Smoke Alarm Batteries

Does it matter what batteries I use?

Smoke alarm batteries seem like a simple topic, but there is much more to know than most people realize. We all have experience with what happens when we DON’T take care of our smoke alarm batteries; that incessant chirping every couple of minutes, usually in the middle of the night. In an effort to avoid that, let’s discuss how your choice in smoke alarms and batteries may impact your satisfaction, or frustration with your smoke alarms.

Most people know that smoke alarms are necessary, yet human nature often keeps people from taking care of them properly and causing themselves irritation when they become annoying. You can read about some things to do if you’ve already reached the irritating stage and you can’t figure out what is wrong with your smoke alarms in this article: "Why Are My Smoke Alarms Chirping / Beeping? And How to Stop Them...”

One of the best ways to avoid the irritation, is to make sure you are taking care of your smoke alarms properly.

Smoke Alarm Power Options

One of the things that all smoke alarms have in common is that they have batteries. Your smoke alarms use batteries in one of several ways:

A/C Powered Alarms with Battery Backup

Most homes built in the past 30 years will have alarms that are wired to your home’s A/C electricity. These alarms also have batteries as a backup, in case the power goes out or is severed in a fire. Wired alarms also are wired so that if one alarm goes off, they all go off, providing a warning in every area of your home.

Battery Powered Alarms 

Some alarms are only powered by batteries. Battery powered alarms can be stand-alone devices or can wirelessly talk to each other so they can all alert at the same time, much like wired alarms. Since battery powered alarms only use batteries as their power source, it is even more critical to take care of the batteries in these types of alarms.

Smoke Alarm Battery Types

Along with two primary types of power sources for smoke alarms, there are also several different types of batteries used in alarms:

9-volt batteries 

This is still the most common battery used in alarms today. The disadvantage of 9-volt batteries is that most people don’t keep a supply of them around because very few things use 9-volt batteries these days.

AA batteries

A lot of newer alarms have started to use two AA batteries instead of a single 9-volt battery. This is great for two reasons. AA batteries are used in all kinds of household devices, such as remote controls, so most people have a supply of them around. AA batteries are also much less expensive than 9-volt batteries. Usually, two AA batteries cost about one third the cost for a single 9-volt battery.

Lithium batteries 

Current recommendations is that all new battery powered alarms use lithium batteries. These are often billed as 10-year battery alarms, even though the batteries usually never actually last 10 years. Most lithium battery alarms do not have user replaceable batteries, so when the battery dies, the entire alarm needs to be replaced. See our article about 10-year battery alarms for more details: 10 Year Battery Smoke Alarms.

Battery Replacement Intervals

If you have alarms with replaceable batteries, you should set up a regular replacement schedule. Most manufacturers recommend replacing batteries every six months, but we generally recommend using high quality batteries and replacing them every year. This seems more practical and likely to happen in the average home.

If you have smoke alarms with lithium, or “10-year batteries”, you should follow the alarm manufacturer’s recommendations on when to replace the alarm. You should also know what happens when the alarm reaches its end of life. This is often a chirping sound every minute or two, much like a low battery chirp. Check your alarm’s documentation.

Battery Brands and Types

There are a lot of battery brands and types out there. For most applications we say, use whatever you want, but for smoke alarms we always recommend buying the best batteries possible. For us, through experience, we only use Duracell Copper Top batteries in every alarm installation or maintenance. We can’t speak to other uses, but for smoke alarms, these batteries seem to last longer and have less failures than any other brand and type.

When we install new smoke alarms, they usually come with manufacturer supplied batteries. We NEVER use the supplied batteries because we have had too many incidents where the supplied batteries fail before a year has passed. We always replace the supplied batteries with fresh Duracells at installation and we only use Duracell Copper Tops for our annual maintenance plans.

None of this is to say that other brands and types couldn’t work for you, but for us, when we find something that works, we tend to stick with it and recommend it to others.

Last Updated: 11/30/2023