How often should you change your smoke alarm batteries

Q: How long do AA batteries last in smoke detectors?

However, nowadays, it is more common to see two or three AAs in smoke detectors. AA batteries have about three times as much energy as a 9V. When using batteries like these, its important that you check them consistently and replace your smoke alarm batteries every 6 months.

Daylight Saving Time (DST) came to an end on Sunday, November 6 at 2 a.m. Though we may have "gained" an hour of sleep this morning as our clocks fell back, it does mean slightly less light at the end of the day. As we look around today and see that some clocks need to be manually changed, it's also the perfect time to adjust other household items such as your smoke detector.

Table of Contents Show

How often should I be replacing my smoke detector batteries anyway?
How to test your smoke detectors
How to know when it's time to retire your smoke detector
Our favorite combination smoke and carbon monoxide detector
What happens if you don't replace battery in smoke alarm?
How do you know when smoke alarm battery needs changing?
How long do 9V batteries last in smoke detectors?
Do smoke alarm batteries last 10 years?
How long do AA batteries last in smoke detectors?
How long do 10 year smoke alarms really last?

The “Change Your Clocks, Change Your Batteries” campaign created by the National Fire Protection Association (NFPA) encourages homeowners to change their smoke detector batteries whenever they're changing their clocks for DST, equating to twice a year.

Checking and changing your smoke detector batteries is easy to do—the hard part is actually remembering to do so, which is why this handy pairing with Daylight Saving Time is ideal. With DST now over, here's your friendly reminder to change those batteries, along with smoke detector tips and information to keep them properly maintained year-round.

How often should I be replacing my smoke detector batteries anyway?

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Depending on the type of batteries used in your smoke detectors, you may need to replace your battery annually at the minimum.

Smoke detectors with non-replaceable, 10-year batteries are designed to work for up to 10 years, according to the NFPA. Once you start hearing that dreaded "chirping" noise, signaling that the battery is low, you'll need to replace the entire smoke detector promptly.

For smoke detectors that use any other type of batteries, they'll most likely need a new battery at least once a year—and for those who may need a gentle reminder to check on your smoke detector's batteries, using the beginning and end of Daylight Saving Time is a great way to remember.

When in doubt about when to change the batteries or what kind of batteries to use, the NFPA recommends following the alarm manufacturer's instructions, which may end up being brand- or even model-specific.

How to test your smoke detectors

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Take the time to test your smoke detectors regularly.

Smoke detector maintenance is key to protecting you and your family from a potential house fire. Regularly testing your smoke detectors ensures that the batteries and the alarm itself are all working correctly.

All smoke detectors in the home should be tested at least once a month—but don't worry, it's quick and easy to test them. Simply push the "test" button on the exterior alarm and wait for it to respond.

If your detector is not responding, check the batteries to make sure they’re still good. If not, replace them as soon as possible. If this isn’t a battery issue, it may be time for a replacement.

To make sure you're fully covered, you’ll need to check up on all of the detectors in your home on a regular basis.

How to know when it's time to retire your smoke detector

Credit: Getty Images / AndreyPopov

Some smoke detectors will simply need to be replaced, especially after their expiration date of 10 years.

No matter how well an appliance or tech gadget is working, it'll have an expiration date. The same goes for smoke detectors, which the NFPA recommends replacing after 10 years regardless of their condition.

Along with this information, you can check your alarm's expiration date, which makes it easier to know exactly when it's been 10 years. You can find this by removing the smoke detector from the wall or ceiling and looking for the date on the back.

Our favorite combination smoke and carbon monoxide detector

Credit: Reviewed / Betsey Goldwasser

Our favorite smart smoke and carbon monoxide detector, the Nest Protect, is easy to install and comes with plenty of protective features.

While smoke detectors are historically known for alerting your family of a fire emergency, combination smoke and carbon monoxide detectors (CO) can do even more, keeping your family safe from dangerous CO exposure. Even more, a smart smoke and carbon monoxide detector can make protecting your family even easier with features like real-time notifications to your phone and voice alerts.

Out of all the smart smoke and carbon monoxide detectors we put to the test, the Nest Protect Smoke & Carbon Monoxide Alarm is our top choice. The fairly-priced alarm uses a split-spectrum sensor to sense both smoldering and fast-burning fires, helping to keep your family safe no matter the fire emergency. It also features intuitive features like push notifications, a night light option, and even a monthly self-test feature.

$119 from Amazon

The product experts at Reviewed have all your shopping needs covered. Follow Reviewed on Facebook, Twitter, Instagram, TikTok, or Flipboard for the latest deals, product reviews, and more.

Prices were accurate at the time this article was published but may change over time.

What happens if you don't replace battery in smoke alarm?

A smoke alarm will eventually stop chirping if you do nothing. Once the battery has run out completely, the device will switch to residual power. Eventually, this will also drain and the device won't have enough power to beep and let you know it's out of power. You should change the battery before this happens.

How do you know when smoke alarm battery needs changing?

Low Battery As the battery in a smoke alarm gets weak, the smoke alarm will “chirp” about once a minute to let you know that the battery needs to be replaced. Note: Only the device with a low battery will chirp. The other interconnected alarms should be silent.

How long do 9V batteries last in smoke detectors?

9-Volt Battery The 9-volt battery smoke detectors are the standard and most common model. These detectors require you to change out your batteries once every year or so. After they hit the 8-year mark you should consider replacing it. A 9-volt battery detector can live up to 10 years if you take care of it.

Do smoke alarm batteries last 10 years?

Testing and Changing Your Fire Alarm Battery If your smoke alarms are powered by a nine-volt battery, the battery should be replaced every 6 months, while the alarm itself should be replaced once every 10 years. For 10-year lithium-powered fire detectors, you won't need to replace the battery.

How long do AA batteries last in smoke detectors?

However, nowadays, it is more common to see two or three AA's in smoke detectors. AA batteries have about three times as much energy as a 9V. When using batteries like these, it's important that you check them consistently and replace your smoke alarm batteries every 6 months.

How long do 10 year smoke alarms really last?

Ten-year sealed battery smoke alarms are powered by sealed lithium batteries that have a life span of ten years. These alarms provide 10 years of continuous protection with no need to replace the battery for the life of the alarm.