Walk through your house and count the lithium-ion batteries. Phones, tablets and laptops. The cordless drill, the circular saw, the leaf blower and the string trimmer, plus a shelf of spare packs. The robot vacuum, the electric toothbrush, a couple of power banks, and maybe an e-bike or scooter in the garage. Most households have dozens.
Almost all of them will work for years without trouble. But when a lithium-ion battery fails, it fails fast. A damaged or defective cell can overheat and set off a chain reaction called thermal runaway. Within seconds the battery can be venting toxic gas, shooting out flames and spreading to the cells around it. These fires are hot, hard to put out and can start again after they look like they’re out.
Firefighters see this more every year. NFPA made lithium-ion batteries the theme of Fire Prevention Week 2025, and the U.S. Consumer Product Safety Commission (CPSC) lists fire among the leading hazards in e-bike and e-scooter deaths.
The good news is that a few habits prevent most of these fires. Here’s what the fire service, regulators and the tool makers themselves recommend.
Learn the warning signs
The UL Fire Safety Research Institute’s Take C.H.A.R.G.E. of Battery Safety campaign, developed with the FDNY and the U.S. Fire Administration, lists the signs that a battery is in trouble:
- Swelling, bulging or a cracked or punctured case
- Heat beyond normal warmth while charging or in use
- A strange smell
- Hissing, popping or crackling sounds
- Leaking or a change in color
If you notice any of these, stop using the device and stop charging it. If you see white or gray wispy smoke coming from a battery, a fire may be seconds away. Get everyone out, close the door behind you and call 911.
E-bikes and scooters: the biggest batteries in most homes
An e-bike battery holds far more energy than a phone or a drill pack, and it’s often charged inside, in a hallway or by the front door. That’s why the fire service worries about it most.
Buy certified
Look for an e-bike certified to UL 2849 (which covers the whole electrical system, battery and charger together) or a scooter or hoverboard certified to UL 2272. CPSC has urged manufacturers to meet these standards. The certification should be from a nationally recognized testing lab, like UL, Intertek (ETL) or CSA, and you should be able to look it up. A logo printed on a box from an unknown online seller isn’t proof.
Charge it like it matters
CPSC’s advice for charging any e-bike, scooter or hoverboard:
- Stay nearby while it charges, and never charge it while you’re asleep or away from home.
- Use only the charger that came with it, or a replacement approved by the manufacturer.
- Use only an approved replacement battery. Never ride on a battery that’s been rebuilt or modified by someone unqualified, or that uses recycled cells.
- Unplug it when it’s full.
The fire service adds: charge and store it on a hard surface, away from anything that burns, and never in a hallway or by a door you’d need to get out through.
Make sure the maker is still standing behind it
This one is easy to miss. A battery is only as safe as the company that supports it, and some companies don’t.
In November 2025, CPSC warned owners of certain Rad Power Bikes batteries (models RP-1304, RAD-S1304Y and HL-RP-S1304) to stop using them right away. CPSC knew of 31 fires, some of which started while the battery wasn’t charging or the bike was in storage. The company refused to agree to a recall and told CPSC it couldn’t afford to offer replacement batteries or refunds to everyone. In March 2026, CPSC issued a similar warning for Ridstar Q20 and Q20 Pro e-bikes, whose overseas maker also refused a recall.
When a manufacturer goes out of business or won’t stand behind a product, owners are left with a battery that can’t be replaced through the proper channels. That’s when people turn to cheap, uncertified replacements, which is exactly what fire investigators warn against.
So for every e-bike, scooter and large battery-powered item in your home, find out:
- Has it been recalled or flagged? Search the model at cpsc.gov/Recalls and SaferProducts.gov.
- Is the manufacturer still in business and selling genuine replacement batteries and chargers for your model?
- Is it registered? Registering a product with its maker is how they reach you about a recall.
If the answer to any of these is no, plan to retire it before the battery wears out, not after.
Power tools: should batteries stay on the charger?
This is one of the most common questions we hear, and the honest answer is that the tool makers’ own advice is more cautious than most people’s habits.
Modern chargers from the major brands stop charging once a pack is full. Milwaukee, for example, says its chargers and packs talk to each other to prevent overcharging, and that leaving the charger plugged in won’t immediately damage the charger or the battery. But Milwaukee also says that, as a general practice, it’s best to unplug the charger and remove batteries when they’re not in use, and store them somewhere dry and away from extreme heat or cold. Fire departments say the same thing for all lithium-ion devices: unplug once it’s fully charged.
Our take: treat the charger as a place to charge, not a place to store. Take the pack off when the light says it’s full.
The Power Tool Institute’s battery tips, which DEWALT republishes, add a few more:
- Store and charge batteries in a cool, dry place, away from liquids, oils and extreme temperatures. A garage that bakes in summer or freezes in winter is hard on them. Check your manual for the temperature range it allows for charging.
- Take the battery out of the tool before you put the tool away for a long time.
- Charge the battery before long-term storage if it’ll sit for more than six months.
- Keep loose batteries away from metal. Keys, coins, nails and screws can bridge the terminals and cause a short circuit. Use the terminal covers if your packs came with them.
- Don’t use a damaged battery, and don’t try to repair one.
- Use the brand’s own batteries and chargers. Cheap knockoff packs sold online often skip the protective electronics that keep genuine packs safe.
Set up a charging spot on a metal shelf or workbench, away from gas cans, oily rags, sawdust and paint thinner. If a battery has been dropped hard or got wet, look it over before you charge it again.
Appliances and everyday gadgets
The same rules apply, just on a smaller scale:
- Charge on a hard surface, never on a bed, couch or pillow, where heat can’t escape and the fabric can catch fire.
- Use the charger that came with the device, or a certified replacement from a reputable brand.
- Check the recall list for robot vacuums, power banks, laptops and other battery devices, especially cheap ones.
- Pay attention when an older device stops getting support. When a maker stops selling replacement batteries for a laptop or robot vacuum, it’s usually time to replace the device rather than buy a no-name battery for it.
Getting rid of old batteries
The EPA says lithium-ion batteries should never go in the trash or your curbside recycling bin, where they can be crushed and start fires in garbage trucks and recycling plants. Instead:
- Cover the terminals with electrical tape or other non-conductive tape.
- Put each battery in its own plastic bag.
- Drop them off at a battery recycler, a store with a take-back program or your local household hazardous waste collection. Call2Recycle has a drop-off locator.
For a damaged, swollen or recalled battery, call your household hazardous waste program first, or contact the manufacturer for instructions. CPSC’s recall warnings often specifically say not to use retail recycling bins for these.
How Dwell Secure helps
Battery safety is mostly about knowing what you have and keeping track of it. That’s what Dwell Secure is good at.
- Record your battery-powered equipment. Add the e-bike, the mower and the big tool kit as service items, with make, model, serial number, purchase date and warranty expiration. Snap a photo of the label on the battery itself. When a recall comes out, you can check in seconds instead of crawling around the garage with a flashlight.
- Keep the paperwork together. Store owner’s manuals, warranty cards and receipts in your encrypted document vault, under Manuals, Warranties and Home Inventory.
- Show everyone where the charging spot is. Mark it on your floor plan and add a note, so the whole household knows the rules.
Then put the checks on a schedule. Recurring maintenance schedules handle the jobs that are easy to forget, and each one shows up on your dashboard as it comes due:
- Inspect e-bike and tool batteries for damage: quarterly
- Check for recalls on battery-powered devices: every six months
- Take old and damaged batteries to recycling: every six months
- Test the smoke alarms near where you charge: monthly
A 15-minute battery check
- List every large battery device in your home: e-bikes, scooters, mowers, tools, power stations.
- Look up each model on CPSC’s recall site.
- Inspect the packs for swelling, cracks, damage or corrosion. Retire any that fail.
- Move the charging spot to a hard, clear surface away from exits and anything that burns.
- Take any packs off the chargers that are full, and unplug the chargers.
- Bag and tape dead batteries for recycling.
- Make sure there’s a working smoke alarm near where you charge.
Sources
- NFPA, Lithium-ion battery safety
- UL Fire Safety Research Institute, Take C.H.A.R.G.E. of Battery Safety
- U.S. Consumer Product Safety Commission, micromobility injuries, deaths and safety tips (2023)
- CPSC, warning on Rad Power Bikes batteries (November 2025)
- CPSC, warning on Ridstar e-bikes (March 2026)
- DEWALT and the Power Tool Institute, battery safety tips
- SlashGear, Can you leave your Milwaukee charger plugged in all the time?, citing Milwaukee’s manual and FAQ
- U.S. EPA, Used lithium-ion batteries
