The Batteries Everywhere Around You: How Dangerous Are Lithium-Ion Batteries, Really?

Your phone has one.

So does your laptop, cordless drill, lawn mower, leaf blower, e-bike — and perhaps your car.

Lithium-ion batteries have become one of the invisible foundations of modern life. They're small, relatively light and capable of storing a remarkable amount of energy.

They're also generally safe when properly designed, manufactured, charged and used.

But when something goes wrong, the consequences can be serious.

And that's the part worth understanding.

The question isn't:

“Are lithium-ion batteries dangerous?”

It's:

“When do they become dangerous — and what can I do about it?”

First, how common are battery fires?

This is where the story needs some perspective.

There isn't a reliable national number that tells us the percentage of lithium-ion batteries that catch fire. The data are scattered among fire departments, manufacturers, regulators, hospitals and other sources.

A 2026 analysis from the National Institute of Standards and Technology found that lithium-ion battery-fire data are fragmented and mostly incomplete. NIST estimated that consumer lithium-ion battery fires have been increasing, but the researchers also noted substantial limitations in the available reporting.

So we should be careful with phrases like “lithium batteries are becoming increasingly dangerous.”

What we can say with confidence is that serious battery fires occur, regulators are documenting them, and some products and charging practices create substantially more concern than others.

The e-bike experience illustrates the difference.

The CPSC's April 2026 report identified 310 e-bike-related fatalities from 2017 through 2024. But only 19 of those deaths were associated with 13 lithium-ion battery-fire incidents. Most e-bike fatalities involved motor-vehicle crashes or control problems rather than battery fires.

And CPSC cautions that these fatality reports are not nationally representative, are based on reports from multiple sources, and are incomplete for the most recent years.

So battery fires are real.

But they are not the normal outcome of owning an e-bike or another lithium-powered product.

What makes a lithium-ion battery dangerous?

A lithium-ion battery stores a lot of energy in a relatively small package.

Under normal conditions, that energy is released gradually.

But a damaged or defective cell can begin heating itself faster than the heat can escape.

That's called thermal runaway.

In a battery pack containing multiple cells, one failing cell can trigger neighboring cells, potentially creating a rapidly escalating fire.

CPSC identifies manufacturing defects, excessive temperatures, electrical abuse such as improper charging, and physical damage among the circumstances that can contribute to cell failure.

This is one reason a damaged battery isn't something to casually ignore.

E-bikes are the category I would pay particular attention to

For older adults, this deserves special attention because e-bikes are increasingly popular for exercise, transportation and simply getting around without the physical demands of a conventional bicycle.

CPSC's latest data found 106 fire hazards among 145 e-bike incidents it investigated in depth from 2017 through 2024.

Of those 106 fire-related reports:

• 62 described fires that started while the e-bike was charging
• 13 occurred while the battery was not charging
• 4 occurred during use
• 5 were associated with battery maintenance such as removing or replacing the battery

CPSC's investigators also found cases involving aftermarket batteries or chargers, faulty wiring and overloaded extension cords.

Again, these are investigated reports, not a percentage of all e-bikes.

But the pattern is useful:

Charging is an important moment to pay attention.

The charger may be the weak link

This is one of the most useful things in the entire story.

In 2024, CPSC warned consumers not to use so-called “universal” chargers for e-bikes, e-scooters and other micromobility products unless they had been specifically tested and approved for that device.

Between January 1, 2023 and May 16, 2024, CPSC received 156 reports of fire and thermal incidents involving universal micromobility chargers, including reports of serious injuries and property damage.

CPSC subsequently identified two specific chargers — the SafPow SPC-42020 and AMPOWSURE ASP-C10S42020 — that were associated with 47 reports of fire or other thermal incidents, including three reports of burn or smoke-inhalation injuries and three reports of property damage totaling $100,200.

The lesson is wonderfully simple:

Use the charger that came with your device, or a replacement specifically approved for that device.

A charger that physically fits doesn't necessarily mean it's electrically compatible.

Don't assume a safety mark means nothing

CPSC has specifically urged manufacturers of e-bikes and other micromobility products to comply with applicable UL safety standards.

For e-bikes, one important standard is UL 2849, which addresses the electrical systems of e-bikes.

CPSC says compliance with applicable UL standards can significantly reduce the risk of injuries and deaths from micromobility fires, and it has called for certification by an accredited testing laboratory.

That's particularly relevant when buying an e-bike or replacement battery from an unfamiliar seller.

A suspiciously cheap battery with an unknown manufacturer, questionable certification or a modification that wasn't approved by the manufacturer deserves more scrutiny than a properly certified product from an established manufacturer.

Where you charge matters

This is one area where a simple habit can make a difference.

Don't charge them on a bed or sofa.

Don't charge them where a fire could block your way out.

Don't store or charge them in a hallway or immediately beside an exit you would need to use during a fire.

The U.S. Fire Administration specifically advises that large lithium-ion-powered devices such as e-bikes and scooters should not be positioned so they block an exit route or fire escape. It also recommends following manufacturer charging instructions and avoiding extension cords or multiplug adapters.

And make sure you have working smoke alarms in and around the areas where batteries are charged or stored.

CPSC has noted that many micromobility battery fires and deaths have occurred at night while batteries were charging and families were asleep.

That's why CPSC says:

Never charge an e-bike or other micromobility product while you're sleeping.

What about mobility scooters and power wheelchairs?

This deserves a special mention for older adults.

Many modern mobility scooters and power wheelchairs can use lithium-ion battery systems, although some still use other battery chemistries.

The same basic principles apply:

• Use the battery and charger specified for your particular device.
• Don't substitute an incompatible charger.
• Don't use a damaged or modified battery.
• Follow the manufacturer's charging instructions.
• Keep charging equipment away from flammable materials.
• Don't place the device where a battery fire could block your escape route.

For anyone who depends on a mobility device for independence, there's an additional reason to take battery safety seriously:

Your mobility equipment may be essential to your ability to get out of the house.

That makes where you charge and store it a safety decision, not merely a battery-maintenance decision.

What if the battery starts swelling?

A swollen battery is not normal aging.

The EPA says swelling indicates battery damage and represents a potential fire hazard.

Other warning signs include:

• unusual heat
• a strange odor
• leaking
• smoke
• hissing or popping
• visible physical damage
• a change in shape
• a battery that has been crushed or punctured

If you notice these signs, stop using and charging the battery.

And here's an important distinction:

If it's smoking or appears to be catching fire, get out.

Don't try to carry the battery outside.

Don't try to fight a lithium-ion battery fire yourself.

Don't sacrifice your safety trying to save the device.

The U.S. Fire Administration's guidance is straightforward: if a lithium-ion battery fire occurs, evacuate and call 911.

If the battery is damaged but there is no immediate threat of fire, contact the manufacturer, retailer or your local household hazardous-waste program for instructions on how to handle it.

And please don't throw the battery in the trash

This may be the most overlooked part of the whole subject.

Lithium-ion batteries do not belong in your household garbage or curbside recycling bin.

The EPA says they can be damaged or crushed during collection, transportation or recycling and cause fires at waste facilities.

Instead, take them to an appropriate battery-recycling or household hazardous-waste collection site.

And if the battery is damaged, swollen or recalled, don't simply drop it into a normal battery-recycling box at a store.

Ask the facility first about its procedures for damaged lithium batteries.

Check for recalls

Here's another easy habit worth developing.

If you own an e-bike, scooter, power tool, battery pack, charger, mobility device or other lithium-powered product, periodically check for recalls.

The Consumer Product Safety Commission maintains current recall and safety-warning information.

And if a product causes a fire, overheats, shocks you, fails dangerously or otherwise creates a safety problem, you can report it through SaferProducts.gov.

Consumer reports are one of the ways regulators identify dangerous products that might otherwise remain on the market.

So, should you be worried?

Probably not in the way you might think.

A lithium-ion battery in a reputable phone, laptop or power tool isn't something you need to lie awake worrying about.

The larger concern is risk concentration:

• large battery packs
• questionable or modified batteries
• incompatible chargers
• poorly manufactured products
• damaged batteries
• improper charging
• charging in places where a fire could trap people
• improper disposal

And e-bikes and similar high-energy micromobility products deserve particular attention because regulators have documented repeated serious fires and deaths associated with them.

The good news is that many of the sensible precautions are remarkably simple.

The Watchdog Takeaway

Lithium-ion batteries aren't inherently dangerous. They're powerful. And powerful things deserve a little respect.

The available evidence does not give us a reliable percentage chance that your phone, e-bike or lawn mower battery will catch fire. Much of the evidence consists of government incident reports, recalls, safety investigations and laboratory research rather than comprehensive population-level risk studies.

What we do know is that serious failures occur — and the risk can increase with damaged batteries, incompatible chargers, questionable replacement batteries, modifications and unsafe charging practices.

For older adults, pay particular attention to e-bikes, scooters, mobility devices and other large battery packs.

Use the correct charger. Don't use a damaged or swollen battery. Don't charge large battery devices on a bed or sofa or where a fire could block your escape. Keep working smoke alarms in place. Never charge an e-bike while you're asleep.

And if a lithium-ion battery is smoking, burning or showing signs of an imminent fire, don't try to save it. Get out and call 911.

Finally, check CPSC.gov for recalls and safety warnings, and report dangerous products through SaferProducts.gov.

You don't need to fear the batteries all around you.

You just need to know which ones deserve your attention.