coin cells or specialty batteries labeled “lithium,” those may contain lithium metal.
How to Put Out a Lithium-Ion Battery Fire
For a burning phone, laptop, power tool, or any rechargeable device, the approach is straightforward: use water, and use a lot of it. The goal isn’t just to knock down the visible flames. You need to cool the battery cells enough to stop a chemical chain reaction called thermal runaway, where internal temperatures can spike to 750°C (nearly 1,400°F). A standard ABC fire extinguisher or a halon extinguisher can briefly suppress open flames, but neither one stops the thermal runaway process. The battery will reignite once the chemical suppression dissipates.
Water works because it absorbs enormous amounts of heat. The FAA’s current guidance for battery fires on aircraft is clear: cooling the device with water is essential to prevent the reaction from continuing until all cells have discharged their energy. That principle applies on the ground, too. If you have a garden hose or buckets of water available, keep pouring water on the device until it stops smoking and feels cool.
Research from the National Institute for Occupational Safety and Health found that water mist combined with an additive called F-500 was the most effective suppressant among the agents tested on lithium-ion battery pack fires. Dry chemical extinguishers quenched flames momentarily but couldn’t prevent reignition because they don’t provide enough cooling. This reinforces the core lesson: heat removal is what actually stops these fires.
Steps for a Small Device Fire
- Move the device if you can safely do so. Use tongs, a shovel, or push it with a non-flammable object onto a non-combustible surface like concrete, a metal tray, or a sink.
- Douse it with water. Submerge the device in a bucket or container of water if possible, or pour water continuously over it. Don’t be conservative with the amount.
- Ventilate the area. Open windows and doors. The fumes are toxic (more on that below).
- Keep watching. Lithium-ion batteries can reignite minutes or even hours later if internal cells haven’t fully discharged. Monitor the device for at least an hour after the fire appears to be out.
For larger battery systems like an e-bike or EV battery pack, call the fire department. These packs contain dozens to thousands of individual cells, and thermal runaway can cascade from cell to cell over an extended period. Fire departments fighting EV fires routinely use thousands of gallons of water over the course of an hour or more.
What Makes These Fires So Stubborn
A lithium-ion battery fire isn’t like a grease fire or a paper fire. It’s a self-sustaining chemical reaction that generates its own oxygen. Inside the battery, the cathode material begins releasing highly reactive oxygen at around 230°C (446°F). That oxygen immediately reacts with the flammable electrolyte, generating intense heat. The heat then triggers neighboring cells, and the chain reaction spreads.
The process starts slowly. Internal temperatures as low as 65°C (149°F) can kick off mild reactions between the battery’s anode and electrolyte. But the real danger point is around 218°C (424°F), when the temperature begins climbing at 1°C per second or faster. Above 300°C, a thermite-like reaction involving the battery’s aluminum components adds even more heat. By the time you see flames or smoke, the battery is already well into this cascade, which is why cooling with water needs to be aggressive and sustained.
The Fumes Are the Hidden Danger
A burning lithium-ion battery releases a cocktail of toxic gases that can be more dangerous than the fire itself. The most concerning is hydrogen fluoride, a gas that forms when the fluorine-containing components inside the battery break down at high temperatures. Hydrogen fluoride is immediately dangerous to life at concentrations as low as 30 parts per million, a level you can’t reliably detect by smell.
Breathing hydrogen fluoride causes irritation and burns to the nose, throat, and lungs at low exposures. At higher concentrations, it can trigger throat swelling, fluid buildup in the lungs, and dangerous drops in blood calcium levels that lead to seizures or cardiac arrest. It can also be absorbed through the skin on contact. Beyond hydrogen fluoride, burning batteries release carbon monoxide and carbon dioxide in concentrations high enough to displace oxygen in an enclosed space.
This is why ventilation matters as much as extinguishing the fire. If a battery catches fire indoors, get everyone out of the room first, then address the fire. If you’re in a garage, open the door. If you’re fighting the fire, stay upwind. Even after the flames are out, the residue and off-gassing can be hazardous.
What to Do With the Battery Afterward
A lithium-ion battery that has been through a fire, even one that’s been fully extinguished, is still a hazard. It can reignite. It may leak corrosive material. And it’s classified as hazardous waste for transport purposes.
Don’t throw a damaged battery in the trash or in your regular recycling. Place it in a non-metallic container, surround it with non-combustible material like sand or vermiculite, and keep it in a well-ventilated area away from anything flammable. Store it outdoors if possible.
For disposal, contact your local hazardous waste facility. The U.S. Department of Transportation requires that damaged or defective lithium batteries be individually packaged in non-metallic, electrically non-conductive containers and shipped only by ground or sea, never by air. Each battery needs its own packaging, and the outer container must be clearly marked as “Damaged/defective lithium ion battery.” Your local fire department or waste authority can point you to approved drop-off locations.
What Not to Do
Don’t use sand or dirt on a lithium-ion fire. While it might smother surface flames, it insulates the battery and traps heat, making thermal runaway worse. Don’t use a CO2 extinguisher for the same reason: it displaces oxygen around the flames but does nothing to cool the cells. Don’t try to puncture or disassemble a swollen battery to “release pressure.” The gases inside are flammable and toxic.
And to repeat the most critical point: never use water on a lithium metal battery. If you work in a lab, military, or medical setting where lithium metal batteries are present, keep a Class D extinguisher with copper powder rated for lithium fires within easy reach. Standard ABC extinguishers and water will cause a violent reaction that spreads the fire and can cause an explosion.