How Long Do Batteries Last in Smoke Detectors?

Smoke Detectors are devices that sense smoke and give a warning alarm, usually as an indication of fire.

In this article, we discuss the lifespan of smoke detector batteries and more.

How Long Does the Battery in a Smoke Detector Last? 

The 9-volt battery in smoke detectors has a lifespan of six months if properly used. Long-life battery smoke detectors last up to 10 years before they need a replacement. Because the battery is inbuilt, you may have to change the entire system after 10 years of active usage.

On the other hand, the batteries in hard-wired smoke alarms can also last for ten years, though not as the primary source of power.

However, you may have to replace these batteries every year to ensure the device works effectively.

How Long Do Batteries Last in Smoke Detectors

How Often Should You Change Batteries in Smoke Detectors?

A smoke alarm powered by a 9-volt battery needs replacement every 6 months.

But it would be best if you replace the alarm itself once every 10 years.

For 10-year lithium-powered smoke alarms, you don’t need to replace its batteries. Rather, replace the entire alarm after 10 years.

For the alarm hard-wired into the home’s electrical system, you only need to replace its backup battery at least every 6 months of usage.

Signs You Need to Replace the Batteries in Your Smoke Detector

You’ll likely notice a high-pitched chirping noise coming from your smoke alarm if the batteries need replacement.

When you change the batteries in one alarm, make sure you change the batteries in the rest of the alarms in your home as well.

A helpful reminder to check your smoke alarms and change the batteries every 6 months is Daylight Saving Time. Check your fire alarms when you change your clocks.

What Type of Batteries Are Used in Smoke Detectors? 

The batteries of smoke detectors can be lead-acid or lithium-ion types. Smoke detectors have unique power requirements.

Batteries for these devices have long idle times with short periods of high current demand for testing.

Also, they require constant availability of power at all times.

Smoke detectors require batteries with a very low self-discharge rate, high voltage, and the ability to deliver high current on demand.

Do You Have to Change the Battery in a Hard-Wired Smoke Detector? 

Hard-wired smoke alarms must be connected to your home’s power supply.

However, you have to change the backup batteries every six months.

The batteries are not the main power source for the device-they are just for backup in case the mains power fails.

Do All Smoke Detectors Use Battery?

There are battery-powered smoke detectors and hard-wired smoke detectors.

The functions of both are the same. However, the former relies solely and heavily on battery usage to function while the latter uses mains electricity.

Hard-wired smoke detectors do not necessarily require a battery to work.

But you can install a battery as a secondary source and back up. However, it can function without the use of a battery.

You may also read our article about how long router batteries last.

How to Change Smoke Alarm Batteries

Here are the steps you should take when changing your smoke alarm batteries:

  • Step 1: Remove the cover or body: Gently pry the cover open or unclip the detector’s body from its base with a slight twisting motion.
  • Inside, you will find three main parts: the sensing chamber, a loud horn, and a battery (and in some cases, a house voltage power source).
  • Step 2: Replace the battery: Detach the old battery from its holder. Most detectors utilize a 9-volt battery; use a brand new lithium 9-volt battery as a replacement.
  • Ensure you connect the two terminals properly with the base.
  • Step 3: Close the cover or replace the body and snap the cover shut or lock the smoke detector’s body back into its base.
  • Step 4: Test the detector. Press the test button on the surface of the detector to make sure the battery is working. Once done, the detector should beep or chirp.

Do you use a Google Pixel phone? Make sure to read our article about why Google Pixel batteries drain fast.

What Are The Best Batteries For Smoke Detectors? 

The 9V PP3 battery is the standard for most manufacturers of these safety products, thanks to its compact size and high-power potential.

While long-life alkaline cells were the optimum choice for many years, today’s lithium 9V battery meets this application’s needs much more efficiently. This makes it the battery of choice for most brands.

9V has been the battery of choice for smoke alarms for many years. However, nowadays, it is more common to see two or three AAs.

AA batteries have about three times as much energy as a 9V. When using batteries like these, you must check them consistently and replace your smoke alarm batteries every 6 months.

A good reminder is to change your AA batteries every time you change your clock for daylight savings.

The EN22 Energizer Industrial Alkaline 9V Battery is undoubtedly a favorite 9-volt battery for battery-operated smoke detectors.

This is one of the very best 9v batteries for smoke detectors. Similarly, the 1222 Everyday 1.5V Super Heavy Duty 9V battery is another superb smoke detector battery.

The EN22 Energizer Industrial Alkaline 9V Battery is a solid, inexpensive option—perfect to buy in bulk and have a pile in the closet somewhere to swap in every 6 months or thereabout.

The LA522 Energizer 9V Advanced Lithium Battery could last for a period of ten years without replacement. However, the first 6-7 years are the most effective period of its usage.

Also read our article about how long Lenovo laptop batteries last.

Why Does My Smoke Detector Battery Keep Dying?

Many factors could cause a smoke detector battery to go off continually or drain excessively. They include:

1. Power Supply Failure

An erratic power supply may continually lead to smoke detectors’ disconnection, especially if it’s the hard-wired type. Smoke detectors need a constant power source, either from the battery or direct electricity.

2. Installation Error

An error during installation may also alter the battery’s functioning and may make it disconnect from the smoke detector, thereby halting its function.

3. Absence of AC Power

With a tripped circuit breaker, the smoke alarm will operate exclusively off the battery. The alarm will run off the battery for about 25 days before it will require replacement.

If your smoke alarm does not indicate that AC power is present, check the circuit breaker and/or have an electrician check the circuit.

How Do You Get a Smoke Alarm to Stop Chirping Without Changing Battery?

Here are ways to stop your smoke detector to stop chirping without removing the battery:

  1. Turn off the power to the smoke alarm at the circuit breaker.
  2. Remove the smoke alarm from the mounting bracket and disconnect the power.
  3. Remove the battery.
  4. Press and hold the test button for at least 15 seconds. The unit may chirp or beep for a few seconds before going silent.
  5. Reconnect the power and reinstall the battery. The unit will chirp once the power is restored and should not chirp afterward.

The above methods will stop the smoke alarm from chirping without changing the battery.

Final Words

A smoke alarm is an important device that can protect your family’s lives and property. But it won’t work without adequate power.

This makes it important to ensure the device has a healthy battery at all times.

We hope this article has answered all your questions about smoke detectors and their batteries.