Button batteries at home: where they hide and how to store spares

Most of the batteries in a house are easy to see: the AA cells in the flashlight, the big pack in the smoke alarm, the phone on the counter. The ones I worry about are the small, flat, shiny ones. Button and coin batteries power dozens of things that never look like they have a battery at all, and they are exactly the size and shape a small child picks up and puts in their mouth, nose or ear.

The US National Capital Poison Center (poison.org) singles out the larger lithium coin cells, about 20 mm across, roughly the size of a US penny or bigger, as one of the most serious problems when swallowed. They are usually stamped with a code such as CR2032, CR2025 or CR2016. Smaller button cells, including the zinc-air cells used in hearing aids, are also a risk, especially to young children and to older adults who mistake them for tablets.

Before anything else, the one rule that matters most. If you think a child or anyone else may have swallowed a button or coin battery, or pushed one into a nose or ear, call your local emergency number or a poison center immediately. Do not wait for symptoms. In the US that is Poison Help at 1-800-222-1222, or 911. In the UK, call 999 or NHS 111. In the EU, call 112. That is all the "what to do" this page will give, and it is all you need to remember. Our official help page lists the contacts we point readers to.

The rest of this piece is about making that call less likely: finding the batteries, closing the compartments, and storing spares and spent cells where small hands cannot get them.

What changed in the US: Reese's Law

In August 2022 the US enacted Reese's Law. The law directed the US Consumer Product Safety Commission (CPSC) to set mandatory rules, which have since come into force in stages. In plain terms:

• Consumer products that use button or coin batteries must have battery compartments that need a tool, such as a screwdriver or coin, or at least two independent and simultaneous hand movements to open. The compartment also has to stay shut through drop and abuse tests.
• Warnings must appear on the product packaging, on the product itself where practical, and in the instructions.
• The batteries themselves must be sold in child-resistant packaging. CPSC says that applies to batteries manufactured or imported after February 12, 2023.

There are limits. Toys for children under 14 already fall under the US toy standard, which calls for a battery compartment that needs a tool to open, so they sit under that rule instead. Zinc-air hearing aid batteries are not covered by the product requirements, though their packaging is. And none of this reaches back into your drawer: the remote you bought before the rules, or a cheap gadget from abroad, may still have a cover that slides off with a thumbnail. CPSC's button cell and coin battery information center explains the rules and what to check at home.

In the UK, the government has run its own awareness campaigns, and the same practical advice applies on both sides of the Atlantic.

A room-by-room hunt

Here is the walk-through I suggest, with the usual suspects for each room. It is easy to find more than you expect, and your list will differ from mine, which is the point of doing it.

Living room

• TV, sound bar and streaming box remotes. Many slim remotes use a coin cell behind a twist or slide cover.
• Wireless game controllers and small headsets.
• Flameless LED candles and tea lights, often bought in packs and left on low tables.
• Clocks, digital photo frames and small thermometers or weather stations.

For each one, try the compartment. If it opens with fingers alone, or the screw is missing, that item goes out of reach or gets a strip of strong tape over the cover until you repair or replace it. The poison center's advice includes taping compartments that children can open or that might pop open when dropped.

Kitchen

• Kitchen scales and digital timers.
• Meat thermometers and other small gadgets in the utensil drawer.
• The drawer itself. Kitchens collect loose spare cells, old cells "to recycle later" and the occasional battery that rolled out of something.

Hall and entrance

• Car key fobs and keyless entry remotes, often left in a bowl by the door at toddler height.
• Garage door openers and parking transponders.
• Bags. Visitors' handbags and coat pockets carry key fobs, hearing aid cells and spares. A high hook for guests' bags is an easy habit.

Bathroom and bedroom

• Bathroom scales, which sit on the floor.
• Digital thermometers, electric toothbrush timers and some trimmers.
• Hearing aids and their spare cells. These look a lot like tablets on a bedside table.
• Watches, fitness trackers and their chargers.

Children's rooms and toy boxes

• Toys that light up, talk or play music.
• Flashing shoes and light-up jewelry.
• Musical greeting cards. These are easy to forget because they look like paper. Once the birthday is over, take the card's sound module out, tape the cell and put it with the spent batteries.

Garage and shed

• Bike lights, tire gauges, digital calipers and the spare key fob in the glovebox.

Write down what you found and which items had loose covers. That list is your to-do list for the weekend.

Worked example: one kitchen drawer

Here is how a sorting session on a typical "everything" drawer might go. Empty it onto the counter, out of a child's reach, then sort into three piles:

1. New spares still in their sealed pack. These go into one lidded box on a high shelf or in a locked cupboard. Not loose, and not in the drawer.
2. Loose cells of unknown age. You cannot tell a dead coin cell from a fresh one by looking at it, and the UK government campaign points out that even "dead" batteries can still seriously harm a child. Treat all of them as live. Tape each one and move it to the spent-battery container.
3. Everything else. Back in the drawer.

The whole job takes a quarter of an hour, and the drawer no longer holds anything that can do this kind of harm.

Storing spares

• Keep spare button and coin batteries in their original packaging, in a closed box, up high or locked away. The UK campaign advises against leaving them loose in drawers or on surfaces.
• Open multipacks carefully, over a table, because the cells can scatter across the floor.
• Change batteries away from small children, so they do not see where the batteries came from or watch you doing it. The poison center makes this point too.
• Count them. If you take two out of a pack and fit one, find the other before you walk away. A missing battery is worth searching for straight away.
• Do not put batteries in your mouth to hold them while you work, and keep hearing aid cells well apart from any tablets.

The same habits that keep laundry capsules out of reach apply here: one closed container, one high place, back in it every time. Our laundry capsule storage piece covers that routine in more detail, and our guide to childproofing the cupboard under the sink covers latches that work on a battery drawer too.

Getting rid of used ones

Spent coin cells need the same care as new ones until they leave the house.

1. As soon as you take a used cell out, cover its terminals with non-conductive tape, such as electrical tape. CPSC recommends this before disposal, and it also stops cells shorting against each other in a box.
2. Keep taped cells in a small closed container, stored as high as your spares, not in the kitchen bin.
3. Take them to a battery collection point promptly rather than letting them pile up. CPSC says to discard used cells at a battery collection center, and the UK campaign says to recycle them properly and promptly. Many shops and local recycling centers accept small batteries; check your local authority for details.

Do not put coin cells in household recycling bags or the general bin unless your local rules say you may. Tape also keeps cells from touching each other or loose metal in a box or bag. Our disposal section has more on getting household hazards out of the house safely.

Buying with batteries in mind

When you replace something, look at the battery compartment before you look at anything else. A screw-secured cover, or one that takes two separate movements to open, is the thing to look for, and in the US it is now required for most products that use these cells. Read the warning on the packaging, even if you think you know it. If a product's cover breaks, CPSC's advice is to replace, repair or get rid of it as soon as possible, and to keep it away from children in the meantime.

A last check

Batteries move. The remote that was safe on the shelf ends up on the sofa, and the key fob lands on the floor with the shopping. A quick look under cushions and along the baseboards once a week, with the toddler's eye level in mind, finds the strays. If you ever find a gap where a battery should be and cannot account for it, and a child may have had it, call the emergency number or a poison center right away, without waiting to see whether anything seems wrong.