It’s something you never expect to happen: your phone hissing, smoking or suddenly bursting into flames. Maybe your e-bike battery overheats in the garage or your laptop starts to spark on your desk. It’s scary and can happen in just seconds.
Lithium-ion batteries power many of the devices we use every day, from smartphones and laptops to e-bikes, scooters, power tools and vaping devices. While these batteries are usually safe, when something goes wrong the results can be dangerous.
We spoke with Jasjot Johar, MD, an emergency medicine physician with Banner Health, about the dangers of lithium-ion batteries and what to do to protect your health.
Why lithium-ion batteries overheat and explode
Lithium-ion batteries overheat and can explode due to a process called thermal runaway, a chain reaction that causes the battery to heat up and potentially explode.
“Lithium-ion batteries release stored energy through controlled chemical reactions,” Dr. Johar said. “But when that reaction becomes uncontrolled, it can trigger dangerous heat buildup and even fire.”
Thermal runaway can happen for several reasons:
- Physical damage: Dropping, crushing or puncturing a battery can cause an internal short circuit by damaging the separator between components.
- Overcharging: “Charging with an incompatible or faulty charger can lead to excessive heat buildup or the formation of metallic lithium, which can cause a short circuit or fire,” Dr. Johar said.
- Manufacturing defects: Impurities or flaws in the manufacturing process can increase a battery’s likelihood of failure.
- Extreme heat: Leaving your device in a hot car or in direct sunlight can destabilize its chemical structure.
- Aging or wear: “As batteries age, they can become less stable and more prone to self-discharge or internal failures that generate heat,” Dr. Johar said.
You might think this only happens to cheap products but even reputable brands can have problems. The devices most often involved in lithium-ion battery fires are e-bikes and e-scooters followed by e-cigarettes and vaping devices, though fires can also happen to laptops, smartphones, power tools and hoverboards.
Warning signs that a battery is unsafe
Before a battery overheats or explodes, it often shows signs of trouble. If you notice any of these, stop using the device immediately and move it to a safe place:
- The battery feels abnormally hot to the touch
- The device or battery looks swollen or bulging
- You smell a strong, chemical or burning odor
- You hear popping, cracking or hissing sounds
- The battery is leaking fluid or discolored
- You see smoke coming from the device
“These warning signs mean the battery is unstable,” Dr. Johar said. “Continuing to use the device could cause it to ignite or explode.”
What to do right away if your device overheats or catches fire
If your device starts smoking, hissing or heating up quickly, act fast but stay calm. Dr. Johar recommends:
- Stop using it: Discontinue using the device immediately.
- Move to safety: If it’s safe, move the device to a hard, nonflammable surface like concrete or tile. Keep it away from paper, fabric or anything that can burn. Never touch a swelling or leaking battery with your bare hands.
- Use a fire extinguisher or water for small devices: Small electronic battery fires can be treated with water, baking soda or a fire extinguisher.
- Call for help for larger fires: For larger batteries like those in e-bikes, water may not be effective. Lithium metal can react with water and become more combustible. In these cases, you need special equipment. Evacuate and call 911.
- Evacuate immediately if flames spread: Get everyone out and call 911 from a safe distance.
If you’re burned or exposed to smoke
If a device battery explodes or catches fire, it can cause both thermal burns (from heat) and chemical injuries (from battery gases and melted metal).
If you have a burn:
- Cool the area under running water for at least 10 minutes.
- Do not use ice, butter or ointments.
- Remove jewelry or tight clothing near the burned area.
- Cover the burn with a clean, nonstick bandage or cloth.
“Simple thermal burns can often be managed at home or in urgent care,” Dr. Johar said. “But more severe burns with blistering or uncontrolled pain may need treatment in the emergency room.”
[Also read: Ouch! Burned Yourself? Here's What to Do Next]
If you breathe in smoke or fumes:
Move to fresh air right away. If you’re coughing, feeling dizzy or having trouble breathing, call 911 or have someone take you to the ER.
“Inhalation injury is a serious but rare complication,” Dr. Johar said. “Like any fire, the fumes and chemicals can irritate your lungs. In severe cases, they can cause inflammation and fluid buildup.”
Dr. Johar added that lithium-ion batteries can release toxic gases, such as carbon monoxide and hydrogen fluoride. “While cyanide gas release is fortunately rare, it’s very serious and requires immediate medical attention,” he said.
When to go to the ER
Even if you think the injury is mild, some signs mean you need emergency care. Go to the ER or call 911 if you notice:
- Deep or blistering burns
- Burns larger than three inches
- Burns on the face, eyes, mouth, hands or genitals
- Severe pain that doesn’t improve
- Difficulty breathing or swallowing
- Chronic coughing or vomiting
- Confusion, seizures or loss of consciousness
“The biggest concern specific to these injuries is chemical exposure,” Dr. Johar said. “Trouble breathing, uncontrolled coughing, vomiting or any change in mental status could mean toxic fumes have been inhaled. These are emergencies.”
What happens in the ER
If you go to the ER for a battery-related injury, your care will depend on how severe the burn or exposure is.
“In most cases, burns from a battery are thermal burns and treated like any other heat injury,” Dr. Johar said. “Treatment consists of cleaning the area, managing pain and protecting it from infection.”
For deeper burns, your care team might use topical medications or refer you to a specialized burn center. If you’ve inhaled fumes, your breathing and oxygen levels will be monitored to make sure your lungs are working properly.
How to prevent battery fires and explosions
Thankfully, most battery fires can be prevented with a few simple habits.
- Use approved chargers: Only use chargers made for your specific device.
- Avoid overcharging: Don’t store batteries that are plugged in and don't leave them charging overnight.
- Inspect batteries: Check for cracks, swelling or leaks on a regular basis and especially after dropping a device.
- Charge on a hard surface: Avoid charging on beds or couches, where heat can build up.
- Store safely: Keep spare batteries in a cool, dry place away from sunlight and metal objects.
- Let professionals handle repairs: Always have a professional change or replace batteries. Minor damage can cause leaks or fires later.
If you notice abnormal warmth, a burning smell, smoke or fluid leaking from a device, unplug it right away and replace the battery before it becomes a bigger problem.
Takeaway
Lithium-ion batteries keep our lives running. They power our phones, tools and bikes. But when something goes wrong, the results can be dangerous.
Remember to act fast if a battery overheats or explodes, protect yourself and get the care you need.
If you experience burns or breathing problems after a device fire, don’t wait it out. Go to the nearest emergency room. Quick treatment can make a difference in your recovery.
