What’s New

When Should I Change My Smoke Alarm Batteries?

Dec 22 2019

This is part of our ongoing series on the basics of owning a home.

Don’t wait for the chirp.

Like opening your mail or cleaning out your coffee pot, changing your smoke alarm batteries tends to land on the list of things that rarely get done. But it’s actually really important (as is opening your mail, honestly) and it’s never too late to get in the habit.

Nearly three out of five of residential fire deaths occur in homes that either have faulty smoke alarms or none at all, according to the National Fire Protection Association.

One way to remember the chore is with the simple phrase, “change your clocks, change your batteries.” When you turn the clocks back after daylight savings time ends in the fall, switch out the batteries in your smoke alarms.

Yep, just once a year – not so bad, right? It’s a good idea to test them once a month too, however. This is more of a hassle, but it’ll give you the peace of mind that they’re in good working condition.

But what about your other questions, like which batteries are the best to buy, and when should you switch out the alarms themselves? Here is a deeper dive into the science of maintaining smoke alarms:

Which batteries do smoke detectors need?

Most use 9-volt alkaline (you know, those rectangular boxes with two prongs at the end?) but some use AA. It’ll be specified in the battery compartments in your smoke alarms, so have a look to be sure.

Can you use rechargeable batteries in a smoke detector?

Using rechargeable batteries in something as important as a smoke alarm isn’t typically advised, since their charge levels aren’t reliable.

Can you use lithium batteries in a smoke detector?

Lithium batteries carry more charge than alkaline, so they may last longer. However, they tend to be more expensive. Plus, you can throw alkaline batteries away in the trash, but lithiums must be recycled at facilities that accept them.

Do all smoke detectors need batteries?

Yes, but not all can be switched out. Some smoke alarms come with 10-year tamper-free batteries, meaning the battery compartments cannot be opened and the devices can be used for a decade. Others are hardwired to your home’s electrical system and have back-up batteries in case you lose power.

When should you replace your smoke alarms?

The alarms will have expiration dates written on the back, but every 10 years is recommended.


Onto the next project? Our post “5 Easy Ways to Keep Up With Kitchen Maintenance” offers ideas.

Ready to assess more key parts of your home for possible maintenance? Download Keep by Framework™ to access our Maintenance Assessments tool.

Recent Posts