Do Batteries Expire? How to Store Them for an Outage

Yes, batteries expire, but slowly. Duracell guarantees its Coppertop AA and AAA alkaline batteries for 12 years in storage, and Energizer says its lithium AA batteries can last up to 25 years. Those are the makers’ claims. Heat, damp and loose storage cut that short, so keep spares in their packaging, cool and dry.

That matters in an outage, when the flashlight and the radio are the two things you reach for. A drawer of old batteries is easy to forget. This page covers what the makers say about shelf life, how to store spares, and what to keep on hand. We are passing along their figures and the federal guidance, not testing the batteries ourselves.

How long do batteries last in storage?

It depends on the chemistry and the brand. Every number below comes from the maker’s own product page, so read it as the maker’s claim. Energizer’s pages say “up to” and “based on standard use”. Duracell calls its figures a guarantee.

Energizer’s own pages disagree on the alkaline AA figure, 12 years on one and 15 on another, so we show both. If you are buying for an outage kit, check the date and the storage claim printed on the package you are holding.

Rechargeable batteries are a different case. Energizer’s care guidance says rechargeables lose a percentage of their charge each day when left off the charger, and advises charging them at least every 6 to 9 months.

What shortens battery life in a drawer?

Both makers name the same few things.

• Heat. Energizer says not to store batteries or battery-powered devices in hot places, because high temperatures can lead to capacity loss, leakage or rupture. Duracell says extreme heat or cold reduces performance.
• Loose storage. Both makers say not to carry or store loose batteries with metal objects such as coins, keys or paper clips, because the metal can short the battery and cause heat, leaks or rupture.
• Staying in a device. Duracell says many devices do not switch off completely, so batteries left in a device you will not use for months can eventually leak.
• Mixing batteries. Both makers say not to mix old and new batteries, or different brands or types, in one device.

The refrigerator is a common myth. Energizer says it is not necessary to store batteries in a refrigerator, and Duracell says it will not recharge them or increase storage life.

How to store batteries for an outage

These steps follow the makers’ guidance, with a couple of habits of our own labeled as such.

1. Keep them in the original packaging. Duracell advises storing batteries in their packaging, in a dry place at normal room temperature, until you are ready to use them.
2. Pick a cool, dry spot. A closet or a kitchen drawer away from the stove beats a hot garage or a car. Both makers say room temperature.
3. Keep the contacts from touching. If you move batteries out of the package into a case, use a case with separate slots so the ends cannot touch each other or metal.
4. Write the date on the package. This one is our habit, not a maker rule. A marker date tells you which pack to use first.
5. Keep a spare set next to the light. Duracell suggests removing batteries from devices you will not use for several months. A flashlight you want ready in the dark pulls the other way, so the compromise we use is a spare, packaged set kept right beside it. That one is our judgment, not a maker’s instruction.
6. Charge rechargeables on a schedule. Energizer says every 6 to 9 months at least. Ready.gov also suggests a portable charger or power bank for the outage.

Button and coin batteries

Small round batteries run key fobs, thermometers and some lights, and they are the ones to keep away from kids. The EPA says:

Button-cell or coin batteries can be a potential swallowing hazard; store them out of the reach of young children.

Source: EPA, Used Household Batteries, accessed November 2026.

The Consumer Product Safety Commission adds:

Do not allow children to play with or be in contact with button cell or coin batteries.

If a button cell or coin battery is swallowed, immediately seek medical attention.

Source: U.S. Consumer Product Safety Commission, Button Cell and Coin Batteries, accessed November 2026.

The Consumer Product Safety Commission has a button cell and coin battery information page with more on storage and what to do after a swallowing. If you think a child has swallowed a battery, treat it as an emergency and call 911 or go to the emergency room. Energizer’s care page gives the same direction, to go to the emergency room immediately.

The EPA also says to tape the terminals or bag lithium batteries separately:

Handling precautions: Place each battery in separate plastic bags or place non-conductive tape (e.g., electrical tape) over the battery’s terminals or around the entire button. A lithium battery may spark and cause fires if damaged or the terminal ends touch. If the battery becomes damaged, contact the manufacturer for specific handling information.

Source: EPA, Used Household Batteries, accessed November 2026.

That page is about used batteries, but the point is how a lithium battery behaves, so it is a sensible habit for loose spares too. That extension is ours.

What to keep on hand for a power outage

Ready.gov’s basic kit list includes a flashlight, extra batteries, a battery-powered or hand crank radio, and a cell phone with chargers and a backup battery. On its power outage page it adds:

Plan for batteries and other alternative power sources to meet your needs when the power goes out, such as a portable charger or power bank. Have flashlights for every household member.

Source: Ready.gov, Power Outages, accessed November 2026.

A simple way to turn that into a shopping list:

1. List what takes batteries. Flashlights, the radio, the carbon monoxide detector, the remote for the garage door. Note the size each one uses.
2. Check the detectors. Carbon monoxide detectors with battery backup count too. Follow each detector maker’s instructions for its batteries.
3. Stock one spare set per size. We do not have a federal number for how many to keep, so match it to your list. For the longest rated storage, lithium AA and AAA batteries carry the longest claims in the table above, at a higher price.
4. Keep them organized. A battery storage case with separate slots keeps the contacts apart and shows what you have.
5. Add a no-battery backup. Our flashlight roundup covers crank and solar lights, which sidestep the shelf-life question. For alerts, see the NOAA weather radio guide and the two-way radio guide.

Ready.gov’s power outage page also names the detectors:

Install carbon monoxide detectors with battery backup in central locations on every level of your home.

Source: Ready.gov, Power Outages, accessed November 2026.

Then check the stock once a year. Ready.gov’s “Maintaining Your Kit” section says:

Replace expired items as needed.

Re-think your needs every year and update your kit as your family’s needs change.

Source: Ready.gov, Build A Kit, accessed November 2026.

Write down where the spare batteries live. The emergency binder checklist is built on noting where things are, and the Home & Property section is a natural place for it. That is our suggestion.

What do you do with old or leaking batteries?

Check with your local officials or your local solid waste authority before you throw batteries out, because rules vary. The EPA says:

Do not put button-cell, coin, or lithium single use batteries in the trash or municipal recycling bins.

Source: EPA, Used Household Batteries, accessed November 2026.

The same page says that in most communities, used alkaline and zinc-carbon batteries can go in household trash, and it recommends sending them to a battery recycler or checking with your local or state solid waste authority.

If a battery has leaked, Duracell’s advice is to work in a well-ventilated area, wear household gloves and glasses, and make sure the device is completely dry before putting in a new battery. If leaked material gets on skin or in eyes, follow the warning on the battery package and get medical advice. When in doubt, don’t handle it. In an emergency, call 911 and follow your local officials’ instructions.

Frequently asked questions

Do unopened batteries expire?

They lose charge slowly even unopened, and the makers print storage claims for that reason. Duracell guarantees its Coppertop AA and AAA for 12 years in storage, and Energizer’s pages list its MAX AA and AAA at up to 12 to 15 years. Check the package you own, since figures vary by brand and type.

Should I keep batteries in the refrigerator?

No. Energizer says it is not necessary, and Duracell says it will not recharge batteries or extend their storage life. Both say a cool, dry spot at room temperature is enough.

How long do rechargeable batteries hold a charge in a drawer?

The makers do not give one number. Energizer says rechargeables lose a percentage of their charge each day off the charger and advises charging them at least every 6 to 9 months. Top them up before storm season.

Should I leave batteries in my emergency flashlight?

Duracell advises removing batteries from devices you will not use for several months, since some devices drain them or let them leak. Another option is a spare packaged set kept next to the light, which is what we do. Whatever you pick, test the light every so often.

Can I mix old and new batteries?

No. Both Duracell and Energizer say not to mix old and new batteries, or different brands or types, in one device, because it can cause leaks.

How do I dispose of old batteries?

Follow the EPA’s guidance above and check with your local solid waste authority. Button-cell, coin and lithium single-use batteries should not go in the trash or municipal recycling bins.

Final thoughts

Batteries do expire, but a few simple habits cover most of it: original packaging, cool and dry, contacts apart, and a yearly check against your list. Pair a set of spares with a crank or solar light so one dead pack never leaves you in the dark. Follow your local officials in an outage, and when in doubt, don’t rely on a battery you can’t vouch for.